Methimazole is also given before surgery to determine if the cat has a secondary medical condition, such as kidney or liver disease masked by hyperthyroidism.
Hypocalcemia can be life-threatening and may require either short-term or long-term medication postoperatively should it occur. If your cat does not have elevated T4 levels but your veterinarian still suspects your cat has hyperthyroidism, additional tests may be recommended. This is due to increased stimulation in the nervous system which is a common occurrence in cats with feline hyperthyroidism. Many organs are affected by hyperthyroidism, especially the heart. However, unless the retinal detachment is treated immediately, permanent blindness can occur. 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. . Discuss these issues with your veterinarian when considering dietary iodine restriction as a treatment for hyperthyroidism in cats. It will take about a month for thyroid levels to return to normal in most cats. The 1-month level thyroid may be slightly high, low or normal. Of course, some people receive no radiation and others much, much more. Ten patients (6.4%) had DS (Down Syndrome) and 33 (21.0%) had received ATDs before RAI ablation. People may take RAI . A swollen or tender neck and feeling flushed. Radioactive iodine therapy is curative within three months of therapy in approximately 95 percent of all hyperthyroid cases. Most of the extra radioactive iodine is eliminated in your urine. An anti-thyroid medication, like methimazole. Title 10, Code of Federal Regulations Subscribe to always know when we add new material! In cats, an underactive thyroid is extremely rare. 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. It requires two round-trips for you. 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. 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. If this is accompanied by clinical signs such as lethargy, obesity, and poor hair coat, then thyroid hormone supplementation may be required. Medication Research into this potential treatment option is ongoing. Answer posted on 30 March 2019. 1. The food isnotmedicated. The clinical significance of weight gain from the time of diagnosis of hyperthyroidism to 2 years after radioactive iodine therapy is unclear. Giving him medication once or twice a day isn't an option, although if it's a medication that can be mixed in with his food, it's something you could discuss with the veterinary staff at the facility. Hyperthyroidismis characterized by the overproduction of thyroid hormone and a subsequent increase in metabolic rate. Subscribe to always know when we add new material! These medications do not provide a cure for the disease, but they do allow either short-term or long-term control of hyperthyroidism. Because of strict treatment guidelines, most facilities will not allow visitors during this quarantine period. 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. At 1 and 3 months after the treatment, a blood test for thyroid and kidney function should be done by your veterinarian. Environmental risk factors have been investigated and may predispose some cats to hyperthyroidism, although the specific mechanisms are unknown. Because metabolism is altered in hyperthyroidism, its important to monitor your cats weight and muscle mass.
To the best of our knowledge, answers are correct at the time they are posted. . The information provided is not a substitute for professional advice and should not be relied upon in the absence of such professional advice. Risks unrelated to radioiodine therapy: But there are clear reasons for the precautions that the veterinarian has given you and I also recommend that you follow them. Surgical removal of the gland under general anesthetic was another option. 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. Hyperthyroidism is a common disease in cats, and mostly afflicts cats middle-aged and older. Of 247 patients receiving RAI for GD, 157 (79.6% female) had complete data and were included in the analysis. The other conditions that cats can develop at this age are numerous and varied. . The remainder is gone in about the next two months or so. Cats exclusively fed the prescription diet will remain normal, but if the diet is discontinued, they will once again become hyperthyroid. Long-Term Follow-up of Hyperthyroid Cats Treated with Iodine-131. Until then, the radiation safety guidelines of Michigan and the NCR are followed. radioactive iodine All three treatments will reduce thyroid hormone levels and the signs of hyperthyroidism. The medication can be given life-long or to stabilize the cat before other treatment. Weight seemed to stabilize in the long-term setting, with minimal increases between 8 and 12 months and at 24 months after radioactive iodine treatment. The coat of affected cats may appear unkempt, matted, or greasy (see Figure 1). Cats with hyperthyroidism exhibit symptoms that are similar to those of humans with the disease: weight loss, increased appetite, excessive . I-131 therapy does not require anesthesia and eliminates the need for daily medication. 