Ascorbic Acid, or more commonly called Vitamin C, is a naturally occurring substance that plays a significant role in the formation of collagen. Unlike humans and other primates and birds, dogs and cats produce ascorbic acid naturally in the liver. However, there are some situations that require a pet to be treated with the administration of ascorbic acid.

Ascorbic Acid is prescribed in veterinary medicine for the treatment of Vitamin C deficiency caused by liver disease and for certain toxicity syndromes, like acetaminophen toxicity. Other uses include treating feline immunodeficiency virus infections and as a preventative measure against the formation of struvite uroliths. It has also shown to be beneficial as a supportive measure in the treatment of Ehlers-Danlos syndrome.

Possible Interactions & Precautions with Ascorbic Acid

For the most part, Ascorbic Acid is safe for animals; however, excessive use of the vitamin can cause the formation of calculi in the kidneys. Intestinal irritation and diarrhea can also occur with large doses and in very rare cases, anemia can develop.

Because Vitamin C is water soluble, it breaks down quickly in the body so toxicity is generally not a problem, but the vitamin can cause an interaction with other prescription medications such as cyclosporine, tetracycline, beta-blockers, loop diuretics, aspirin and acetaminophen and other acid-based medications. In addition, some animals have been found to be sensitive to Ascorbic Acid so if your pet acts differently when taking the vitamin, contact your veterinarian immediately.

Ascorbic Acid Dosage & Administration

Ascorbic acid is available for administration in various compounding formulations, including tablets (250 mg, 500 mg, 100 mg, 1500 mg), capsules (500 mg), crystals (1000 mg per quarter teaspoon), powder (60 mg and 1060 mg per quarter teaspoon), solution (100 mg/mL), liquid (500 mg/mL) and by injection (500 mg/mL).

Typical dosages include:

For the treatment of Ehlers-Danlos syndrome, dogs typically receive 250 mg, orally, twice a day.

For acetaminophen toxicity, the veterinary dosage is 15 mg per pound (30 mg/kg) injected under the skin or 10 mg per pound (20 mg/kg) given intravenously every six hours for seven treatments.

The duration of Ascorbic Acid administration ultimately depends on the condition being treated, the animal’s response to the medication and the evidence of any side effects. Once treatment is initiated, it’s important to complete the course of therapy unless instructed by your veterinarian.

Although Ascorbic Acid can be purchased over the counter, it’s extremely important to follow the dosage directions as indicated by your veterinarian. Different treatments require different dosage amounts.