Abstract
Aim: Osteodystrophia fibrosa is known as nutritional secondary hyperparathyroidism which is considered a rare disease. This study aimed to determine the occurrence, serum biochemical, levels of calcium and phosphorus in the faeces, and phytate-oxalate levels in feeds. The clinical features along with the clinical parameters of the horses were evaluated.
Methods: Blood samples were collected for serum biochemical analysis and parathyroid hormone levels were evaluated using standard procedures.
Results: The clinical features of Osteodystrophia fibrosa observed were enlarged facial bone, poor body condition score, and lameness with an occurrence of 71.2% among sampled horses. The respiratory and pulse rates along with the body temperature of the clinically diseased horses were all within normal ranges and were not significant (p > 0.05). On haematology, no significant difference (p > 0.05) was observed in the evaluated parameters. The serum calcium of clinically diseased horses was significantly (p < 0.05) decreased in Zaria (2.47±0.03) and Sabon gari (2.24±0.02) when compared to non-clinically diseased. Phosphorus levels were not significantly different (p > 0.05) while parathyroid hormones of clinically diseased horses were significantly (p < 0.05) higher in Zaria (93.01±6.44) and Sabon gari (81.01±6.34) when compared to non-clinically diseased. The faecal calcium and phosphorous level were not significantly different (p > 0.05). Oxalate was found in Vossia cuspidate, phytate was recorded in corn bran and soya bean hull fed to the horses.
Conclusion: Osteodystrophia fibrosa exists in the study area and the nature of the horses’ feeds could predispose horses to the occurrence of the condition.

Key words: Bone disease, Equine, Kaduna, Mineral, Secondary hyperparathyroidism