Home Again & Post Treatment Guidelines

Timeline and Post-Treatment Instructions

Cat - Home Timeline

We will give you an estimate for your cat's length of stay on the day of your consultation. This estimate is based on I-131 dosage (the larger the dose, the longer the stay, generally speaking), as well as the average number of days cats in the past (who have received the same I-131 dose your cat) have stayed. Please be prepared to be flexible; individuals vary, and we must comply with Washington State law.

We will call between 9 and 11 AM daily, starting tomorrow. We do not call on Sundays unless there is an issue of concern. We are here taking care of our patients on weekends and holidays, but the Shoreline office is closed for business on Sundays.

  • Discharge times: 8:00 AM -5:30 PM weekdays
  • 8:00 AM - 4:30 PM Saturdays, except 12:00-12:30 midday break

We give anti-anxiety medication daily while your cat is here (gabapentin). Your cat may be slightly woozy when you pick them up.

Home Again
For the first two weeks after I-131:

  • Keep your cat indoors or supervised when outside to prevent contact with other people.
  • Limit close contact (closer than 1 foot) to one hour per day. Do not allow your cat to sleep against your body. Under or next to the bed, or off your feet is safe.
  • Wash your hands after handling your cat, its dishes, and litter box.
  • Do not allow pregnant women or children to hold your cat.
  • The dose you are exposed to is extremely low and will have no medical consequences for you. We are attempting to minimize your lifetime exposure.

Other Animals
There are no contact restrictions for this cat with other animals as this small amount of radiation has no impact in their relatively shorter lives with little exposure to other sources of radiation. They may safely share feeding bowls, cat beds and litter boxes.

Litter Disposal
The level of radiation in your cat’s waste is not high enough to be harmful, but may be detectable in the litter for months. For our national security, if radiation is detected in garbage going through waste disposal stations, it must be traced to the point of origin to make sure it is not related to the production of explosives. In order to prevent this ‘goose chase’ which could result in a significant fine for you, the litter must be collected for two weeks and either flushed or stored until the radiation decays below detectable levels.

Scoop urine and feces daily into a garbage-bag-lined bucket (any material) for two weeks. If you have multiple cats, scoop for the group into the storage container. At the end of two weeks, the remaining litter in the box must be emptied into the bucket. Put a lid on the bucket and store out of your way (garage, basement, outdoors) for 80 days, after which time the contents of the bucket may be placed out for collection or taken to the dump. You may recycle or reuse the bucket. SCOOP 2 WEEKS, STORE 80 DAYS.

The I-131 decays rapidly and is in such small amounts, which are diluted so much in the mainstream sewers, that the radiation itself is not a problem. However, even ‘flushable’ corn and wheat litters are clogging our city sewer lines, so this method of disposal is best avoided. If you simply have no space to store a bucket, and must flush litter, then use one labeled ‘flushable’ so you will not clog your own plumbing. Scoop and flush litter daily. At the end of two weeks, all remaining litter in the box would also have to be flushed.

At 1 and 3 months post I-131, please return to your regular veterinarian. A physical exam and blood work should be performed at both visits.

Possible Outcomes
Our treatment objectives are to eliminate all hyperactive thyroid tissue and to avoid lifelong methimazole. If these are met, your cat will be healthier.

The vast majority of cats will be cured with just one I-131 treatment.

Even so, some cats have unusually ‘stubborn’ tissue that may require a second treatment with I-131. We typically re-treat these ‘outliers’ at no cost to the owner, other than the exam fee ($190), unless the second dose necessary is quite large.

On the other hand, some cats have insufficient normal thyroid hormone production after the abnormal tissue is destroyed, and may require a natural supplement daily for life. Consider this a tolerable adjustment after successful cure of hyperthyroidism.

We will do everything we can to help your cat be comfortable during their stay with us and to restore health and happiness for years to come.

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