Vet Rad & Ultrasound, 1994. Iodine is an element normally taken up in large amounts by the thyroid gland, even more so in cats that are hyperthyroid. Radioactive iodine is an effective and safe treatment option for children and teenagers with an overactive thyroid gland, but will usually be given as a second-line treatment after a reasonably long course of antithyroid medication. American Academy of Pediatrics. Treatment usually requires one or two weeks of hospitalization at a veterinary hospital licensed to administer radiation therapy. He's radioactive, so it's not safe even for humans wearing protective clothing to spend too much time around him. Usually this means that the cat will need to be hospitalized for between three and five days after treatment. Try mixing baby food chicken or turkey in with some Fancy Feast. The medication can be given life-long or to stabilize the cat before other treatment. These medications do not provide a cure for the disease, but they do allow either short-term or long-term control of hyperthyroidism. Fewer than 2% of hyperthyroid cases in cats involve malignant thyroid gland tumors. Research into this potential treatment option is ongoing. Most cats with uncomplicated hyperthyroidism will live several years following treatment of hyperthyroidism, unless they develop another disease. Weight change was analyzed in only 228 patients and 84% gained weight by 1 year after radioactive iodine therapy. When it comes to survival, the studies that have been done show that cats cured of their thyroid disease by radioactive iodine live much longer (up to twice as long) when compared to hyperthyroid cats treated by methimazole. It is used less commonly in younger children. Although the cause of feline hyperthyroidism is not known, possible contributing factors include deficiencies or excesses of certain compounds in the diet and chronic exposure to thyroid-disrupting chemicals in food or the environment. 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. Subscribe to always know when we add new material! Although it has a slightly higher iodine content than the previous option, Tiki Cat Hanalei Luau Wild Salmon is the best value for money. Radioactive iodine therapy. That was part of the problem we had before treatment. What is happening in this procedure is that a portion of the radioactive iodine is being taken up by the cat's thyroid to treat its condition (hyperthyroidism, I assume?). Clients owning hyperthyroid cats undergoing radioiodine therapy are always considered members of the general public. . One way to treat a cat with hyperthyroidism is with an oral medication that contains methimazole. With your cat's diseased thyroid, after methimazole treatment failed, large doses of iodine might have proven effective. For this prescription diet to work, it must be the only food fed, which means no cheating with treats. Hypothyroidism, is a condition resulting from a deficiency of thyroid hormone. Radioactive iodine therapy is the treatment of choice, however, because it destroys abnormal thyroid tissue without damaging the surrounding tissue, providing a more permanent form of treatment. 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. When the dose of radiation to the thyroid is very low, like might occur by accidental ingestion of litter box contents, then mutations leading to cancer can ensue. This is because the parathyroid glands (responsible for calcium balance in the body) are near the thyroid gland and may be damaged or accidentally removed during surgery. The most common clinical signs of hyperthyroidism are weight loss, increased appetite, and increased thirst and urination. During treatment, radioactive iodine is administered as an injection and is quickly absorbed into the bloodstream. 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. Pediatrics, 1998. Each treatment option has its advantages and disadvantages. The study followed people for 26 years after two or more treatments. 1 INTRODUCTION. Why isn't there a study directly linking medical imaging and cancer? In some of these cats, blood pressure can become so high that retinal bleeding or retinal detachment will occur, resulting in sudden blindness. In many cats, only one thyroid lobe is abnormal, so only one surgery is needed. You can't visit Fluffy during his stay at the veterinary facility. If hypertension is diagnosed along with hyperthyroidism, drugs may be needed to control the blood pressure and reduce the risk of damaging other organs. Dr. Heinze is an employee of Mark Morris Institute and has provided professional serviceshas done consulting for Lafeber and WellPet, given sponsored talks for Nestl Purina PetCare and the Pet Food Institute, and provided professional services to Balance IT.com and Mark Morris Institute. Chance of significant, unhealthy weight gain is increased. Several complications of hyperthyroidism can be significant, includinghypertension(high blood pressure) and a heart disease called thyrotoxic cardiomyopathy. Ultrasound of the heart (called echocardiography) may be recommended based on your cat's condition, especially if there is any concern about cardiomyopathy. This lowers the amount of radiation exposure to your bladder. Because each cat is different, your veterinarian will advise you on the best treatment for your cat. As in the case of heart disease, after the hyperthyroidism has been successfully treated, high blood pressure will often resolve, and permanent treatment for it may not be required. 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. People may take RAI . 