Radioactive iodine (I-131) is a very safe and effective treatment for hyperthyroidism. 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. Gained over three pounds! People may take RAI . Cats havetwo thyroid glands in the neck that are vital in regulating the body's metabolic rate. The medication can be given life-long or to stabilize the cat before other treatment. Thus, pate is a better choice for your cat than gravy food due to the latter's higher . Some cats may experience side effects from medication, however, including vomiting, anorexia, fever, anemia, and lethargy. However, once the underlying hyperthyroidism has been controlled, the cardiac changes will often improve or may even resolve completely. Most of the extra radioactive iodine is eliminated in your urine. Other than unexplained weight loss, your cat may also become more restless, hyperactive, vocal, and extremely hungry! 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. If left untreated, a hyperthyroid cat can exhibit many, if not all, of the following signs: extreme weight loss, excessive appetite in most cases, but decreased appetite in some, muscle weakness, heart disease (increase in the size of the heart, increased rate, changes in heart rhythm, cardiac arrest), intolerance to stress, and eventually death. Slater M.R., Geller S. and Rogers K., Long-Term Health and Predictors of Survival for Hyperthyroid Cats Treated with Iodine 131. These positive ions, or free radicals, can cause damage to DNA. 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. The injection has no direct side effects. 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. . My pet has kidney disease what kind of diet should I feed. Risks from other illness. You can't visit Fluffy during his stay at the veterinary facility. To answer these questions we have to separate the risks associated with internalizing (i.e., ingesting) radioactive iodine from the risks of being around a patient that has been treated with radioactive iodine. Diagnosis of feline hyperthyroidism is generally straightforward. 20.1301 Dose limits for individual members of the public. Hypertension develops due to the increased pumping pressure and elevated heart rate that occurs with hyperthyroidism. 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? 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. Studies show that weight gain is inevitable after radioiodine-induced hypothyroidism. Surgery will be performed if your cat successfully undergoes the initial treatment without complication. Clinical signs include lethargy, dullness, obesity, oily skin, and matted fur. The cell repairs itself perfectly (most common result). At the time of discharge, exposure levels measured at 6 feet from the patient are virtually indistinguishable from background levels. As stated above, it may also be used for a few weeks to stabilize a cat at increased surgical risk because of cardiac complications. . Is radioactive iodine treatment safe? Rarely, people can feel pain in their neck. At 1 and 3 months after the treatment, a blood test for thyroid and kidney function should be done by your veterinarian. In almost all cases, your thyroid hormone levels will return to normal or below normal after radioactive iodine treatment. Thyroidectomy (largely replaced by radioactive iodine . Depending on the dose, radioactive iodine can kill a portion, or all, of your thyroid. Hence people who's hyperthyroid cats are treated with radioiodine would be expected to have a potentially increased risk of developing cancer over the remainder of their lifetime as the result of that exposure of no more than 1/100th of 1 percent. The prognosis for cats with hyperthyroidism is generally good with appropriate therapy. In most cases, only enough radioiodine is given to destroy that part of the gland that is functioning . Clients frequently have the following 2 questions when considering radioiodine therapy for their cat's hyperthyroidism. Dietary restriction of iodine is, however, somewhat controversial because of concerns about the effects of long-term iodine restriction on overall health and the possibility that such a diet may actually backfire and worsen hyperthyroidism. If surgery is the chosen treatment method, the anti-thyroid medication methimazole (Tapazole, Felimazole) may be prescribed for several weeks before the operation. Lifelong administration of methimazole can control the effects of an overactive thyroid gland. Cats are homed in our spacious, purpose-built radioactive iodine unit and cared for by our dedicated team of radioiodine nurses. A Multicompartmental Model for Iodide, Thyroxine, and Triiodothyronine Metabolism in Normal and Spontaneously Hyperthyroid Cats. Some cats develop side effects from methimazole, such as vomiting, lethargy, anorexia, fever, liver damage, anemia, and a decrease in white blood cells. and Turrel J.M., A Multicompartmental Model for Iodide, Thyroxine, and Triiodothyronine Metabolism in Normal and Spontaneously Hyperthyroid Cats. These complications include cerebrovascular events (i.e., strokes) and the premature exacerbation of pre-existing kidney disease. After treatment, the normal thyroid tissue will regain full function within 1-3 months. The majority of cancers occur later in life and the average lifetime risk of dying from cancer is 25%. 1. Several complications of hyperthyroidism can be significant, includinghypertension(high blood pressure) and a heart disease called thyrotoxic cardiomyopathy. Even after treatment it may take a long time to reverse weight loss and muscle loss that occurred before your cat's diagnosis. Keeping your pets food temperature just right. A swollen or tender neck and feeling flushed. 