Clinical signs of Cushing’s, no matter its primary cause, may include one or most of the following:
- Polyuria (increased frequency of urination), polydipsia (increased thirst), and polyphagia (increased, ravenous hunger).
- Weakening and atrophy of the muscles of the extremities and abdomen, resulting in gradual abdominal enlargement, lordosis (sway back), muscle trembling, and weakness.
- Weight loss. While most dogs appear fat, they may actually lose weight due to the loss of muscle mass.
- Fat deposits in the liver, resulting in diminished liver function.
- Skin lesions are common and are often the most recognizable symptoms of the disease. The skin may thin, or mineral deposits may occur within the skin, especially along the dorsal midline. The dog may also exhibit hair loss in a non-itchy “hormonal pattern” (bilateral and symmetrical hair loss, not patchy as typically seen with allergies, and often associated with thinning of hair and poor regrowth, rather than a complete loss of hair). This hair loss may be concentrated over the body, groin, and flanks, and spare the head and extremities. In chronic hormonal conditions the hair thinning may be associated with a thickening and a black discoloration of the abdominal skin called acanthosis.
- Behavior changes: lethargy, sleep-wake cycle disturbances, panting, and decreased interaction with owners.
A tentative diagnosis may be inferred from the clinical signs, but positive diagnosis requires laboratory confirmation. Differentiating pituitary-dependent from primary-adrenal Cushing’s is impossible without lab tests.