Symptoms and Diagnosis

Posture of sick birds.

Outward signs of coccidiosis in chickens include droopiness and listlessness, loss of appetite, loss of yellow color in shanks, pale combs and wattles, ruffled, unthrifty feathers, huddling or acting chilled, blood or mucus in the feces, diarrhea, dehydration, and even death. Other signs include poor feed digestion, poor weight gain, and poor feed efficiency. Some symptoms can be confused with other diseases. For example, necrotic enteritis is a gut disease that also causes bloody diarrhea.

Producers in the past identified coccidiosis outbreaks as either severe-acute or chronic, which was less severe but more widespread.

If concerned about coccidiosis, do a necropsy – put on plastic gloves and cut open the chicken. Look at the intestines and then cut them open. If done soon after death, it may be possible to identify characteristic lesions or sores in the gut. Coccidiosis causes a thickening of the intestines, which make them feel like a sausage. There may be light-colored spots on the surface of the gut, and inside the gut, hemorrhages and streaks. If you want to confirm a diagnosis, you can send scrapings of the gut lining to a state diagnostic lab. The USDA’s Animal and Plant Health Inspection Service’s Web site lists diagnostic labs.

Small intestines affected by Eimeria maxima. The middle sample is opened to show white spots.

Note the ballooning.