He's radioactive, so it's not safe even for humans wearing protective clothing to spend too much time around him. Researchers estimated a 12% increased risk for death from breast cancer and a 5% increased risk for death from . 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. In some cases, the cat will develop a heart murmur associated with cardiomyopathy. Overall, weight gain was associated with development of hypothyroidism despite levothyroxine replacement . The radioactive iodine damages these cells and causes your thyroid to shrink and thyroid hormone levels to go down over a few weeks. Rarely, people can feel pain in their neck. Ultrasound of the heart (called echocardiography) may be recommended based on your cat's condition, especially if there is any concern about cardiomyopathy. These tests are needed to evaluate your cats overall health and predict the likelihood of complications with the chosen treatment protocol. 20.1301 Dose limits for individual members of the public. Jeff Brunette, CHP, Ask the Experts is posting answers using only SI (the International System of Units) in accordance with international practice. 6. The typical cat with hyperthyroidism is middle-aged or older; the average age of affected cats is approximately 12 years. The risks of ingesting radioactive iodine and the risks of being around a patient that has been treated with radioactive iodine are very different. There are virtually no side effects, and there is no pain associated with 131I treatment. This can best be done by monitoring your cats body condition, muscle condition, and weight. 7. 15(1): p. 47-51. . Aim: Analysis and follow up of body weight after radioiodine therapy (RITh) of hyperthyroidism, since excessive weight gain is a common complaint among these patients. Some people also feel flushed. Prominent in the regulations established by the Nuclear Regulatory Commission for radioactive materials users are guidelines that limit exposure to radiation workers, and members of the general public. Gradual weight gain and return to healthy body condition are expected. Already have a myVCA account? Affiliate of Mars Inc. 2023 | Copyright VCA Animal Hospitals all rights reserved. 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. Miles K.G., Simpson S.A., Zimmerman R.B., et al. All rights reserved. There are four treatment options for feline hyperthyroidism: medication, radioactive iodine therapy, surgery, and dietary therapy. Symptoms include weight loss, muscle wasting, increased appetite, increased thirst and urination, vomiting, unkempt appearance, and sometimes hyperactivity. . Did she have stage 1 prior to treatment for hyperthyroidism or did the stage 1 unmask after treatment started and then jump to stage 4? However, once the underlying hyperthyroidism has been controlled, the cardiac changes will often improve or may even resolve completely. This means that our radioactive materials license requires our practice ensure that our clients receive less than 1 mSv of radiation exposure as the result of our treatment of their hyperthyroid cat with radioiodine. Learn more about radioiodine therapy for hyperthyroidism, Learn about radioiodine therapy for thyroid carcinoma, Learn more aboutSamariumtherapy for primary or metastatic bone tumors. In almost all cases, your thyroid hormone levels will return to normal or below normal after radioactive iodine treatment. 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. A small number of cats will remain hyperthyroid after treatment, if this is the case your cat will need . Radioactive iodine (RAI) is a treatment method for hyperthyroidism and thyroid cancer. 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. 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. She gained and ate a lot and we were more than happy. Before treatment he was ravenous and losing weight -- typical of cats with that disorder I'm told. Try mixing baby food chicken or turkey in with some Fancy Feast. 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. The cell repairs itself with mistakes (rare). 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. However, since wild-caught flaked Alaskan salmon is the first ingredient, it provides a lot of moisture. 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. It is given one to three times daily and must be continued for the remainder of the pet's life. There are three common forms of treatment for hyperthyroidism in cats: medication, radioactive iodine therapy and surgery. That was part of the problem we had before treatment. Vet Rad & Ultrasound, 1994. I might even suggest using disposable gloves when handling the litter box duties and when caring for the cat during the isolation time. 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. You'll have to give him this drug twice daily for the rest of his life, which treats but doesn't cure the condition. 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. 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. But this generally resolves without intervention. When an injection of radioactive iodine is given, it destroys the abnormal thyroid tissue without endangering other organs. In some cats, anorexia develops as the disease progresses. Additionally, diet may play a significant role in managing the disease, whether as a sole treatment or as an adjunct tool to address changes in your cats body related to hyperthyroidism. People may take RAI . 4. Prior to the onset of symptoms he was eating a high quality dry cat food but when he started losing weight and begging for food we were told we could give him some baby food and wet cat food. A single injection is given subcutaneously (i.e. With your cat's diseased thyroid, after methimazole treatment failed, large doses of iodine might have proven effective. If this is accompanied by clinical signs such as lethargy, obesity, and poor hair coat, then thyroid hormone supplementation may be required. They may have increased water consumption and urination. 