Podcast
Questions and Answers
What pathological condition is characterized by inflammation of the small intestine?
What pathological condition is characterized by inflammation of the small intestine?
- Proctitis
- Typhlitis
- Colitis
- Enteritis (correct)
Which of the following is the term for inflammation of the colon?
Which of the following is the term for inflammation of the colon?
- Typhlitis
- Colitis (correct)
- Enteritis
- Proctitis
What is the primary cause of death in animals suffering from diarrhea/enteritis/colitis?
What is the primary cause of death in animals suffering from diarrhea/enteritis/colitis?
- Dehydration (correct)
- Toxemia/Sepsis
- Electrolyte imbalance
- Nutrient malabsorption
What term describes the inflammation of the cecum?
What term describes the inflammation of the cecum?
What process leads to toxemia/sepsis in animals with compromised intestinal mucosa?
What process leads to toxemia/sepsis in animals with compromised intestinal mucosa?
How do intestinal viruses primarily cause disease?
How do intestinal viruses primarily cause disease?
Why is diarrhea more life-threatening in young animals compared to adults?
Why is diarrhea more life-threatening in young animals compared to adults?
Which of the following is NOT a possible location of lesions within the gastrointestinal tract?
Which of the following is NOT a possible location of lesions within the gastrointestinal tract?
Which type of inflammation is characterized by the presence of granulomas?
Which type of inflammation is characterized by the presence of granulomas?
What is the effect of villous enterocyte damage on absorption?
What is the effect of villous enterocyte damage on absorption?
What is the consequence of losing stem cells within the crypt epithelium?
What is the consequence of losing stem cells within the crypt epithelium?
Which of the following viruses primarily target crypt cells in the intestinal epithelium?
Which of the following viruses primarily target crypt cells in the intestinal epithelium?
What clinical presentation should raise strong suspicion for CPV enteritis in dogs?
What clinical presentation should raise strong suspicion for CPV enteritis in dogs?
Which disease is directly associated with granulomatous inflammation thickening the ileum and expansion of the lamina propria and submucosa by macrophages?
Which disease is directly associated with granulomatous inflammation thickening the ileum and expansion of the lamina propria and submucosa by macrophages?
What clinical signs are most commonly associated with Paratuberculosis (Johne's disease)?
What clinical signs are most commonly associated with Paratuberculosis (Johne's disease)?
Which viral pathogen primarily causes acute diarrhea in young animals across multiple species?
Which viral pathogen primarily causes acute diarrhea in young animals across multiple species?
Which part of the intestine is most affected by rotavirus?
Which part of the intestine is most affected by rotavirus?
Compared to rotavirus, what is a key characteristic of coronaviruses regarding virulence and affected regions?
Compared to rotavirus, what is a key characteristic of coronaviruses regarding virulence and affected regions?
What cell type does parvovirus require to replicate?
What cell type does parvovirus require to replicate?
Which of the following statements is true about Bovine Viral Diarrhea Virus (BVDV)?
Which of the following statements is true about Bovine Viral Diarrhea Virus (BVDV)?
What is the primary mechanism of disease for enterotoxigenic E. coli (ETEC)?
What is the primary mechanism of disease for enterotoxigenic E. coli (ETEC)?
What distinguishes Shiga toxin-producing E. coli from enterotoxigenic E. coli (ETEC) in swine?
What distinguishes Shiga toxin-producing E. coli from enterotoxigenic E. coli (ETEC) in swine?
An animal presents with diarrhea and malabsorption due to Salmonella infection. Which of the following explains this?
An animal presents with diarrhea and malabsorption due to Salmonella infection. Which of the following explains this?
What is the MAIN difference between the actions of Clostridia and Salmonella in the intestines?
What is the MAIN difference between the actions of Clostridia and Salmonella in the intestines?
What is the key predisposing factor for Clostridium perfringens type D infection?
What is the key predisposing factor for Clostridium perfringens type D infection?
Which of the following is most characteristic of Mycobacterium avium subspecies paratuberculosis infection lesions in ruminants regarding location?
Which of the following is most characteristic of Mycobacterium avium subspecies paratuberculosis infection lesions in ruminants regarding location?
What is the most common clinical sign observed in animals with swine dysentery?
What is the most common clinical sign observed in animals with swine dysentery?
What cellular change is characteristic of Porcine Proliferative Enteritis caused by Lawsonia intracellularis?
What cellular change is characteristic of Porcine Proliferative Enteritis caused by Lawsonia intracellularis?
Which of the following best describes the infection preference of Lawsonia intracellularis?
Which of the following best describes the infection preference of Lawsonia intracellularis?
Which of the following fungal or fungal-like diseases is associated with standing water and can cause gastrointestinal disease in dogs?
Which of the following fungal or fungal-like diseases is associated with standing water and can cause gastrointestinal disease in dogs?
What microscopic finding is most consistent with animals affected by pythiosis?
What microscopic finding is most consistent with animals affected by pythiosis?
What is the primary diagnostic method for Cryptosporidium?
What is the primary diagnostic method for Cryptosporidium?
What microscopic feature is most closely associated with Eimeria & Cystoisospora (coccidia)?
What microscopic feature is most closely associated with Eimeria & Cystoisospora (coccidia)?
Where does Coccidia pose a problem in ALL species EXCEPT cattle?
Where does Coccidia pose a problem in ALL species EXCEPT cattle?
What best characterizes Cryptosporidium parvum?
What best characterizes Cryptosporidium parvum?
What intestinal parasite depends on a vector, and transmission includes the use of antihelminthics?
What intestinal parasite depends on a vector, and transmission includes the use of antihelminthics?
What is a distinctive feature of hookworms in terms of their parasitic activity?
What is a distinctive feature of hookworms in terms of their parasitic activity?
A horse presents with signs of protein loss and diarrhea. Which parasite is MOST likely to be responsible if inflammation and mucosal damage are observed during the intestinal lumen?
A horse presents with signs of protein loss and diarrhea. Which parasite is MOST likely to be responsible if inflammation and mucosal damage are observed during the intestinal lumen?
Following a particularly inept and careless necropsy technique, the veterinary student punctures the small intestine of a cow. The odor is immediately repugnant, and the only disinfectant available is rubbing alcohol. Later, the student develops a fever, diarrhea, and severe abdominal cramps. Given that bacterial load was high, what organism should the student be concerned about?
Following a particularly inept and careless necropsy technique, the veterinary student punctures the small intestine of a cow. The odor is immediately repugnant, and the only disinfectant available is rubbing alcohol. Later, the student develops a fever, diarrhea, and severe abdominal cramps. Given that bacterial load was high, what organism should the student be concerned about?
Where are lesions likely found in Mycobacterium avium subspecies paratuberculosis?
Where are lesions likely found in Mycobacterium avium subspecies paratuberculosis?
If Coccidia is a small intestinal problem across all species and a large intestinal problem for cattle, what would make the BEST choice for a combination of treatments?
If Coccidia is a small intestinal problem across all species and a large intestinal problem for cattle, what would make the BEST choice for a combination of treatments?
