Hypothyroidism is a disorder of the thyroid gland, it produces a hormone, thyroxine, which primarily regulates the metabolism of nearly all the bodies systems
When not producing enough thyroxine many of the normal functions are adversly affected
The most common cause is destruction of the gland by the bodies own immune system and this is the disorder we will look at here
The destruction of the gland can begin very early in the dogs life, however it may take some years until the gland is almost completely destroyed before symptoms become evident. During this time research has shown the dog is more likely to develop other autoimmune conditions
Hypothyroidism once diagnosed is fairly easy to treat ,the condition cannot be cured but can be successfully managed. The difficult part is the diagnosis... the symptoms can be due to many conditions and its usually the presence of two or three that may alert your vet to the possibility.
Signs of Hypothyroidism;
As well as physical changes lack of Thyroxine can alter behaviour dramatically
-Thinning of the skin
-Black pigmentation of the skin
-Cold intolerance - seeks warm places to lie down
-Fat deposits in the cornea of the eye (lipidosis)
-Dry eye (keratitis sicca)
-Slow heart rate (bradycardia)
The usual test your vet may perform is a baseline T4 level, if this test is “in range” your vet may well consider your dog is not hypothyroid This is NOT a definitive test.
However a FULL THYROID PANEL measuring T4 , Free T4, and TSH ( Thyroid stimulating hormone) is the best way to assess thyroid function thoroughly
From the whippet perspective , sighthounds have a naturally lower baseline T4 than other dogs and older dogs also have a lower T4, make sure your vet is aware of this difference
Treatment is daily doses of Thyroxine , this will continue for life, it is critical that all prescribed doses must be taken and the dog monitored closely. Overdose will cause weight loss, anxiety, restlessness, excessive drinking and hyperactivity so its crucial to keep follow up appointments.
After treatment has started the dog should begin to improve quite quickly and seem more energetic,skin may take a month or so , in general the prognosis is excellent .