Advice about radioactive cat.
July 31, 2018 11:46 AM Subscribe
Cat recently had radioiodine treatment for hyperthyroid, and is now in quarantine at home. I'm seeking advice about what rules can be bent, from people who have been through this, or who know about radioactivity.
I've been advised to keep Moose (cat tax) in quarantine for two weeks. The vet's documents say: "Upon discharge your cat will still be minimally radioactive. Even though the level of radioactivity is very low (much lower than the level at which human patients are discharged from the hospital), you should still exercise caution during this period."
"Caution" involves the following:
- wearing gloves when scooping litter
- getting rid of radioactive poops and peeps as quickly as possible, via flushing
- keeping Moose in a separate room and visiting her only briefly (two 10-min visits per day); this is about keeping her radioactive body away from me and the other cat, as well as giving the cats separate litterboxes.
The official documents, and multiple people at the clinic, were very stern about these guidelines. I have a healthy respect for / fear of radiation, and would like to do this safely. However, I spoke with one vet who pointed out that these are blanket regulations, written with everyone's safety in mind, with the assumption that some pet owners are elderly, in frail health, or already frequently exposed to radiation. She described the guidelines as well-intentioned but perhaps overprotective for someone like me (I am 42, healthy, and not exposed to excessive radiation elsewhere).
This vet described the amount of radiation as being equivalent to what one might absorb in a cross-country flight, although I'm not clear on whether she meant this was the total amount remaining in Moose's body, or the amount I might absorb every time I'm near her. I have no idea if there's any truth to this description at all, but the vet who told me this is highly qualified, is a specialist in the radioiodine procedure, and was recommended by my regular vet, who I trust completely.
So... how strictly should I be following these official guidelines? They're overkill, right (as per this thread)? If I spend more time with Moose than I'm "supposed" to, are there warning signs I should watch out for? Am I gonna mutate? I'm afraid to google this, but if you have real, actual information about symptoms, I welcome it.
My main priority here is to protect the other cat, who is in great health.
I am hoping someone will give me the go-ahead to a) spend more than 20 minutes a day with Moose (which frankly I'm doing anyway, and would love to be told this isn't going to melt me), and b) end the quarantine period early. Not only is quarantine a giant pain in the ass, but I have a potential death in the family looming closer, and I may have to go out of town soon. Ending the quarantine early would simplify things for my cat-sitter. I can't imagine it would be a big deal to shave a day or two off the two-week period... could I get away with more than that?
Potentially relevant other facts: once let out of quarantine, Moose will only have contact with the other cat and me. I have no contact with babies or anyone in poor health. The cats don't groom each other.
Other facts from her release documents:
"The radiation received by the cat poses no danger to the public and it is allowed by NRC medical use regulations... the cat may set off radiation detectors for up to 91 days, depending on the sensitivity of the detector."
Radioisotope: I-131
Half-life: 8.1 days
Total activity: 3.5 mCi as capsule
Type of radiation: Gamma/Beta
Thank you for any help!
I've been advised to keep Moose (cat tax) in quarantine for two weeks. The vet's documents say: "Upon discharge your cat will still be minimally radioactive. Even though the level of radioactivity is very low (much lower than the level at which human patients are discharged from the hospital), you should still exercise caution during this period."
"Caution" involves the following:
- wearing gloves when scooping litter
- getting rid of radioactive poops and peeps as quickly as possible, via flushing
- keeping Moose in a separate room and visiting her only briefly (two 10-min visits per day); this is about keeping her radioactive body away from me and the other cat, as well as giving the cats separate litterboxes.
The official documents, and multiple people at the clinic, were very stern about these guidelines. I have a healthy respect for / fear of radiation, and would like to do this safely. However, I spoke with one vet who pointed out that these are blanket regulations, written with everyone's safety in mind, with the assumption that some pet owners are elderly, in frail health, or already frequently exposed to radiation. She described the guidelines as well-intentioned but perhaps overprotective for someone like me (I am 42, healthy, and not exposed to excessive radiation elsewhere).
