Veterinary Pathology Quiz on Obstructive Disorders

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Questions and Answers

What leads to the development of intraluminal blood clots in perfringens type A infections?

Rapid fermentation of ingested substrates

Nutritional deficiencies from malabsorption

Acute, localized inflammation of the stomach

Physical obstruction caused by necrotizing enteritis (correct)

Which of the following is a common clinical sign of obstructive disorders?

Excessive salivation

Sudden intestinal perforation

Increased appetite

Reduced fecal output, mucous, and blood-tinged (correct)

What is one potential consequence of necrosis extending through the intestinal wall within 24-48 hours?

Formation of new blood vessels

Complete recovery without treatment

Fibrinous peritonitis and death (correct)

Reduction of abdominal pain

Which of the following treatments may be attempted for emergency cases of obstructive disorders?

Immediate surgery to explore and remove obstructions Signup and view all the answers

What diagnostic method can reveal distended loops of intestines in obstructive disorders?

Abdominal ultrasound or rectal examination Signup and view all the answers

What is one of the clinical signs of Johne’s disease in ruminants?

Intermittent diarrhoea without blood or mucus Signup and view all the answers

Which supportive therapy is commonly indicated for patients suffering from peritonitis due to obstructive disorders?

Antibiotics to address the infection Signup and view all the answers

Which diagnostic method has the highest specificity for confirming Johne’s disease?

Bacteriological culture of faeces Signup and view all the answers

What is a notable risk associated with the use of NSAIDs in treating obstructive disorders?

Risk of toxic shock upon reduction Signup and view all the answers

Which condition is associated with a high prognosis of 70-80% following treatment?

Caecocolic volvulus Signup and view all the answers

What percentage decrease in milk yield is associated with the presence of clinical signs of Johne’s disease?

20% Signup and view all the answers

Which of the following options does NOT belong to the differential diagnoses for non-stomach GI diseases?

Foot and Mouth Disease Signup and view all the answers

What characterizes the diagnosis of Johne’s Disease?

High specificity but variable sensitivity Signup and view all the answers

What is a potential consequence of Johne’s disease in ruminants?

Reduced production Signup and view all the answers

During which stage of Johne’s disease does the animal typically begin to shed bacteria?

After the onset of clinical signs Signup and view all the answers

Which of the following conditions would likely be managed through surgical intervention?

Mesenteric torsion Signup and view all the answers

What is a primary treatment option for effective parasite control in livestock?

Use of strategic benzimidazole anthelmintics Signup and view all the answers

Which of the following clinical signs may indicate poisoning from acorns?

Foetid, tarry diarrhoea Signup and view all the answers

What is an important prevention measure against Yew poisoning?

Prevent access to Yew trees Signup and view all the answers

Which condition is characterized by the obstruction of the oesophagus due to food or foreign objects?

Choke Signup and view all the answers

What clinical sign might suggest an animal is experiencing choke?

Nasal discharge of food and water Signup and view all the answers

What is a common approach to managing pasture contamination in lambs?

Rotating grazing areas Signup and view all the answers

Which pharmacological category do most anthelmintics belong to?

POM-VPS Signup and view all the answers

What is one of the clinical signs associated with Yew poisoning?

Sudden death Signup and view all the answers

What is the minimum yearly testing requirement for calves to control Johne's disease?

Minimum yearly testing Signup and view all the answers

What percentage sensitivity (Se) is required to detect infected animals in the most optimistic scenario for TB tests?

70% Signup and view all the answers

Which animal management practice helps in protecting calves from Johne's disease?

Culling of red cows Signup and view all the answers

When is the earliest testing permissible for calves suspected of BVD?

3 months Signup and view all the answers

What is a key symptom of BVD affected animals?

Depression and anorexia Signup and view all the answers

What is one method for controlling Salmonella outbreaks?

Prompt removal of calves Signup and view all the answers

How is Winter Dysentery typically transmitted?

