Antithyroid medications are also available in a gel that can be applied to the skin. Treating Hyperthyroidism in Cats. By 14 days after treatment, the radioactivity will have decayed to a very low level. Reduce the time near a source, increase the distance from the source, or use some sort of radiation absorbing shielding between you and the source of radiation and you will reduce your radiation dose. "The most common clinical sign of hyperthyroidism is weight loss due to the increased rate of metabolism despite an increased appetite.". Cats afflicted with hyperthyroidism usually develop a variety of signs that may be subtle at first but that become more severe as the disease progresses. However, once the underlying hyperthyroidism has been controlled, the cardiac changes will often improve or may even resolve completely. Because of strict treatment guidelines, most facilities will not allow visitors during this quarantine period. What may work for one cat may not work for another. For this prescription diet to work, it must be the only food fed, which means no cheating with treats. If radioactive iodine therapy won't work for you and your cat, alternatives are available. Natural background radiation exposure accounts for an average of 3.1 mSv/yr with variations depending on where you live. This can be accomplished in several ways: Radioactive iodine therapy. 7. Many older cats with overactive thyroids have actual enlargement of the gland which can be felt in the neck by your veterinarian. Thank you! For example, some families cant medicate cats every day, so a more permanent solution such as radioactive iodine treatment or surgery may be best. Thyroid hormone regulates the metabolic rate of an animal. Some hyperthyroid cats have thyroid cells in abnormal locations calledectopicthyroid tissue (thyroid tissue under the tongue, further down the neck, or all the way to the base of the heart), and they may remain hyperthyroid after surgery. It is important to drink fluids after your treatment and for the next 2 days. Medications for hyperthyroidism in cats are prescribed on a case by case basis. Also, you might get some good ideas about what to feed him on Dr. Lisa Pierson's web site. One major risk associated with surgical thyroidectomy is inadvertent damage to the parathyroid glands, which lie close to or within the thyroid gland and are crucial in maintaining stable blood calcium levels. This surgery requires general anesthesia, however, and there might be added risks if older cats have heart, kidney, or other problems that could cause complications. He rejected the Fancy Feast stuff and gobbled the baby food along with eating a little variety of the many dry foods we tried in an effort to find one that he really liked. I-131 is normally a health concern after the . A small number of cats will remain hyperthyroid after treatment, if this is the case your cat will need . The medication can be given life-long or to stabilize the cat before other treatment. Due to the damaging effects of hyperthyroid-induced hypertension on your cats kidneys, blood kidney values must be reassessed once the thyroxine level has normalized, even if they were normal on initial blood tests. Most cats with hyperthyroidism have elevated levels of the thyroid hormone T4 in their bloodstream, but a small percentage of cats with hyperthyroidism have T4 levels within the normal range. 2. Cats also sweat through their paws and the sweat will have trace amounts of radioactive iodine. Our cat was treated for hyperthyroidism and has been back home for about two weeks. What they are trying to prevent is the intake (ingestion, etc.) Other therapeutic monitoring. Want to read more information on feeding your pet? The coat of affected cats may appear unkempt, matted, or greasy (see Figure 1). The treatment lowers or eliminates hormone production and may decrease the size of the goiter. These include an iodine-restricted diet, medications, and radioactive iodine therapy. Radioactive iodine (RAI) is a treatment method for hyperthyroidism and thyroid cancer. It is used less commonly in younger children. Many doctors recommend that women avoid becoming pregnant for 6 months to a year after treatment. Subpart D-Radiation Dose Limits for Individual Members of the Public It does, however, involve the handling and injection of a radioactive substance that is only permitted at facilities specially licensed to use radioisotopes. Risks unrelated to radioiodine therapy: If possible, I would like to wear protective clothing so we can return to our familiar habit of living/sleeping in 24-hour close physical contact to minimize his stress and promote his recovery. He also can't sleep with you during that time, and the facility will inform you about special arrangements you'll have to make for disposing of his litter. Clients