Thyroid disease is one of the most common autoimmune diseases facing dogs, but it can be difficult to diagnose because the symptoms are so subtle. Though older dogs of certain breeds are more likely to develop thyroid problems, all dogs are susceptible, so consult your veterinarian if you notice changes in your dog.
Personality Changes
When dogs aren't feeling well, it can cause personality changes, such as increased irritability or anxiety. Thyroid disease is no exception. Dogs suffering from hyperthyroidism may show increased activity or anxiety while dogs suffering from hypothyroidism may show signs of aggression or irritability.
More than 60 percent of humans with thyroid problems show behavioral changes that are greatly reduced once being treated. Recent research has shown that dogs are similar, often showing signs of unprovoked aggression toward both people and dogs that wasn't present before thyroid problems developed.
The thyroid controls your dog's metabolism, so changes in hormone levels can affect your dog's activity level. Hypothyroid dogs may become very lethargic, losing interest in activities that used to interest them and tiring more easily during physical activity.
Appetite Changes
Changes in your dog's metabolism may also affect their appetite and ability to lose or gain weight. Dogs with hyperthyroidism may always appear hungry, becoming more demanding for food and eating more quickly, while still losing weight. Dogs with hypothyroidism may lose interest in food or eating and begin to put on weight rapidly.
Coat and Skin Changes
Many dogs suffering from thyroid disease will have changes in their coat or skin, which may be subtle and appear to be caused by another illness, such as allergies. Dogs with thyroid disease may have a dull, dry coat and yeasty smell coming off the skin. Skin may appear dry and flaky, causing dandruff.
These changes may cause irritation, which can lead to skin infections, scratching and chewing. These symptoms appear to be caused by allergies and may be ignored for some time. Excess scratching can lead to hair loss and sores or red skin rashes.
Dogs may also show signs of skin pigmentation or scaly, greasy skin, which can also have an offensive odor.
Additional Symptoms
Many veterinarians now believe that though thyroid disease often can't be detected until dogs are older, it is present from birth and may cause long-term problems that aren't even associated with the disease, such as stunted growth, chronic infections and personality changes.
In addition, dogs with thyroid problems may suffer from cold intolerance, drooping eye lids, facial or partial paralysis, muscular stiffness and slowed heart rate. Though not as common, digestive problems such as vomiting, diarrhea and constipation may also be present.
If left untreated, severe symptoms may include seizures, paralysis, incontinence and difficulty reproducing or giving birth to stillborn puppies. It can also lead to many other problems, such as liver and kidney problems since the thyroid participates in most of the body's internal functions.
Thyroid disease is easy to treat if diagnosed properly. It requires a small pill twice daily, which reduces or eliminates most symptoms. If you suspect your dog may be suffering from thyroid disease, consult your veterinarian for treatment.