Ideally, the total GFR should be above 2.25 mL/min/kg. 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. The iodine is taken into the thyroid gland and incorporated into thyroxine. Of 247 patients receiving RAI for GD, 157 (79.6% female) had complete data and were included in the analysis. As for equipment for tracking radioactive contamination, there really is no readily available "home-testing" equipment.
Endocrinology, 1988. A standard Chest x-ray is 0.1 mSv. TheCatSite.com participates in select affiliate advertising programs, including the Amazon Services LLC Associates Program. We fed him some Fancy Feast again last night and he ate it all without vomiting. Side effects may include fluid retention, weight gain, elevated . Radioactive iodine. What happens after radioactive iodine treatment for cats? In most cases, only enough radioiodine is given to destroy that part of the gland that is functioning . This can best be done by monitoring your cats body condition, muscle condition, and weight. 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. Rarely, a permanent reduction in thyroid-hormone levels called hypothyroidism occurs after radioactive iodine treatment. This disease is common in older cats. There are two types of radiation exposure that your vet is trying to minimizeexternal exposure from the radioactive material within the cat's body, and the radioactive materials in the cat's urine and other bodily fluids released by the cat that you may come into contact with and may end up being ingested or absorbed by you accidentally. Hyperthyroidism, or an overactive thyroid, is a common disease of older cats. Log in 24/7 to access your pets health care information. Committee on Environmental Health. Dr. Linder has received speaker fees or research fudning from Hills Pet Nutrition, Nestl Purina PetCare, Royal Canin, and Virbac, and has provided professional services for Mark Morris Institute. 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. These include an iodine-restricted diet, medications, and radioactive iodine therapy. Of course, some people receive no radiation and others much, much more. 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. Weight change was analyzed in only 228 patients and 84% gained weight by 1 year after radioactive iodine therapy. Radioactive iodine therapy is curative within three months of therapy in approximately 95 percent of all hyperthyroid cases. In most cases, enlargement of thyroid glands is caused by a non-cancerous tumor called an adenoma. 1 Radioactive iodine (RAI)] is generally considered the optimal treatment for hyperthyroidism in cats.
Malcolm Weir, DVM, MSc, MPH; Krista Williams, BSc, DVM; Robin Downing, DVM, CVPP, CCRP, DAAPM; Ernest Ward, DVM. They may develop periodic vomiting or diarrhea, and fur may appear unkempt. Cats also sweat through their paws and the sweat will have trace amounts of radioactive iodine. Many times the only symptoms these other conditions cause are weight loss. Regardless of the medication, blood tests should be conducted periodically during treatment to evaluate whether the therapy is effective and to monitor kidney function and for potential side effects. This cat is showing weight loss and poor coat - typical signs of hyperthyroidism. Most cats respond to treatment within weeks, although some take up to 6 months to gain the full benefit. Until then, the radiation safety guidelines of Michigan and the NCR are followed. By
Remember that theNRC regulationsrequire that release criteria and discharge instructions provided to owners of hyperthyroid cats prevent exposures of more than 1 mSv. American Academy of Pediatrics. Risks from hyperthyroidism. 2004. If hypertension is diagnosed along with hyperthyroidism, drugs may be needed to control the blood pressure and reduce the risk of damaging other organs. 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. Weight gain was similar for patients who received antithyroid drugs or radioiodine treatment but was significantly greater for patients who had been treated with thyroidectomy (5 kg vs 10 kg; P = 0.007). 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. Subscribe to always know when we add new material! 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. Some cats develop side effects from methimazole, such as vomiting, lethargy, anorexia, fever, liver damage, anemia, and a decrease in white blood cells. (For example, for human patients we provide instructions such as "sleep in separate beds" and "stay at least 1 meter away from others as much as possible.") By 14 days after treatment, the radioactivity will have decayed to a very low level. Cats can receive a second treatment, if necessary. Also, you might get some good ideas about what to feed him on Dr. Lisa Pierson's web site. Is radioactive iodine treatment safe? Exposure limitations: Many doctors recommend that women avoid becoming pregnant for 6 months to a year after treatment. Part 20, Standards for protection against radiation The 1-month level thyroid may be slightly high, low or normal. But this generally resolves without intervention. As stated above, it may also be used for a few weeks to stabilize a cat at increased surgical risk because of cardiac complications. 20.1301 Dose limits for individual members of the public. Radioactive iodine treatment is a therapy that your veterinary surgeon may recommend if your cat is diagnosed with hyperthyroidism. Risk of Ionizing Radiation Exposure to Children: A Subject Review. Actually it is quite safe, because the radioactive iodine is absorbed only by thyroid cells; no other cells in the body are exposed to the radiation. If we restrict iodine, production of thyroxine decreases. 