This vet described the amount of radiation as being equivalent to what one might absorb in a cross-country flight, although I'm not clear on whether she meant this was the total amount remaining in Moose's body, or the amount I might absorb every time I'm near her. I have no idea if there's any truth to this description at all, but the vet who told me this is highly qualified, is a specialist in the radioiodine procedure, and was recommended by my regular vet, who I trust completely.
So... how strictly should I be following these official guidelines? They're overkill, right (as per this thread)? If I spend more time with Moose than I'm "supposed" to, are there warning signs I should watch out for? Am I gonna mutate? I'm afraid to google this, but if you have real, actual information about symptoms, I welcome it.
My main priority here is to protect the other cat, who is in great health.
I am hoping someone will give me the go-ahead to a) spend more than 20 minutes a day with Moose (which frankly I'm doing anyway, and would love to be told this isn't going to melt me), and b) end the quarantine period early. Not only is quarantine a giant pain in the ass, but I have a potential death in the family looming closer, and I may have to go out of town soon. Ending the quarantine early would simplify things for my cat-sitter. I can't imagine it would be a big deal to shave a day or two off the two-week period... could I get away with more than that?
Potentially relevant other facts: once let out of quarantine, Moose will only have contact with the other cat and me. I have no contact with babies or anyone in poor health. The cats don't groom each other.
Other facts from her release documents:
"The radiation received by the cat poses no danger to the public and it is allowed by NRC medical use regulations... the cat may set off radiation detectors for up to 91 days, depending on the sensitivity of the detector."
Radioisotope: I-131
Half-life: 8.1 days
Total activity: 3.5 mCi as capsule
Type of radiation: Gamma/Beta
Thank you for any help!
Response by poster: Oh sorry, I should have been more specific (as well as mentioned that I'm in the US). She stayed at the clinic for the first 3 days, then was released to me. The two-week quarantine was to start at home. That mention of the 8-day half-life was actually news to me, as nobody ever mentioned it and I only read it in the documents when writing this post.
I was also told that all items that were with her during her time at the clinic would be thrown out (i.e. I couldn't send toys or a blanket) because of contamination. But I guess that's not an issue now that she's at home.
Also, I'm asking this a few days into the quarantine period. Moose had the treatment on the 24th, stayed at the clinic until the 27th, and has been in home quarantine up until now, the 31st. So she got the actual treatment one week ago.
(Urbanlenny, that cat is such a fancy man.)
posted by jessicapierce at 12:10 PM on July 31, 2018
I was also told that all items that were with her during her time at the clinic would be thrown out (i.e. I couldn't send toys or a blanket) because of contamination. But I guess that's not an issue now that she's at home.
Also, I'm asking this a few days into the quarantine period. Moose had the treatment on the 24th, stayed at the clinic until the 27th, and has been in home quarantine up until now, the 31st. So she got the actual treatment one week ago.
(Urbanlenny, that cat is such a fancy man.)
posted by jessicapierce at 12:10 PM on July 31, 2018
There aren't going to be any symptoms, and NIH says there is little risk of thyroid cancer for adults from I-131 exposure.
If it were me, I would keep the litterbox precautions in play, wash hands often, and avoid too much close-up fuzzy snuggling. I don't think shaving a few days off the quarantine is a big deal, but it would be rude not to inform your sitter of the situation.
posted by RobotVoodooPower at 12:19 PM on July 31, 2018 [1 favorite]
If it were me, I would keep the litterbox precautions in play, wash hands often, and avoid too much close-up fuzzy snuggling. I don't think shaving a few days off the quarantine is a big deal, but it would be rude not to inform your sitter of the situation.
posted by RobotVoodooPower at 12:19 PM on July 31, 2018 [1 favorite]
Physicist here, but not a medical physicist. There are two potential modes of exposure for you and your other cat here: (1) direct absorption of the beta/gamma radiation coming from Moose, and (2) ingestion/absorption of iodine-131.
I suspect the latter is the thing you really want to avoid -- this is where the advice about wearing gloves and avoiding touching is coming from. You should definitely wash your hands thoroughly after touching her and definitely before eating/drinking/etc.
To reduce direct absorption, remember that the radiation intensity falls off like 1/r^2. If you lie on the floor and stretch out your arm to pet Moose, most of your body will be as far as possible from her -- consider this as an alternative to close snuggling.