frequently have the following 2 questions when considering radioiodine therapy for their cat's hyperthyroidism. As for equipment for tracking radioactive contamination, there really is no readily available "home-testing" equipment. Exposure to high levels of dietary iodine may cause susceptible cats to develop hyperthyroidism. The treatment a cat receives for hyperthyroidism will depend on specific circumstances, including the patients overall health status, the owners ability and willingness to medicate the cat regularly, and financial considerations. The dose of radiation used during radioactive iodine treatment is very low, but there are some precautions you'll need to take after treatment: avoid prolonged close contact with children and pregnant women for a few days or weeks women should avoid getting pregnant for at least 6 months men should not father a child for at least 4 months This is very important meaning that cats rarely develop an underactive thyroid gland (hypothyroidism) after radioiodine therapy. Regardless of radiation exposure, the average overall lifetime risk of developing an invasive cancer is 37.5% for women and 44.9% for men. These tests are needed to evaluate your cats overall health and predict the likelihood of complications with the chosen treatment protocol. Treatment for hypothyroidism in cats is . What is the biggest concern with nuclear meltdown and why? Because of the short distances they travel they never exit the patient and as a result no one other than the patient is at risk from exposure to the beta particles unless they internalized the radioiodine excreted by the patient. Hence for a transient period following radioiodine therapy, the patient's urine contains excreted radioiodine which will emit beta particles as it continues to decay. Research into this potential treatment option is ongoing. There are several hypothesized causes of hyperthyroidism. Iodine is an element normally taken up in large amounts by the thyroid gland, even more so in cats that are hyperthyroid. Generally, about 5 to 10 pounds of excess weight can likely be attributed to the lack of thyroid hormones that occurs in people diagnosed with hypothyroidism. While the concept of radiation hormesiswould suggest a potential benefit from exposure to low levels of ionizing radiation by stimulating the immune system's ability to repair DNA, any potential benefit is poorly defined and hence the current recommendations surrounding radiation exposure follow the As Low As Reasonably Achievable (ALARA) concept. And I'm so glad she did, since her kidney disease (that unmasked after methimazole treatment) went from Stage 1 chronic to Stage 4 acute on chronic last weekend. Feeding Hyperthyroid Cats Iodine restriction may help; weight loss is a . Cats with hyperthyroidism exhibit symptoms that are similar to those of humans with the disease: weight loss, increased appetite, excessive . Domestic airline pilots are exposed to an additional 2.2 mSv per year, about the same dose as a brain CT. As you can see from the table below, the estimated risk of developing cancer from exposure to 0.1 Gy (= 100mSv), while it varies with the age of the individual, is something less than 1% for adults. That was part of the problem we had before treatment. Elevated thyroid hormones stimulate an increased heart rate and a stronger contraction of the heart muscle, and can cause thickening of the left ventricle of the heart over time. Methods: Therapy and body weight related data of 100 consecutive RITh-patients were retrospectively analysed from the time before up to three years after RITh. Radioactive iodine therapy. However, caution should be taken in disposal of products that may contain trace amounts of this radioactive substance. Prescription nutrition. Tiki Cat Hanalei Luau Wild Salmon Wet Cat Food. In addition to reporting for a major newspaper chain, she has been published in "Horse News," "Suburban Classic," "Hoof Beats," "Equine Journal" and other publications. Treatment usually requires one or two weeks of hospitalization at a veterinary hospital licensed to administer radiation therapy. The advantages of radioactive iodine therapy are that the procedure most often cures hyperthyroidism, has no serious side effects, and does not require anesthesia. What happens after my cat is released from the hospital? The advantage of surgery is that it is likely to produce a long-term or permanent cure in most cats, and therefore eliminates the need for long-term medication. Radioactive iodine therapy is becoming the treatment of choice for felines with hyperthyroidism. To convert these to traditional units we have prepared a. Radioactive iodine targets the thyroid tissue - as this is the only tissue in the body that uses significant quantities of iodine. The following question was answered