Scooter Weighs In

Scooter is a long time patient of ours, a wonderful, handsome black cat with a human so loving and dedicated to his care it is awe-inspiring. She has done everything we have asked of her in the course of his care, including braving the slippery icy roads today to bring him in for his monthly weigh in. No, Scooter is not a fat cat-at 9 pounds he is just about right. We weigh him in every month because he has what every human dieter could only wish for-(not really, it can really be a serious condition as you will read about Scooter- but as some one who has battled weight issues my whole life, just a "little" bit of his condition sounds appealing....) Scooter has hyperthyroidism.

Hyperthyroidism is a disease of the thyroid glands, usually due to a benign mass or tumor that produces too much of the hormone responsible for, well, virtually all of the metabolism in the body. It can affect so many systems and organs, but we primarily see patients for the first time because they begin to lose weight despite often having great appetites. I have seen cats lose almost half of their initial body weights. They can develop cardiac (heart) and hepatic (liver) issues. Hyperthyroidism is almost always seen in cats; dogs usually have the opposite condition of under production of the thyroid hormone-hypothyroidism. Hyperthyroidism is actually quite common in our older cats; it can be seen in one out of every 300 or so, and the average age at diagnosis is 13 years. Scooter was 11 when his owner brought him in for his yearly health exam and vaccines, but we noted this once 14 pound cat was down suddenly to 11 pounds with no diet change or anything else to "explain" the weight loss. We typically screen all of our senior or geriatric patients after the age of 8 years or so with a simple blood test, and we did so for Scooter. Sure enough, he had a slightly elevated T-4 level. This was over 2 years ago, and was the beginning of our "journey" with his disease.

There are three basic treatment options for hyperthyroid cats, and the choice for an individual cat is made based on location, difficulty in medicating the patient, (those darned cats!) how the cat tolerates the medication, as well as owner finances. We explored all three options with Scooter over the last two years. Initially, all cats go on a medication called Tapezole or methimazole to help stabilize the patient by bringing the T-4 level down. It can be expensive and, while transdermal (preparations rubbed into the skin of the cat, usually the hairless inner ear flap) formulations are available, they aren't likely to bring blood levels of the drug up to therapeutic levels. So that means getting a pill or multiple pills into your cat every day. We were fortunate in that Scooter was a good boy and his owner did not have a problem getting his pills in him. The bigger problem with methimazole is it can be toxic to the kidneys over time, and this was the case for Scooter. Cats often have issues with renal (kidney) function as they age, so medications that could exacerbate this just aren't a good idea long term. We had to take Scooter off this medication and look for another treatment option.

Radioactive iodine therapy is the "gold standard" of hyperthyroid treatment-for cats as well as for humans. I heard that the first President George and Barbara Bush had this treatment! We are very fortunate that there is actually a center for hyperthyroid treatment for cats very close by. Not all patients are as lucky and owners might have to travel great distances for referral to facilities that offer this treatment. The benefits of radioctive iodine are significant: a cure rate of 90 to 95 percent, with no further treatment needed in most cases. Yes, it can be expensive, but the costs seem to have come down over the years as the average time the cats are hospitalized has gone down. The cat gets one dose of a radioactive substance that kills the overproducing cells. This only takes a day to perform, but because the patient will then be "radioactive" for some time, isolation is often recommended to prevent human exposure. This is especially important for exposure to the cat's waste products-urine and feces. You also don't want to allow your cat to sit on your chest for prolonged periods or cuddle up next to you to sleep, as Stella and Spartacus are doing right now to use my body heat! The doctors and staff at the treatment facilities are great at explaining the aftercare required. No, the kitties don't glow in the dark :)
Scooter's owner took him for a consultation to our local treatment facility, but he was found to be unsuitable for treatment due to some already elevated kidney values. That was two strikes against poor Scooter!

The third option for treatment is surgery to remove the tumor or overproducing tissue. It can be a very good option, especially if radioactive iodine therapy isn't available or suitable as in Scooter's case. Problems are it can be a delicate procedure, (there are some HUGE blood vessels in this area-the jugular vein and carotid artery) and because very tiny adjacent and embedded glands called the parathyroids are often removed along with the thyroid gland. These are very important for calcium regulation in the body, so this must be monitored carefully post-operatively, especially if both thyroid glands need to be removed.

Scooter's owner elected to take him to surgery a few months ago. His weight had dropped another 2 pounds despite her aggressively searching for foods he would love (doesn't it figure he would be a typical finicky cat?). His body condition actually looked pretty good, but we knew how that could change if we left his disease untreated. Scooter did great for his surgery, good anesthesia and all, but we had a big problem-we couldn't find his thyroid glands! Usually located in the neck or just at the thoracic inlet near the throat, affected glands are usually abnormally large, discolored, very obviously "not right" and just sort of pop out at you. They can often be palpated (felt) during a physical exam, an important part of checking over a senior cat. I knew that the glands could rarely be located in the chest cavity itself, and we weren't prepared for the type of extensive anesthesia and surgical exploration it would require to go blindly searching for them in such a large space. Their location can be identified ahead of time by doing a scan (injecting the patient with a contrast media and taking images to identify the tissue that picks up the dye.) This has to be done by a specialist in this type of imaging and can be very expensive. I have never had a patient referred for this, but after Scooter's surgery, I am considering it (if Scooter's owner can afford it. She really has gone above and beyond what most owners would do for their pets and times are tough right now.)

So, now what? Scooter has run out of his treatment options for now. His owner is distraught, but she is doing a wonderful job of pumping calories into him. She gives him appetite stimulant medications when he needs it, and all sorts of tasty foods. And guess what? He is up 8 ounces at today's weigh in! That is pretty significant in a 9 pound animal. He'll never be a 14 pound cat again, but that is OK-he was really too fat back then. We'll give him a break and extend out his weigh-in appointments to every few months or so, or anytime his owner thinks he might be getting finicky again or having problems (he still has those kidney issues to deal with.) And I'll keep going to seminars and consulting online for any new ideas the endocrinologists/internal medicine specialists might come up with to help him. He is one lucky kitty to be loved and cared for this much.

Peace,
DrReneigh