So far what's linked to from here is:

Constipation in Cats - This article is, for now, specifically about constipation in cats (though you can get some good pointers from it for other animals).

Cushing's Disease - This section includes an article titled Treating Cushing's Disease with Homeopathy and Other Alternative Therapies, and other information on Cushing's Disease as it affects both dogs and horses.

Kidney Failure - This is an article on kidney failure in cats or dogs.

Seizures - An article on seizures (most common in dogs, but for other animals too).