Underactive thyroid in dogs: symptoms

Underactive thyroid gland (hypothyroidism) in dogs is accompanied by severe symptoms of the disease. Fortunately, once the disease is identified, it can be treated fairly well. In most cases, the dogs affected become completely healthy again. But where does the underactive thyroid come from and how can you recognize it? If a dog is constantly tired, an underactive thyroid can be responsible - Image: Shutterstock / Bartek Lichocki

An underactive thyroid in dogs means that the thyroid does not produce enough hormones. The thyroid gland lies on the underside of the neck on both sides of the trachea. The hormone deficiency affects the entire metabolism and slows it down. As a result, the heart slows down, mental abilities are reduced, and body temperature drops. Nevertheless, the symptoms of hypothyroidism differ from animal to animal and the disease is often only recognized when it is quite advanced. Fortunately, it is easy to treat; You can find out how in our guide "Dog with hypothyroidism: treatment".

Causes of an underactive thyroid in dogs

The underactive thyroid can either directly affect the thyroid gland or be caused by another disease. If the thyroid itself is the problem, there are usually two possible causes behind it: Most often, chronic inflammation of the organ leads to healthy tissue being destroyed and replaced by connective tissue that does not produce hormones. Rarely is an autoimmune disease to blame - the immune system incorrectly evaluates the cells of the thyroid tissue as pathogens and fights them with antibodies. Here too, more and more hormone-forming tissue is being destroyed.

If the hypothyroidism is a concomitant symptom of other diseases, it is, for example, a serious bacterial inflammation. Cushing's syndrome is also associated with an underproduction of thyroid hormones. In addition, some drugs trigger an underactive thyroid, such as cortisone supplements, some antibiotics, or the epilepsy and anesthetic phenobarbital. If your dog needs these medicines and shows symptoms of an underactive thyroid, talk to your veterinarian about possible alternatives.

Possible symptoms of hypothyroidism

The entire organism is affected by an underactive thyroid. The severity of the symptoms depends, among other things, on how much the hormone production is already limited and the hormone deficiency has progressed. Most of the time, the signs begin to creep and are unspecific, which is why the disease is often recognized late. Which symptoms occur can differ from patient to patient. However, if you have any of the following signs, you should definitely go to the vet to find out the cause:
● Hair loss without itching
● Thin, dull fur with brittle, dry hair
● dandruff
● Frequent ear infections and skin infections caused by bacteria or yeast
Lethargy, lack of stamina and reluctance to move
● Eating and weight gain
● The dog does not tolerate temperature sensitivity, heat in summer and cold in winter
● For bitches: irregular cycle in heat
● heart problems
Hearing loss and deafness
● Corneal ulcers on the eyes

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Blood test for diagnosis

If your pet suffers from these symptoms, a visit to a veterinarian is advisable. He can measure the thyroid hormone thyroxine in the blood and thus recognize whether the gland is working well. Or your dog will do an ultrasound of the thyroid gland. If the examination reveals that the thyroid is actually underactive, the missing hormones must be replaced.

But then the symptoms gradually subside and your dog can lead an (almost) normal life. It can take a few weeks or even months for the deficiency to be remedied. If there is no improvement, ask your veterinarian again whether the dosage of the hormone preparations is correct and, if in doubt, get a second opinion from another veterinarian.

Underactive thyroid: are some dogs particularly vulnerable?

In principle, any dog ​​breed can be affected by the disease. But according to veterinarians, medium-sized and large breeds such as the Golden Retriever and Doberman, as well as German Shepherd, Boxer, Giant Schnauzer and Airedale Terrier are particularly affected. The only exception: The small dachshund also seems to be susceptible to hypothyroidism. In most cases, the disease occurs in middle-aged dogs, i.e. at four to eight years. However, it may be that the thyroid has not worked properly for several years, but the hormone deficiency only becomes noticeable in the advanced stage.