Companion Cats and Hypervitaminosis A

Feeding raw liver or all-fish diets to cats causes Vitamin A toxicity — a preventable condition causing severe joint pain, restricted movement, and skeletal deformity.

Key Facts

Hypervitaminosis A causes new bone formation on the spine and joints — painful and irreversible
The condition typically develops after months to years of excessive liver feeding
Affected cats show neck stiffness, reluctance to move, and pain when handled
Treatment requires diet correction and pain management — bone changes cannot be reversed
The condition was common before commercial cat food formulation eliminated single-ingredient feeding

Welfare Considerations

Cats with hypervitaminosis A experience chronic joint and skeletal pain from bony outgrowths that progressively restrict movement. The condition develops slowly — cats endure months of increasing discomfort before owners recognize the problem. By the time bone changes are visible on radiographs, they cannot be reversed. The welfare tragedy is that the disease is entirely diet-caused and entirely preventable — yet owners feeding raw liver as a natural treat believe they are benefiting their cat.

What You Can Do

Never feed raw liver more than once weekly as an occasional treat
Do not feed all-fish or all-organ meat diets — use complete commercial or veterinary-formulated foods
Consult a veterinary nutritionist before formulating homemade raw or cooked diets
Seek veterinary assessment if your cat shows stiffness, reduced mobility, or pain during handling
Ensure any raw feeding protocol uses properly balanced complete prey-model or commercial raw formulations