Could your older dog be suffering from Hypothyroidism?

Hypothyroidism is the most common hormone imbalance in dogs.  It usually occurs in canines over 5 years of age, and is caused most frequently by an immune-mediated destruction of thyroid gland tissue, or occasionally by the natural shrinking or atrophy of the glands.  Any breed of dog can develop this problem; but certain breeds such as Great Danes, Doberman Pinchers, Irish Setters, Golden Retrievers, Boxers, Miniature Schnauzer, Cocker Spaniel, and Dachshunds are more commonly affected.

The thyroid glands are paired, and sit on each side of the airway or trachea.  The hormones produced here affect the metabolic rate for every system in the body.  Hypothyroidism occurs when too little hormone is produced.

Multiple symptoms can occur with hypothyroidism, and many organ systems can be affected.  Visibly, the most obvious change is with a canine's coat.  It tends to become dry, brittle, and thin, with areas of hair loss or alopecia.  Secondary skin infections are very common; as are thickening of the skin, scales, oil, and odor.  Many dogs will become significantly overweight even though their diet hasn't changed.  Low energy is also a frequent finding, as is a decline in mental alertness.  Many patients are no longer able to tolerate very cold temperatures.  Abnormal heart rhythms, and slow heart rates can be identified on a physical exam.  If left untreated, cardiac abnormalities can result in heath issues throughout the body.  Nerve problems can occur that affect mobility.  And surface changes to the eyes can take place; but are not very common.

Hypothyroidism is diagnosed with lab work.  This disease is not always easy to identify, and some medications can affect thyroid levels.  Blood values that are typically evaluated include T4, T3, TSH, and free floating T4.  Other changes on lab work include a low red blood cell count and a high cholesterol level.

Therapy involves lifelong treatment thyroid supplementation, that is usually given twice a day.  Blood values are typically monitored annually.  Symptoms generally improve within 2-8 weeks of starting medication.  Fortunately this therapy is relatively inexpensive.

Hypothyroidism is a serious health risk for dogs.  Any canine that demonstrates typical symptoms should be evaluated and receive treatment as soon as possible.  Your veterinarian can help in the diagnosis and treatment recommendations.  Annual blood work is an important tool in protecting the health of your cherished canine, especially for pets five years and older.