Hypovitaminosis A

• Vitamin A is essential for normal bone growth in foetus and neonates
• Hypovitaminosis from dietary deficiency of dam -> teratogenic in pigs and large cats
• More commonly, deficiency in neonates (puppies, kittens, calves, piglets) on vitamin-deficient diets
• Dietary deficiency -> failure of osteoclastic remodelling resulting in bone overgrowth and nerve compression
• Optic nerves particularly affected