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. The normal thyroid cells will therefore not take up any radioactive iodine. While I do not know the amount of radioactive 131I that was administered to your cat, the recommendations that your veterinarian has given you are very standard for the industry. To help your cat gain weight, you need to increase the protein and . What is taken up by the thyroid will be released slowly over the next days/weeks to the other bodily fluids which is why they have the precautions that you describe. The routine stay in our radioactive iodine unit is currently 12 days. Diagnosis of feline hyperthyroidism is generally straightforward. We found out about the radioactive iodine treatment and after lots.of research decided this was the way to go. However, these options tend to be expensive and not possible for all pet owners. After treatment, the normal thyroid tissue will regain full function within 1-3 months. Risks related to radioiodine: It is also common for hyperthyroid cats to exhibit increased vocalizing, particularly at night. Ten patients (6.4%) had DS (Down Syndrome) and 33 (21.0%) had received ATDs before RAI ablation. In some cats, anorexia develops as the disease progresses. Your veterinarian has recommended I131 for your cat. Radioactive iodine therapy is a very effective way to treat hyperthyroidism (I-131). Surgery. Let's tackle the external exposure first as it is the simplest concept. You should talk with your veterinarian about what diets may be best for him in this case. Slater M.R., Geller S. and Rogers K., Long-Term Health and Predictors of Survival for Hyperthyroid Cats Treated with Iodine 131. One to two weeks after surgery, another TT4 level is measured. The goal of hyperthyroidism treatment is to lower the levels of thyroid hormones in the body. If methimazole dosing is discontinued, hyperthyroidism will return. . These include surgical removal of the thyroid gland (thyroidectomy) or treatment with radioactive iodine. In a cat treated with radioactive iodine, the drool will contain radioactive materials. This isnotan iodine-free diet but a diet with a controlled iodine content of 0.2ppma minimal amount. What Treats Can I Give my Dog with CalciumOxalateStones? 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. Protein and Carbohydrate Sources of Home-cooked Pet Diets, Deborah E. Linder, DVM, MS, DACVIM (Nutrition), Diet-associated dilated cardiomyopathy: The cause is not yet known but it hasnt gone away, Too hot? You must log in or register to reply here. The advantages of medication are that the drugs are readily available and relatively inexpensive. Get exceptional Radioactive Iodine Therapy for Feline Hyperthyroidism services from highly experienced & loving pet care professionals in Downers Grove, IL. Unfortunately these cats may continue to deteriorate and may even die from their other non-thyroid diseases. 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. Thus, individuals who opt for . However, because your cat will be radioactive for several days after receiving the shot, precautions must be taken during and after the treatment. Now that I know my cat has hyperthyroidism, what do I do? Once the correct dose of radioiodine has been determined and administered, most of the time the tumors responsible for causing the elevated thyroid levels resolve and the cats are cured. This helps us offset the costs of running this site, so thank you for your support! 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. But those instruments are quite expensive and are not readily available in stores. As the thyroid levels return to normal, some cats may be able to adjust to their new diets quickly after treatment. She gained and ate a lot and we were more than happy. However, since wild-caught flaked Alaskan salmon is the first ingredient, it provides a lot of moisture. For some cats, a veterinary therapeutic diet low in iodine may be all thats required to control symptoms. 35(3): p. 204-209. While in radiology we use radiation shielding garments (lead aprons) to reduce gamma and x-ray exposure, the energy of the 131I gamma is four to five times higher and those garments are ineffective as a shield. Medications for hyperthyroidism in cats are prescribed on a case by case basis. Toxicology and Applied Pharmacology, 2004. As for your dose, my primary concernespecially if you were allowing the cat to have direct, prolonged contact within the first week of releasewould be the potentially contaminated materials that could result in your intake of radioactive 131I. When x-rays, or any ionizing radiation, pass through the body they cause electrons to be ejected from atoms, leaving behind positive ions. Nearly all cats will be cured by a second treatment. So in this case the targeted radiation exposure is actually increasing survival for these patients. What happens after my cat is released from the hospital? 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. It will take about a month for thyroid levels to return to normal in most cats. Studies show that weight gain is inevitable after radioiodine-induced hypothyroidism. He's radioactive, so it's not safe even for humans wearing protective clothing to spend too much time around him. You'll need to consider whether to have radioactive iodine (RAI) vs. other treatments for hyperthyroidism and Graves' disease (an immune system disorder that can cause hyperthyroidism). My pet has kidney disease what kind of diet should I feed. The advantages of radioactive iodine therapy are that the procedure most often cures hyperthyroidism, has no serious side effects, and does not require anesthesia. There are virtually no side effects, and there is no pain associated with 131I treatment. This is very important meaning that cats rarely develop an underactive thyroid gland (hypothyroidism) after radioiodine therapy. 