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. Cats also sweat through their paws and the sweat will have trace amounts of radioactive iodine. The advantages of radioactive iodine therapy are that the procedure most often cures hyperthyroidism, has no serious side effects, and does not require anesthesia. Your cat may be hospitalized for one to two nights following surgery and should begin to eat and behave normally after returning home. Many times the only symptoms these other conditions cause are weight loss. Many doctors recommend that women avoid becoming pregnant for 6 months to a year after treatment. Mean baseline age was 12.7 3.0 years and mean baseline BMI SDS was 0.003 1.18 kg/m 2. We love them, too! Survival Times for Cats with Hyperthyroidism Treated with Iodine 131, Methimazole, or Both, http://www.nrc.gov/reading-rm/doc-collections/cfr/part020/, Determination of Release Criteria for I-131 Therapy Cats, Risk of Ionizing Radiation Exposure to Children: A Subject Review, Hormesis: From Marginalization to Mainstream: A Case for Hormesis as the Default Dose-Response Model in Risk Assessment. For this long-term treatment, the cat is injected with the radioactive iodine, which destroys the tissue of the overactive thyroid gland. To date the studies following hyperthyroid cats treated with radioiodine have not shown any increased incidence of cancer (thyroid or other types) associated with radioiodine therapy. In some cases, a decrease in blood platelets (thrombocytopenia) may also occur. Montreal. 1. The cell repairs itself perfectly (most common result). The majority of cancers occur later in life and the average lifetime risk of dying from cancer is 25%. For example, some families cant medicate cats every day, so a more permanent solution such as radioactive iodine treatment or surgery may be best. 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. Now that I know my cat has hyperthyroidism, what do I do? Risks unrelated to radioiodine therapy: The 1-month level thyroid may be slightly high, low or normal. Iodine is an element normally taken up in large amounts by the thyroid gland, even more so in cats that are hyperthyroid. 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. 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. 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). About 25% of cats with hyperthyroidism become hypertensive. The "radiation badge" worn by x-ray techs for example is good for measuring external exposure to radiation but does nothing to measure intakes of radioactive materials which is the primary concern in the case of a cat treated with radioactive 131I. Over time, this progresses to increased blood pressure, severe weight loss, heart disease, blindness, and kidney damage. 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. Other than unexplained weight loss, your cat may also become more restless, hyperactive, vocal, and extremely hungry! Lack of appetite. 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. TheCatSite.com is a community of cat lovers dedicated to quality cat care and cat welfare. Although this procedure is usually very effective, it is more expensive and requires the cat being . ), family history (genetics) or radiation exposure. The chronic elevation of circulating thyroid hormone levels in cats with hyperthyroidism leads to changes in their heart muscle that predispose them to developing heart failure. Fewer than 2% of hyperthyroid cases in cats involve malignant thyroid gland tumors. Often, treating hyperthyroidism will unmask hidden kidney failure that will require additional care and is best detected early in the course of the disease. It is also common for hyperthyroid cats to exhibit increased vocalizing, particularly at night. Radioactive iodine therapy. The goal of hyperthyroidism treatment is to lower the levels of thyroid hormones in the body. I-131 therapy does not require anesthesia and eliminates the need for daily medication. 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. A seven hour airplane trip exposes passengers to 0.02 mSv of radiation, which is a fraction of the exposure of a standard Chest x-ray (0.1 mSv). In many cats, only one thyroid lobe is abnormal, so only one surgery is needed. Standards for Protection against Radiation. Prognosis The advantages of medication are that the drugs are readily available and relatively inexpensive. The effectiveness of this transdermal gel is acceptable in most cases. Before deciding the form of treatment, several tests are performed, including additional blood tests, a urinalysis, chest radiographs (X-rays), an ECG, and blood pressure measurements. If left untreated and unmanaged, these changes may eventually compromise the normal function of the heart and can even lead to heart failure. 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. This test can also help the doctor determine the cause of your hyperthyroidism and get other information about your 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. Cats also sweat through their paws and the sweat will have trace amounts of radioactive iodine. Although the thyroid gland enlarges in hyperthyroidism, it is usually a benign or non-malignant change. 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). Keeping your pets food temperature just right. If radioactive iodine therapy won't work for you and your cat, alternatives are available. Some cats develop side effects from methimazole, such as vomiting, lethargy, anorexia, fever, liver damage, anemia, and a decrease in white blood cells. After administration of 131 Iodine, your cat is . Prescription nutrition. The radioiodine (I-131) used to treat thyroid disease in people and animals emits both gamma rays and beta particles. Radioactive iodine therapy is a very effective way to treat hyperthyroidism (I-131). Radioiodine treatment avoids surgery, anesthesia, and anti-thyroid drugs. Did You Know? . 