Hypothyroidism is an increasing problem in canines; here's what you need to know about it.

When my German shepherd, Guinness, was diagnosed with hypothyroidism, we were at the end of our rope with a cornucopia of symptoms, the most dominant of which was severe, chronic itching. After the diagnosis, everything started making sense and the seemingly random assortment of odd symptoms—hair loss and “tragic face,” for example—all started lining up into a much clearer picture.

What Is Hypothyroidism?

The thyroid is a butterfly-shaped gland located along your dog’s trachea producing the thyroid hormone thyroxine which is instrumental in key functions in the body like food metabolism, reproduction, and resistance to infection, according. There are two types of hypothyroidism, according to Becker: the more common autoimmune thyroiditis, where your dog’s immune system malfunctions and attacks its own thyroid gland, and then there are the cases when a dog’s body produces less and less thyroxine over time. “Hypothyroidism and its underlying heritable form of autoimmune thyroiditis is becoming more prevalent today. This is not merely because of increased awareness of and testing for the problem. It likely reflects the cumulative effects on dogs with susceptible genotypes of today's pollution with exposures to chemicals, pesticides, herbicides, toxins, as well as dietary effects,” said Dr. W Jean Dodds, an international thyroid expert who offers breed-specific thyroid testing at Hemopet in Garden Grove, California. While hypothyroidism in dogs doesn’t always easily present itself with a standard set of symptoms, here are some to watch out for.

Skin Problems

Guinness’s issues started with an itchy back paw. Over time, it progressed into itching all over his body. He lost the hair on his paws, abdomen, sides, and neck. He had severe dandruff and thick, elephant-like darkened skin where there was no hair. He also had a strong, foul odor to his skin.

Tiredness

If you have an energetic dog that suddenly starts to slow down for no apparent reason, you may want to check his thyroid. Always a ball of energy, Guinness started to take shorter walks and at his lowest, didn’t even want to get up when called.

Weight Gain

This one is a good example of how there really is no standard hypothyroidism pattern because Guinness has always been very lean. But many other hypothyroid dogs may start gaining weight without any food increases.

Cold Sensitivity

Guinness is a strapping 110-pound double-coated force to be reckoned with. Not the kind of dog you’d expect to see shivering at the age of three. It was a mystery that wasn’t resolved until he was diagnosed and I learned from my research that cold intolerance is a sign of hypothyroidism.

Tragic Face

This symptom came at Guinness’s worst, right before we got his thyroid checked. It’s pretty much what it sounds like: his face’s skin started changing so that he looked perpetually sad.

Behavior Issues

According to Dodds’ blog, there’s a connection between abnormal behavior and thyroid dysfunction in dogs. Some examples are unprovoked aggression, sudden seizures in adulthood, disorientation, moodiness, erratic temperament, depression, fearfulness and phobias, anxiety, compulsiveness, and irritability. Fortunately, Guinness avoided most of these, except for maybe the anxiety. Remember, there is no set of symptoms that will automatically confirm a thyroid issue, so paying attention to your dog’s behavior and following up with some testing is key—especially since the classic clinical signs of hypothyroidism like weight gain, tiredness, and aversion to cold don't occur until at least 70 percent of a dog's thyroid gland has been damaged or destroyed by the disease. When it comes to initial testing, she recommends a complete thyroid antibody profile and not relying on a typical wellness panel because it is insufficient and often is misleading. Guinness is finally on the mend with the help of thyroid supplementation as well as holistic support like homeopathy. His hair is starting to grow back, his skin feels more like skin again, he no longer looks sad, the itching is slowly decreasing, and his energy level is back.