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. Overall, weight gain was associated with development of hypothyroidism despite levothyroxine replacement . I have a cat also and I know when she is happy and purring while sitting on my lap getting strokes, she drools. The radioiodine is eliminated in urine and feces. In a study of 524 hyperthyroid cats treated with I-131, only 11/524 (2.1%) developed Treatment for hypothyroidism in cats is . The anti-thyroid pill is methimazole, also known as Tapazole. Environmental risk factors have been investigated and may predispose some cats to hyperthyroidism, although the specific mechanisms are unknown. Annual blood and urine tests are important in all cats seven years and older to detect hyperthyroidism before potentially irreversible damage occurs. He rejected the Fancy Feast stuff and gobbled the baby food along with eating a little variety of the many dry foods we tried in an effort to find one that he really liked. 1. Recurrence of hyperthyroidism is rare after I-131 therapy. 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. 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. Since you'll have to leave your cat at the facility for several days or more, it's not a question of dropping him off at a distant veterinary hospital and then picking him up the next day. 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. Long-Term Follow-up of Hyperthyroid Cats Treated with Iodine-131. The iodine is taken into the thyroid gland and incorporated into thyroxine. 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. To the best of our knowledge, answers are correct at the time they are posted. By 14 days after treatment, the radioactivity will have decayed to a very low level. The radioiodine (I-131) used to treat thyroid disease in people and animals emits both gamma rays and beta particles. Cornell University College of Veterinary Medicine, Cornell Ruffian Equine Specialists, on Long Island, Cornell Veterinary Experts Address Feline Nutrition. Thyroid hormones affect nearly all of the organs in the body; therefore, thyroid disease often causes secondary problems. For comparison, the dose for a standard Chest CT is 7 mSv. Clients owning hyperthyroid cats undergoing radioiodine therapy are always considered members of the general public. Now the question is what risk does one obtain from receiving an exposure of 1 mSv? The treatment a cat receives for hyperthyroidism will depend on specific circumstances, including the patients overall health status, the owners ability and willingness to medicate the cat regularly, and financial considerations. 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. 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. Hyperthyroidismis characterized by the overproduction of thyroid hormone and a subsequent increase in metabolic rate. The coat of affected cats may appear unkempt, matted, or greasy (see Figure 1). There are three common forms of treatment for hyperthyroidism in cats: medication, radioactive iodine therapy and surgery. The normal thyroid cells will therefore not take up any radioactive iodine. Their hyperthyroidism won't come back, and they don't need ongoing medication. Subscribe to always know when we add new material! Your veterinarian has recommended I131 for your cat. The remainder is gone in about the next two months or so. The treatment of choice for hyperthyroid cats is radioactive iodine therapy, which is a cure. 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. Dry, dull coat. Get exceptional Radioactive Iodine Therapy for Feline Hyperthyroidism services from highly experienced & loving pet care professionals in Downers Grove, IL. For this long-term treatment, the cat is injected with the radioactive iodine, which destroys the tissue of the overactive thyroid gland. Also, you might get some good ideas about what to feed him on Dr. Lisa Pierson's web site. Did You Know? These statistics are averages and do not predict what is going to happen to you. 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 . . Before treatment he was ravenous and losing weight -- typical of cats with that disorder I'm told. . These tests are needed to evaluate your cats overall health and predict the likelihood of complications with the chosen treatment protocol. 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. What happens after radioactive iodine treatment for cats? All bodily fluids in the cat will have trace amounts of radioactive material within them, but it will be most prevalent within the urine. Secondary Problems Removal of the thyroid glands, called surgical thyroidectomy, is a relatively straightforward surgical procedure that has a good success rate. How can the age of a material be determined from the decay of a radioactive element quizlet? 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. The veterinarian's recommendations are to isolate my cat for at least two weeks. It might not be an option for a frail cat who shouldn't undergo anesthesia. Radioactive iodine therapy. Many owners of cats with hyperthyroidism are hesitant to have radiation therapy or surgery because of their cat's advanced age. All middle-aged and senior cats should receive a complete physical examination by a veterinarian every six months. This treatment involves administering an injection of iodine with a radioactive substance attached. By