Fecal-oral route Signup and view all the answers

What is an important factor in diagnosing Winter Dysentery?

Exclusion of other pathogens Signup and view all the answers

What condition is characterized by chronic diarrhea in calves and can lead to death within a week?

Salmonella infection Signup and view all the answers

Which practice is recommended for heifer management to prevent diseases?

Isolating them from mature cows Signup and view all the answers

What is the common outcome of high morbidity associated with Winter Dysentery?

Spontaneous recovery Signup and view all the answers

Which animals should be culled first in a herd with Johne's disease?

The red cows Signup and view all the answers

What may interfere with antibody testing in BVD until 4-5 months of age?

Maternal-derived antibodies (MDA) Signup and view all the answers

What is an indicator that an animal has developed mucosal disease due to BVD?

Presence of mucosal lesions Signup and view all the answers

What is the typical duration before spontaneous recovery occurs in parasitic gastroenteritis in cattle?

3-5 days Signup and view all the answers

Which treatment is specifically recommended for Type II Ostertagia ostertagi in cattle?

Ivermectin at housing Signup and view all the answers

What clinical signs are most commonly associated with Type I Ostertagia ostertagi infection in cattle?

Sudden, profuse green diarrhea and high morbidity Signup and view all the answers

What is the primary cause of outbreaks of Nematodirus battus in lambs?

Overwintered larvae mass-hatching due to temperature Signup and view all the answers

What type of weather conditions typically lead to the peak clinical signs of Nematodirus battus in young lambs?

Warm weather above 10°C Signup and view all the answers

What is the probable observation of faecal egg counts in Type II Ostertagia ostertagi infections?

Probably absent in severely affected animals Signup and view all the answers

Which factor is NOT considered during the diagnosis of parasitic gastroenteritis in cattle?

Body hair condition Signup and view all the answers

In the context of supportive therapy for cattle with parasitic gastroenteritis, which option is essential?

Free-choice salt and fluids Signup and view all the answers

Study Notes

Adult Ruminant Non-Stomach Conditions

Learning Objectives: Students should be able to construct differential diagnoses for non-stomach GI diseases in ruminants, choose appropriate diagnostics, determine appropriate medical and surgical interventions, estimate prognosis for individual animals and herds, and identify control measures for disease prevention.

Differential Diagnoses

Infectious: Johne's Disease, Bovine Viral Diarrhea, Salmonella, Winter Dysentery, Parasitic Gastroenteritis
Poisoning: Acorn, Yew
Obstruction: Choke, Caecocolic dilation and volvulus, Mesenteric torsion
Other: Peritonitis

Johne's Disease

Description: Chronic wasting disease, chronic granulomatous enteritis and lymphadenitis. Signs appear 2-5 years after a stressful event.
Clinical Signs: Reduced production and fertility, 10% decrease in milk yield before clinical signs, 20% decrease after, severe progressive weight loss, intermittent diarrhea, absence of blood or mucus, submandibular edema, emaciation, and death.
Diagnosis: Ziehl-Neelsen staining of faecal smear or histologic section, bacteriological culture of faeces, faecal PCR, blood or milk ELISA (detect antibodies, but often late).
Control/Prevention: Minimum yearly testing of red cows, culling cows when prevalence is low. Protect calves from manure and milk from amber cows, use responsible replacements from accredited herds, separate positive animals. Don't test for Johne's within 6 weeks of TB testing.