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%). The injection has no direct side effects. You may also be advised to suck on sour candy after treatment to help the radioactive iodine come out in your saliva. Some cats develop side effects from methimazole, such as vomiting, lethargy, anorexia, fever, liver damage, anemia, and a decrease in white blood cells. Regardless of radiation exposure, the average overall lifetime risk of developing an invasive cancer is 37.5% for women and 44.9% for men. If left untreated and unmanaged, these changes may eventually compromise the normal function of the heart and can even lead to heart failure. The treatment options for hyperthyroidism are: Oral medication. All bodily fluids in the cat will have trace amounts of radioactive material within them, but it will be most prevalent within the urine. Radioactive iodine therapy offers a cure through a simple injection that returns thyroid function to normal levels. 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 word "individuals" in this context means "people". Why is the average risk of developing cancer so high? The thyroid takes up the radioactive iodine, which destroys cells in the thyroid. She gained and ate a lot and we were more than happy. 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. If your cat is showing signs of illness or depression, please contact PVESC. Since platelets are essential for blood clotting, thrombocytopenia may lead to problems with excessive bleeding. For the same reasons as surgical treatment, your cat will likely be started on methimazole for about a month before radioactive iodine therapy. The required dose of methimazole can change over time, so monitoring thyroid levels in treated animals is recommended every 3-6 months once their condition is stable. 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. 3. It might not be an option for a frail cat who shouldn't undergo anesthesia. It is given one to three times daily and must be continued for the remainder of the pet's life. Learn more about radioiodine therapy for hyperthyroidism, Learn about radioiodine therapy for thyroid carcinoma, Learn more aboutSamariumtherapy for primary or metastatic bone tumors. All rights reserved. If hypertension is diagnosed along with hyperthyroidism, drugs may be needed to control the blood pressure and reduce the risk of damaging other organs. As a cat owner, I completely understand your desire to get your cat back to his normal routine as soon as possible. It has the advantage of being curative in most cases with no ongoing treatment. Many older cats with overactive thyroids have actual enlargement of the gland which can be felt in the neck by your veterinarian. Radioactive iodine therapy. A single injection is given subcutaneously (i.e. If radioactive iodine therapy won't work for you and your cat, alternatives are available. More specific information on what to expect when your cat is treated with radioactive-iodine therapy at Cornell can be found here. Their hyperthyroidism won't come back, and they don't need ongoing medication. Thank you! 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. Until then, the radiation safety guidelines of Michigan and the NCR are followed. J Vet Intern Med, 2001. TheCatSite.com is a community of cat lovers dedicated to quality cat care and cat welfare. Many doctors recommend that women avoid becoming pregnant for 6 months to a year after treatment. 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? 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? . A small number of cats will remain hyperthyroid after treatment, if this is the case your cat will need . 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. 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. Def scared about this possibility with Fluff, Our cat was treated for hyperthyroidism and has been back home for about two weeks. The cell dies (only occurs with very high doses). You should talk with your veterinarian about what diets may be best for him in this case. 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. 6. 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. Medications for hyperthyroidism in cats are prescribed on a case by case basis. 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. If the total GFR is below this number, medical therapy for hyperthyroidism may be recommended, although I-131 treatment may still be an option in specific patients. The average age of cats with hyperthyroidism is approximately 12 years and about 5% of hyperthyroid cats are younger than 10 years of age. With your cat's diseased thyroid, after methimazole treatment failed, large doses of iodine might have proven effective. Follow up blood work is essential to ensure kitty does not become hypothyroid which is too little thyroid. The American Thyroid Association notes that weight gain develops over a long time and may have many causes other than the underactive thyroid. She has a Bachelor of Arts in English from New York University and an Associate of Arts from the American Academy of Dramatics Arts, New York City. If methimazole dosing is discontinued, hyperthyroidism will return. It is used less commonly in younger children. In the hospital (or veterinary hospitals) we would use a Geiger counter with a thin-window probe to find the radioactive contamination. 