by an expert in the appropriate field: What testing equipment and protective clothing do you recommend for a nontechnical person who will be giving home care to an 18-year-old blind cat after he has spent four days recovering in the animal hospital from 131I treatment? Weigh the pros and cons of various treatments and discuss options with your vet. Recurrence of hyperthyroidism is rare after I-131 therapy. The 1-month level thyroid may be slightly high, low or normal. In most cases, only enough radioiodine is given to destroy that part of the gland that is functioning . Overall, weight gain was associated with development of hypothyroidism despite levothyroxine replacement . Too cold? If this is the case with your cat, paying special attention to specific nutrients such as dietary phosphorus (a key player in chronic kidney disease) may be required. Methimazole blocks excess thyroid hormone production rather than destroying the abnormal thyroid tissue, so the medication must be given for the rest of the cat's life. Consider Hyperthyroid Treatment . Many owners of cats with hyperthyroidism are hesitant to have radiation therapy or surgery because of their cat's advanced age. and Turrel J.M., A Multicompartmental Model for Iodide, Thyroxine, and Triiodothyronine Metabolism in Normal and Spontaneously Hyperthyroid Cats. Part 20, Standards for protection against radiation Radioactive iodine may also affect a woman's ovaries, and some women may have irregular periods for up to a year after treatment. Looking for a convenient way to access your pets health records, refill prescriptions, view upcoming appointments and more? With your cat's diseased thyroid, after methimazole treatment failed, large doses of iodine might have proven effective. Scaly skin. Cats havetwo thyroid glands in the neck that are vital in regulating the body's metabolic rate. Feeding an iodine-limited diet (Hills Prescription Diet y/d) can resolve clinical signs and lower thyroid hormone concentration. There are virtually no side effects, and there is no pain associated with 131I treatment. The study followed people for 26 years after two or more treatments. Committee on Environmental Health. Calabrese E.J., Hormesis: From Marginalization to Mainstream: A Case for Hormesis as the Default Dose-Response Model in Risk Assessment. Surgical removal of the gland under general anesthetic was another option. NRC Regulations This information is not a substitute for a vets opinion. Hyperthyroidism, or an overactive thyroid, is a common disease of older cats. How does airline travel expose me to radiation? For some cats, a veterinary therapeutic diet low in iodine may be all thats required to control symptoms. This lowers the amount of radiation exposure to your bladder. The estimates of risk currently used are extrapolated from patients that have received much higher doses (e.g., atomic bomb survivors) using the linear, no-threshold model of radiation exposure risk. If the nearest facility is far away, there's the stress or travel for both you and Fluffy, as well as possible hotel and other travel expenses. In a cat treated with radioactive iodine, the drool will contain radioactive materials. Log in 24/7 to access your pets health care information. Luckily these risks will diminish in time following successful radioiodine therapy and a return to a persistently normal thyroid level. It is acceptable to feed your feline products containing at least 30% protein and less than 15% carbohydrates. I-131 therapy does not require anesthesia and eliminates the need for daily medication. Design and methods: Five hundred and four patients over 40 years of age with diffuse toxic goiter were treated with MMI for 18 months. The beta particles, which are much more potent forms of radiation, travel an average distance of less than 1 mm. At 1 and 3 months after the treatment, a blood test for thyroid and kidney function should be done by your veterinarian. Since platelets are essential for blood clotting, thrombocytopenia may lead to problems with excessive bleeding. Side effects may include fluid retention, weight gain, elevated . Risk of Ionizing Radiation Exposure to Children: A Subject Review. All bodily fluids in the cat will have trace amounts of radioactive material within them, but it will be most prevalent within the urine. 