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. This is due to increased stimulation in the nervous system which is a common occurrence in cats with feline hyperthyroidism. If left untreated and unmanaged, these changes may eventually compromise the normal function of the heart and can even lead to heart failure. However, once the underlying hyperthyroidism has been controlled, the cardiac changes will often improve or may even resolve completely. Employees of facilities that utilize radioactive materials may be categorized as "radiation workers" depending on their role. By 14 days after treatment, the radioactivity will have decayed to a very low level. Subscribe to always know when we add new material! Rarely, people can feel pain in their neck. It is acceptable to feed your feline products containing at least 30% protein and less than 15% carbohydrates. Of course some cats treated with radioiodine for their hyperthyroidism will go on to get cancer, but in the same proportion as hyperthyroid cats treated with methimazole or surgery. At 1 and 3 months after the treatment, a blood test for thyroid and kidney function should be done by your veterinarian. In most cases, enlargement of thyroid glands is caused by a non-cancerous tumor called an adenoma. Facilities that use radioactive materials like I-131 must have radioactive materials licenses. Surgery will be performed if your cat successfully undergoes the initial treatment without complication. Of 247 patients receiving RAI for GD, 157 (79.6% female) had complete data and were included in the analysis. AAFCO Doesnt Approve Pet Foods, A broken heart: Risk of heart disease in boutique or grain-free diets and exotic ingredients, Its Not Just Grain-Free: An Update on Diet-Associated Dilated Cardiomyopathy. These include weight loss, increased activity, and kitten like behaviour. To convert these to traditional units we have prepared a. 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. The current Nuclear Regulatory Commission radiation dose limits for individual members of the public are listed below.
Diagnosis of feline hyperthyroidism is generally straightforward. . Vet Rad & Ultrasound, 1994. This disease is common in older cats. Hopefully this answers your questions and good luck with your cat. If your cat is showing signs of illness or depression, please contact PVESC. If DNA is damaged, there are three possible outcomes: Now that he's back home, he still exhibits the behavior of wanting food all the time but I wonder if it's a habit he picked up before treatment or perhaps the symptoms won't completely gone away until the treatment has time to take hold. The prognosis for cats with hyperthyroidism is generally good with appropriate therapy.
Annual blood and urine tests are important in all cats seven years and older to detect hyperthyroidism before potentially irreversible damage occurs. He also can't sleep with you during that time, and the facility will inform you about special arrangements you'll have to make for disposing of his litter. When a radioactive form of iodine is given to hyperthyroid cats, the radiation destroys a portion of the thyroid gland. 2 The goal of RAI treatment is to restore euthyroidism while avoiding the development of hypothyroidism. Treating Hyperthyroidism in Cats. A swollen or tender neck and feeling flushed. Radioactive-iodine therapy is becoming increasingly popular when dealing with hyperthyroidism in cats. Although the thyroid gland enlarges in hyperthyroidism, it is usually a benign or non-malignant change. Surgical removal of the affected thyroid gland(s) may be very effective. 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. She has spoken at national and international conferences and a Capitol Hillbriefing, and is an expert in pet obesity, nutrition communication, and in the human-animal bond. Some places realize that the stress of being away from home for so long is not good for older cats. For the first two weeks after I-131: Keep your cat indoors or supervised when outside to prevent contact with other people. 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. In the US, the average person is exposed to an additional 3.0 mSv/yr from medical sources (predominantly CT scans). Some cats develop side effects from methimazole, such as vomiting, lethargy, anorexia, fever, liver damage, anemia, and a decrease in white blood cells. This single treatment will cure 95-98% of cats. 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. To the best of our knowledge, answers are correct at the time they are posted. J Vet Intern Med, 2001. Subscribe to always know when we add new material! Radioactive iodine may also affect a woman's ovaries, and some women may have irregular periods for up to a year after treatment. Recurrence of the disease is a possibility in some cats. In cases where radioactive iodine therapy is not successful, the treatment can be repeated. As stated above, it may also be used for a few weeks to stabilize a cat at increased surgical risk because of cardiac complications. However, because your cat will be radioactive for several days after receiving the shot, precautions must be taken during and after the 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. The radioactive iodine damages these cells and causes your thyroid to shrink and thyroid hormone levels to go down over a few weeks. What may work for one cat may not work for another. I-131 therapy does not require anesthesia and eliminates the need for daily medication. Older cats are at greater risk for developing hyperthyroidism. It is important to drink fluids after your treatment and for the next 2 days. Weight change was analyzed in only 228 patients and 84% gained weight by 1 year after radioactive iodine therapy. The routine stay in our radioactive iodine unit is currently 12 days. Hyperthyroidism may also cause vomiting, diarrhea, and hyperactivity. 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. Is radioactive iodine treatment safe? Nearly all cats will be cured by a second treatment. They may develop periodic vomiting or diarrhea, and fur may appear unkempt. This test can also help the doctor determine the cause of your hyperthyroidism and get other information about your thyroid tissue. Research into this potential treatment option is ongoing. During that time, the ravenous appetite should subside, your cat will probably gain weight, and her blood pressure and heart rate should normalize. The injection has no direct side effects. Radioactive iodine (I-131) is a very safe and effective treatment for hyperthyroidism. Before treatment he was ravenous and losing weight -- typical of cats with that disorder I'm told. It is also common for hyperthyroid cats to exhibit increased vocalizing, particularly at night. The cell repairs itself perfectly (most common result). More specific information on what to expect when your cat is treated with radioactive-iodine therapy at Cornell can be found here. The School of Veterinary Medicine's Ryan Hospital, however, is one of the few veterinary centers in the region to offer a treatment that can cure the disease: a single shot of radioactive iodine, I-131. 