Hypothyroidism is a clinical condition that results from inadequate production and release of tetraiodothyronine (levothyroxine, T4) and tri-iodothyronine (liothyronine, T3) by the thyroid gland and characterised by a generalised decrease in cellular metabolic activity.
Treatment of hypothyroidism is more likely to succeed if there is good compliance with the dosing regimen. Canine hypothyroidism can be challenging to diagnose but can be managed successfully and easily with replacement therapy.
The thyroid gland produces thyroid hormones which have a number of functions in the body and are particularly critical in maintaining your pet’s metabolic rate. Any change in the functioning of this gland can have varied effects on your pet’s health. In some animals, the function of the thyroid gland may become compromised and decrease as your pet ages or due to inflammation of the gland.
Although hypothyroidism (decreased functioning of the thyroid) is not a life-threatening condition, it can certainly decrease your dog’s or cat’s quality of life.
Pet parent’s role
Pet owners play a crucial role in the successful management of canine hypothyroidism. Your attitude will largely determine your dog’s response to treatment.
Watch out for…
Here are a few symptoms of hypothyroidism in pets, where pet parents should pay immediate attention:
- Gain of weight without any change in their diet.
- Many become lethargic and seem to lack energy.
- Hair loss or excessive shedding, and dry or lusterless haircoat.
- Excessive scaling & hyper-pigmentation.
- Constipation and cold intolerance.
- Slow heart rate.
Management & treatment of hypothyroidism
Hypothyroidism in pets is conventionally treated by administering a daily dose of synthetic thyroid hormones. This can often restore healthy thyroid functioning very effectively.
One of the main problems with synthetic thyroid hormones, however, is that they may result in too much thyroid hormone in the body, resulting in hyperthyroidism. This is because it is often difficult to determine exactly how much of the synthetic hormones are needed for optimal thyroid functioning.
For this reason, periodic blood tests for thyroid hormones are absolutely necessary for the exact dosing of Synthetic Thyroid Hormone.
Your veterinarian will need to monitor T4 levels in your dog periodically during the course of treatment. This requires taking a blood sample and measuring the amount of T4 in the blood. After starting thyroid hormone replacement therapy, your veterinarian will usually evaluate peak blood T4 levels every four weeks, 4-6 hours after treatment administration until the correct dose is determined. Once the correct dose is determined, your veterinarian will measure peak T4 levels about every three months.
After about one month of treatment, a blood sample must be taken for analysis of thyroxine (T4) and thyroid stimulating hormone (TSH). If the dose is changed, a blood sample is usually taken about four weeks later to check that this dose is suitable. Once your dog’s condition is stable, he should be re-checked at least every three months.
(The author is managing director, Myvets Integrated Solutions Pvt Ltd, with a vision for developing excellent veterinary heath care and related services in India for pets and exotic animals.)