In cases of severe malabsorption due to villous damage, what is the MOST likely consequence?
In cases of severe malabsorption due to villous damage, what is the MOST likely consequence?
What is the MOST significant immediate threat to an animal experiencing severe diarrhea?
What is the MOST significant immediate threat to an animal experiencing severe diarrhea?
Which of the following represents a type of inflammatory lesion seen in the context of gastrointestinal disease?
Which of the following represents a type of inflammatory lesion seen in the context of gastrointestinal disease?
What is the MOST accurate description of how intestinal bacteria cause disease?
What is the MOST accurate description of how intestinal bacteria cause disease?
What is the long-term consequence of losing stem cells within the crypt epithelium?
What is the long-term consequence of losing stem cells within the crypt epithelium?
Compared to coronaviruses, which characteristic is LESS typical of rotaviruses regarding intestinal disease?
Compared to coronaviruses, which characteristic is LESS typical of rotaviruses regarding intestinal disease?
What cellular feature is FIRST targeted during parvovirus infection?
What cellular feature is FIRST targeted during parvovirus infection?
How does E. coli cause secretory diarrhea in piglets?
How does E. coli cause secretory diarrhea in piglets?
What is the hallmark pathological change in swine affected by edema disease due to Shiga toxin-producing E. coli?
What is the hallmark pathological change in swine affected by edema disease due to Shiga toxin-producing E. coli?
What is a common predisposing factor that allows Clostridium perfringens Type D to proliferate and cause disease?
What is a common predisposing factor that allows Clostridium perfringens Type D to proliferate and cause disease?
Which of the following is an important characteristic to note regarding animals with subclinical paratuberculosis?
Which of the following is an important characteristic to note regarding animals with subclinical paratuberculosis?
What is the MAIN presenting complaint of an animal with swine dysentery?
What is the MAIN presenting complaint of an animal with swine dysentery?
Which cellular structure does Lawsonia intracellularis MOST directly target?
Which cellular structure does Lawsonia intracellularis MOST directly target?
A dog is diagnosed with gastrointestinal pythiosis. What is the MOST important environmental factor to consider in its history?
A dog is diagnosed with gastrointestinal pythiosis. What is the MOST important environmental factor to consider in its history?
What is the MOST important identifying feature for Cryptosporidium?
What is the MOST important identifying feature for Cryptosporidium?
What is a distinct morphologic feature of Coccidia within the intestinal cells?
What is a distinct morphologic feature of Coccidia within the intestinal cells?
How is diarrhea a greater threat to young animals than adults?
How is diarrhea a greater threat to young animals than adults?
Which lesion location is LEAST likely to be directly affected by a gastrointestinal pathogen?
Which lesion location is LEAST likely to be directly affected by a gastrointestinal pathogen?
What is the MOST direct consequence of enterocyte damage on villi?
What is the MOST direct consequence of enterocyte damage on villi?
What feature do rotaviruses, coronaviruses, and parvoviruses share in the context of intestinal disease?
What feature do rotaviruses, coronaviruses, and parvoviruses share in the context of intestinal disease?
Which of the following lesions is MOST suggestive of Mycobacterium avium subspecies paratuberculosis infection?
Which of the following lesions is MOST suggestive of Mycobacterium avium subspecies paratuberculosis infection?
What is the primary mechanism of Bovine Viral Diarrhea Virus (BVDV) in causing intestinal disease?
What is the primary mechanism of Bovine Viral Diarrhea Virus (BVDV) in causing intestinal disease?
Why are Clostridial infections considered opportunistic?
Why are Clostridial infections considered opportunistic?
Which of the following is true regarding the systemic effects of toxins produced by intestinal pathogens?
Which of the following is true regarding the systemic effects of toxins produced by intestinal pathogens?
If you observe that the ileocecal valve of a ruminant is markedly thickened, what is the MOST likely cause?
If you observe that the ileocecal valve of a ruminant is markedly thickened, what is the MOST likely cause?
What is the PRIMARY lesion caused by Lawsonia intracellularis within affected cells?
What is the PRIMARY lesion caused by Lawsonia intracellularis within affected cells?
Which of the following is the MOST consistent sign of Canine Parvovirus (CPV)?
Which of the following is the MOST consistent sign of Canine Parvovirus (CPV)?
What is the main pathogenesis mechanism for Salmonella? The organisms ...
What is the main pathogenesis mechanism for Salmonella? The organisms ...
An 8-week old pig presents with a history of diarrhea and edema. Lesions are discovered lining the gut. Given these signs, which of the following is MOST associated with the primary pathogenic mechanism? The disease ...
An 8-week old pig presents with a history of diarrhea and edema. Lesions are discovered lining the gut. Given these signs, which of the following is MOST associated with the primary pathogenic mechanism? The disease ...
A farmer in Oregon loses several 4-month-old feeder calves to an unknown disease. One calf showed evidence of stumbling, which rapidly progressed to recumbency. At necropsy, there were widespread lesions on the gut, as well as evidence of an enlarged heart. What may this disease be?
A farmer in Oregon loses several 4-month-old feeder calves to an unknown disease. One calf showed evidence of stumbling, which rapidly progressed to recumbency. At necropsy, there were widespread lesions on the gut, as well as evidence of an enlarged heart. What may this disease be?
The small strongyles encyst in what tissue?
The small strongyles encyst in what tissue?
How do anthelmintics relate to parasite infections?
How do anthelmintics relate to parasite infections?
What region of the gut do whipworms infect?
What region of the gut do whipworms infect?
Which of the following is NOT one of the learning objectives?
Which of the following is NOT one of the learning objectives?
Cryptosporidium parvum poses a zoonotic risk for which animal?
Cryptosporidium parvum poses a zoonotic risk for which animal?
While Coccidia is located in the small intestine across species, where is it located on the intestinal tract for cattle?
While Coccidia is located in the small intestine across species, where is it located on the intestinal tract for cattle?
A veterinarian is presented with a fecal sample. Given this, what parasites can be diagnosed?
A veterinarian is presented with a fecal sample. Given this, what parasites can be diagnosed?
If normal villi are very tall, what does losing enterocytes along the villi indicate?
If normal villi are very tall, what does losing enterocytes along the villi indicate?
When describing lesion distribution for Mycobacterium avium subsp. paratuberculosis, what intestinal regions are involved EXCEPT the:
When describing lesion distribution for Mycobacterium avium subsp. paratuberculosis, what intestinal regions are involved EXCEPT the:
Which of the following viral intestinal pathogens targets dividing host cells for replication?
Which of the following viral intestinal pathogens targets dividing host cells for replication?
In the context of intestinal disease, what is the MOST immediate threat to an animal's survival?
In the context of intestinal disease, what is the MOST immediate threat to an animal's survival?
How does the pathogenesis of enterotoxigenic E. coli (ETEC) primarily lead to diarrhea in affected animals?
How does the pathogenesis of enterotoxigenic E. coli (ETEC) primarily lead to diarrhea in affected animals?
