Can Coccidia Cause Fever?
Can coccidia cause fever of 105 degrees in cats?
Coccidia are microscopic intestinal parasites of cats and dogs. The organisms are ubiquitous. Adult animals with mature immune systems generally are not made sick by coccidia. Puppies and kittens are not as consistently immune, so they may experience diarrhea that in severe cases can lead to dehydration and malaise.
I have yet to see coccidia cause a significant fever in a cat, dog, puppy, or kitten (animals normally have temperatures as high as 102.5 degrees Fahrenheit). Although you haven't said as much, I suspect that your cat became sick at home, leading you to seek care for him. I'm guessing the vet recommended diagnostic testing, and one of the findings was an infestation with coccidia. In this case, I doubt that coccidia is playing a role in your cat's clinical situation.
Fevers may be caused by infection (with viruses or bacteria), inflammation, certain forms of toxicity, and (rarely — especially in young cats) cancer. Cats with fevers generally need IV fluids and antibiotics. Treatment for coccidia won't hurt, but it also is unlikely to address the fever.