I-131 Treatment For Hyperthyroid Cat

chris gadbois

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My girl Onyx (maybe 5 years old) was diagnosed last night with Hyperthyroid. I noticed the changes in her eating and restlessness over the past 3-4 weeks. My vet gave me credit for seeing slight behavioural changes before the other symptoms onset. So I think we caught it very early.
She is starting the 2x's daily pills today and in 30 days we'll check her blood panels again. I already know that the Iodine Radiation is the way to go with her (provided she is a good candidate). Because of Onyx's young age this seems the way to go as opposed to pilling EVERYDAY and monitoring her dietary intake.

Can I hide these pills in her food, or do they have to be given without food?

BTW - Radioactive Iodine laws/rules are handled differently from state to state. I live in Rhode Island and the expected interment time is 5-7 days.

If anyone has a reason why I SHOULDN'T use the I-131 treatment please feel free to tell me. Thanks
 

silkenpaw

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I’m all for radioactive iodine. I think it provides a much better quality of life for everyone and is, in the end, cheaper than Tapazole, if your cat lives for a year or more afterwards (which is the point). Also, my cat got elevated liver enzymes and bilirubin on methimazole, so we had no choice but to stop it.

You can give the Tapazole (methimazole) with food or without food, it doesn’t matter.

Good luck with your cat. Please keep us updated on how she does :)
 

LTS3

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You can try a Pill Pocket to hide the pills in if your cat won't eat "tampered" food. The medicine might be compoundable into a liquid or chew treat or another form. Ask the vet if your cat won't take the pills even with a Pill Pocket.
 
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chris gadbois

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I just gave her her 1st pill this afternoon. I just hid it in a single bite of Pate and she snarffed it down. Then I gave her a bunch more after it was gone. I hope it all goes this easily. In 30 days we'll reassess. She had one Liver enzyme that was a little high but her T4 panel was way up (10.something). Hopefully we can bring those numbers down in a month and see how she looks as a candidate for the I-131
 

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My first cat had the I-131 treatment. The vet did not even tell me about food and pills. Straight up he just said radioactive iodine is the way to go. He also gave me two websites to read more about it. What I learned was 95% of cats who get it are cured the first time so repeats are rare. As expected, it worked for mine. It is worth paying $2,000 with one signature instead of $2,000 over the rest of your cat's life.
 

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I had my cat in for l-131 treatment last fall. Didn't even hesitate. I didn't want to go the medication route as that doesn't cure the HT. It was expensive but so worth it. But considering what is involved with just treating the HT with meds, vet bills (blood work etc) it will be cheaper in the long run.
 
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chris gadbois

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This is all pretty new to me...Onyx is on day 5 of the pills. I've been doing some research and here's some adjustments i've made. No more dry food, too many carbs and fillers (i used to only give as treats). Instead of 2x's daily feeding i've upped it to 6 or so in smaller portions. So she doesn't have muscle wasting i'm cooking skinless organic chicken for her (which she loves). Here is a great listing of all canned cat foods. It breaks down all the protein, carb and fat levels. Onyx has always been on the Merrick Limited Ingredient foods and she loves the duck and chicken ones, so I'm reasonably good there (for now).

https://catinfo.org/docs/CatFoodProteinFatCarbPhosphorusChart.pdf


Question though - I've read in some cases of the I-131 treatment that the cat may have to be given a LOW thyroid pill daily for the rest of their lives after the I-131. Is anyone experiencing that? (my vet is calling this AM for an update I will discuss with him as well).
 

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My cat was treated with I-131 last year in August, and her thyroid levels came down after 3 months from the treatment.
What I know is that 95-97% of cats get benefits from this treatment, meaning that they will never need another pill in their life.
A small percentage of them might need a second treatment, that some facilities perform for free. Some other cat might get HYPO thyroid and would need a pill for this. But this pill is less harmful than the methimazole, it seems it has no side effects on the body, unlike the methimazole that is heavy on the liver, kidneys and pancreas.

My cat is currently sick with liver disease and pancreatitis bouts.
I'm sure that she's sick because my vets wasted time before the I-131 therapy.
I live in Italy, over here there are NO facility for this therapy, I had to go abroad, and without ANY help from my vets. They only assisted me with the methimazole for a year, but they took no responsibility for the iodine therapy, and I had to manage it on my own. I'm sure that waiting a year before the therapy affected her body, and now she's sick.

So, do it as soon as you can.
It can be costly, but you get even 12-15 months afterwards compared to methimazole and continuous blood tests.
 

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I had radiation therapy done on a cat I had back in the 1980's. She was in the lab for a week and I picked her up. She never took a pill for anything and lived to be 18 years old. No regrets.
I was told she would be radioactive for a month and not to cuddle with her, but I didn't listen. Also the cat litter had to be scooped wearing gloves and stored for three months in the garage before I could put it out with the trash. I'm sure that is still true.
 
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chris gadbois

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As I've been researching here's what I'm learning. The I-131 should ONLY affect the tumor part of the Thyroid glands. In some cases (-5%) I also destroys the healthy part of the Thyroid. In this instance the patient (Cat OR Human) becomes Hypo-Thyroid and needs daily meds to assist body metabolism.

There is a place in Boston (I'm 30 miles south of) where they take the cat in on Monday, do X-Ray, blood panel and urinalysis. Give her the injection on Wed and pick her back up on Saturday morning. Approx cost - $2100

There is a place closer to me in Rhode Island where your own vet does most of the pre-lab work and faxes over the info. My cat should only be with them 3-4 days as opposed to 5+ with the Boston based one. Still trying to get the costs down but it looks in the range of $1500 + your vet bills.

