When the engine runs at less than idle speed
The thyroid gland has two lobes, two halves that sit at both sides of the trachea. It produces thyroxin, a hormone that is involved in many processes in the body and regulates the basal metabolism, which is the biological equivalent to the idle speed of an engine.
Dog owners, and Dobermann owners in particular – as it is one of the predisposed breeds – may notice this little organ for the first time when they visit their Vet due to a skin complaint, typically appearing in middle age (2-6 years) . The majority of cases of hypothyroidism, which means under-active thyroid, occur due to changes in the gland, which is called Lymphocytic Thyroiditis, an inflammatory process of autoimmune nature (that is when the immune system loses the plot and attacks your own cells instead of viruses, bacteria and so on…). This change in the gland translates into less thyroxin being produced.
The most common signs of this condition to be first noticed by dog owners are those affecting the skin: these tend to be bilaterally symmetrical non pruritic trunk alopecia, which means bald – or less-dense patches affecting both sides of the body without an itch. Unfortunately this type of pattern is followed by other endocrine conditions and sometimes hypothyroidism manifests in a less typical form. It is common to see an alopecic tail (rat tail) as a first sign and we often see seborrhoea (dandruff, oily hair…) or secondary skin infections, that will make our pooches very itchy.
These cutaneous changes occur once the production of Thyroxin has been decreasing for a long time and therefore there are normally other general metabolic signs that precede the dermatological manifestation, but they can be missed as they tend to be slow in progression. Hypothyroidism initially causes lethargy, weight gain without an increase in food intake, exercise intolerance, cold intolerance.
The third group of signs most commonly seen are neurological; they can vary from weakness to, in rare cases, even coma. Luckily these signs are a lot less common.
Diagnosing this disease is sometimes quite straight forward but it can be challenging in many cases, so don’t get frustrated when your Vet is investigating it, as it often requires several blood tests to confirm it, and other conditions have to be ruled out before these tests are ordered.
The good news is that, once diagnosed, it is quite easy to treat in the great majority of cases; you just have to give your doggy the hormone, normally in a tablet form, although regular blood tests are necessary to make sure the dose is right.
The skin abnormalities can take months to go away, but some improvement is normally noticed within a month and with medication and appropriate follow up the prognosis is good.
This article was reproduced by kind permission of Andre Escudeiro-Vieites LV MRCVS
Andre is a partner at Quinton Vets4Pets in the heart of England.