Why are young animals generally more susceptible to severe outcomes from intestinal viral infections compared to adult animals?
Why are young animals generally more susceptible to severe outcomes from intestinal viral infections compared to adult animals?
A veterinary pathologist observes marked thickening of the ileocecal valve and adjacent ileum during a necropsy of a 5-year-old dairy cow. Microscopic examination reveals granulomatous inflammation with macrophages containing acid-fast bacilli. Which of the following is the MOST likely diagnosis?
A veterinary pathologist observes marked thickening of the ileocecal valve and adjacent ileum during a necropsy of a 5-year-old dairy cow. Microscopic examination reveals granulomatous inflammation with macrophages containing acid-fast bacilli. Which of the following is the MOST likely diagnosis?
A ferret presents with chronic weight loss and poor body condition. Histopathological examination reveals pyogranulomatous vasculitis in multiple tissues. Infection with which agent is MOST likely to be indicated by these findings?
A ferret presents with chronic weight loss and poor body condition. Histopathological examination reveals pyogranulomatous vasculitis in multiple tissues. Infection with which agent is MOST likely to be indicated by these findings?
Which characteristic is LEAST related to viral-induced diarrhea in various animal species?
Which characteristic is LEAST related to viral-induced diarrhea in various animal species?
What feature distinguishes endotoxins from exotoxins?
What feature distinguishes endotoxins from exotoxins?
How does damage to villous enterocytes typically lead to diarrhea?
How does damage to villous enterocytes typically lead to diarrhea?
What is the primary role of M cells in the pathogenesis of intestinal diseases?
What is the primary role of M cells in the pathogenesis of intestinal diseases?
Which inflammatory change is characterized by increased numbers of goblet cells?
Which inflammatory change is characterized by increased numbers of goblet cells?
Which of the following viruses targets the tip of the villi?
Which of the following viruses targets the tip of the villi?
Which of the following viruses infects both the tip AND lateral aspects of the villi?
Which of the following viruses infects both the tip AND lateral aspects of the villi?
What is the main reason why coronaviruses are more virulent than rotaviruses in producing intestinal disease?
What is the main reason why coronaviruses are more virulent than rotaviruses in producing intestinal disease?
How does the mutated form of feline coronavirus (FIP) cause systemic disease?
How does the mutated form of feline coronavirus (FIP) cause systemic disease?
What lesion is MOST closely associated with Feline Infectious Peritonitis (FIP)?
What lesion is MOST closely associated with Feline Infectious Peritonitis (FIP)?
What feature of systemic coronavirus infection in ferrets MOST closely resembles FIP?
What feature of systemic coronavirus infection in ferrets MOST closely resembles FIP?
Why is canine parvovirus (CPV) especially harmful?
Why is canine parvovirus (CPV) especially harmful?
Bovine Viral Diarrhea Virus (BVDV) and malignant catarrhal fever both cause ulcers in the GI tract. What is a key feature to differentiate them?
Bovine Viral Diarrhea Virus (BVDV) and malignant catarrhal fever both cause ulcers in the GI tract. What is a key feature to differentiate them?
A veterinarian suspects a bacterial etiology for enteritis in a group of weaned pigs. What is the PRIMARY consideration in the initial assessment?
A veterinarian suspects a bacterial etiology for enteritis in a group of weaned pigs. What is the PRIMARY consideration in the initial assessment?
Which structure enables certain strains of E. coli to adhere to the intestinal mucosal lining?
Which structure enables certain strains of E. coli to adhere to the intestinal mucosal lining?
Enterotoxigenic E. coli (ETEC) causes diarrhea through which mechanism?
Enterotoxigenic E. coli (ETEC) causes diarrhea through which mechanism?
What type of toxin is produced by the strain of E. coli that causes edema disease in pigs?
What type of toxin is produced by the strain of E. coli that causes edema disease in pigs?
The Shiga toxin produced by E. coli in edema disease primarily targets what cell type?
The Shiga toxin produced by E. coli in edema disease primarily targets what cell type?
A pig necropsy reveals edema in the spiral colon mesentery, gastric submucosa, and eyelids. Which bacterial agent is MOST likely involved?
A pig necropsy reveals edema in the spiral colon mesentery, gastric submucosa, and eyelids. Which bacterial agent is MOST likely involved?
How does Salmonella cause disease?
How does Salmonella cause disease?
In animals with salmonellosis, which areas of the intestines are most likely affected?
In animals with salmonellosis, which areas of the intestines are most likely affected?
What type of diarrhea is most common with Salmonella?
What type of diarrhea is most common with Salmonella?
What is the MOST important factor in the epidemiology of Salmonella infections?
What is the MOST important factor in the epidemiology of Salmonella infections?
A horse is diagnosed with Salmonellosis. Petechia are observed in the small intestines. What does this imply?
A horse is diagnosed with Salmonellosis. Petechia are observed in the small intestines. What does this imply?
Rectal strictures secondary to salmonellosis in pigs result from what?
Rectal strictures secondary to salmonellosis in pigs result from what?
What is the key feature that distinguishes Clostridium from Salmonella regarding intestinal damage?
What is the key feature that distinguishes Clostridium from Salmonella regarding intestinal damage?
What is the role of trypsin inhibitors relative to clostridial infections?
What is the role of trypsin inhibitors relative to clostridial infections?
Which best describes the pathogenesis of Clostridium perfringens type D in sheep?
Which best describes the pathogenesis of Clostridium perfringens type D in sheep?
What organ shows focal symmetrical encephalomalacia?
What organ shows focal symmetrical encephalomalacia?
What is the MAIN difference between the lesions caused by Clostridium difficile and Clostridium perfringens?
What is the MAIN difference between the lesions caused by Clostridium difficile and Clostridium perfringens?
How do animals MAINLY become infected with Mycobacterium avium subspecies paratuberculosis (MAP)?
How do animals MAINLY become infected with Mycobacterium avium subspecies paratuberculosis (MAP)?
What is a key gross finding in ruminants affected by Mycobacterium avium subspecies paratuberculosis (Johne's disease)?
What is a key gross finding in ruminants affected by Mycobacterium avium subspecies paratuberculosis (Johne's disease)?
Histopathology of an intestinal biopsy from a ruminant reveals macrophages with abundant acid-fast bacilli in the lamina propria. What disease is MOST likely?
Histopathology of an intestinal biopsy from a ruminant reveals macrophages with abundant acid-fast bacilli in the lamina propria. What disease is MOST likely?
Which section of the intestinal tract is MOST commonly affected by Mycobacterium avium subspecies paratuberculosis?
Which section of the intestinal tract is MOST commonly affected by Mycobacterium avium subspecies paratuberculosis?
Which cell type is MOST linked with swine dysentery lesions?
Which cell type is MOST linked with swine dysentery lesions?
What cellular change is MOST characteristic of swine dysentery?
What cellular change is MOST characteristic of swine dysentery?
What specific region shows lesions caused by swine dysentery?
What specific region shows lesions caused by swine dysentery?
Porcine proliferative enteritis is caused by Lawsonia intracellularis. What microscopic feature would suggest possible proliferation?