All that being said we have to wait for her 1st blood re-check after 4 weeks on the meds.
 

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Question though - I've read in some cases of the I-131 treatment that the cat may have to be given a LOW thyroid pill daily for the rest of their lives after the I-131. Is anyone experiencing that? (my vet is calling this AM for an update I will discuss with him as well).
Where did you read this? Only the amount needed to return the T4 level back to a normal level is given. Hypothyroidism is very rare in cats.
 
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chris gadbois

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I've read so many websites in the past few days + I-131 people's feedback I can't recall....but, yes, in less than 5% of cats the I-131 also can harm the healthy portion of the thyroid and thus the need for daily meds for the hypo-thyroid cat.

This YouTube vid is compelling.....LOTS of info here (I just finished watching) -
 

Daisy6

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The one thing that confused me when I read about I-131 was why other cats stay at thev hospital a different number of days and nights. Siome cats stay there only one week and others two weeks.
 
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chris gadbois

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I can answer that. Every state treats how you handle radioactive materials differently.....it has nothing to do with your pet. So one state may say we have to have to hold the cat until we see 'this' reading on radioactivity while another stae may say less (or more).

Usually it's 3-5 days. But they dont want the cat sleeping with you for 2 weeks....also you must handle the little box carefully for those 2 weeks. So some people may leave the cat in the treatment center for the full duration if they don't want to deal with the 'post-treatment' restrictions.
 

Daisy6

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I am sure when the vet sees a specific reading varies too based on how advanced the HT was.
 

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I was told she would be radioactive for a month and not to cuddle with her, but I didn't listen.
Neither did I.
I allowed Pallina stay curled next to me as long as she wanted from day 1 after she came back home.

Also the cat litter had to be scooped wearing gloves and stored for three months in the garage before I could put it out with the trash. I'm sure that is still true.
I did wear gloves and stored the used litter in a separate bin at the end of the backyard... where it still is a year later :lol:
I am so proud of that bin with the safety label on a side :flail:

danger-radioactive-hazard.jpg
 

Antonio65

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Where did you read this? Only the amount needed to return the T4 level back to a normal level is given. Hypothyroidism is very rare in cats.
Some cats do become HYPOthyroid after the treatment, just a 1-2% of the cases, but it does happen. Those cats will have to take a pill (overe here it is named EUTIROX) for the rest of their life. This med, though, has very little or no side effects, unlike Methimazole.
 

Antonio65

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Usually it's 3-5 days. But they dont want the cat sleeping with you for 2 weeks....also you must handle the little box carefully for those 2 weeks. So some people may leave the cat in the treatment center for the full duration if they don't want to deal with the 'post-treatment' restrictions.
It depends on the facility's instructions. Some clinics might ask you to follow these safety procedures for a longer time.
 
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chris gadbois

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Following up and then asking for some advice -

1. Onyx did NOT do well on the Methimazole. She was depressed, lethargic, throwing up bile and started scratching her face till she bled. After 15 days the decision was to stop the meds and get the best blood sample we could. Her liver and kidney values all look great, heart is fine. We stopped the medication last Thursday.
If your cat is having a bad reaction to this med it can be quite toxic for them, so be aware of the side effects and get them off it as quickly as possible. After stopping the meds Onyx continued to throw up bile for an additional 2 days. That has stopped now. She is back to snuggling, purring, rolling over for belly scratches, etc....lots of her normal behavior.
I'm trying to keep her belly full to minimize muscle wasting. Every couple hours I feed her a 1/4 can of high protein wet food. She currently consumes about 2 cans a day. Now her T4 levels are starting to climb again and I'm seeing the effects of HT. (dilated eyes, breathing is more shallow and rapid, restlessness, tail twitching).

2 (advice?) - Is there anything I can do to help make her comfortable for the next couple weeks until treatment?

I also emailed this question to her vet in Boston (waiting for her reply).

Here is the link to the Boston hospital in you want to check them out. I-131 Therapy - MSPCA-Angell
 

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We had i-131 done on our cat last summer and it was BEST decision we made! She was allergic to both the oral and topical Methimazole so we really didn't have a choice.

You DO NOT need to quarantine afterwards. We got all freaked out about it, and sent the scary handout they gave us to my best friend who is an environmental engineer in our state. She had a really good laugh about it. The problem is they are applying different regulations (environmental/corporate) to cats, and it doesn't translate at all. Radioactive iodine has a fast half life. She assured us by the time our cat left the 2 days in quarantine, she'd have no more radiation than a person would get from flying across the country. In other words, it's not dangerous. And since the radiation was safe for her (there is no higher death or cancer rate for cats that receive i-131) we knew that after her short hospital stay, she could also be around our other cats with no worries. We signed whatever scary form they gave us about bagging up her litter separately etc. and brought her home, and let her live her life. We did watch some old 1950s science fiction giant bug films (where they get exposed to radiation) just for fun!

It's completely ridiculous they scare people with regulations that don't apply to cats. I repeat that it's no more radiation than you (or your cat) would get from a flight across the country, so it's completely harmless.

Or let me put it another way-- my best friend (a person) had i-131 treatment for thyroid cancer. She was isolated for 2 days and they let her home after that with no weird instructions. She could go out in public, hug people, etc. So yeah, your cat will not be radioactive afterwards-- although we had fun teasing her she was glow-in-the-dark!

Get it done. It was the best decision we made!
 
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