I'm going to try to do the calculation about the cross-country flight.
posted by heatherlogan at 12:41 PM on July 31, 2018 [4 favorites]
I suspect the latter is the thing you really want to avoid -- this is where the advice about wearing gloves and avoiding touching is coming from. You should definitely wash your hands thoroughly after touching her and definitely before eating/drinking/etc.
To reduce direct absorption, remember that the radiation intensity falls off like 1/r^2. If you lie on the floor and stretch out your arm to pet Moose, most of your body will be as far as possible from her -- consider this as an alternative to close snuggling.
I'm going to try to do the calculation about the cross-country flight.
posted by heatherlogan at 12:41 PM on July 31, 2018 [4 favorites]
From the point of view of a human who was irradiated, after a few hours in isolation at the hospital, I was under stricter quarantine for about 3 days (no physical contact, separate eating/drinking utensils, flushing toilet repeatedly, etc.), and a little less strict for 7 days (avoiding physical contact, no sleeping in the same bed as someone or sitting next to someone for extended periods of time), and then pretty much good to go after that apart from no getting pregnant for a year.
Cats get lower dosages, but also can't understand things like "Don't sleep next to me"; your other cat also can't understand that they're not supposed to be near the other cat, so you at night, and your other cat would worry me a little bit for breaking quarantine early. Ditto sharing litter box and water/food dishes (the I-131 is mostly going to come out through urine and saliva and in humans, sweat--do cats sweat??) .
Also, I'd say definitely keep cat away from pregnant women and small children for the duration, since the children/fetuses will be at the most risk of developing thyroid cancer from I-131 exposure.
posted by damayanti at 12:48 PM on July 31, 2018 [1 favorite]
Cats get lower dosages, but also can't understand things like "Don't sleep next to me"; your other cat also can't understand that they're not supposed to be near the other cat, so you at night, and your other cat would worry me a little bit for breaking quarantine early. Ditto sharing litter box and water/food dishes (the I-131 is mostly going to come out through urine and saliva and in humans, sweat--do cats sweat??) .
Also, I'd say definitely keep cat away from pregnant women and small children for the duration, since the children/fetuses will be at the most risk of developing thyroid cancer from I-131 exposure.
posted by damayanti at 12:48 PM on July 31, 2018 [1 favorite]
Best answer: I think cats sweat through their paw pads. Also, licking. Were you advised to wear gloves during pettings? It will probably be good to thoroughly wash Moose's food and water dishes.
That radiation dose calculation was way more complicated than I expected and I've made a ton of "spherical cow" assumptions, so take this with a huge grain of (iodized) salt. The betas at that energy are basically all going to be absorbed in your cat's thyroid (range < 5 mm). The gammas range out much farther and for these the 1/r^2 rule of thumb is a good one. Very roughly it looks like your vet's comparison to a trans-continental flight was indeed per 10 minute session, but that assumes full-body cuddles such that you're essentially absorbing the full emission in all directions. If your body subtends a smaller angle as seen from the cat, you'll be absorbing a correspondingly smaller fraction of the total radiation.
If you happen to have one lying around, a 5 cm thick steel plate will cut the gamma transmission by a factor of 10 for the 7% of gammas with energy ~600 keV; the rest are ~400 keV and will be attenuated even more quickly.
As for the health effects, keep in mind that pilots and flight attendants can log 300 trans-continental flights per year for the length of a career without particularly dramatic radiation-induced consequences, though I suspect their doctors are aware and maybe do certain screenings more than for the general population. The average annual background radiation dose from all sources in North America is about 300 mrad, or the equivalent of 100 trans-continental flights. (Thanks Fermilab General Employee Radiation Training!)
posted by heatherlogan at 1:24 PM on July 31, 2018 [18 favorites]
That radiation dose calculation was way more complicated than I expected and I've made a ton of "spherical cow" assumptions, so take this with a huge grain of (iodized) salt. The betas at that energy are basically all going to be absorbed in your cat's thyroid (range < 5 mm). The gammas range out much farther and for these the 1/r^2 rule of thumb is a good one. Very roughly it looks like your vet's comparison to a trans-continental flight was indeed per 10 minute session, but that assumes full-body cuddles such that you're essentially absorbing the full emission in all directions. If your body subtends a smaller angle as seen from the cat, you'll be absorbing a correspondingly smaller fraction of the total radiation.