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. 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. This can be accomplished in several ways: Radioactive iodine therapy. It is actually the best approach to take to minimize exposures to you and your family while allowing the cat to have post-treatment recovery time at home and not in a veterinary hospital. About 25% of cats with hyperthyroidism become hypertensive. They will then need to take a thyroid supplement. In some cats, anorexia develops as the disease progresses. Fewer than 2% of hyperthyroid cases in cats involve malignant thyroid gland tumors. Most cats with uncomplicated hyperthyroidism will live several years following treatment of hyperthyroidism, unless they develop another disease. You can't visit Fluffy during his stay at the veterinary facility. Certain studies suggest that in some hyperthyroid cats, limiting the amount of iodine in the diet may be a viable option for treating this disease. It has to do with how important your thyroid is in regulating your metabolism and your weight. 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. 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 effectiveness of this transdermal gel is acceptable in most cases. Oftentimes it takes decades for cancer to be detected following radiation exposure. Also called thyrotoxicosis, hyperthyroidism is caused by an increase in production of thyroid hormones (known as T3 and T4) from an enlarged thyroid gland in a cats neck. The principle advantage of Radioactive Iodine treatment for hyperthyroidism is that it tends to have a much higher success rate than medications. The good news is that virtually every client will already take steps to avoid this, even when radioactive iodine in their cat's urine is not the motivation. 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. However, unless the retinal detachment is treated immediately, permanent blindness can occur. An anti-thyroid medication, like methimazole. It will take about a month for thyroid levels to return to normal in most cats. 8. . Although this procedure is usually very effective, it is more expensive and requires the cat being . Medications for hyperthyroidism in cats are prescribed on a case by case basis. The study followed people for 26 years after two or more treatments. 4. 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. There are no studies that directly link cancer to the low dose radiation used in current medical imaging. Number of cases per 100,000 persons exposed to a single dose of 0.1 Gy. NRC Regulations The risks of ingesting radioactive iodine and the risks of being around a patient that has been treated with radioactive iodine are very different. Subpart D-Radiation Dose Limits for Individual Members of the Public Too cold? Copyright 2019 Advanced Veterinary Medical Imaging. TheCatSite.com is a community of cat lovers dedicated to quality cat care and cat welfare. Secondary Problems The cell repairs itself with mistakes (rare). 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. Not all veterinary facilities perform the procedure. The more common symptoms are an increase in thirst, urination, and appetite, as well as weight loss. Iodine is an element normally taken up in large amounts by the thyroid gland, even more so in cats that are hyperthyroid. Because the thyroid needs iodine to produce hormones, the thyroid takes the radioiodine into the thyroid cells and the radiation destroys the overactive thyroid cells over time. The radioactive iodine is administered as a single injection . Want to read more information on feeding your pet? If the disease involves both lobes of the thyroid gland, two surgeries may be required, depending on the surgeon's choice of procedures. 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. How does airline travel expose me to radiation? 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. Blog written by Dr. Daisy Spears in conjunction with Dr. Linder. The radioiodine is eliminated in urine and feces. Medication typically. If thyroid disease is a possibility, your veterinarian will likely order a blood chemistry panel and an analysis of thyroid hormone levels. Weight gain after RAI is typical. (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.) For a better experience, please enable JavaScript in your browser before proceeding. Treatment for Hypothyroidism in Cats. But this generally resolves without intervention. 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. Mean baseline age was 12.7 3.0 years and mean baseline BMI SDS was 0.003 1.18 kg/m 2. They were randomized into 2 groups for continuous antithyroid and radioiodine treatment. Also, you might get some good ideas about what to feed him on Dr. Lisa Pierson's web site. Natural background radiation exposure accounts for an average of 3.1 mSv/yr with variations depending on where you live. All three have risks and benefits. (a) Each licensee shall conduct operations so that -. . 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. A medication called methimazole, which interferes with thyroid hormone production, is less expensive but requires daily administration. Most hyperthyroid cats respond fully to a single injection with radio-iodine. Until then, the radiation safety guidelines of Michigan and the NCR are followed. 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. But there are clear reasons for the precautions that the veterinarian has given you and I also recommend that you follow them. 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 an effort to put some weight back on him we are still feeding him turkey and gravy baby food in the morning to supplement the dry food. Cats also sweat through their paws and the sweat will have trace amounts of radioactive iodine. This helps us offset the costs of running this site, so thank you for your support! Occasionally cats will act like they may have a sore throat for a couple of days after the radioiodine therapy. Because of strict treatment guidelines, most facilities will not allow visitors during this quarantine period. Signs of anxiety in a cat including pacing, yowling for no apparent reason, and restlessness are a common symptom of feline hyperthyroidism. No ill effects have been noted in the children born to parents who received radioactive iodine in the past. What Treats Can I Give my Dog with CalciumOxalateStones? I have a cat also and I know when she is happy and purring while sitting on my lap getting strokes, she drools. 5. However, your cat will still have a low amount of radiation in his or her body. Rarely, a permanent reduction in thyroid-hormone levels called hypothyroidism occurs 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. Hypertension, or high blood pressure, is another potential complication of hyperthyroidism, and can cause additional damage to several organs, including the eyes, kidneys, heart, and brain. 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. For this reason, some cats with hyperthyroidism may require additional treatment to control secondary heart disease. 1 Radioactive iodine (RAI)] is generally considered the optimal treatment for hyperthyroidism in cats.
