Hypothyroidism is a malfunction of the thyroid gland. It shows up in problems related to obesity, lethargy, coat problems, skin problems, reproduction problems, irregular heat cycles, and sterility. Though hypothyroidism is not life-threatening, it disrupts the rhythm of the whole body. The thyroid gland is one of the major sources of hormone production. If it is not operating properly, the whole body is affected.

The skin and coat problems alone are very disruptive to the animal. They cause him an extreme amount of discomfort and a fair amount of lost sleep. When the thyroid is not functioning properly, the animal will often gain an excessive amount of weight without increasing the amount of caloric intake, and his energy level will be very low. The treatment for hypothyroidism is fairly simple. Daily medication and periodic blood tests are used to determine whether the hormone level is correct or if the dosage must be adjusted. The main diagnostic tool to rule out hypothyroidism is a blood test that measures the T3 and T4 levels in the blood. Not all skin and coat problems are a result of hypothyroidism, but it is worth ruling out as a cause.