Coccidiosis in Animals

Study Notes

Most animals acquire Eimeria or Isospora infections between 1 month and 1 year old
Older animals are usually resistant to clinical disease but may have sporadic inapparent infections
Clinically healthy, mature animals can be sources of infection to young, susceptible animals
Clinical signs of coccidiosis include destruction of intestinal epithelium and underlying connective tissue, accompanied by hemorrhage, catarrhal inflammation, and diarrhea
Signs may include discharge of blood or tissue, tenesmus, and dehydration

Oocysts can be identified in feces by salt or sugar flotation methods
Multiple examinations may be required to diagnose coccidiosis due to timing of oocyst discharge
The life cycles of Eimeria and Isospora are considered self-limiting and end spontaneously within a few weeks unless reinfection occurs
Sick animals should be isolated and treated individually with sulfonamides or amprolium

Continuous low-level feeding of amprolium, decoquinate, lasalocid, or monensin during the first month of feedlot confinement can prevent coccidiosis

Many species of coccidia infect the intestinal tract of cats and dogs
All species appear to be host-specific
The most common coccidia of cats and dogs are Isospora
Clinical signs in severe cases include diarrhea (sometimes bloody), weight loss, and dehydration
Amprolium can be used for prophylaxis in kennel conditions

Cryptosporidiosis is an enterocolitis caused by the coccidian parasite Cryptosporidium parvum
The disease is not host-specific and is common in young ruminants
Clinical signs include weight loss and watery diarrhea
Cryptosporidium parvum infections pose a significant risk to immunocompromised people
The disease is self-limiting, and supportive therapy is usually sufficient

Giardiasis is a chronic, intestinal protozoal infection that occurs worldwide in most domestic and wild mammals, many birds, and people
There is circumstantial evidence that Giardia spp that infect domestic animals can infect people

Eimeria zuernii, Eimeria bovis, and Eimeria auburnensis are most often associated with clinical disease in cattle
Coccidiosis is commonly a disease of young cattle (1-2 months to 1 year) and usually is sporadic during the wet seasons of the year
The incubation period is 17-21 days
Clinical signs include watery feces, with little or no blood, and the animal shows only slight discomfort for a few days
Severe infections are rare, and severely affected cattle develop diarrhea with thin bloody fluid, streaks or clots of blood, shreds of epithelium, and mucus.