Porcine proliferative enteritis is caused by Lawsonia intracellularis. What microscopic feature would suggest possible proliferation?
What unique characteristic makes Lawsonia intracellularis different than other porcine enteric pathogens?
What unique characteristic makes Lawsonia intracellularis different than other porcine enteric pathogens?
Within the cells it infects, Lawsonia displays what?
Within the cells it infects, Lawsonia displays what?
What region shows a thickened mucosa due to crypt hyperplasia?
What region shows a thickened mucosa due to crypt hyperplasia?
What is the typical source of Pythium insidiosum that causes gastrointestinal disease in dogs?
What is the typical source of Pythium insidiosum that causes gastrointestinal disease in dogs?
What type of inflammation is characteristically caused by gastrointestinal pythiosis?
What type of inflammation is characteristically caused by gastrointestinal pythiosis?
How does gastrointestinal pythiosis typically lead to clinical signs?
How does gastrointestinal pythiosis typically lead to clinical signs?
How do protozoal parasites typically cause diarrhea?
How do protozoal parasites typically cause diarrhea?
With protozoan parasites, how do they cause malabsorptive diarrhea.
With protozoan parasites, how do they cause malabsorptive diarrhea.
What does an Eimeria infection cause in cattle?
What does an Eimeria infection cause in cattle?
Inflammation of which intestinal segment is specifically termed 'typhlitis'?
Inflammation of which intestinal segment is specifically termed 'typhlitis'?
In animals with severe diarrhea due to infectious diseases, what directly contributes to septicemia and shock?
In animals with severe diarrhea due to infectious diseases, what directly contributes to septicemia and shock?
What are exotoxins?
What are exotoxins?
Why does a lower cellular turnover rate worsen the prognosis for young animals with intestinal infections?
Why does a lower cellular turnover rate worsen the prognosis for young animals with intestinal infections?
What type of diarrhea is MOST commonly associated with rotavirus and coronavirus infections?
What type of diarrhea is MOST commonly associated with rotavirus and coronavirus infections?
What is a primary consequence of damage to the villus enterocytes in the small intestine?
What is a primary consequence of damage to the villus enterocytes in the small intestine?
What is the primary function of the crypt epithelial cells in the intestinal villi?
What is the primary function of the crypt epithelial cells in the intestinal villi?
What type of inflammatory lesion is characterized by a proliferation of goblet cells?
What type of inflammatory lesion is characterized by a proliferation of goblet cells?
What is the primary effect of coronavirus infection on the intestinal villi?
What is the primary effect of coronavirus infection on the intestinal villi?
In what region of the intestine do rotaviruses primarily target their effects?
In what region of the intestine do rotaviruses primarily target their effects?
What distinguishes coronavirus infection from rotavirus infection in terms of affected area of the villi?
What distinguishes coronavirus infection from rotavirus infection in terms of affected area of the villi?
Why can a parvovirus infection lead to bloody diarrhea?
Why can a parvovirus infection lead to bloody diarrhea?
Why are M cells significant in the pathogenesis of certain intestinal bacterial infections?
Why are M cells significant in the pathogenesis of certain intestinal bacterial infections?
What is the primary mechanism by which Mycobacterium avium subspecies paratuberculosis causes chronic diarrhea?
What is the primary mechanism by which Mycobacterium avium subspecies paratuberculosis causes chronic diarrhea?
What is a key post-mortem finding associated with Mycobacterium avium subspecies paratuberculosis (Johne's disease)?
What is a key post-mortem finding associated with Mycobacterium avium subspecies paratuberculosis (Johne's disease)?
Which region of the intestine is MOST commonly affected by Mycobacterium avium subspecies paratuberculosis?
Which region of the intestine is MOST commonly affected by Mycobacterium avium subspecies paratuberculosis?
What is the primary cellular change observed in swine dysentery?
What is the primary cellular change observed in swine dysentery?
Why does the bacterium causing swine dysentery have a tropism for the hindgut (cecum and colon)?
Why does the bacterium causing swine dysentery have a tropism for the hindgut (cecum and colon)?
Where within the cell does Lawsonia intracellularis reside?
Where within the cell does Lawsonia intracellularis reside?
What is the MOST likely consequence of severe crypt hyperplasia in porcine proliferative enteritis?
What is the MOST likely consequence of severe crypt hyperplasia in porcine proliferative enteritis?
What type of inflammation is MOST commonly associated with gastrointestinal pythiosis?
What type of inflammation is MOST commonly associated with gastrointestinal pythiosis?
How does gastrointestinal pythiosis lead to intestinal obstruction?
How does gastrointestinal pythiosis lead to intestinal obstruction?
How does the clinical presentation of Cryptosporidium differ significantly from that of E. coli in causing neonatal diarrhea?
How does the clinical presentation of Cryptosporidium differ significantly from that of E. coli in causing neonatal diarrhea?
What is the PRIMARY mechanism by which Cryptosporidium parvum induces diarrhea in young animals?
What is the PRIMARY mechanism by which Cryptosporidium parvum induces diarrhea in young animals?
The severity of disease caused by intestinal protozoal parasites is most dependent on what factor?
The severity of disease caused by intestinal protozoal parasites is most dependent on what factor?
How do parasites such as Giardia contribute to malabsorption in the intestines?
How do parasites such as Giardia contribute to malabsorption in the intestines?
Hookworms such as Ancylostoma cause what MAIN pathogenic effect in puppies?
Hookworms such as Ancylostoma cause what MAIN pathogenic effect in puppies?
How should antimicrobial usage be viewed in the development of bacterial diseases in adult animals?
How should antimicrobial usage be viewed in the development of bacterial diseases in adult animals?
What is the role of pili (fimbriae) in the pathogenesis of certain E. coli strains?
What is the role of pili (fimbriae) in the pathogenesis of certain E. coli strains?
What is the mechanism of diarrhea caused by enterotoxigenic E. coli (ETEC)?
What is the mechanism of diarrhea caused by enterotoxigenic E. coli (ETEC)?
In pigs affected by edema disease due to Shiga toxin-producing E. coli, what cell type is primary target of the toxin?
In pigs affected by edema disease due to Shiga toxin-producing E. coli, what cell type is primary target of the toxin?
What systemic effect is MOST characteristic of Shiga toxin-producing E. coli in edema disease?
What systemic effect is MOST characteristic of Shiga toxin-producing E. coli in edema disease?
Why is Salmonellosis particularly concerning in a hospital setting for horses?
Why is Salmonellosis particularly concerning in a hospital setting for horses?
What is the underlying cause of rectal strictures that sometimes develop secondary to Salmonellosis in pigs?
What is the underlying cause of rectal strictures that sometimes develop secondary to Salmonellosis in pigs?
How do Clostridial exotoxins lead to the hemorrhage observed in Clostridial enteritis?
How do Clostridial exotoxins lead to the hemorrhage observed in Clostridial enteritis?
What part does trypsin play in preventing development of Clostridium?
What part does trypsin play in preventing development of Clostridium?
