Coccidia (Cystoisospora/Isospora spp.)
Why it matters: Common in puppies; can cause significant diarrhea in young dogs.
How dogs get it: Ingesting oocysts from contaminated feces or environments; exposure risk increases with group housing.
Common signs: Watery diarrhea, sometimes with mucus, decreased appetite; adults may carry without illness.
Diagnosis: Fecal testing.
Treatment & prevention: Treatment is prescription-based; prompt feces removal and environmental cleaning are key prevention steps.