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. To scientifically prove a connection would require nearly one million patients followed closely over decades to detect the small increased risk with any confidence. What may work for one cat may not work for another. For the same reasons as surgical treatment, your cat will likely be started on methimazole for about a month before radioactive iodine therapy. 1. It does, however, involve the handling and injection of a radioactive substance that is only permitted at facilities specially licensed to use radioisotopes. It might not be an option for a frail cat who shouldn't undergo anesthesia. The three ways that we control exposures to external sources of radiation are time, distance, and shielding. When choosing the best therapy for an individual cat, many factors must be considered. When x-rays, or any ionizing radiation, pass through the body they cause electrons to be ejected from atoms, leaving behind positive ions. Depending on the dose, radioactive iodine can kill a portion, or all, of your thyroid. You should talk with your veterinarian about what diets may be best for him in this case. The AVMI radioactive materials license utilizes release criteria and precautionary instructions specifically based on the evaluation of the relative exposure levels to clients following radioiodine therapy for hyperthyroid cats treated with I-131. However once the diagnosis of hyperthyroidism has been made, and no other illnesses are identified, the motivation to perform further diagnostics, especially those that require the need for anesthetics or are invasive may be lost. Therefore if you adhere to the release instructions we provide you with (copies provided on admission and again at discharge), you should be assured of getting less than 1 mSv exposure from interacting with your cat. Lifelong administration of methimazole can control the effects of an overactive thyroid gland. Surgery. Studies show that weight gain is inevitable after radioiodine-induced hypothyroidism. You'll have to give him this drug twice daily for the rest of his life, which treats but doesn't cure the condition. We fed him some Fancy Feast again last night and he ate it all without vomiting. Endocrinology, 1988. This can best be done by monitoring your cat's body condition, muscle condition, and weight. No ill effects have been noted in the children born to parents who received radioactive iodine in the past. In a cat treated with radioactive iodine, the drool will contain radioactive materials. Milner R.J., Channell C.D., Levy J.K., et al., Survival Times for Cats with Hyperthyroidism Treated with Iodine 131, Methimazole, or Both: 167 Cases (1996-2003). 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. Rarely, a permanent reduction in thyroid-hormone levels called hypothyroidism occurs after radioactive iodine treatment. This cat is showing weight loss and poor coat - typical signs of hyperthyroidism. A special diet for cats with hyperthyroidism. Thyroidectomy (largely replaced by radioactive iodine . Of 135 patients with documented pubertal status . There are no studies that directly link cancer to the low dose radiation used in current medical imaging. Malcolm Weir, DVM, MSc, MPH; Krista Williams, BSc, DVM; Robin Downing, DVM, CVPP, CCRP, DAAPM; Ernest Ward, DVM. The principle advantage of Radioactive Iodine treatment for hyperthyroidism is that it tends to have a much higher success rate than medications. How can the age of a material be determined from the decay of a radioactive element quizlet? . Your doctor will order a test called a radioactive iodine uptake and scan to determine the dose you will need. However, your cat will still have a low amount of radiation in his or her body. Slater M.R., Komkov A., Robinson L.E., et al., Long-Term Follow-up of Hyperthyroid Cats Treated with Iodine-131. A swollen or tender neck and feeling flushed. (a) Each licensee shall conduct operations so that -. And, if you destroy your thyroid gland, it turns out that that may have consequences on your metabolism. Number of cases per 100,000 persons exposed to a single dose of 0.1 Gy. 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. The veterinarian's recommendations are to isolate my cat for at least two weeks. The majority of cancers occur later in life and the average lifetime risk of dying from cancer is 25%. Having said that, the clients who own the cats we treat with radioiodine should make every effort to avoid ingesting any contents from the litter box. Dr. Deborah Linder, a board-certified veterinary nutritionist, is the head of the Tufts Obesity Clinic for Animals and has had articles appear in Eating Well, the Boston Globe, AARP, SHAPE, and XM Sirius Radio Doctor Channel. Your veterinarian's instructions regarding separation for the two weeks are simply doing the same thing we do with people. The good news is that there are many treatment options available to our hyperthyroid cats. Treatment for hypothyroidism in cats is . Discuss these issues with your veterinarian when considering dietary iodine restriction as a treatment for hyperthyroidism in cats. Hence people who's hyperthyroid cats are treated with radioiodine would be expected to have a potentially increased risk of developing cancer over the remainder of their lifetime as the result of that exposure of no more than 1/100th of 1 percent. Cat Articles | Site Help | In some cats, anorexia develops as the disease progresses. . The word "individuals" in this context means "people". The inaccurate repair of DNA is rare, but can cause a cell to act wildly or grow into a cancer. How to choose the right food for your cat. The more common symptoms are an increase in thirst, urination, and appetite, as well as weight loss. This helps us offset the costs of running this site, so thank you for your support! 