Image Quiz: A skinny Lab with a swollen face

Renal secondary hyperparathyroidism is correct!

Renal secondary hyperparathyroidism, or renal osteodystrophy, is an osteopenic disorder that results from chronic renal failure. Dogs and cats can be affected, and younger animals tend to be overrepresented since growing bones are more metabolically active and, thus, susceptible to the adverse effects of hyperparathyroidism.

Renal secondary hyperparathyroidism results from impaired renal excretion of phosphate and subsequent hyperphosphatemia as well as decreased blood calcium concentration. This alteration in calcium and phosphorus homeostasis leads to increased concentrations of parathyroid hormone and ultimate bone resorption.

Radiographically, loss of the lamina dura and demineralization of the mandible and maxilla result in a floating appearance to the teeth. The mandible and maxilla are also frequently swollen and pliable, which is sometimes referred to as rubber jaw.

In this case, the serum chemistry profile results supported the radiographic diagnosis because severe azotemia was noted. The goal of treatment is to decrease parathyroid hormone concentrations and slow the rate of chronic kidney disease progression.