How Coccidia Are Diagnosed
Dogs that are seen by a veterinarian for coccidial diarrhea – especially young puppies – often have normal results on their routine blood work and urinalysis, with the possible exception of showing the effects of dehydration. The best way to diagnose coccidiosis is to examine a fresh fecal sample for the presence of the oocyst form of the parasite. The veterinarian usually will mix a small amount of feces with either a sugar or salt solution, zinc sulfate or a special stain, before looking at drops of the mixture under a microscope. There are several different ways to perform a fecal assessment, including fecal floatation, fecal suspension or fecal smear. Each of these is about equally effective in identifying coccidial cysts, if they are present in the sample. The choice of which technique to use is up to the treating doctor. However, multiple fecal evaluations may be necessary to confirm or rule out coccidia infection, because oocysts are not uniformly excreted in the stool.
Remember, coccidia usually don’t cause companion dogs to become sick, although they can. Illness from coccidia is the exception, rather than the rule.