Cat Hypervitaminosis A Welfare | Animal Welfare Hub

Hypervitaminosis A in cats results from excessive dietary liver feeding and causes painful skeletal deformity. It is entirely preventable and represents a significant welfare harm from inappropriate feeding practices.

Key Facts

Cats eating predominantly raw liver develop vitamin A toxicosis due to the liver's extremely high vitamin A content
Hypervitaminosis A causes new bone formation (exostosis) around the cervical spine, shoulders, and elbows
Affected cats develop progressive neck stiffness, pain, and inability to groom themselves normally
The condition is irreversible - bony changes do not regress after dietary correction, though pain can be managed
Liver should comprise no more than 5-10% of a cat's diet to avoid toxicity

Welfare Considerations

Cats with hypervitaminosis A experience chronic musculoskeletal pain from bony proliferations that restrict movement and cause ongoing discomfort. The inability to groom, adopt normal sleeping positions, or reach the food bowl compounds their distress. The condition develops gradually over months to years, meaning many cats suffer with worsening pain before diagnosis. Once established, the bony changes are permanent, making prevention through dietary correction the only truly welfare-positive intervention. Owners who feed cats raw meat diets need clear guidance about liver quantity limits.

What You Can Do

Limit liver to no more than 5-10% of your cat's total diet and vary protein sources widely
Have cats eating predominantly raw diets checked for neck stiffness and range of motion annually
Seek diagnosis promptly if your cat shows neck stiffness, reluctance to move, or difficulty grooming
Share information about hypervitaminosis A with raw-feeding communities to prevent cases