Log in 24/7 to access your pets health care information. This is very important meaning that cats rarely develop an underactive thyroid gland (hypothyroidism) after radioiodine therapy. Recurrence of the disease is a possibility in some cats. Treatment usually requires one or two weeks of hospitalization at a veterinary hospital licensed to administer radiation therapy. The most common clinical sign of hyperthyroidism is weight loss due to the increased rate of metabolism despite an increased appetite. Medication and radioactive iodine therapy are just as effective at treating hyperthyroidism in cats as surgery and are less invasive, so surgical treatment is rarely chosen for treating this condition. In a cat treated with radioactive iodine, the drool will contain radioactive materials. 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. Why? When x-rays, or any ionizing radiation, pass through the body they cause electrons to be ejected from atoms, leaving behind positive ions. (a) Each licensee shall conduct operations so that -. The average US total radiation exposure (all sources) is 6.2 mSv/yr which is an increase from 20 years ago (3.6 mSv/year) when CT scans were much less common. This test can also help the doctor determine the cause of your hyperthyroidism and get other information about your thyroid tissue. Radioactive iodine (RAI) is a treatment method for hyperthyroidism and thyroid cancer. If methimazole dosing is discontinued, hyperthyroidism will return.
There are four treatment options for feline hyperthyroidism: medication, radioactive iodine therapy, surgery, and dietary therapy. Scaly skin. Many older cats with overactive thyroids have actual enlargement of the gland which can be felt in the neck by your veterinarian. 5. The effectiveness of this transdermal gel is acceptable in most cases. 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. J Am Vet Med Assoc, 2006. The more common symptoms are an increase in thirst, urination, and appetite, as well as weight loss. Hopefully this answers your questions and good luck with your cat. Most hyperthyroid cats respond fully to a single injection with radio-iodine. Cats with hyperthyroidism exhibit symptoms that are similar to those of humans with the disease: weight loss, increased appetite, excessive . 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. These include weight loss, increased activity, and kitten like behaviour. Thyroid hormone regulates the metabolic rate of an animal. Radioactive iodine therapy. Radioactive iodine therapy is curative within three months of therapy in approximately 95 percent of all hyperthyroid cases. Further, the litter will be radioactive as most of the radioactive iodine will be excreted via this route. Hyperthyroidism is too much thyroid hormone that causes weight loss so kitty should gain some weight back to a normal amount after treatment. Do not allow your cat to sleep against your body. Special attention should be given to the thyroid glands to look for evidence of enlargement and the clinical signs of hyperthyroidism. By 14 days after treatment, the radioactivity will have decayed to a very low level. 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. Some places realize that the stress of being away from home for so long is not good for older cats. These medications do not provide a cure for the disease, but they do allow either short-term or long-term control of hyperthyroidism. Diagnosis 6. Interestingly, when higher doses are given, like those received by the patient treated for hyperthyroidism or thyroid cancer, then the injury to the cells is terminal and hence the cells do not survive to go on to become malignant. It is acceptable to feed your feline products containing at least 30% protein and less than 15% carbohydrates. 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. 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. What are the risks of my cat becoming hypothyroid? Your cat can receive methimazole, a medication that inhibits thyroid hormone production. Amazingly despite over 35 years of veterinary experience treating hyperthyroid cats with radioiodine there are virtually no reported side effects. 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. How does airline travel expose me to radiation? As for equipment for tracking radioactive contamination, there really is no readily available "home-testing" equipment. 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. The slow onset of signs means that cat owners will often miss these changes until the late stages of disease. Why is the average risk of developing cancer so high? 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 . Already have a myVCA account?
Hypocalcemia can be life-threatening and may require either short-term or long-term medication postoperatively should it occur. Discuss these issues with your veterinarian when considering dietary iodine restriction as a treatment for hyperthyroidism in cats. Always check with your veterinarian before changing your pets diet, medication, or physical activity routines. Each treatment option has its advantages and disadvantages. GFR results are used to determine the functional status of the kidneys, and identify cats with subclinical renal disease. The recommended food for cats with thyroid problems is high in protein yet low in carbohydrates, iodine (around 0.32 ppm) and phosphate. In some cases, complications involving other organs may worsen this prognosis. Nuclear Medicine Patient Issues Questions Concerning Domestic Animals.