If you happen to have one lying around, a 5 cm thick steel plate will cut the gamma transmission by a factor of 10 for the 7% of gammas with energy ~600 keV; the rest are ~400 keV and will be attenuated even more quickly.
As for the health effects, keep in mind that pilots and flight attendants can log 300 trans-continental flights per year for the length of a career without particularly dramatic radiation-induced consequences, though I suspect their doctors are aware and maybe do certain screenings more than for the general population. The average annual background radiation dose from all sources in North America is about 300 mrad, or the equivalent of 100 trans-continental flights. (Thanks Fermilab General Employee Radiation Training!)
posted by heatherlogan at 1:24 PM on July 31, 2018 [18 favorites]
Best answer: My advice is if it's just you and the other cat: wear gloves on the kitty litter part (which is easy and why not), wash your hands more frequently and ignore the rest. Even that I feel is pretty cautious.
I am pretty risk tolerant on this stuff so take that into account. But ninety percent of the radiation is beta radiation and basically won't penetrate your skin; the real health risk with iodine is ingestion, where it can be concentrated in your thyroid and do damage without needing to penetrate your skin.
I can't say ending quarantine is zero risk: if the cats share a litter box minute amounts could end on a paw then fur then tongue during grooming, so it'd be a tiny bit safer. But it's way down on the list of risks.
The dosing risk directly from being near the cat just seems ridiculous to me. Heatherlogan did all the math and it matches my intuition. Maybe if one of your cats were always radioactive I'd start worrying about it but this situation won't last for more than a month.
If you had kids I'd be more rigorous about scooping up and quarantining just so they aren't getting stuff in their mouth.
Also, I'd like to point out (and can't believe no one has) that in these troubled times America needs a good person with feline super powers more than ever, and it just won't happen if people are too cautious with cuddling their radioactive cats.
posted by mark k at 6:28 PM on July 31, 2018 [3 favorites]
I am pretty risk tolerant on this stuff so take that into account. But ninety percent of the radiation is beta radiation and basically won't penetrate your skin; the real health risk with iodine is ingestion, where it can be concentrated in your thyroid and do damage without needing to penetrate your skin.
I can't say ending quarantine is zero risk: if the cats share a litter box minute amounts could end on a paw then fur then tongue during grooming, so it'd be a tiny bit safer. But it's way down on the list of risks.
The dosing risk directly from being near the cat just seems ridiculous to me. Heatherlogan did all the math and it matches my intuition. Maybe if one of your cats were always radioactive I'd start worrying about it but this situation won't last for more than a month.
If you had kids I'd be more rigorous about scooping up and quarantining just so they aren't getting stuff in their mouth.
Also, I'd like to point out (and can't believe no one has) that in these troubled times America needs a good person with feline super powers more than ever, and it just won't happen if people are too cautious with cuddling their radioactive cats.
posted by mark k at 6:28 PM on July 31, 2018 [3 favorites]
You may want to take a bit of normal iodine, like iodine water purification tablets from REI (in water), as a supplement. This would give your thyroid a reasonable and healthy dose of normal iodine which would block uptake of radioisotope: I-131 if you ingest a bit. (You know, like the iodine kits they have around nuclear power plants.)
posted by sebastienbailard at 8:54 PM on July 31, 2018 [2 favorites]
posted by sebastienbailard at 8:54 PM on July 31, 2018 [2 favorites]
I took a 150 mCi capsule after my entire thyroid was taken out due to cancer. The primary ways that I-131 leaves the body are through the urine and feces, but for some reason salivary glands concentrate iodine in them. For the first 24+ hours i was instructed to be eating sour lemon hard candy to empty out the salivary glands as much as possible to reduce radiation damage to them. I was instructed to personally put any silverware/dishes i had used (thus possible saliva) in the dishwasher myself. I was also told to flush the toilet twice after each use. Additionally, i was to avoid being closer than six feet / a couple of meters to people for extended periods of time during the first week or so (i forget exactly).
