Coccidiosis

Coccidiosis is an infection of the lower small intestine, cecum, colon, and rectum, caused by the protozoan parasite Eimeria.
A wide range of species are involved, with E. zuernii and E. bovis being the most pathogenic.
Infestations in the small intestine are considered to be less pathogenic due to the more rapid cellular regeneration than in the large intestine, and because the large intestine provides a further opportunity for the resorption of water.

Clinical features:
disease is usually associated with calves crowded in damp and unhygienic conditions.
Adult animals (e.g., suckler cows) may be carriers, though oocysts may survive many months in the environment. The incubation period is 17–21 days.
Affected calves are dull, pyrexic, and typically produce watery feces, usually mixed with blood. Tenesmus, with continued straining and frequent passage of small quantities of blood and feces, is a characteristic sign.
The anal sphincter is open, exposing the rectal mucosa.
Hair loss on the inside of the leg results from fecal soiling.
Another calf shows a thickened and inflamed colonic mucosa. Blood on the surface of freshly passed feces unrelated to coccidiosis, is a normal feature of some calves, but it occurs more often following stress, e.g., transport, or sale through a livestock market.

Differential diagnosis:
diagnosis depends on clinical signs, the demonstration of oocysts on fecal lotation or
direct smear, and autopsy changes such as thickening and inflammation of the intestinal mucosa.

Treatment:
amprolium |oral|, and sulfonamides |injection| .

Prevention:
is by management changes to avoid fecal contamination of feed, cleaning between batches using an ammonia-based disinfectant or other suitable oocide, and by strategic use of coccidiostats soon after the expected period of exposure.

 

occidiosis with severe tenesmus and bloody feces.  (1)

Coccidiosis showing thickened hemorrhagic colon.(2)