Primary hyperparathyroidism is generally seen in older animals and is more common in dogs than cats. Animals with primary hyperparathyroidism may lose their appetite, vomit, drink and urinate more, and may appear drowsy or listless. The signs often come on gradually and considerable organ damage may occur before the animal shows significant symptoms. The treatment of primary hyperparathyroidism is removal of the abnormal or cancerous gland. For this reason, the animal must be monitored closely after surgery and given calcium if the level becomes too low.
Meat contains an excess of phosphorous and inadequate amounts of calcium.
Although cats and dogs are carnivores, they not only eat meat, but the bones as well, which supply the needed calcium and help to create a better calcium and phosphorous balance. Because of the low intake of calcium, the parathyroid gland produces more parathyroid hormone, and calcium is removed from the bones. Kittens and puppies with secondary hyperparathyroidism are often reluctant to move, may stand splay-legged, and may easily develop fractures because of the thinning of the bones. The changes in the density of the bones often cause abnormal growth, especially in the spinal column and pelvis. This places stress on the joints and can result in arthritis.