122(6): p. 2444-61. Home & Forums | The average US total radiation exposure (all sources) is 6.2 mSv/yr which is an increase from 20 years ago (3.6 mSv/year) when CT scans were much less common. Having lost my 18-year-old feline member of the family a few years ago, I completely understand the attachment and your desire to not stress the cat. Some people also feel flushed. Researchers estimated a 12% increased risk for death from breast cancer and a 5% increased risk for death from . Out little Nera was diagnosed with hyperthyroidism about 4-5 months ago. These complications include cerebrovascular events (i.e., strokes) and the premature exacerbation of pre-existing kidney disease. Radioactive iodine (I-131) is a very safe and effective treatment for hyperthyroidism. In some of these cats, blood pressure can become so high that retinal bleeding or retinal detachment will occur, resulting in sudden blindness. . So, we must use distance and reduction of time near the source when dealing with patients and pets treated with 131I. In cases where radioactive iodine therapy is not successful, the treatment can be repeated. . The treatment you and your vet choose depends on several factors including how severe the disease is, your cats health, and what works best for your family. A blood chemistry panel and urinalysis will provide information about other organs and provide your veterinarian with an overall picture of your cats health. Of 247 patients receiving RAI for GD, 157 (79.6% female) had complete data and were included in the analysis. And not only do we love the pets, we also love their people, and you are our reason for making this site. These include surgical removal of the thyroid gland (thyroidectomy) or treatment with radioactive iodine. The majority of cats treated with radioactive iodine have normal hormone levels within one to two weeks of treatment.
The dose of radioactive iodine is taken orally. About 25% of cats with hyperthyroidism become hypertensive. This disease is common in older cats. Hyperthyroidism is a common disease in cats, and mostly afflicts cats middle-aged and older. To help your cat gain weight, you need to increase the protein and . The cell repairs itself perfectly (most common result). The current Nuclear Regulatory Commission radiation dose limits for individual members of the public are listed below. The routine stay in our radioactive iodine unit is currently 12 days. I'll be honest, the last thing I (or my vet) worried about with Sara was gaining weight. Should we just cut him off "cold turkey" (pun intended) and hope he finds fulfillment and eventual weight gain with his old diet of dry food? First we need to put this exposure level into some context: How do x-rays increase your risk for cancer? This treatment involves administering an injection of iodine with a radioactive substance attached. At the time of discharge, exposure levels measured at 6 feet from the patient are virtually indistinguishable from background levels. Follow up blood work is essential to ensure kitty does not become hypothyroid which is too little thyroid. For the first two weeks after I-131: Keep your cat indoors or supervised when outside to prevent contact with other people. The good news is that there are many treatment options available to our hyperthyroid cats. Surgery. In order to produce thyroid hormone (thyroxine), the body needs a supply of iodine. If you can't bear to be away from him, or if he becomes very stressed or frightened when you're not around, that isolation could be difficult. Environmental risk factors have been investigated and may predispose some cats to hyperthyroidism, although the specific mechanisms are unknown. Thyroid hormones affect nearly all of the organs in the body; therefore, thyroid disease often causes secondary problems. Radioactive-iodine therapy is becoming increasingly popular when dealing with hyperthyroidism in cats. Standards for Protection against Radiation. Hyperthyroidism in cats is a commonly diagnosed endocrinopathy with an overall prevalence of 2.4% in England which increases to 8.7% in cats aged 10 years or older. I-131 therapy does not require anesthesia and eliminates the need for daily medication. As stated above, it may also be used for a few weeks to stabilize a cat at increased surgical risk because of cardiac complications. What happens after radioactive iodine treatment for cats? More specific information on what to expect when your cat is treated with radioactive-iodine therapy at Cornell can be found here. Subscribe to always know when we add new material! Vet Rad & Ultrasound, 1994. Do not allow your cat to sleep against your body. This is why one of the first signs of thyroid disease may be a change in weight weight gain if the thyroid is underactive and weight loss if the thyroid is overactive. Treatment The normal thyroid cells will therefore not take up any radioactive iodine. Cats can receive a second treatment, if necessary. The iodine is taken into the thyroid gland and incorporated into thyroxine. We fed him some Fancy Feast again last night and he ate it all without vomiting. An anti-thyroid medication, like methimazole. Mean baseline age was 12.7 3.0 years and mean baseline BMI SDS was 0.003 1.18 kg/m 2. They may develop periodic vomiting or diarrhea, and fur may appear