Excessive levels of T4 cause an increase in the cat

When Mie S. brought her 15-year-old cat, Cookie, pharmacy to my cats-only veterinary hospital , she was well aware that he had lost a substantial amount of weight. However, she was shocked when I announced the current reading on the scale. “Wow! Eight and a quarter pounds?” she exclaimed. “He pharmacy used to weigh 16 pounds!” Knowing that the most common disorders that result in weight loss in geriatric cats are diabetes , hyperthyroidism and chronic kidney disease (CKD), I was already formulating my questions for her as I carried him back from the scale to the exam table.
Was he drinking pharmacy a lot of water and urinating excessively? Yes, Mie said, he was. I wasn’t surprised, as all three of the illnesses mentioned above can present with excessive thirst and urination. How about his appetite? “Ravenous,” pharmacy she said. Cats with CKD tend to have a decreased appetite, so kidney dysfunction moved a notch lower on my list. Cats with diabetes and hyperthyroidism tend to have good appetites. Not just good, though. Exceptionally good, like Cookie’s. While diabetes can occur in almost any age of cat, it classically hits cats in middle age, around 8 or 9 years old. Hyperthyroidism, however, is a geriatric cat disease, tending to affect cats around 13 or older. With Cookie being 15 years old, my mental pharmacy list had hyperthyroidism first, diabetes second and kidney disease third.
Typically, you cannot feel the thyroid pharmacy gland in a normal cat’s neck during a physical examination. In cats with hyperthyroidism, however, pharmacy the gland enlarges and begins to drift downward on the neck. I carefully felt the groove between Cookie’s trachea and the jugular vein, and as I got a little lower … presto! I could easily feel an enlarged thyroid gland. pharmacy Looks like Cookie read the textbook.
Hyperthyroidism is the most common glandular disorder in cats. As noted above, it is mainly a disease pharmacy of elderly cats, with cats typically being around 13 or 14 years of age at the time of diagnosis. Hyperthyroidism occurs when a tumor develops in one or both lobes of the thyroid gland. This causes the thyroid gland to secrete an amount of thyroxine (commonly abbreviated as T4), the main thyroid hormone in cats. Fortunately, 98% of these tumors are benign.
Excessive levels of T4 cause an increase in the cat’s metabolism, and cats start burning pharmacy calories like crazy. They try to compensate by eating more food, but they usually cannot keep pace, and these cats will lose weight despite having an excellent appetite. Other clinical signs that might or might not be seen in hyperthyroid pharmacy cats are excessive thirst and urination, vomiting, diarrhea, panting, restlessness or hyperactivity, and excessive vocalization at night.
The diagnosis is usually achieved by measuring the blood level of thyroxine. Most cats with overt signs of hyperthyroidism will have a T4 level above the high end of the reference range. If a cat is suspected of having hyperthyroidism but the T4 level falls in the high end of (but still within) the reference range, a more sensitive blood test, called the “free T4” (FT4) test, can be run. In most cases, the FT4 level will reveal the cat to have hyperthyroidism.
The ideal treatment is the administration of radioactive iodine, as is done for people with thyroid tumors. pharmacy This is usually performed at a referral center. An injection of radioactive iodine pharmacy is administered under the skin. The radioactive iodine concentrates in the thyroid gland, pharmacy and this destroys the tumor. The disadvantages of this treatment are the cost (at the time of this writing, the typical cost of treatment is somewhere between $1,500 and $2,000) and the need for the cat to stay at the treatment facility for approximately 4 to 10 days until the levels of radioactivity in the urine and feces have decreased to an acceptable level. pharmacy
If you are unable or unwilling to pursue radioactive iodine therapy, anti-thyroid medication would be the next most likely treatment. The drug methimazole (brand names Tapazole and Felimazole), pharmacy when administered twice daily, will prohibit the thyrid tumor from being able to produce thyroid pharmacy hormone. The advantage of oral medication is that it is less expensive than radioactive iodine. A disadvantage is the need to give the drug twice daily. As most cat parents know, cats can be notoriously difficult to medicate. For cats that fight taking a pill, the medication pharmacy can be compounded into a liquid formulation. For those cats who refuse to allow anything to be put into their mouth, the medication can be formulated into a gel that is smeared onto the hairless, inside part of the ear. The gel is absorbed through the skin, and it will lower the blood level of thyroid hormone. Another disadvantage is the potential for side effects. In some cats, methimazole will affect the bone marrow, causing either a low white count and/or a low platelet count. In some cases, methimazole