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. Get exceptional Radioactive Iodine Therapy for Feline Hyperthyroidism services from highly experienced & loving pet care professionals in Downers Grove, IL. Many times the only symptoms these other conditions cause are weight loss. If you know that your cat has hyperthyroidism, you probably have already seen your vet in order to have this disease properly treated. Radioactive iodine therapy. For some cats, a veterinary therapeutic diet low in iodine may be all thats required to control symptoms. Scaly skin. Because of the important role the thyroid gland plays in the body, some cats with hyperthyroidism develop secondary problems, including heart disease and high blood pressure. Did You Know? There are no studies that directly link cancer to the low dose radiation used in current medical imaging. Your cat will not experience nausea, hair loss, lethargy, or decreased appetite as a result of the procedure. The anti-thyroid pill is methimazole, also known as Tapazole. DNA can also be damaged directly by radiation. Chance of significant, unhealthy weight gain is increased. Hyperthyroidism, or an overactive thyroid, is a common disease of older cats. 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. In a cat treated with radioactive iodine, the drool will contain radioactive materials. What happens after my cat is released from the hospital? Treatment for hypothyroidism in cats is . 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. As stated above, it may also be used for a few weeks to stabilize a cat at increased surgical risk because of cardiac complications. Radioactive iodine therapy offers a cure through a simple injection that returns thyroid function to normal levels. 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). 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). Clients owning hyperthyroid cats undergoing radioiodine therapy are always considered members of the general public. They may have increased water consumption and urination. 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. 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. 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. JavaScript is disabled. Dry, dull coat. Radioactive iodine treatment is a therapy that your veterinary surgeon may recommend if your cat is diagnosed with hyperthyroidism. During that time, the ravenous appetite should subside, your cat will probably gain weight, and her blood pressure and heart rate should normalize. The only method to estimate that dose is to measure the radioiodine within your own thyroid and the types of equipment to measure that uptake are very expensive and difficult to interpret. There are three common forms of treatment for hyperthyroidism in cats: medication, radioactive iodine therapy and surgery. Ultrasound of the heart (called echocardiography) may be recommended based on your cat's condition, especially if there is any concern about cardiomyopathy. Note that the reference above excluding licensee's from considering "exposure to individuals administered radioactive material" in their compliance with the NRC regulartions does not apply to animals. 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. 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. By
Signs of anxiety in a cat including pacing, yowling for no apparent reason, and restlessness are a common symptom of feline hyperthyroidism. While the treatment is fairly expensive, over the long term it could be cheaper than medication and is on a par with surgical treatment. The cats heart rate and blood pressure may also be checked. Now let's deal with the issue of radioactive iodine released by the cat, which I believe is actually the bigger concern. Your veterinarian's instructions regarding separation for the two weeks are simply doing the same thing we do with people. Currently, there's only one FDA approved medication to treat feline hyperthyroidism called methimazole. The brand name of methimazole is called Felimazole. The dosage may vary but typically a cat is given this oral medication twice a day, every 12 hours. . The first step is determining the blood level of one of the thyroid hormones calledtotal thyroxine (TT4). This lowers the amount of radiation exposure to your bladder. 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. Lack of appetite. Gradual weight gain and return to healthy body condition are expected. This cat is showing weight loss and poor coat - typical signs of hyperthyroidism. Hyperthyroidism is a common condition in older cats because of an excess of circulating thyroid hormone, called thyroxine. The thyroid gland, located in the neck, is responsible for the bodys metabolism. The radioiodine (I-131) used to treat thyroid disease in people and animals emits both gamma rays and beta particles. Recurrence of hyperthyroidism is rare after I-131 therapy. This I131 injection accumulates in the abnormal thyroid tissue, and the radioactivity kills the abnormal tissue without harming other vital structures nearby.