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. Clinical Signs The good news is that there are many treatment options available to our hyperthyroid cats. Consider Hyperthyroid Treatment . This problem resolved rapidly after treatment. Because of these rare but serious side effect risks, your cat will need to be closely monitored by having simple blood tests performed every three to six months when using this medication. 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 During treatment, radioactive iodine is administered as an injection and is quickly absorbed into the bloodstream. However, because your cat will be radioactive for several days after receiving the shot, precautions must be taken during and after the treatment. In some of these cats, blood pressure can become so high that retinal bleeding or retinal detachment will occur, resulting in sudden blindness. In some cases, complications involving other organs may worsen this prognosis. The clinical significance of weight gain from the time of diagnosis of hyperthyroidism to 2 years after radioactive iodine therapy is unclear. . Thyrotoxic cardiomyopathy may develop because the heart enlarges and thickens to meet the increased metabolic demands. 8. J Vet Intern Med, 2001. 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. Diagnosis Clients owning hyperthyroid cats undergoing radioiodine therapy are always considered members of the general public. Copyright 2023 Leaf Group Ltd. / Leaf Group Media, All Rights Reserved. The injection has no direct side effects. After initial stabilisation with oral medications, a number of curative treatments are also available. 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? Slater M.R., Komkov A., Robinson L.E., et al., Long-Term Follow-up of Hyperthyroid Cats Treated with Iodine-131. NRC Regulations 1 Radioactive iodine (RAI)] is generally considered the optimal treatment for hyperthyroidism in cats. Gained over three pounds! Affected cats produce too much thyroid hormone. Despite the extensive blood and urine tests, chest x-rays and physical exams that we require before radioiodine therapy, some of these conditions remain undiagnosed at the time of radioiodine therapy. In most cases, enlargement of thyroid glands is caused by a non-cancerous tumor called an adenoma. 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. By 14 days after treatment, the radioactivity will have decayed to a very low level. Usually this means that the cat will need to be hospitalized for between three and five days after treatment. If we restrict iodine, production of thyroxine decreases. 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. Hypocalcemia can be life-threatening and may require either short-term or long-term medication postoperatively should it occur. However, unless the retinal detachment is treated immediately, permanent blindness can occur. 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. Depending on the dose of radioactive iodine chosen, and the disease under treatment (Grave's vs toxic goitre, vs hot nodule etc), success rate in achieving definitive resolution of the hyperthyroidism . (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.") This helps us offset the costs of running this site, so thank you for your support! If your cat requires daily medications for issues other than hyperthyroidism, he's not a candidate for radioactive iodine therapy. Another significant risk for hyperthyroid cats is not actually related to their thyroid disease. 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. What is the biggest concern with nuclear meltdown and why? 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. 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. In a study of 524 hyperthyroid cats treated with I-131, only 11/524 (2.1%) developed Radioactive iodine treatment is a therapy that your veterinary surgeon may recommend if your cat is diagnosed with hyperthyroidism. It is also common for some cats to hide under the bed for a day or so after returning home as they de-stress following their out of home experience. Medication typically. These include weight loss, increased activity, and kitten like behaviour. And, if you destroy your thyroid gland, it turns out that that may have consequences on your metabolism. Of 247 patients receiving RAI for GD, 157 (79.6% female) had complete data and were included in the analysis. Many owners of cats with hyperthyroidism are hesitant to have radiation therapy or surgery because of their cat's advanced age. (8,9) Replacement hormone products currently on the market, both synthetic and glandular, are not comparable to our own hormone, and in some people, never feel "right". 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. During that time, the ravenous appetite should subside, your cat will probably gain weight, and her blood pressure and heart rate should normalize. To help your cat gain weight, you need to increase the protein and . 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. Ten patients (6.4%) had DS (Down Syndrome) and 33 (21.0%) had received ATDs before RAI ablation. GFR results are used to determine the functional status of the kidneys, and identify cats with subclinical renal disease. 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 are the risks of my cat becoming hypothyroid? In a cat treated with radioactive iodine, the drool will contain radioactive materials. These complications include cerebrovascular events (i.e., strokes) and the premature exacerbation of pre-existing kidney disease. What happens after radioactive iodine treatment for cats? A standard Chest x-ray is 0.1 mSv. How does airline travel expose me to radiation? Nearly all cats will be cured by a second treatment. All three have risks and benefits. 