What is the primary mechanism by which Clostridium perfringens type D causes neurological signs in affected animals?
What is the primary mechanism by which Clostridium perfringens type D causes neurological signs in affected animals?
What is the primary reason that routine antiparasitic treatment has reduced the presence of metazoan intestinal parasites?
What is the primary reason that routine antiparasitic treatment has reduced the presence of metazoan intestinal parasites?
In horses, what is the key pathogenic action of cyathostomins (small strongyles) following encystment in the gut wall?
In horses, what is the key pathogenic action of cyathostomins (small strongyles) following encystment in the gut wall?
How do whipworms (Trichuris vulpis) cause clinical signs in dogs?
How do whipworms (Trichuris vulpis) cause clinical signs in dogs?
In a case of suspected intestinal disease, which combination of factors provides the MOST comprehensive basis for a differential diagnosis?
In a case of suspected intestinal disease, which combination of factors provides the MOST comprehensive basis for a differential diagnosis?
What is the MOST critical factor determining the severity of disease caused by intestinal protozoal parasites?
What is the MOST critical factor determining the severity of disease caused by intestinal protozoal parasites?
What is the MOST likely effect of the toxins produced by Clostridium species on host tissues during an enteric infection?
What is the MOST likely effect of the toxins produced by Clostridium species on host tissues during an enteric infection?
Which mechanism is MOST directly responsible for the chronic wasting observed in animals with Mycobacterium avium subspecies paratuberculosis (Johne's disease)?
Which mechanism is MOST directly responsible for the chronic wasting observed in animals with Mycobacterium avium subspecies paratuberculosis (Johne's disease)?
Which feature is MOST characteristic of rotavirus infection in piglets?
Which feature is MOST characteristic of rotavirus infection in piglets?
How does the pathogenesis of Feline Infectious Peritonitis (FIP) differ from that of typical feline enteric coronavirus (FECV) infection?
How does the pathogenesis of Feline Infectious Peritonitis (FIP) differ from that of typical feline enteric coronavirus (FECV) infection?
How do hookworms, such as Ancylostoma, cause clinical signs in infected animals?
How do hookworms, such as Ancylostoma, cause clinical signs in infected animals?
A pig farmer is experiencing high mortality rates in 6-14 week old pigs. Necropsy reveals edema in the spiral colon mesentery and gastric submucosa. What is the MOST likely cause?
A pig farmer is experiencing high mortality rates in 6-14 week old pigs. Necropsy reveals edema in the spiral colon mesentery and gastric submucosa. What is the MOST likely cause?
What role do M cells play in the pathogenesis of intestinal diseases?
What role do M cells play in the pathogenesis of intestinal diseases?
Which type of diarrhea is MOST associated with rotavirus and coronavirus infections?
Which type of diarrhea is MOST associated with rotavirus and coronavirus infections?
How does Lawsonia intracellularis cause the characteristic thickening of the intestinal mucosa?
How does Lawsonia intracellularis cause the characteristic thickening of the intestinal mucosa?
What is the PRIMARY mechanism by which enterotoxigenic E. coli (ETEC) strains cause diarrhea?
What is the PRIMARY mechanism by which enterotoxigenic E. coli (ETEC) strains cause diarrhea?
In swine dysentery, which cell type is the PRIMARY target of Brachyspira hyodysenteriae, leading to the characteristic lesions?
In swine dysentery, which cell type is the PRIMARY target of Brachyspira hyodysenteriae, leading to the characteristic lesions?
What environmental factor is MOST associated with gastrointestinal pythiosis in dogs?
What environmental factor is MOST associated with gastrointestinal pythiosis in dogs?
Which of the following BEST describes the typical gross appearance of the intestinal mucosa in a case of Mycobacterium avium subspecies paratuberculosis (Johne's disease)?
Which of the following BEST describes the typical gross appearance of the intestinal mucosa in a case of Mycobacterium avium subspecies paratuberculosis (Johne's disease)?
Which outcome is MOST linked to severe crypt damage caused by parvovirus?
Which outcome is MOST linked to severe crypt damage caused by parvovirus?
Why might antibiotic use in adult animals be a predisposing factor for bacterial intestinal infections?
Why might antibiotic use in adult animals be a predisposing factor for bacterial intestinal infections?
A dog presents with chronic weight loss and a thickened small intestine. Histopathology reveals granulomatous inflammation with numerous eosinophils and multinucleated giant cells centered around hyphae-like structures. GMS staining highlights the fungal organisms. What is the MOST likely diagnosis?
A dog presents with chronic weight loss and a thickened small intestine. Histopathology reveals granulomatous inflammation with numerous eosinophils and multinucleated giant cells centered around hyphae-like structures. GMS staining highlights the fungal organisms. What is the MOST likely diagnosis?
An owner reports that their horse suddenly developed severe diarrhea after being treated with broad-spectrum antibiotics for an unrelated infection. Fecal analysis reveals the presence of toxins A and B. Which agent is MOST likely responsible for these clinical signs?
An owner reports that their horse suddenly developed severe diarrhea after being treated with broad-spectrum antibiotics for an unrelated infection. Fecal analysis reveals the presence of toxins A and B. Which agent is MOST likely responsible for these clinical signs?
What is MOST true when comparing the effects of classical swine fever (CSFV) with the effects of rotavirus on the intestinal tract of infected piglets?
What is MOST true when comparing the effects of classical swine fever (CSFV) with the effects of rotavirus on the intestinal tract of infected piglets?
A researcher is investigating the pathogenesis of a novel enteric bacterium in livestock. The bacterium produces a toxin that inhibits protein synthesis in eukaryotic cells, disrupts tight junction proteins in epithelial cells, and induces apoptosis, yet minimal inflammatory cytokine production occurs. Based on these findings, what would be the MOST anticipated outcome of infection?
A researcher is investigating the pathogenesis of a novel enteric bacterium in livestock. The bacterium produces a toxin that inhibits protein synthesis in eukaryotic cells, disrupts tight junction proteins in epithelial cells, and induces apoptosis, yet minimal inflammatory cytokine production occurs. Based on these findings, what would be the MOST anticipated outcome of infection?
Flashcards
Enteritis
Enteritis
Inflammation of the small intestine.
Colitis
Colitis
Inflammation of the colon.
Typhlitis
Typhlitis
Inflammation of the cecum.
Proctitis
Proctitis
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Dehydration: Sunken Eyes
Dehydration: Sunken Eyes
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Toxemia/Sepsis
Toxemia/Sepsis
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Intestinal Viruses
Intestinal Viruses
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Rotaviruses
Rotaviruses
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Coronaviruses
Coronaviruses
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Parvoviruses
Parvoviruses
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Damage to Villous Enterocytes
Damage to Villous Enterocytes
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Damage to Crypt Epithelium
Damage to Crypt Epithelium
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Lamina Propria/Submucosal Injury
Lamina Propria/Submucosal Injury
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Granulomatous Inflammation
Granulomatous Inflammation
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Escherichia coli (E. coli)
Escherichia coli (E. coli)
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Enterotoxigenic E. coli (ETEC)
Enterotoxigenic E. coli (ETEC)
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Shiga toxin-producing E. coli
Shiga toxin-producing E. coli
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Salmonella sp.
