Hypothyroidism
Hypothyroidism refers to insufficient output of the thyroid hormone by the thyroid gland. It may slow down the whole body functions; the dog may become lethargic, mentally slow, without much energy. Its coat may become dull, thin and fall out easily. In males it can lower the sperm count and reduce secual activity. In females it may cause irregular heat cycles. The signs may develop very slowly, and the condition can be detected with a blood test. Usually, it is a permanent condition and is treated with thyroid hormones. Hypothyroid is generally considered to be an inherited trait.
Hypothyroidism is the most common hormone imbalance of dogs. As the proper function of thyroid gland is very important for the metabolism to function well, there can occur:
• Cardiovascular Signs (found in 26% of hypothyroid dogs);
• Neurologic Signs (found in a minority of 2-4%), Polyneuropathy, as the nerves do not conduct electrical impulses normally; CNS-problems (ataxia, hemiparesis), and;
• Some conditions are suspected to be associated with hypothyroidism (megaesophagus, LP, infertility, aggressive behaviour).
As the "underlying" disease is the hypothyroidism, and if that is treated well with hormonal substitution, these disorders should benefit from that too.
Testing regular thyroid function in studdogs and brood bitches is recommended.
Treatment consists in application of L-thyroxine (T4) tbl. twice a day (dosage depending on weight). Research and studies done suggest that hypothyroidism is inherited (but there is as well the "old-age-hypothyroidism" known).