1. Answers are the professional opinions of the expert responding to each question; they do not necessarily represent the position of the Health Physics Society. Why isn't there a study directly linking medical imaging and cancer? 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. If you know that your cat has hyperthyroidism, you probably have already seen your vet in order to have this disease properly treated. In a cat treated with radioactive iodine, the drool will contain radioactive materials. However, it may not be appropriate for all cats (depending on other medical conditions) so important to work with your veterinarian and decide if using this therapeutic diet is the best way to manage your cats condition. Jane Meggitt has been a writer for more than 20 years. All middle-aged and senior cats should receive a complete physical examination by a veterinarian every six months. Hays M.T., Broome M.R. 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. Cats exclusively fed the prescription diet will remain normal, but if the diet is discontinued, they will once again become hyperthyroid. Dietary Therapy Cat Articles | A small number of cats will remain hyperthyroid after treatment, if this is the case your cat will need . The cell repairs itself perfectly (most common result). Nuclear Medicine Patient Issues Questions Concerning Domestic Animals. Most hyperthyroid cats respond fully to a single injection with radio-iodine. Also, I wonder if there is home-testing equipment to track the household dispersal of the radioactive contaminants that he emits after his treatment and something else to monitor and determine my exposure to the 131I remnants. In some cases, the cat will develop a heart murmur associated with cardiomyopathy. The typical cat with hyperthyroidism is middle-aged or older; the average age of affected cats is approximately 12 years. I-131 therapy does not require anesthesia and eliminates the need for daily medication. Only the bare necessitiesfood and water and quick litter cleanupsare provided by veterinary technicians during your cat's hospital stay. The food isnotmedicated. Studies have shown that cats treated with I-131 live longer than those treated with pills, added Mosenco, citing a study where I-131-treated cats lived an average of four to five years following treatment, versus an average of only two years for cats on medication.Dec 19, 2016. To convert these to traditional units we have prepared a. 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. 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. Def scared about this possibility with Fluff, Our cat was treated for hyperthyroidism and has been back home for about two weeks. Iodine-131, Hyperthyroidism, and Radioactive Iodine Therapy Iodine-131 (I-131) is a radioisotope of iodine with a physical half-life of 8.02 days; its primary decay emissions include a 606 keV - particle with 89.6% abundance and a 364 keV -ray with 81.5% abundance (Knolls Atomic Power Lab 2010). We love them, too! The other conditions that cats can develop at this age are numerous and varied. "The most common clinical sign of hyperthyroidism is weight loss due to the increased rate of metabolism despite an increased appetite.". . (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.) In some cases, a decrease in blood platelets (thrombocytopenia) may also occur. Site Help | The majority of cats treated with radioactive iodine have normal hormone levels within one to two weeks of treatment. Specific facts and circumstances may affect the applicability of concepts, materials, and information described herein. ), family history (genetics) or radiation exposure. Amazingly despite over 35 years of veterinary experience treating hyperthyroid cats with radioiodine there are virtually no reported side effects. 122(6): p. 2444-61. 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? Removal of the thyroid glands, called surgical thyroidectomy, is a relatively straightforward surgical procedure that has a good success rate. Surgery will be performed if your cat successfully undergoes the initial treatment without complication. These include weight loss, increased activity, and kitten like behaviour. About TheCatSite.com. 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. Before treatment he was ravenous and losing weight -- typical of cats with that disorder I'm told. Radioactive iodine (I-131) is a very safe and effective treatment for hyperthyroidism. The information posted on this web page is intended as general reference information only. Hopefully this answers your questions and good luck with your cat. 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. There are fundamental differences between a continuous dose over a year (background radiation) and a dose that occurs over a few seconds like in CT, but these are helpful comparisons. 3. These positive ions, or free radicals, can cause damage to DNA. Excessive weight gain. A medication called methimazole, which interferes with thyroid hormone production, is less expensive but requires daily administration. 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?). 