Bovine Viral Diarrhea Virus (BVD)

Types: Type I (UK), Type II (Europe)
Disease Forms: Acute, immunosuppression (particularly calves), reproductive.
Clinical Signs (Mucosal Disease): Fatal disease of PI animals, BVDV mutation into cytopathic form, animals 6-24 months old typically will show depression, anorexia, drooling, and mucosal lesions (lips, gums, tongue, esophagus, and intestines). Diarrhea (foul-smelling, bloody, or mucous), death in 5-7 days
Clinical Signs (Acute): Any animal, small production losses, lasts less than 14 days. Immunosuppression, particularly calves, can lead to scours and pneumonia.
Diagnosis: MDA can interfere with Ab testing until 4-5 months, PCR for antigen, re-test for 4 weeks, ear notch testing for antigen ELISA or PCR, bulk tank PCR for herd screen. Can do 10-animal young-stock screen at 9-15 months via Ab ELISA. Test all animals after positive results of PI, test for 12 months after removal.
Control: Vaccination (prevents foetal infection, will not remove PIs), biosecurity (avoid buying from antibody-positive pregnant animals).

Salmonella

Description: High infective dose or altered GIT motility allows bacteria to invade the small intestine. Most common in calves 2-6 weeks old. Zoonotic.
Herd Level Risk Factors: Buying-in animals; direct contact with other animals, neighboring herds being seropositive, visitors not wearing appropriate PPE, increased herd size and stocking density, surface water on farm, liver fluke infestation on farm.
Clinical Signs: Clinical signs - higher doses produce more severe clinical signs, acute enteritis ( +/- systemic involvement), pyrexia, severe watery feces, putrid odor, mucous, and fibrin casts, pneumonia, septicemia, arthritis, and sloughing of extremities, abortions 5-8 months
Diagnosis: Enriched Salmonella faecal culture in clinically ill animals, Se 60 – 100%, isolation from chronic or treated animals is difficult, and culture of aborted foetal stomach.
Treatment: Antimicrobials if septicaemic (TMPS, be cautious of resistance), fluids, NSAIDs, vaccination reduces abortions and shedding.
Control Points: Calving pen management to reduce exposure, removal of calves, low stocking density, regular bedding and cleaning, pre-weaning management, and good colostrum. Avoid feeding waste milk, keep separate from cows, and hygiene.

Winter Dysentery

Description: Acute, highly contagious disease causing watery diarrhea, mostly in housed adult dairy cows in the winter. Bovine Coronavirus is a probable cause. Faeco-oral route.
Clinical Signs: Acute onset explosive diarrhea (sometimes dysentery), dark greenish-black color, may have blood and mucus. Variable anorexia/depression/dehydration, drop in milk production, mild respiratory signs, high morbidity but spontaneous recovery in 2 -3 days.
Risk Factors: Diet changes, cold temperatures, high stocking density, poor ventilation, concurrent microorganisms.
Diagnosis: Exclusion of other pathogens (BVD, Salmonella), negative cultures, and Coronavirus ELISA.
Treatment: Mostly spontaneous recovery (3-5 days), supportive therapy (fresh water, palatable feed, free-choice salt, fluids - IV in severely affected).

Parasitic Gastroenteritis (Cattle)

Type I: Late summer/early autumn, larvae ingestion causes immediate maturation of large numbers, dry summers transition to wet summers. Sudden, profuse green diarrhea, high morbidity, low mortality, potential for 10% weight loss.
Type II: Infective larvae ingested from autumn onwards, arrested development (stage L4 within abomasal glands). Mass emergence late winter, profuse, unresponsive diarrhea, poor treatment response.
Diagnosis: History, grazing pattern, weather, previous anthelmintic treatments, faecal egg counts (Type I probably high, Type II probably absent), pepsinogen levels.
Treatment (Cattle): Type I: All anthelmintics (avoid resistance!), Type II: Group 3 anthelmintics (avermectin). Supportive therapy.
Prevention (Cattle): Grazing management, strategic anthelmintic treatments (Type I: 3, 8 and 13 weeks post turnout, Type II: Ivermectin at housing); faecal egg counts.

