What Are the Symptoms of Vitamin A Toxicity in an Adult Cat?

Supplementing your cat's diet with cod liver oil, fish and liver organ meat, and other foods high in vitamin A provides the essential nutrients needed for adequate bone growth and good eyesight. Toxicity occurs when the amount of ingested vitamin overwhelms your cat's liver where it is stored as retinol, and vitamin A floats free in his blood. Called hypervitaminosis A, this condition results in serious side effects that are painful and potentially fatal for your cat.

  1. Skeletal Symptoms

    • Vitamin A toxicity in your cat often results in a type of arthritis in which new bone develops around the animal's joints. According to Dr. Ernest Ward of Cherokee Hills Veterinary Hospital in Oklahoma City, this new growth "leads to stiffness and immobility of the joints; in some cases; the joint may become totally fused."

      New bone formation typically occurs in the cat's neck vertebrae, interfering with your pet's ability to move his neck and turn his head and resulting in serious discomfort and pain. He may stop grooming himself and have difficulty eating.The cat's coat becomes dirty and unkempt and he begins to lose weight. When the hips and shoulder become involved, the cat may start limping and appear to be in pain---crying out when picked up and retreating from human contact.

    Heart and Kidney Symptoms

    • Excessive amounts of vitamin A cause an increase in blood calcium; your cat may experience abnormal heart rhythms and kidney disorders. Heart arrhythmias may bring about instances of lethargy and depression in your cat. Hypertension (high blood pressure) and kidney damage can result from the inability of the kidneys to remove excess calcium from your cat's body.

    Nerve Damage

    • Your cat may experience sensitivity changes and numbness in the body area encompassing the neck and forelimbs. Because of the overgrowth of bone and cartilage in the animal's shoulder joint, the brachial nerve (the nerve that services your cat's foreleg) becomes compressed and entrapped, causing a loss of feeling in the leg and surrounding regions.

    Constipation

    • Over-calcification in the cat's blood can also result in your pet becoming constipated, and, in serious cases, developing intestinal blockage.

    Treatment

    • Veterinarians begin treating hypervitaminosis A by immediately removing organ meat and cod liver oil from the cat's diet. Some cases may need hospitalization and intravenous therapy with electrolytes to minister to kidney damage, abnormal heart rhythms and high calcium levels. Your vet may suggest surgically removing new bone growth if your cat is seriously affected.