Other than unexplained weight loss, your cat may also become more restless, hyperactive, vocal, and extremely hungry! The clinical significance of weight gain from the time of diagnosis of hyperthyroidism to 2 years after radioactive iodine therapy is unclear. 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. Until then, the radiation safety guidelines of Michigan and the NCR are followed. Several complications of hyperthyroidism can be significant, includinghypertension(high blood pressure) and a heart disease called thyrotoxic cardiomyopathy. 15(1): p. 47-51. 1. Generally, about 5 to 10 pounds of excess weight can likely be attributed to the lack of thyroid hormones that occurs in people diagnosed with hypothyroidism. 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? The risks associated with low level ingestion of radioactive iodine relate to an increased risk of developing thyroid cancer. However, it may not be the best treatment for your particular cat. For comparison, the dose for a standard Chest CT is 7 mSv. The majority of cancers occur later in life and the average lifetime risk of dying from cancer is 25%. The medication can be given life-long or to stabilize the cat before other treatment. Cats can receive a second treatment, if necessary. For this long-term treatment, the cat is injected with the radioactive iodine, which destroys the tissue of the overactive thyroid gland. Treatment usually includes an adjustment to your cat's diet, medication, radioactive iodine therapy, or surgery. What Are The Side Effects Of Radioactive Iodine Treatment In Cats? Depending on the dose, radioactive iodine can kill a portion, or all, of your thyroid. 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. Hyperthyroidism is a common disease in cats, and mostly afflicts cats middle-aged and older. Surgical removal of the gland under general anesthetic was another option. You may feel a lump on your cat's throat under his jaw. The remainder is gone in about the next two months or so. 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. Answers are the professional opinions of the expert responding to each question; they do not necessarily represent the position of the Health Physics Society. One study looked at patients with Graves' disease who were treated with RAI over five years. You should use the following methods for disposing of your cat's waste that may contain trace amounts of radiation. During treatment, radioactive iodine is administered as an injection and is quickly absorbed into the bloodstream. Overall, weight gain was associated with development of hypothyroidism despite levothyroxine replacement . Unfortunately these cats may continue to deteriorate and may even die from their other non-thyroid diseases. And, if you destroy your thyroid gland, it turns out that that may have consequences on your metabolism. Although it has a slightly higher iodine content than the previous option, Tiki Cat Hanalei Luau Wild Salmon is the best value for money. Why isn't there a study directly linking medical imaging and cancer? Design and methods: Five hundred and four patients over 40 years of age with diffuse toxic goiter were treated with MMI for 18 months. . Now that I know my cat has hyperthyroidism, what do I do? Surgery. The anti-thyroid pill is methimazole, also known as Tapazole. This isnotan iodine-free diet but a diet with a controlled iodine content of 0.2ppma minimal amount. 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. Only about 5% of hyperthyroid cats are younger than 10. 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. Part 20, Standards for protection against radiation 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. Prognosis 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. In many cats, only one thyroid lobe is abnormal, so only one surgery is needed. 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). Anti-thyroid drugs act by reducing the production and release of thyroid hormone from the thyroid gland. With your cat's diseased thyroid, after methimazole treatment failed, large doses of iodine might have proven effective. Your cat will not experience nausea, hair loss, lethargy, or decreased appetite as a result of the procedure. Radioactive iodine (RAI) is a treatment method for hyperthyroidism and thyroid cancer. In cats, an underactive thyroid is extremely rare. What happens after my cat is released from the hospital? Feeding an iodine-limited diet (Hills Prescription Diet y/d) can resolve clinical signs and lower thyroid hormone concentration. The advantages of medication are that the drugs are readily available and relatively inexpensive. . The typical cat with hyperthyroidism is middle-aged or older; the average age of affected cats is approximately 12 years. Purraise. The good news is that there are many treatment options available to our hyperthyroid cats. Environmental risk factors have been investigated and may predispose some cats to hyperthyroidism, although the specific mechanisms are unknown. A standard Chest x-ray is 0.1 mSv. Thyroid scintigraphy may also be recommended to confirm a diagnosis and determine the size of the organ before surgery or radioactive iodine.