DNA can also be damaged directly by radiation. Now that I know my cat has hyperthyroidism, what do I do? There are several treatment options, and your veterinarian will determine the best choice for your cat. 8. Lack of appetite. J Vet Intern Med, 2001. 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. Out little Nera was diagnosed with hyperthyroidism about 4-5 months ago. During treatment, radioactive iodine is administered as an injection and is quickly absorbed into the bloodstream. Unfortunately these cats may continue to deteriorate and may even die from their other non-thyroid diseases. 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. Your doctor will order a test called a radioactive iodine uptake and scan to determine the dose you will need. Vet Rad & Ultrasound, 1994. Feeding Hyperthyroid Cats Iodine restriction may help; weight loss is a . If thyroid disease is a possibility, your veterinarian will likely order a blood chemistry panel and an analysis of thyroid hormone levels. In many cats, only one thyroid lobe is abnormal, so only one surgery is needed. 4. A large study found an increase in some cancer types in people who had radioactive iodine treatment for hyperthyroidism compared with the general population. Weight change was analyzed in only 228 patients and 84% gained weight by 1 year after radioactive iodine therapy. Of 247 patients receiving RAI for GD, 157 (79.6% female) had complete data and were included in the analysis. Symptoms include weight loss, muscle wasting, increased appetite, increased thirst and urination, vomiting, unkempt appearance, and sometimes hyperactivity. 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. Supporting Cat Health with Information and Health Studies. Tiki Cat Hanalei Luau Wild Salmon Wet Cat Food. Affiliate of Mars Inc. 2023 | Copyright VCA Animal Hospitals all rights reserved. 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. 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. 15(1): p. 47-51. There are virtually no side effects, and there is no pain associated with 131I treatment. Category: Nuclear Medicine Patient Issues Questions Concerning Domestic Animals. 3. It does, however, involve the handling and injection of a radioactive substance that is only permitted at facilities specially licensed to use radioisotopes. Dietary Therapy Follow up blood work is essential to ensure kitty does not become hypothyroid which is too little thyroid. In some of these cats, blood pressure can become so high that retinal bleeding or retinal detachment will occur, resulting in sudden blindness. Feeding an iodine-limited diet (Hills Prescription Diet y/d) can resolve clinical signs and lower thyroid hormone concentration. How long can a cat live after radioactive iodine treatment? What this means is that occasionally we invest clients economic and perhaps more importantly, emotional resources in treating and resolving hyperthyroidism is cats with other, currently unknown diseases. Treatment The dose of radioactive iodine is taken orally. Subscribe to always know when we add new material! Regardless of radiation exposure, the average overall lifetime risk of developing an invasive cancer is 37.5% for women and 44.9% for men. 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. Research into this potential treatment option is ongoing. Risks related to radioiodine: 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. Although many cats diagnosed with hyperthyroid disease already have kidney disease, untreated hyperthyroidism can also cause kidney disease due to the damaging effects of hypertension on the kidneys. The majority of cats treated with radioactive iodine have normal hormone levels within one to two weeks of treatment. . What Treats Can I Give my Dog with CalciumOxalateStones? For this prescription diet to work, it must be the only food fed, which means no cheating with treats. 4. The inaccurate repair of DNA is rare, but can cause a cell to act wildly or grow into a cancer. However, these options tend to be expensive and not possible for all pet owners. However, your cat will still have a low amount of radiation in his or her body. 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. Your cat will not experience nausea, hair loss, lethargy, or decreased appetite as a result of the procedure. American Academy of Pediatrics. What may work for one cat may not work for another. If both thyroid glands require removal, there is a risk of developing hypocalcemia (low blood calcium levels) after surgery. Surgery or radioactive iodine therapy to regulate overactive hormone production can sometimes leave cats with the opposite problem: their levels of thyroid hormone are now too low. So in this case the targeted radiation exposure is actually increasing survival for these patients. Although the thyroid gland enlarges in hyperthyroidism, it is usually a benign or non-malignant change.