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. Only certain facilities perform this procedure, which consists of giving your cat a shot of radioactive iodine, which gets rid of abnormal thyroid cells without harming normal ones. 2. Cats also sweat through their paws and the sweat will have trace amounts of radioactive iodine. If the disease involves both lobes of the thyroid gland, two surgeries may be required, depending on the surgeon's choice of procedures. Because metabolism is altered in hyperthyroidism, its important to monitor your cats weight and muscle mass. Design and methods: Five hundred and four patients over 40 years of age with diffuse toxic goiter were treated with MMI for 18 months. Over ten years of clinical nutrition research revealed that by controlling dietary levels of iodine, the hyperthyroid cat's body would resume normal thyroid hormone production. For a better experience, please enable JavaScript in your browser before proceeding. More specific information on what to expect when your cat is treated with radioactive-iodine therapy at Cornell can be found here. Will he come around at some point or have we created a monster who will run off to the food dish every time we get up from the chair. What about radioactive iodine treatment for children and teenagers? When available, radioactive iodine therapy is the treatment of choice for cats with hyperthyroidism. Hyperthyroid cats are also at risk for complications related to the hypertension that frequently accompanies hyperthyroidism. This means that in order for this diet to work, your cat must eat the therapeutic diet exclusively and cannot eat any treats or supplements that might contain iodine and allow the thyroid gland to continue to make thyroxine. By 14 days after treatment, the radioactivity will have decayed to a very low level. 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. This may take 8 to 12 weeks or longer. J Vet Intern Med, 2001. To the best of our knowledge, answers are correct at the time they are posted. However, since wild-caught flaked Alaskan salmon is the first ingredient, it provides a lot of moisture. radioactive iodine All three treatments will reduce thyroid hormone levels and the signs of hyperthyroidism. It requires two round-trips for you. Many owners of cats with hyperthyroidism are hesitant to have radiation therapy or surgery because of their cat's advanced age. Surgery Hays M.T., Broome M.R. 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. Signs of anxiety in a cat including pacing, yowling for no apparent reason, and restlessness are a common symptom of feline hyperthyroidism. But this generally resolves without intervention. The 1-month level thyroid may be slightly high, low or normal. When an injection of radioactive iodine is given, it destroys the abnormal thyroid tissue without endangering other organs. Medications for hyperthyroidism in cats are prescribed on a case by case basis. Answer posted on 30 March 2019. 122(6): p. 2444-61. Many organs are affected by hyperthyroidism, especially the heart. 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. In some cases, a decrease in blood platelets (thrombocytopenia) may also occur. Affected cats produce too much thyroid hormone. If these tests are not diagnostic, athyroid scan (thyroid scintigraphy)can be performed at a veterinary referral center, or the TT4 can be measured again in a few weeks. 2000-2023 TheCatSite.com. 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? Always check with your veterinarian before changing your pets diet, medication, or physical activity routines. However, because your cat will be radioactive for several days after receiving the shot, precautions must be taken during and after the treatment. The risk to these cats is the simple fact that many cats in the age range when cats develop hyperthyroidism (8+ years) also develop other diseases. 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. Risk of Ionizing Radiation Exposure to Children: A Subject Review. This is very important meaning that cats rarely develop an underactive thyroid gland (hypothyroidism) after radioiodine therapy. These complications include cerebrovascular events (i.e., strokes) and the premature exacerbation of pre-existing kidney disease. Exposure to high levels of dietary iodine may cause susceptible cats to develop hyperthyroidism. There are virtually no side effects, and there is no pain associated with 131I treatment. Home & Forums | JavaScript is disabled. Even after treatment it may take a long time to reverse weight loss and muscle loss that occurred before your cats diagnosis. The radioactivity carries no significant risk for the cat, but precautionary protective measures are required for people who come into close contact with the cat. In cats, an underactive thyroid is extremely rare. In a study of 524 hyperthyroid cats treated with I-131, only 11/524 (2.1%) developed Medication and radioactive iodine therapy are just as effective at treating hyperthyroidism in cats as surgery and are less invasive, so surgical treatment is rarely chosen for treating this condition. The cell dies (only occurs with very high doses). Hyperthyroidismis characterized by the overproduction of thyroid hormone and a subsequent increase in metabolic rate. During that time, the ravenous appetite should subside, your cat will probably gain weight, and her blood pressure and heart rate should normalize. Nera just had her 3 month checkup and her T4 level is down to 2.3! 