Vitamin C has long been considered the cure for the common cold in humans. In pets, it has been thought to prevent hip dysplasia, cure feline leukemia, and prevent urinary tract infections. Studies seem to suggest that given high levels of vitamin C, animals that had clinical hip dysplasia, seemed to exhibit fewer signs of joint pain. It did not cure the condition, but it did seem to allow the patient to better live with the problem.
Vitamin C has been used with varying degrees of success in helping prevent the formation of some bladder stones in dogs and cats. The vitamin C makes the urine more acidic and maintaining an acid urine helps discourage the creation of most stone types.
vitamin C is widely used as a supplement in growing, pregnant, lactating, stressed, and working pets. There is no concern for vitamin C toxicity.