Feeding excessive amounts of raw liver to cats causes vitamin A toxicity, leading to painful bone and joint disease that permanently deforms the skeleton.
Hypervitaminosis A is entirely owner-caused and entirely preventable — yet cases continue to present to veterinarians because raw feeding communities sometimes recommend liver as a primary ingredient. The resulting skeletal deformities cause chronic, severe pain. Affected cats cannot turn their heads, groom themselves, or move comfortably. The bony changes develop gradually over months, meaning cats suffer progressively worsening pain before the problem is recognized. Veterinary nutrition guidelines are clear: liver is a healthy supplement in small quantities but becomes a significant welfare hazard when fed as a dietary staple. Balance and variety — not any single ingredient in excess — define healthy raw or fresh food diets.