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. Now the question is what risk does one obtain from receiving an exposure of 1 mSv? Ultimately of course, these conditions can be diagnosed. J Am Vet Med Assoc, 2006. The cell repairs itself perfectly (most common result). Feeding Hyperthyroid Cats Iodine restriction may help; weight loss is a . Some cats develop side effects from methimazole, such as vomiting, lethargy, anorexia, fever, liver damage, anemia, and a decrease in white blood cells. The injection has no direct side effects. If this is accompanied by clinical signs such as lethargy, obesity, and poor hair coat, then thyroid hormone supplementation may be required. Since hyperthyroid cats are usually over eight years of age, there is a degree of risk involved. This disease is common in older cats. However, caution should be taken in disposal of products that may contain trace amounts of this radioactive substance. Occasionally cats will act like they may have a sore throat for a couple of days after the radioiodine therapy. The beta particles, which are much more potent forms of radiation, travel an average distance of less than 1 mm. Radioactive iodine therapy offers a cure through a simple injection that returns thyroid function to normal levels. These licenses establish the basis for the facilities compliance with federal regulations established by the United States Nuclear Regulatory Commission. In some cases, the cat will develop a heart murmur associated with cardiomyopathy. Recurrence of hyperthyroidism is rare after I-131 therapy. All rights reserved. I am certain that your veterinarian probably told you to take care when handling the litter and to wash your hands thoroughly after handling litter, the cat, and items that the cat came into contact with. Why is the average risk of developing cancer so high? When clicking a link here and buying, we may be able to make a small commission, at no additional cost to you. Hopefully this answers your questions and good luck with your cat. Hair loss. An important take-away message about your newly-diagnosed hyperthyroid cat is that there is a wide range of treatment options, so you can likely find something that works for your family. Dry, dull coat. hypothyroidism was only treated if it was associated with clinical signs like excessive weight gain, lethargy, and skin problems. Cats with hyperthyroidism exhibit symptoms that are similar to those of humans with the disease: weight loss, increased appetite, excessive . Because the risk from exposure to radiation in children is generally considered greater than the risk from the same exposure in adults[7], radiation precautions for children and pregnant women are more restrictive than for adults.The release instructions advising clients of hyperthyroid cats being discharged following radioiodine therapy at AVMI advise that pregnant women and children (defined as individuals less than 18 years of age) avoid contact (defined as a proximity of less than 6 feet) with the patient for a period of 12 days following discharge. under the skin, like a vaccine) and the radioactive iodine is quickly absorbed into the bloodstream. Standards for Protection against Radiation. Thyroid hormone regulates the metabolic rate of an animal. Some places realize that the stress of being away from home for so long is not good for older cats. Radioactive iodine therapy is curative within three months of therapy in approximately 95 percent of all hyperthyroid cases. The coat of affected cats may appear unkempt, matted, or greasy (see Figure 1). Mean baseline age was 12.7 3.0 years and mean baseline BMI SDS was 0.003 1.18 kg/m 2. The routine stay in our radioactive iodine unit is currently 12 days. This information is not a substitute for a vets opinion. It is best to perform a nuclear scan before surgery to rule out ectopic thyroid tissue. If surgery is the chosen treatment method, the anti-thyroid medication methimazole (Tapazole, Felimazole) may be prescribed for several weeks before the operation. (At my facility we treat people but many of the concepts are the same, it is just that patient compliance is easier to obtain with people.) 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. Once your cat's radiation levels have declined below the maximum allowed by federal and state law prior to being released from the hospital (usually 1-5 days), your cat is able to return home. Keeping your pets food temperature just right. If DNA is damaged, there are three possible outcomes: I might even suggest using disposable gloves when handling the litter box duties and when caring for the cat during the isolation time. Unfortunately these cats may continue to deteriorate and may even die from their other non-thyroid diseases. It has the advantage of being curative in most cases with no ongoing treatment. The advantages of medication are that the drugs are readily available and relatively inexpensive. An anti-thyroid medication, like methimazole. Prognosis Only the bare necessitiesfood and water and quick litter cleanupsare provided by veterinary technicians during your cat's hospital stay. Supporting Cat Health with Information and Health Studies. The total effective dose equivalent to individual members of the public from the licensed operation does not exceed 1 mSv in a year, exclusive of the dose contributions from background radiation, from any administration the individual has received, from exposure to individuals administered radioactive material. A Multicompartmental Model for Iodide, Thyroxine, and Triiodothyronine Metabolism in Normal and Spontaneously Hyperthyroid Cats. However, unless the retinal detachment is treated immediately, permanent blindness can occur. 