Salmonella sp.
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Clostridium sp.
Clostridium sp.
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C. perfringes and C. difficile: predisposing factors
C. perfringes and C. difficile: predisposing factors
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Clostridium perfringens
Clostridium perfringens
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Clostridium perfringens type D
Clostridium perfringens type D
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Mycobacterium avium subsp. paratuberculosis
Mycobacterium avium subsp. paratuberculosis
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Swine dysentery (Brachyspira hyodysenteriae)
Swine dysentery (Brachyspira hyodysenteriae)
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Lawsonia intracellularis
Lawsonia intracellularis
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Pythiosis
Pythiosis
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Protozoal Diseases
Protozoal Diseases
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Coccidia
Coccidia
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Cryptosporidiosis
Cryptosporidiosis
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Ascarids
Ascarids
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Hookworms
Hookworms
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Whipworms
Whipworms
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Small Strongyles in Horses
Small Strongyles in Horses
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Diarrhea
Diarrhea
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Exotoxins
Exotoxins
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Endotoxins
Endotoxins
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Invasive Bacteria
Invasive Bacteria
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Vulnerability of Young Animals
Vulnerability of Young Animals
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Villi
Villi
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Enterocytes
Enterocytes
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Crypt
Crypt
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Inflammation Inducing Agent
Inflammation Inducing Agent
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Hemorrhagic
Hemorrhagic
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Granulomatous
Granulomatous
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Catarrhal
Catarrhal
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Hyperplasia
Hyperplasia
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Functional Alterations
Functional Alterations
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Villi Atrophy
Villi Atrophy
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Coronavirus & Rotavirus Mechanism
Coronavirus & Rotavirus Mechanism
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Parvovirus and Bloody Diarrhea
Parvovirus and Bloody Diarrhea
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M Cells
M Cells
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Mycobacteria
Mycobacteria
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Clostridial Enteritis
Clostridial Enteritis
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Rotavirus: Key points
Rotavirus: Key points
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Coronavirus: Target Cells & Species
Coronavirus: Target Cells & Species
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Feline Infectious Peritonitis (FIP)
Feline Infectious Peritonitis (FIP)
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Parvovirus: Immune System
Parvovirus: Immune System
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Mucosal Disease
Mucosal Disease
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BVD vs. Malignant Catarrhal Fever
BVD vs. Malignant Catarrhal Fever
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Dysbiosis
Dysbiosis
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Pili or fimbriae in E. coli
Pili or fimbriae in E. coli
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Heat-stable and heat-labile toxins
Heat-stable and heat-labile toxins
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Salmonella: Key points
Salmonella: Key points
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Small strong gels in horses
Small strong gels in horses
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Protozoal disease: Key points
Protozoal disease: Key points
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Cryptosporidium: Key points
Cryptosporidium: Key points
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Study Notes
Infectious Diarrheas of Intestines I
- Diarrhea/enteritis/colitis are causes of animal deaths.
- Infectious diarrheas can be viral, bacterial, fungal, protozoal, or parasitic.
- Focus on mechanisms of injury, target cells for viruses, inflammation location for bacteria.
- Note pathogenesis in bacteria, and animal age.
Etiology
- Enteritis: inflammation of the small intestine (duodenum, jejunum, ileum).
- Colitis: inflammation of the colon.
- Typhlitis: inflammation of the cecum.
- Proctitis: inflammation of the rectum.
Causes of Death
- Dehydration is a primary cause of death in animals with diarrhea, indicated by sunken eyes, dry gums, and loss of skin elasticity.
- Loss of the mucosal barrier leads to toxemia/sepsis
- Normal mucosa is beige, smooth, and shiny, while necrotic mucosa is rough, granular, covered in a fibrin membrane.
Core Concepts of Infectious Diarrheas
- Intestinal viruses cause disease by infecting and rupturing cells, disrupting cellular processes, causing necrosis.
- Intestinal bacteria cause disease by:
- Invading cells (e.g., Salmonella).
- Producing exo-(secreted) toxins (Gram-positive bacteria).
- Producing endotoxins (component of Gram-negative bacteria, released upon cell death, e.g., LPS).
- Secreting toxins that stimulate chloride secretion into the lumen (some E. coli strains).
- Diarrhea is more life-threatening in young animals due to the slower cell turnover rate, leading to prolonged fluid loss.
- Epithelial cells have a lifespan of roughly 10 days, needing continuous replacement.
Classes of Agents Causing Diarrhea
- Viruses are common in all species, especially young animals, and often cause acute disease.
- Rotaviruses, coronaviruses, and parvoviruses are viral causes. Viruses often induce acute diarrhea.
- Bacteria are more important in large animals.
- Acute or chronic forms result, depending on the bacteria.
- Fungi/algae are generally rare and usually cause chronic diseases, excluding Florida and southern states where fungal infections are mor common due to the hot and humid climate.
- Parasites/protozoa significance is heavily dependent on the burden (often asymptomatic).
- Likely to be a bigger issue in younger animals.
GIT Lesions
- Damage to villi results in enterocyte injury.
- Crypt injury can occur.
- The microvilli are prone to alteration.
- Injury to the lamina propria, submucosa, and deeper layers is possible.
- Hemorrhagic and granulomatous inflammation is a common kind of GIT injury.
- Catarrhal inflammation is rich in goblet cells.
- Inflammation can also be lymphoplasmocytic.
Damage to villious enterocytes
- Villous atrophy is a disease where villi are damaged and normal villi are tall.
- Loss of enterocytes on villi due to villi damage causes blunting and fusion, decreasing absorptive surface area, leading to malabsorption and therefore diarrhea.
- Coronavirus and rotavirus can target cells of the villi, leading to villi atrophy.
Damage to Crypt Epithelium
- Losing stem cells causes loss of entire crypt/villus unit, leading to severe maldigestion/malabsorption, possibly also exudation of blood, serum, and inflammatory cells, leading to diarrhea.
- Parvovirus can cause damage to crypt epithelium.
- Crypt epithelial cell damage leads to villi atrophy.
Lamina Propria/Submucosal Injury
- Bacteria and infectious agents that infect macrophages or crypt epithelial cells enter the lamina propria through M cells
- M cells are epithelial cells overlying Peyer's patches that present antigens.
- Macrophages can cause granulomatous disease, causing severe infection.
- Examples include mycobacteria.
- Crypt epithelial cells can cause proliferative or hyperplastic disease.
- Exotoxins produced kill the lamina propria, submucosa and blood vessels.
- Invasive bacteria can invade enterocytes and M cells.
- Clostridial enteritis can cause severe mucosa necrosis, leading to bloody diarrhea.
Viral Diseases of the Intestines
- Common viral causes: rotaviruses, coronaviruses and parvoviruses.
Rotaviruses
- Rotaviruses happen in neonates, about any species
- Such as in calves less than 1 week old and in pigs in their first 7 weeks.