Now, your cat has taken much less (though proportionally to body weight the difference is not as much; i estimate i took around 2.5 times the dosage calculating by body weight). I agree that radiation from proximity to the cat from a 3.5 mCi capsule is probably not a big deal, especially after the first few days, but you should be careful about the radioactive iodine that has left the cat in the litter box and its saliva. That cats wash themselves with saliva is probably a concern. I’d definitely be washing my hands well every time i touched the cat for the first few weeks.
posted by D.C. at 10:39 PM on July 31, 2018
Now, your cat has taken much less (though proportionally to body weight the difference is not as much; i estimate i took around 2.5 times the dosage calculating by body weight). I agree that radiation from proximity to the cat from a 3.5 mCi capsule is probably not a big deal, especially after the first few days, but you should be careful about the radioactive iodine that has left the cat in the litter box and its saliva. That cats wash themselves with saliva is probably a concern. I’d definitely be washing my hands well every time i touched the cat for the first few weeks.
posted by D.C. at 10:39 PM on July 31, 2018
My cat had this treatment 18 months ago and in reading about different people's experiences it seems like the recommendations for how much to avoid contact vary widely. The litterbox recommendations do seem to be pretty universal and make sense for avoiding ingestion of radioactive particles. After the initial quarantine period, the specialist vet we went to basically said that we could interact with the cat as normal, but to avoid prolonged snuggling and sleeping together for at least 2 weeks. Fortunately our cat is not very snuggly and doesn't like sleeping with people, so we were back to the status quo very quickly.
posted by The Elusive Architeuthis at 3:52 AM on August 1, 2018
posted by The Elusive Architeuthis at 3:52 AM on August 1, 2018
Minor point; it sounds like you have the relevance of age backwards. Radiation is more dangerous the younger you are, not the older you are. This is because minor genetic damage to a cell will propagate to all descendants of that cell for the rest of your lifetime, which is potentially a lot more of your body for a lot longer if you're young. The more cells you have that are damaged, the greater the risk that another source of damage (or routine cell replication error) will affect an already-damaged cell, potentially resulting in cancer. Likewise the longer you still have to live, the more time exposure there is for another error to affect an already-damaged cell, or for a slow cancer to become a problem.
Eg Generally with medical radiation, the radioactive person is required to stay further away from children specifically.
posted by anonymisc at 11:05 AM on August 1, 2018
Eg Generally with medical radiation, the radioactive person is required to stay further away from children specifically.
posted by anonymisc at 11:05 AM on August 1, 2018
Response by poster: Thanks for all the help, especially heatherlogan - thank you so much for doing the math! I feel like I have a more realistic grasp on this now, and a more reasonable plan going forward. I'm going to keep quarantine going for the full two weeks if I can, but not worry too much if I have to cut it short. I'll be diligent about the sanitary aspects of this, without feeling like I'm not allowed to pet her (not gonna happen even if she were glowing).
I'll update if I get powers.
posted by jessicapierce at 5:36 PM on August 1, 2018 [3 favorites]
I'll update if I get powers.
posted by jessicapierce at 5:36 PM on August 1, 2018 [3 favorites]
About to take my Clio in for this same treatment and I was wondering how Moose has fared after his. Any updates?
posted by octothorpe at 7:44 AM on July 12, 2019
posted by octothorpe at 7:44 AM on July 12, 2019
This thread is closed to new comments.
When my cat had this treatment, she was kept in quarantine by the vet for the half life of her treatment (which in her case was 5 days, based on the dosage they gave her) and once I got her back the guidance was that I could spend 30 minutes a day physically touching her but that was all. However, she did not have to be quarantined in another room and could generally hang out, just not physically touching me. The only time the vet said to keep her quarantined was at night where you have no reasonable control over how much time you are in physical contact.
So if they did not keep Moose (which is a great name, BTW) for those eight days, I would recommend doing the first eight day period as directed and then going to the process my vet recommended. If they did keep her for those eight days, their instructions are overkill and as long as you just don't spend all your time glued to your cat you'll be fine. As an additional anecdonte, my vet (in Canada) mentioned during my orientation that the US was extra cautious about this treatment but that Canada's rules were more relaxed.
posted by urbanlenny at 12:02 PM on July 31, 2018 [1 favorite]