Which of the following is a clinical sign of nutritional secondary hyperparathyroidism?

Nutritional secondary hyperparathyroidism is a condition often seen in animals that are deficient in certain nutrients, particularly calcium and vitamin D, leading to an imbalance in calcium and phosphorus levels. One of the most significant clinical signs of this condition is bone weakness. This occurs because the parathyroid hormone is elevated in response to low calcium levels, stimulating bone resorption to release calcium into the bloodstream, which compromises bone density and strength.

When bone resorption exceeds the formation of new bone tissue, it leads to weaker bones, making the animal more prone to fractures and structural abnormalities. The other options, while they are signs of different underlying health conditions, are not directly associated with nutritional secondary hyperparathyroidism. Hyperglycemia can be seen in diabetes or stress-related conditions, excessive urination might indicate diabetes mellitus or kidney issues, and hypertension can be associated with various cardiovascular issues, but they don’t directly relate to the core pathology of nutritional secondary hyperparathyroidism. Therefore, the correct identification of bone weakness as a clinical sign is key in diagnosing this metabolic bone disorder in affected animals.