- Rotaviruses can cause Shortening and fusion of villi
- They usually target the jejunum and ileum.
- Rotaviruses cause malabsorptive, watery diarrhea, as well as dehydration and weakness.
- Usually self-limiting, generally have low mortality. Gross changes are subtle.
- When death occurs due to Rotavirus, a concurrent infection often accompanies it, likely from coronavirus, Cryptosporidium, E.coli or coccidia.
- They target the tip of the villi.
Coronaviruses
- Coronaviruses are associated with:
- Pigs with transmissible gastroenteritis virus (TGE) or porcine epidemic diarrhea virus (PED).
- Often more virulent than rotavirus.
- Can affect colon.
- Cattle with Bovine coronavirus (calf viral enteritis, winter dysentery).
- Horses with Equine coronavirus (disease in adults, colitis>enteritis). - Can affect the colon of horses
- Dogs with canine coronavirus.
- Cats with feline enteric coronavirus (also causes FIP).
- Ferrets with ferret enteric coronavirus. Feline enteric coronavirus, ferret enteric coronavirus are two distinct viruses with no correlation, but cause similar disease in cats and ferrets.
- Pigs with transmissible gastroenteritis virus (TGE) or porcine epidemic diarrhea virus (PED).
- Coronavirus attacks both the tip and lateral surface of the villi, causing more severe disease.
Feline and Ferret Enteric Coronavirus
- The typical infection is asymptomatic, but mild enteritis with diarrhea may be present.
- Viral Mutation can cause the affected virus to survive in macrophages
Virus survival depends on a random mutation allowing virus survival in macrophages.
- Virus survival leads to systemic spread, turning into Feline Infectious Peritonitis (FIP) and Ferret systemic coronaviral disease (FSCD)
- Further virus survival leads to pyogranulomatous vasculitis affecting many tissues and chronic weight loss.
- Virus survival leads to systemic spread, turning into Feline Infectious Peritonitis (FIP) and Ferret systemic coronaviral disease (FSCD)
- FIP is not considered contagious because the mutation leading to macrophage survival occurs within the affected animal.
- Systemic spread of coronavirus leads to vasculitis, resulting in effusions (peritonitis, pleuritis).
Parvovirus
- Requires host cells to be in mitotic division to take hold.
- Targets crypt cells, Hematopoietic cells and lymphoid cells, inflicting segmental, necrotizing enteritis
- Leads to vomiting/diarrhea with dilated, hemorrhagic fluid-filled bowel and Lymphopenia, neutropenia (panleukopenia)
- Parvovirus attacks crypt epithelial cells, causing collapse of the lamina propria, hemorrhage, and bloody diarrhea.
- The mucosa is red, rough, and granular due to cellular debris., and villi and lamina propria collapse
- Is more severe than rota and cornavirus infections
Other Intestinal Viruses
- Bovine Viral Diarrhea Virus "Mucosal Dz" infections cause PI calf to mutate to form Mucosal Disease.
- Leading to ulcers throughout the Gl tract/over PP's as well as direct epithelial injury and Lymphoid depletion.
- Malignant Catarrhal Fever (OHV-2) causes:
- Ulcers throughout Gl tract, Lymphocytic vasculitis and Lymphoid hyperplasia.
Escherichi coli (E.coli)
- E. coli a ubiquitous Gram negative. Can be spore-forming
- Risk factors for E. coli infection include colostrum ingestion, crowding, temperature extremes, environmental contamination, and concurrent infection.
- Multiple strains exist, including enterotoxigenic E. coli (ETEC) and enteropathogenic E. coli (EPEC). Also includes septicemic colibacillosis.
ETEC (Enterotoxigenic E. coli)
- ETEC is common in piglets and calves and affects neonates to post-weaning.
- ETEC often causes secretion of functional alternations in the gut, leading to secretory diarrhea. Functional alterations happen because there is no morphology alteration..
- Infections commonly do not come with lesions.
- Bacteria adheres to the apical surface of enterocytes and secretes heat-stable and heat-labile toxins.
- These toxins induce epithelial cells to secrete chloride into the lumen, drawing water and sodium, causing secretory diarrhea.
Shiga toxin-producing E. coli
- Shiga toxin-producing E. colis often post weaning (6-14 wks) swine.
- Shiga toxin damages endothelium, → causing Edema varying from case to case throughout the body.
- Spiral colonization can lead to neurologic signs.
- Despite the bacteria's presence in the Gl tract, diarrhea or significant mucosal lesions are atypical.
- High morbidity and mortality often result, thus, sudden death is a likely outcome.
- Shiga toxin has tropism for endothelial cells, leading to increased vascular permeability and edema in the spiral colon mesentery, gastric submucosa, eyelids, and brain.
Salmonella sp.
- Salmonella sp. are enteroinvasive.
- Salmonella enter and survive in enterocytes, M cells & macrophages.
- Goes INTO cells, can get INTO circulation, produces endotoxin → septic shock.
- Salmonella adhere to enterocytes and ENTER, cell dies → malabsorption.
- Produce enterotoxin → secretory diarrhea.
- Produce endotoxin - SICK, plus vasculitis/thrombosis → mucosa dies (infarct/ulceration) → effusive diarrhea.
Salmonellosis - Epidemiology
- Usually after a predisposing condition – stress, antibiotics, poor husbandry, in carrier animals – lymphoid tissue in gut and nodes, gall bladder.
- Important to be aware of in hospital setting!
- S. typhimurium, S. enterica, S. dublin, S. cholerasuis and S. typhosa are all types of salmonellosis.
- Salmonella is not a normal inhabitant of the intestines. Important is to identify carriers that shed salmonella and test for it commonly.
Salmonellosis Specifics
- Infections are often acute, with hemorrhagic or fibrinonecrotizing symptoms.
- Infections can also be chronic with button ulcers.
In acute infections, there is severe damage to mucosa, and often are around Peyer's patches.
- Infections cause severe damage to the mocosa (enterovisive and through the Mucosa cells) and affect the large intestine more than the small intestine.
- Chronic forms can result in well demarcated ulcers intestines or button ulcers. The necrotic center often is what leads to the chronic bottom ulcers.
- In pigs, salmonellosis can lead to rectal strictures due to ulceration and subsequent fibrosis, resulting in constipation and megacolon.
Clostridium sp.
- All Clostridida are OPPORTUNISTS and when they get a CHANCE, they grow like crazy and produce exotoxins that kill all nearby cells, usually entering the vasculature → ENTEROTOXEMIA.
- Dysbiosis is often the cause and can come from antibiotics, a change of diet, or an increase of gram-positive bacteria.
Clostridia
- The bacteria create Toxins that attack epithelial cells, the lamina propria and and vasculature in order to cause hemorrhage and/or edema
- Toxins from the clostridia enter and spread systemically.
C. perfringes and C. difficile
- Changing the enteric microenvironment can lead to Clostridia taking hold, this can be influenced by
- Change in feed, abnormally nutrient-rich digesta or even Antimicrobial therapy, Trypsin inhibitors (colostrum) or just a Reduce of motility. Colostrum's trypsin inhibitors can increase susceptibility to clostridial diseases in neonates.