4. By Purraise. Be advised that over time, requirements could change, new data could be made available, and Internet links could change, affecting the correctness of the answers. I'll be honest, the last thing I (or my vet) worried about with Sara was gaining weight. The ALARA recommendation follows the classic "less is more" argument and hence adherence to this philosophy suggests that exposures to ionizing radiation should be minimized whenever possible. and Turrel J.M., A Multicompartmental Model for Iodide, Thyroxine, and Triiodothyronine Metabolism in Normal and Spontaneously Hyperthyroid Cats. Your veterinarian has recommended I131 for your cat. What this means is that occasionally we invest clients economic and perhaps more importantly, emotional resources in treating and resolving hyperthyroidism is cats with other, currently unknown diseases. Rarely, people can feel pain in their neck. To help your cat gain weight, you need to increase the protein and . There are four treatment options for feline hyperthyroidism: medication, radioactive iodine therapy, surgery, and dietary therapy. 2007 07/19/2011; Available from: http://www.nrc.gov/reading-rm/doc-collections/cfr/part020/. Clinical signs include lethargy, dullness, obesity, oily skin, and matted fur. Slater M.R., Geller S. and Rogers K., Long-Term Health and Predictors of Survival for Hyperthyroid Cats Treated with Iodine 131. Clients frequently have the following 2 questions when considering radioiodine therapy for their cat's hyperthyroidism. Radioactive iodine therapy offers a cure through a simple injection that returns thyroid function to normal levels. Radioactive-iodine therapy is becoming increasingly popular when dealing with hyperthyroidism in cats. Radioactive iodine (RAI) is a treatment method for hyperthyroidism and thyroid cancer. Let's tackle the external exposure first as it is the simplest concept. The Disadvantages of Radioiodine Therapy Treatment for Cats, American Veterinary Medical Imaging: Feline Hyperthyroidism, Washington State University College of Veterinary Medicine: Radioactive Iodine Treatment of Hyperthyroid Cats, Washington State University College of Veterinary Medicine: Hyperthyroidism in the Cat, Cornell University College of Veterinary Medicine: Hyperthyroidism in Cats. Cats managed with diet or medication generally do well as long as their feeding is consistent, their medication is administered routinely, and follow-up blood and diagnostic tests are performed as scheduled. All three have risks and benefits. 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. In most cases, only enough radioiodine is given to destroy that part of the gland that is functioning . Now that I know my cat has hyperthyroidism, what do I do? Cats receive a single dose of radioactive iodine by either subcutaneous injection or by a capsule given by mouth. What happens after radioactive iodine treatment for cats? Hyperthyroidism, or an overactive thyroid, is a common disease of older cats. The majority of cats treated with radioactive iodine have normal hormone levels within one to two weeks of treatment. Dr. Freeman has received research or residency funding from, given sponsored lectures for, or provided professional services for Aratana Therapeutics, Elanco, Guiding Stars Licencing Co LLC, Hills Pet Nutrition, Nestl Purina PetCare, P&G Petcare (now Mars), and Royal Canin. DNA can also be damaged directly by radiation. We were told that 90% of the Radioactive Iodine is gone from the cat in two days. To convert these to traditional units we have prepared a. Employees of facilities that utilize radioactive materials may be categorized as "radiation workers" depending on their role. All bodily fluids in the cat will have trace amounts of radioactive material within them, but it will be most prevalent within the urine. There are several hypothesized causes of hyperthyroidism. Removal of the thyroid glands, called surgical thyroidectomy, is a relatively straightforward surgical procedure that has a good success rate. Only about 5% of hyperthyroid cats are younger than 10. Treatment usually includes an adjustment to your cat's diet, medication, radioactive iodine therapy, or surgery. 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. Surgical removal of the affected thyroid gland(s) may be very effective. Subpart D-Radiation Dose Limits for Individual Members of the Public Some rare cases of hyperthyroid disease are caused by malignant tumors known as thyroid adenocarcinomas. If left untreated, a hyperthyroid cat can exhibit many, if not all, of the following signs: extreme weight loss, excessive appetite in most cases, but decreased appetite in some, muscle weakness, heart disease (increase in the size of the heart, increased rate, changes in heart rhythm, cardiac arrest), intolerance to stress, and eventually death. Cats may also continue to show signs of hyperthyroidism, including vomiting and diarrhea, for 3-4 weeks after the radioiodine therapy as the disease continues to resolve. Risks related to radioiodine: This can be accomplished in several ways: Radioactive iodine therapy. Radioiodine treatment avoids surgery, anesthesia, and anti-thyroid drugs. However, because your cat will be radioactive for several days after receiving the shot, precautions must be taken during and after the treatment.