Abnormally High levels of Parathyroid Hormone due to Chronic Kidney Failure in Dogs
Secondary hyperparathyroidism occurs when the parathyroid glands produce an excessive amount of parathyroid hormone (PTH) due to chronic kidney failure in dogs. This condition is primarily attributed to either an absolute or relative deficiency in calcitriol production, which is a form of vitamin D essential for regulating calcium levels. Calcitriol facilitates calcium absorption in the intestines, bone resorption, and enhances the effectiveness of PTH in bone resorption. Additionally, low levels of calcium also contribute to the elevation of PTH in the bloodstream.
Symptoms
Most symptoms are linked to the root cause of chronic kidney failure. In certain cases of chronic kidney disease, bone resorption initiates near the teeth and jaw, leading to tooth looseness and softening of the lower jaw, a condition termed “rubber jaw” in medical circles.
Causes
The causes include any underlying illness that results in chronic kidney failure.
Diagnosis
To diagnose the condition, you’ll need to provide a comprehensive history of your dog’s health, detailing the onset and characteristics of symptoms, as well as any potential triggering incidents. Your veterinarian will conduct a thorough physical examination, assessing all body systems.
Blood tests and biochemical profiles may indicate azotemia, characterized by an accumulation of nitrogenous waste products (urea) in the bloodstream, typically excreted in urine. This condition is also known as uremia. Elevated levels of phosphate and reduced levels of calcium in the blood may also be observed. Definitive diagnosis involves measuring serum PTH concentrations. Additionally, lower to normal calcium levels in the blood aid in confirming secondary hyperparathyroidism. Bone X-rays are valuable for assessing bone density, particularly around the teeth.
Treatment
Treating the primary kidney disease is a key objective of therapy for patients diagnosed with secondary hyperparathyroidism. Elevated levels of phosphorus in the blood are addressed by administering chemicals that bind to the excess phosphorus, while dietary adjustments are made to restrict phosphorus intake from food.
To address calcitriol deficiency, calcitriol supplementation is administered to raise calcium levels, with dosage carefully determined by your veterinarian according to your dog’s individual requirements.
Living and Management
Depending on the extent of kidney failure, it’s crucial to regularly monitor the serum levels of calcium, phosphorus, and urea nitrogen, either on a weekly or monthly basis. If your dog is undergoing calcitriol therapy, diligent observation is necessary as it may lead to adverse symptoms or complications.
Regular assessment of parathyroid hormone (PTH) concentrations is also essential. While treatment for renal secondary hyperparathyroidism may mitigate the advancement of kidney failure, the overall long-term prognosis for these patients remains bleak.