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%). All three have risks and benefits. The iodine, which is required for the production of both T3 and T4, is taken up by the thyroid gland and the emitted radiation destroys the abnormal thyroid tissue without damaging the surrounding tissues or the parathyroid glands. Regardless of radiation exposure, the average overall lifetime risk of developing an invasive cancer is 37.5% for women and 44.9% for men. There are several treatment options, and your veterinarian will determine the best choice for your cat. Lack of appetite. 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. 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. By 14 days after treatment, the radioactivity will have decayed to a very low level. It does, however, involve the handling and injection of a radioactive substance that is only permitted at facilities specially licensed to use radioisotopes. To scientifically prove a connection would require nearly one million patients followed closely over decades to detect the small increased risk with any confidence. Pediatrics, 1998. The cell repairs itself with mistakes (rare). 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. At 1 and 3 months after the treatment, a blood test for thyroid and kidney function should be done by your veterinarian. Radioactive iodine therapy. If we use the linear no-threshold model we could estimate that the exposure to 1 mSv would therefore have a risk of less than 0.01% (or 1/100th of 1 %) of causing cancer over the remaining life of an adult. Over time, this progresses to increased blood pressure, severe weight loss, heart disease, blindness, and kidney damage. Further, the litter will be radioactive as most of the radioactive iodine will be excreted via this route. These licenses establish the basis for the facilities compliance with federal regulations established by the United States Nuclear Regulatory Commission. In order to produce thyroid hormone (thyroxine), the body needs a supply of iodine. Symptoms include weight loss, muscle wasting, increased appetite, increased thirst and urination, vomiting, unkempt appearance, and sometimes hyperactivity. Hair loss. 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. radioactive iodine All three treatments will reduce thyroid hormone levels and the signs of hyperthyroidism. Since hyperthyroidism can predispose a cat to other conditions, it is important to evaluate general health, with particular focus on the heart and kidneys. While my facility does not treat cats with radioactive 131I, I have consulted with a veterinary medicine program at a nearby university that does perform these types of procedures to get myself in the "cat-patient" mode of thought. The effectiveness of this transdermal gel is acceptable in most cases. 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? The radioiodine is eliminated in urine and feces. Annual blood and urine tests are important in all cats seven years and older to detect hyperthyroidism before potentially irreversible damage occurs. If radioactive iodine therapy won't work for you and your cat, alternatives are available. The three ways that we control exposures to external sources of radiation are time, distance, and shielding. Treatment for Hypothyroidism in Cats. TheCatSite.com is a community of cat lovers dedicated to quality cat care and cat welfare. J Am Vet Med Assoc, 2006. Subpart D-Radiation Dose Limits for Individual Members of the Public Copyright 2023 Leaf Group Ltd. / Leaf Group Media, All Rights Reserved. After initial stabilisation with oral medications, a number of curative treatments are also available. However, there are a number of reasons for the precautions that your veterinarian has provided you that I will discuss below. Risks unrelated to radioiodine therapy: All bodily fluids in the cat will have trace amounts of radioactive material within them, but it will be most prevalent within the urine. Feeding an iodine-limited diet (Hills Prescription Diet y/d) can resolve clinical signs and lower thyroid hormone concentration. Often, treating hyperthyroidism will unmask hidden kidney failure that will require additional care and is best detected early in the course of the disease. The veterinarian's recommendations are to isolate my cat for at least two weeks. Our cat was treated for hyperthyroidism and has been back home for about two weeks. It has the advantage of being curative in most cases with no ongoing treatment. Hyperthyroid cats suffer overactive thyroid glands, circulating too much thyroid hormone through their system and affecting nearly every organ. Always check with your veterinarian before changing your pets diet, medication, or physical activity routines. Once his radiation levels come down and you can bring him home, you still have to keep him away from young children and pregnant women, as he'll pass small amounts of radioactive iodine through his urine for approximately two weeks. Radioactive iodine therapy offers a cure through a simple injection that returns thyroid function to normal levels. Nera just had her 3 month checkup and her T4 level is down to 2.3! A Multicompartmental Model for Iodide, Thyroxine, and Triiodothyronine Metabolism in Normal and Spontaneously Hyperthyroid Cats. Despite the extensive blood and urine tests, chest x-rays and physical exams that we require before . When available, radioactive iodine therapy is the treatment of choice for cats with hyperthyroidism. When an injection of radioactive iodine is given, it destroys the abnormal thyroid tissue without endangering other organs. Calabrese E.J., Hormesis: From Marginalization to Mainstream: A Case for Hormesis as the Default Dose-Response Model in Risk Assessment.