Can Hypothyroidism Cause Dogs to Be Aggressive?

Golden retrievers are prone to hypothyroidism.
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Aggressive behavior in dogs has plenty of causes. A multitude of things can cause dogs to adopt fierce behaviors; inadequate socialization as puppies, or inhumane treatment or training will do it; plenty of ailments can cause aggression, too. Hypothyroidism is one of them.

About Hypothyroidism

If a dog has hypothyroidism, he has a lack of hormone production in the thyroid gland. The specific hormones have a lot of duties within the body, mostly to keep other organs functioning properly. If a dog's body doesn't have enough thyroid hormones, the metabolism will slow. Dogs frequently experience hypothyroidism; the condition is rare in other animals, including horses and cats.


Some dogs who have hypothyroidism display clear swings in behavioral patterns. Hypothyroidism can occasionally trigger aggressive patterns, particularly in the German shepherd breed. If your pooch behaves aggressively due to hypothyroidism, keep him away from any children in your home as he receives the necessary veterinary assistance. Never let an aggressive dog go near kids or animals.

Signs of Aggression

Dogs express feelings of aggression through body language and vocalization. A dog who is in a fierce mood might prominently display his teeth, growl, bark, chase or bite. But a dog might show aggression in subtler manners, such as keeping his body extremely tight and motionless. Alert your veterinarian to any aggressive actions you note in your pet. Apart from just thyroid issues, a wide array of other health problems can sometimes bring out aggression in dogs -- think orthopedic and adrenal conditions.

Other Hypothyroidism Symptoms

Aggression is far from the sole symptom of hypothyroidism in dogs. The disease shows itself in numerous ways, including increased shedding, increased body weight, fatigue, loss of fur, avoidance of cold temperatures, skin infection vulnerability, anemia, reduced heart rate and obesity. Despite the numerous possible symptoms, lots of canines with hypothyroidism are symptom-free. Rarely, dogs with hypothyroidism will develop nervous system irregularities. Veterinary care for dogs with hypothyroidism frequently involves lifelong use of synthetic thyroxine medicine.