Hypothyroidism means the thyroid gland does not produce enough thyroid hormone. It affects dogs of various breeds, often in middle age, and can cause weight gain, lethargy and coat changes. It is different from hyperthyroidism, which means excess thyroid hormone.
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What is hypothyroidism?
Both in the case of dogs and humans, the thyroid gland is located in the neck region. It is found near the windpipe or trachea and is made up of two lobes present on either side of the trachea.
The functions of the thyroid gland is monitored by the pituitary gland. It is mainly responsible for the production of a hormone known as thyroxine which is responsible for regulating the metabolism.
If a person or dog is suffering from hypothyroidism, ,the thyroid gland does not produce enough of the thyroxine hormone.
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| Dogs too get affected by hypothyroidism |
What breed of dogs are affected by this?
Hypothyroidism can affect many breeds and is most often diagnosed in middle-aged dogs. Breed and age can influence suspicion, but neither can establish the diagnosis.
Spayed females and neutered males have been observed to be at a higher risk of getting affected than their non-neutered and non-spayed counterparts.
Why does hypothyroidism occur?
There can be multiple reasons behind hypothyroidism:
- The two main causes are lymphocytic thyroiditis, an immune-mediated attack on thyroid tissue, and idiopathic thyroid gland atrophy. They are different processes; idiopathic atrophy should not be described as an autoimmune disease.
In case of the idiopathic thyroid gland atrophy, the normal cells of the thyroid undergoes replacement by adipose (fat) cells.
- Rare causes include thyroid cancer; do not assume a fixed percentage of affected dogs has a tumor.
- Shrinkage of the thyroid gland.
The veterinarian interprets thyroid results alongside clinical signs, other illnesses and medicines. The diagnosis and treatment plan must fit the individual dog.
SYMPTOMS of hypothyroidism in dogs:
The following symptoms indicate that your dog might be suffering from hypothyroidism:
- Hair loss in the following regions
- trunk/snoot
- tail
- back of rear legs
- Dull and thin coat
- Flaky skin (non red or itchy)
- Black patches of skin
- Weight-gain
- Muscle loss
- Slowed heart rate
- Infections of the ear and toenails
- Overall lethargic behavior
- Low cold tolerance
- High levels of blood cholesterol
- Substances called as mucopolysaccharides may get accumulated in the face, giving the face a droopy kind of look, thus giving the dog a facial expression which makes him/her look ‘grumpy.’
Some dogs also exhibit other abnormalities along with hypothyroidism like:
- Seizures need prompt veterinary evaluation; do not assume hypothyroidism is the cause.
- Other unexplained abnormalities require veterinary assessment rather than diagnosis from this list.
- Problems of heart and blood vessels
- Dilatation of the esophagus which leads to regurgitation
- Abnormal muscle function causing weakness and difficulty in walking
- Libido loss and infertility (in case of intact males)
- Absence of heat periods, abortion and infertility in females
- Deposition of fat in the cornea
- Dry eye or keratoconjunctivitis due to absence of proper tear production.
How is hypothyroidism diagnosed ?
Blood testing helps diagnose hypothyroidism, but one low thyroid value alone does not establish the diagnosis.
Total thyroxine (TT4) is a common screening test. A low result can raise suspicion when compatible signs are present, but other illnesses and medicines can also lower thyroid values. The vet may request free T4 by equilibrium dialysis, TSH and other tests before deciding whether treatment is needed.
Follow-up testing is selected for the individual dog; results must be considered together rather than treated as an automatic diagnosis.
Blood testing is mostly performed as a series of tests. Some of these tests can be affected by presence of non-thyroid diseases too, thus the diagnosis is made in the light of the whole picture.
Treatment of hypothyroidism:
Most dogs with properly diagnosed hypothyroidism do well on treatment. Avoid a blanket claim that it is never life-threatening: severe weakness, collapse or reduced responsiveness warrants urgent veterinary attention.
Treatment usually involves lifelong oral levothyroxine. Follow the prescribed dose and schedule consistently; never reduce the frequency just because the coat improves. Repeat blood tests and the dog’s clinical response guide any change.
T3
T4
Levothyroxine is synthetic T4, which the body converts to T3. Do not choose between thyroid products or change the dose yourself. Contact the vet if your dog develops signs of excess thyroid hormone, such as hyperactivity, weight loss or increased thirst.
Clinical and coat improvement takes time. A concurrent ear infection needs its own examination and treatment plan; do not clean a painful ear or start antibiotic drops without veterinary instructions.
Prevention:
There is no proven diet or supplement routine that prevents the usual causes of hypothyroidism. Provide balanced nutrition and appropriate exercise, but do not use “immune-boosting” supplements or iodine as a substitute for diagnosis and prescribed treatment.
Conclusion:
With appropriate lifelong treatment and monitoring, many affected dogs lead a good quality of life. Keep recheck appointments, monitor weight and activity, and report new or worsening signs to your veterinarian.
That’s all for now folks..!!
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