Vitamin A Poisoning in Cats

By PetMD Editorial on Feb. 9, 2011

Vitamin A Toxicity in Cats

Vitamin A is essential for a cat's night vision as well as for a healthy skin. It also supports the cat's immune system and contains important antioxidant properties, which help to protect the body against pollution, cancer formation, and other diseases. If taken in exorbitant levels, however, vitamin A can be toxic.

More commonly referred to as vitamin A toxicity, it usually occurs when vitamin A-rich food such as liver or vitamin A supplements are ingested at high quantities. Though it is likelier to occur in cats ages 2-9, it can affect cats of any age.

Symptoms and Types

  • Lethargy
  • Loss of appetite
  • Weight loss
  • Lameness
  • Rough hair coat
  • Constipation
  • Abnormal sitting posture (e.g., raised front limbs)
  • Skin allergy on neck and front limb regions


  • Vitamin A-enriched diets (raw liver)
  • Excessive vitamin A supplementation (cod liver oil)


Your veterinarian will take detailed history of your cat, including asking questions pertaining to your pet's diet and supplement regimen (if any). A detailed physical examination will be conducted to rule out other diseases. In addition, your veterinarian will order routine laboratory tests, including a complete blood count, biochemistry profile, and urinalysis. However, the results of these tests are often found to be normal unless the cat has some concurrent disease.

In some cats the complete blood count may reveal an increased number of white blood cells (WBCs), especially neutrophils. A biochemistry profile, meanwhile, may indicate abnormally high levels of glucose in the blood. Your veterinarian will also take X-rays of neck regions to visualize the vertebrae present in neck area (cervical vertebrae) as well as other areas; new bone formation is often an indicator of vitamin A toxicity.

In order to confirm the diagnosis, however, your veterinarian will most likely order blood tests to determine the level of vitamin A.


Many cats begin to recover as soon as the source of the vitamin A toxicity is no longer ingested, whether it be due to something in the diet (e.g., raw liver) or supplements. Your veterinarian can recommend a well-balanced diet for your cat's needs. To treat the pain, he or she may recommend painkillers.

Living and Management

The overall prognosis of this type of poisoning depends on the early initiation of treatment and the age of the cat. In mature cats, the symptoms usually resolve successfully, with the exception of the bone malformations. On the other hand, young cats can suffer from permanent damage to long bones which raise various other health concerns.

Periodic determination of vitamin A levels in the blood may be required to confirm the successful resolution of high vitamin A levels in the blood.


The best way to prevent vitamin A toxicity in cats is to consult your veterinarian before changing your pet's diet and/or starting it on a vitamin A supplement regimen. In addition, do not allow others to feed your cat without your permission, especially if the food contains liver.

Help us make PetMD better

Was this article helpful?

Get Instant Vet Help Via Chat or Video. Connect with a Vet. Chewy Health