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. She's lost a pound in less than two weeks, so yeah, I'm glad I let her eat as much as she wanted. It is important to drink fluids after your treatment and for the next 2 days. However, an overactive thyroid is quite common. 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. Thus, pate is a better choice for your cat than gravy food due to the latter's higher . Natural background radiation exposure accounts for an average of 3.1 mSv/yr with variations depending on where you live. 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. Remember that theNRC regulationsrequire that release criteria and discharge instructions provided to owners of hyperthyroid cats prevent exposures of more than 1 mSv. A swollen or tender neck and feeling flushed. Hays M.T., Broome M.R. It does, however, involve the handling and injection of a radioactive substance that is only permitted at facilities specially licensed to use radioisotopes. While the treatment is fairly expensive, over the long term it could be cheaper than medication and is on a par with surgical treatment. Therefore, by using the veterinary therapeutic diet that is currently available and restricted in iodine (the only source the body has of iodine) this will prevent the thyroid from making thyroid hormone. Lifelong treatment, usually involving twice-daily oral dosage, will be required, and for some owners and cats, this dosage schedule may be difficult to maintain. Weigh the pros and cons of various treatments and discuss options with your vet. 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). There are several hypothesized causes of hyperthyroidism. Radioactive Iodine Therapy Medications for hyperthyroidism in cats are prescribed on a case by case basis. 2 The goal of RAI treatment is to restore euthyroidism while avoiding the development of hypothyroidism. This single treatment will cure 95-98% of cats. About TheCatSite.com. There are no studies that directly link cancer to the low dose radiation used in current medical imaging. Unfortunately these cats may continue to deteriorate and may even die from their other non-thyroid diseases. As to your question about "home-testing equipment" and "something else to monitor and determine (your) exposure," there really are no good options for that. Many organs are affected by hyperthyroidism, especially the heart. This information is not a substitute for a vets opinion. Radioactive iodine therapy is becoming the treatment of choice for felines with hyperthyroidism. Wet food is much better for him anyhow, so this is a good time to get him settled on it. Companion Animal Hospital in Ithaca, NY for cats, dogs, exotics, and wildlife, Equine and Nemo Farm Animal Hospitals in Ithaca, NY for horses and farm animals, Cornell Ruffian Equine Specialists, on Long Island for every horse, Ambulatory and Production Medicine for service on farms within 30 miles of Ithaca, NY, Animal Health Diagnostic Center New York State Veterinary Diagnostic Laboratory, Cornell University College of Veterinary Medicine Ithaca, New York 14853-6401. 2004. Until then, the radiation safety guidelines of Michigan and the NCR are followed. What is not taken up by the thyroid will be present in the cat's bodily fluids and will primarily be voided in the cat's urine (in those first four days at the vet hospital). Radioactive iodine targets the thyroid tissue - as this is the only tissue in the body that uses significant quantities of iodine. Prior to the onset of symptoms he was eating a high quality dry cat food but when he started losing weight and begging for food we were told we could . Rarely, a permanent reduction in thyroid-hormone levels called hypothyroidism occurs after radioactive iodine treatment. Cats treated with radioactive iodine for their hyperthyroidism have several risks unrelated to the radioiodine therapy itself. How can the age of a material be determined from the decay of a radioactive element quizlet? However, the risk is minimal if your cat is otherwise healthy, and the initial diagnostic tests and treatment did not reveal any underlying conditions. This cat is showing weight loss and poor coat - typical signs of hyperthyroidism. This usually leads to permanent destruction of the thyroid, which will cure hyperthyroidism. Risks unrelated to radioiodine therapy: Cats treated with radioactive iodine for their hyperthyroidism have several risks unrelated to the radioiodine therapy itself. Hyperthyroidism, or an overactive thyroid, is a common disease of older cats. Radioactive iodine therapy. Long-Term Health and Predictors of Survival for Hyperthyroid Cats Treated with Iodine 131. Hopefully this answers your questions and good luck with your cat. 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. 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. For this reason, some cats with hyperthyroidism may require additional treatment to control secondary heart disease. If thyroid disease is a possibility, your veterinarian will likely order a blood chemistry panel and an analysis of thyroid hormone levels. However, caution should be taken in disposal of products that may contain trace amounts of this radioactive substance. For a better experience, please enable JavaScript in your browser before proceeding. Side effects may include fluid retention, weight gain, elevated . The thyroid takes up the radioactive iodine, which destroys cells in the thyroid. Follow up blood work is essential to ensure kitty does not become hypothyroid which is too little thyroid.