By Gary A. Borgman
In the last issue of Osceola Woman Magazine, I mentioned that cats can develop a serious cardiac condition secondary to uncontrolled feline hyperthyroidism. Fortunately, this seldom occurs because feline hyperthyroidism is usually detected and treated prior to reaching this stage. The typical case presents as a hungry cat with great appetite, lots of energy and usually a rapid and marked weight loss. The thyroid gland produces too much thyroid hormone and this turns up the metabolism thermostat, so these cats are literally using up their body muscles and other tissues. The heart is overworked and becomes enlarged and eventually diseased. The diagnosis is established through a blood panel evaluation showing too much hormone, which can be effectively treated with an injection by a specialist veterinarian, or through an oral medication which slows down the hyperactive thyroid gland. There is also an option of feeding a prescription diet z/d which is deficient in iodine, an essential component of thyroid hormone. Treatment is usually very effective and life-saving.
Dogs seldom get hyperthyroidism. When they do, it is usually due to a malignant hyperactive thyroid gland. The prognosis is not good. Dogs do, however, commonly suffer from hypothyroidism. These patients are often overweight, lethargic or lacking in energy, experiencing skin infection issues and in colder climates seeking a warm place to rest. The diagnosis is made through blood tests. Treatment consists of oral supplementation of thyroid hormones, and the results are usually very effective but the medication is usually lifelong.
As with humans, dogs and cats can develop Diabetes Mellitus (DM), also known as sugar diabetes. This is due to insufficient insulin production by the pancreas. Insulin is an essential hormone which enables glucose to be properly utilized by all the cells of the body. Cats commonly present with good appetites but some weight loss. There is some thought by feline specialists that high carbohydrate cat diets contribute to the development of feline DM. We diagnose the disease in dogs and cats with blood tests. Treatment is twice daily insulin injections at home, often for the rest of their life; however ,some cats can go into remission and injections can discontinue. After we begin treatment with insulin, it is important to do follow-up blood tests to evaluate the effectiveness of insulin dosage and make necessary adjustments as needed. Some owners will choose to purchase home blood glucose monitors to enable home tracking of blood glucose levels, and this would also alert a cat owner if the patient’s blood glucose is hypoglycemic, suggesting remission.
Dogs with DM usually present with good appetites, increased thirst, increased urination volume and frequency, and gradual weight loss. These patients are in starvation mode because the glucose cannot properly enter body cells. Insulin injections are needed and the treatment is usually lifelong and life-saving. I do not recall any canine DM patients going into remission. Diet adjustments are made as needed based on blood chemistry results.
Two final endocrine gland functions to mention are the adrenal gland disorders, hypo-adrenocorticism (Addison’s Disease) and hyper-adrenocorticism (Cushing’s Disease). The adrenal glands are two small glands near the kidneys and they product various hormones which help regulate metabolism, electrolytes, stress and general health. The Addison’s case usually presents as a weak, hypothermic, lethargic, generally “sick dog”. It is very serious and is considered a crisis. Diagnosis is confirmed by blood tests revealing dangerously altered electrolytes. Critical care treatment – including hospitalization, I.V. fluids and electrolyte replacement – is essential, but once regulated, these dogs can live near normal lives with lifelong monthly injections and oral medications.
Canine Cushings’s disease is much more common than Addison’s, and usually presents with vague clinical signs of increased appetite and thirst, increased urine volume, weight gain, a thinning coat, lethargy, sometimes panting and often a large pendulous abdomen due to abdominal muscle loss and increased abdominal fat. The onset of symptoms can be gradual and is often unnoticed. We often get our first clue based on increased liver test values and more diluted urine concentration. These symptoms and blood tests results need to be further explored with specialized blood tests to evaluate the adrenal gland functions. About 85% of these cases in dogs are due to a pituitary gland tumor stimulating the adrenal glands to make too much cortisol. The remaining 15% of cases are due to an adrenal gland tumor. Once diagnosed, there are oral medications which can slow the production and effect of the excess hormone productions. There is a name for artificially induced Cushing’s disease, called iatrogenic Cushing’s. This is caused by administering too much corticosteroid drugs for a prolonged period of time. This is a major reason why veterinarians shy away from using long-term prednisolone medications to control the symptoms of allergies. Fortunately, we now have non-steroidal oral and injectable medications which are very useful for allergic conditions. I will address the newer treatments for allergies in the next issue of Osceola Woman Magazine.
The veterinarians and staff of Kissimmee Animal Hospital (407-846-3912) and Poinciana Pet Clinic (407-518-0880) are available to answer your questions about these endocrine disorders or any other health issues. We are here to help and to serve!