Parasitic Gastroenteritis (Lambs)

Cause: Nematodirus battus immature larvae (L3). Ingestion of infectious L3 from pasture during overwintered mass-hatches onto pasture following warm seasons ( >10°C, forecasts). Development in the small intestine.
Clinical Signs: Weight loss, diarrhea, focal staining around perineum, dehydration, death (usually in spring in young lambs & later in season w/older ones).
Diagnosis: Feco-specific tests helpful/unhelpful for monitoring efficacy; Clinical signs, and post-mortem.
Treatment: Strategic benzimidazole anthelmintics (white drench).
Control: Do not graze next-year's lambs on previous pastures (contamination). Use of risk forecast to predict mass hatchings of L3.

Acorn Poisoning

Cause: Phenols and tannins
Clinical Signs: Severe kidney damage, anorexia, depression, weight loss, rumen stasis, foetid tarry diarrhea, sudden death (4-7 days).
Treatment: Supportive.
Prevention: Avoid grazing around oak trees in autumn.

Yew Poisoning

Cause: toxic alkaloids affecting heart muscle
Clinical Signs: Sudden death. Muscle tremors, incoordination , nervousness, difficulty breathing, vomiting, diarrhea, and convulsions. Lethal dose of fresh material is 1-10g/kg BW. Usually even more toxic after cutting.
Prevention: Prevent access.

Choke

Cause: Oesophagus obstructed by food (e.g., root vegetables), foreign objects.
Clinical Signs: Free-gas bloat, ptyalism, nasal discharge of food and water, may be bloated and in distress or recumbent. Sever free-gas bloat can cause asphyxia.
Diagnosis: Inability to pass a stomach tube (if no other causes).
Treatment: Trocar in left paralumbar fossa, massage free solid objects, caution with oesophageal rupture.

Jejunal Haemorrhage Syndrome

Cause: Uncertain aetiology, often C. perfringens type A bacterial infection of the small intestines causing localized necrotizing hemorrhagic enteritis, leads to the formation of blood clots.
Clinical Signs: Sudden onset of abdominal pain, progressing to sternal recumbency, shock, and death. Proximal accumulation of intestinal fluid and gas, varying degrees of anemia.
Diagnosis: Often requires exploratory laparotomy or necropsy. Ultrasounds may help.
Treatment: Supportive (hospital cases may try laparotomy to remove blood clots).

Obstructive Disorders

Cause: Often unknown aetiology, often altered intestinal motility, mesenteric or caecocolic volvulus, ingestion of rapidly fermentable substrates, peritonitis adhesions, intussusception.
Clinical Signs: Anorexia, reduced faecal output (mucous, blood tinged), sudden milk drop, cardiovascular effects, injected mucous membranes,.
Diagnosis: Abdominal contour (lower right quadrant for small intestine distension), auscultation (pings & splashes), rectal examination (dilated caecum), ultrasound exam (right paralumbar fossa or rectum, small intestinal distension, increased peritoneal fluid), abdominocentesis (haemorrhagic - strangulating obstructions),

Peritonitis

Primary: Subsequent to septicemia, injury, calving injuries, abomasal ulcers, TRP, intestinal torsion, liver abscess, surgery
Secondary: Chronic or non-specific clinical signs, Localized vs Diffuse, Abdominal tenderness and rigidity, Pyrexia, anorexia, and milk drop, Rumen stasis and ileus, low faeces output. Chronic condition = fluid output. Acute condition = dry output.
Diagnosis: Abdominal contour, auscultation for rumen stasis, abdominocentesis (protein >3g/dl, neutrophils), ultrasound for free fluid in abdomen, rectal examination for lack of movement of rectal wall, exploratory laparotomy.
Treatment: Supportive fluids, NSAIDS, antibiotics (broad spectrum), surgery in necessary cases, debridement, irrigation and drainage (ultrasonography guided).
Prognosis: Guarded.

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Description

Test your knowledge on the clinical signs, treatments, and diagnostic methods related to obstructive disorders and infections such as perfringens type A and Johne's disease. This quiz covers key concepts in veterinary pathology, with a focus on intestinal health and disease management in ruminants. Challenge yourself and see how well you understand these critical topics.