unkempt. She's lost a pound in less than two weeks, so yeah, I'm glad I let her eat as much as she wanted. As youre on this website right now, we can assume that you love pets and likely have a special dog or cat (or many) in your life. In some cases, complications involving other organs may worsen this prognosis. For a better experience, please enable JavaScript in your browser before proceeding. Further, the litter will be radioactive as most of the radioactive iodine will be excreted via this route. Because metabolism is altered in hyperthyroidism, its important to monitor your cats weight and muscle mass. GFR results are used to determine the functional status of the kidneys, and identify cats with subclinical renal disease. Most cats with uncomplicated hyperthyroidism will live several years following treatment of hyperthyroidism, unless they develop another disease. The American Thyroid Association notes that weight gain develops over a long time and may have many causes other than the underactive thyroid. He's radioactive, so it's not safe even for humans wearing protective clothing to spend too much time around him. Before treatment he was ravenous and losing weight -- typical of cats with that disorder I'm told. Despite the extensive blood and urine tests, chest x-rays and physical exams that we require before . Finally, thyroid hormone has a role in kidney function and blood flow that may result in either directly damaging the kidney or obscuring underlying kidney disease that your cat may already have. However, the risk is minimal if your cat is otherwise healthy, and the initial diagnostic tests and treatment did not reveal any underlying conditions. When choosing the best therapy for an individual cat, many factors must be considered. I might even suggest using disposable gloves when handling the litter box duties and when caring for the cat during the isolation time. . A medication called methimazole, which interferes with thyroid hormone production, is less expensive but requires daily administration. . No individual breed is known to have a greater risk, although Siamese, Burmese, Persian, Abyssinian, Tonkinese, and British shorthair breeds appear to have a somewhat decreased incidence of hyperthyroidism compared to other breeds. Because the thyroid needs iodine to produce hormones, the thyroid takes the radioiodine into the thyroid cells and the radiation destroys the overactive thyroid cells over time. The information posted on this web page is intended as general reference information only. The radioactive isotope, Iodine-131 ( 131 I), is administered as a one-off injection. Also called thyrotoxicosis, hyperthyroidism is caused by an increase in production of thyroid hormones (known as T3 and T4) from an enlarged thyroid gland in a cats neck. The overwhelming majority of cats (>95%) are cured by a single therapy with only a small percentage of cats requiring additional radioiodine therapy (4%) or becoming persistently hypothyroid (1%). Although many cats diagnosed with hyperthyroid disease already have kidney disease, untreated hyperthyroidism can also cause kidney disease due to the damaging effects of hypertension on the kidneys. Other than unexplained weight loss, your cat may also become more restless, hyperactive, vocal, and extremely hungry! So in this case the targeted radiation exposure is actually increasing survival for these patients. Fluffy might be a candidate for a thyroidectomy, surgery to remove the thyroid glands, which usually results in a cure. When a radioactive form of iodine is given to hyperthyroid cats, the radiation destroys a portion of the thyroid gland. The School of Veterinary Medicine's Ryan Hospital, however, is one of the few veterinary centers in the region to offer a treatment that can cure the disease: a single shot of radioactive iodine, I-131. A veterinarian who suspects a cat has a thyroid problem will conduct a physical examination and palpate the cats neck area to check for an enlarged thyroid gland (see Figure 2). The recommended food for cats with thyroid problems is high in protein yet low in carbohydrates, iodine (around 0.32 ppm) and phosphate. If thyroid disease is a possibility, your veterinarian will likely order a blood chemistry panel and an analysis of thyroid hormone levels.
Upon discharge from PVESC (after an average of 4 to 7 days after treatment), treated cats will still be excreting radioiodine in their urine, saliva, and feces. It will take about a month for thyroid levels to return to normal in most cats. One of the reasons the cat was held for four days was to allow for much of the radioactive 131I to be excreted in urine so that the amount of external radiation exposure is significantly reduced. It is also common for hyperthyroid cats to exhibit increased vocalizing, particularly at night.