Hyperparathyroidism is medical condition in which abnormally high levels of parathyroid hormone (also known as parathormone or PTH) are circulating in the blood as the result of an overactive parathyroid gland. The parathyroid hormone is responsible for regulating calcium and phosphorus levels in the blood, increasing blood calcium levels by causing calcium to be reabsorbed from bone. The parathyroid glands are small, hormone-secreting glands that are located on or near the thyroid glands. The term para- refers to adjacent or alongside, and thyroid refers to the actual thyroid gland; the thyroid and parathyroid glands are located side by side in the neck, near the windpipe or trachea
Primary hyperparathyroidism refers to a condition in which a tumor in the parathyroid gland produces excessive levels of parathyroid hormone, leading to increased blood calcium levels (hypercalcemia).
Secondary hyperparathyroidism can be caused by a deficiency of calcium and vitamin D, and is associated with malnutrition or long-term (chronic) kidney disease.
There is no known genetic cause for primary hyperparathyroidism, but its association with certain breeds suggests a possible hereditary basis in some cases. Secondary hyperparathyroidism can develop in association with hereditary kidney disease (known as hereditary nephropathy), but is not inherited per se. Siamese cats seem to show some predilection for this disease. In cats, the average age is 13 years, with a range of 8 to 15 years of age.
Your veterinarian will be looking for cancer first and foremost for the cause for this disease. However, several other possibilities will also be considered, such as renal failure and vitamin D intoxication, which have been known to be found in some rodenticides. Other possibilities are too much calcium in the blood in cats. A urinalysis will reveal calcium and phosphate levels.
Serum ionized calcium determination is often normal in patients with chronic renal failure and high in patients with primary hyperparathyroidism or hypercalcemia that is associated with a malignancy. If kidney stones are suspected, your veterinarian may use x-ray and ultrasound imaging of the parathyroid gland to discover whether there is tumor there. If nothing can be found using these diagnostic techniques, your veterinarian may need to use surgery to explore the area of the thyroid and parathyroid.
Primary hyperparathyroidism generally requires inpatient care and surgery. Secondary hyperparathyroidism related to malnutrition or long-term (chronic) kidney disease in non-critical patients can be managed on an outpatient basis. Your veterinarian may recommend calcium supplements to stabilize the levels of calcium in the blood and intestines. Low phosphorus diets for secondary hyperparathyroidism related to long-term kidney disease may be recommended as well. Surgery is the treatment of choice for primary hyperparathyroidism and is often important in establishing the diagnosis. If a tumor is found, the best resolution is often surgical removal of the tumor. Medications will be prescribed according to the final diagnosis and treatment plan.
No strategies exist for prevention of primary hyperparathyroidism; however, secondary hyperparathyroidism related to malnutrition can be prevented by proper nutrition.
Postoperative low levels of calcium in the blood (hypocalcemia) is relatively common after surgical removal of one or more parathyroid glands for treatment of primary hyperparathyroidism, especially in patients with presurgical calcium concentrations greater than 14 mg/d. Your veterinarian will want to check serum calcium concentrations once or twice daily for at least one week after surgery, and will schedule your cat for regular blood tests to check the status of the kidney.
The failure of the kidneys to perform their proper functions
A gland found in the neck of humans and animals that secretes glands responsible for metabolic rate, calcitonin, and others.
An in-depth examination of the properties of urine; used to determine the presence or absence of illness
The name for four glands that are located on the top of the thyroid gland that help to regulate the amount of calcium in the blood
The windpipe; it carries air from the bronchi to the mouth
The hormone that is created from the parathyroid glands; helps to regulate the calcium level of an animal’s blood
Something with an electrical charge
Something that becomes worse or life threatening as it spreads
A condition of poor health that results from poor feeding or no feeding at all
A low level of calcium in the blood