- Clostridia never invade cells but they Make toxins that kill everything they encounter, epithelial cells, causing lamina propria or vasculatures tohemorrhage and/or become edemic
- Toxins from the clostridia enter and spread systemically.
Clostridium perfringens type D
- Can cause "Overeating" disease because the starch doesn't digest properly in the small intestine
- This is usually linked to grain and starches, as well enterotoxemia in sheep and goats.
- Epsilon toxin in the clostridium damages to endothelial cells
It's a peculiar disease because it is linked to the change the diet to rich in grain and concentrate diet, so undigested.
- Primarily attacking the brain (internal capsule) and Lung (pulmonary edema), causing symmetrical Encephalomalacia.
Clostridioides difficile (horses and piglets)
- Causes enterocolitis.
- Clostridioides difficile is known to cause damages to the mucosa and damage is more severe with the damage to submucosa Also can have a lot of hemorrhage of the serosa, often confirmed can be done by gram stain and PCR
Mycobacterium avium subspecies paratuberculosis
- Paratuberculosis or Johne's disease affect primarily ruminants, which often causes Clinical disease, characterized by diarrhea, emaciation and hypoproteinemia
- This is usually prevalent in animals older than 2yo, but note that subclinical animals shed mycobacteria!
- Bacteria from infected macrophages enter Mucosa cells, this intrusion cause Malabsorption, protein leakage and Marked mucosal thickening. They enter through mucosol cells and the cause disruption to Mucosa architecture.
Swine dysentery
- Brachyspira hyodysenteriae causes necrotic intestinal issues in weanling pigs between 8-14 weeks old
- Brachyspira invades enterocyte (Brachyspira hyodysenteriae) and then produce toxins to induce proliferation of goblet cells.
- Infections typically result in Mucohemorrhagic diarrhea and/or typhlocolitis of the cecum and colon. Brachyspira target the mucin goblet cells which causes stimulation of mucus.
- Brachyspira invades enterocyte (Brachyspira hyodysenteriae) and then produce toxins to induce proliferation of goblet cells.
Lawsonia intracellularis = Porcine proliferative enteritis
- Infections are usually obligate intracellular with an affinity for crypt cells. Infection can proliferate until crypt hyperplasia turns into necrosis and hemorrhaging.
- Affects a wide variety of species, typically Piggies as well as horses in postweaned pigs often in the Ileum, cecum and proximal spiral colon.
- It creates a cerebriform structure that has high similarities with the Yonis disease It is often a Obligate intracellular bacteria that has tropism for crypt cells which leads to higher stimulation to hyperplasia
Fungal and Algal Diseases of the Intestines
- They are typically sporadic/uncommon/rare, but can be often serious
- Such as Histoplasma capsulatum or Pythiosis - (Pythium insidiosum) or Prototheca.
Pythiosis
- Pythium insidiosum (oomycete, fungal-like) lives in swamps and standing waters.
- Dogs are most susceptible.
- Cutaneous pre-existent lesions/wounds (Cutaneous Form) or by ingestion.
- Symptoms primarily consist of Granulomatous and eosinophil inflammation and Segmental thickening/mass effect. Often in dogs and mostly effects GI system due to the dogs ingesting pynthium It often causes mechanical obstructions Is often surgical, through enterectomy to remove
- Surgical removal is likely recommended.
Protozoal Diseases of the Intestines
- Primarily Eimeria/Cystoisospora (coccidiosis), Giardia and Cryptosporidium sp.
- Infections are often asymptomatic (unless you're very immunosuppressed).
- Commonly found in young animals.
- Infections are primarily diagnosed with Fecal Dx antigen tests. Often diagnose through fecal floatation and mostly test the morphology
- Protozoal diseases of the intestestines cause mild and self-limiting diseases of the most protozoal dieseases. They often cause mucosal damage, which then leads to increased movement of the interstines
Eimeria & Cystoisospora (“Coccidia")
- Infections are host-specific, with tissue-specific apicomplexan infection profiles.
- The Complex life cycle with sexual/asexual stages occur inside of the intestinal epithelial cells and burst, releasing progeny.
- Oocysts persist in the environment.
- Infections are a SMALL INTESTINE problem, except when prevelant in cattle. It then can be Proliferative and nodular in sheep and goats, and can leads to hypertrophic villi and crypts
Cryptosporidiosis
- This zoonotic condition is caused by C. parvum, specifically targetting calves, lambs and foals.
- Diarrhea is the most common symptoms, with primary damage to neonatal calves. They also often present with mild damage, there is often malabsorption and attropy with little of the lesion shown Differential Diagnosis of neonal calves: Rota, Corona, Cryptosproridium, and ETEC E. coli
- Infections typically cause villous atrophy and target Small Intestine.
- Infected brush border's create Malabsorption with not gross lesions. Cryptosporidiosis does not allow the secretion of toxin, but they efface their brush border.
Metazoan parasites of the Intestines
- Prevalence depends on antihelminthic usage in population
- Symptoms depend on of load and lifestyle
- Infections are generally diagnosed by fecal floats or gross exam
Ascarids
- Generally asymptomatic unless causing massive burden or obstruction following tx.
- Toxocara canis is a common variety primarily infecting dogs.
- Parascaris equorum is a common variety primarily infecting foals. Damage the mucosa. Also cause the small amount of bleeding and the exudate increases.
Hookworms
- primarily inhabit the Small intestine and are smaller than ascarids.
- Primarily target bloodsuckers, which consequently induces Aemia, proteinloss and diarrhea.
- Common Hookworm types Ancylostoma spp mostly infect Dogs and cats. They burrow in the intestines and mucous membranes and cause aemia
Whipworms
- Whipworms are known to inhabit the Cecum with some also spreading to the colon. The colon is also common - They cause symptoms because they are Bloodsuckers that induce Anemia. They will often migrate around, causeing blood. - Protein loss and diarrhea are also typical of whipworm infections
- Known types are Trichuris vulpis in dogs or Trichuris suis in pigs. Cats do not get infected with whipworms, only dogs and pigs do.
Small Strongyles
- Small strongyles are a type of horse infection that leads to infection by Cyathostomes Mostly infects the Cecum and colon Larval stages like to live surrounded by mucosa, so they burrow on in (encysted) They burrow here for years without damaging it. - When they emerge in the intestinal lumen, it causesinflammation and mucosal damage - like proteinloss, and diarrhea A stress factor or environment is where the emergence usually happened - A Horse who is a hindgut fermentor is unable to absorb the water from the emerged worms. When you identify the infection often rinse to identify.
Diseases Overview
- Viral diseases: Target cells and mechanisms of injury leading to malabsorptive, secretory, or effusive diarrhea are key.
- Bacterial diseases: Are key with often being caused because of a bad envioroment
- Parasitic diseases: Related to bloodsuckers, also cause damage and inflammation of host and can lead to obstruction
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