What to Expect at Your Cat’s Second Appointment
I-131 treatment is quick and painless with one injection and cozy aftercare setup.
Your cat’s second appointment is the big one—the day they receive I-131 treatment for hyperthyroidism. And while leaving them for a few days can be tough, knowing exactly what to expect makes it easier.
This visit marks a major milestone on your cat’s path to recovery, and after a short stay with us, they’ll head home healthier and one step closer to long-term relief.
At CATT, we walk you through every step with care. From what to pack to how we monitor your cat post-treatment, our process is gentle, thorough, and focused on giving your cat the best possible outcome.
This Blog Covers:
What happens on the day of I-131 treatment
What to bring (and what not to)
How we care for your cat during their stay
What to expect when it’s time to go home
If you’re feeling nervous, you’re not alone. We’re here to guide you and your cat through it with compassion. Let’s walk through the day together, so you feel fully prepared.
Before the Appointment: What to Know
Once your cat’s dose is approved, we’ll schedule your second appointment on a Monday morning. This is a non-cancelable visit, and a non-refundable deposit is required to reserve your spot.
Unlike the first visit, fasting is not required. In fact, we encourage you to feed your cat their regular breakfast before drop-off to help keep them comfortable.
What to Bring
Your cat’s regular food (at least 2–3 days’ worth)
Any prescribed medications with instructions
An optional comfort item with your scent—like a towel or T-shirt
⚠️ Please note: Due to radiation safety protocols, personal items will not be returned. Don’t bring anything valuable or sentimental.
If your cat takes gabapentin or other calming medications, it’s perfectly fine to give it the morning of drop-off, especially if they get anxious traveling or at the vet.
Monday: Drop-Off & Injection
Drop-off is at 8:30 AM on Monday morning. Our team will greet you, review your cat’s intake details, and get them settled in.
Later that morning, your cat will receive a single injection of radioactive iodine (I-131) just under the skin. This procedure is quick, painless, and does not require anesthesia.
We may shave a small patch between the shoulders at the injection site—don’t worry, the fur grows back quickly.
From the moment your cat is admitted, they’ll be closely monitored for comfort, safety, and progress.
Hospital Stay: What It Looks Like
Your cat will board with us for up to three days in our designated cat-only I-131 recovery ward. We’ve designed this space to feel calm and comfortable with cat condos that include a separate litter cubby.
During their stay, your cat receives:
Fresh food and water, twice daily
Litter box cleaning, twice daily
Minimal handling to reduce stress
Medication administration if needed
Regular radiation level evaluations
Most cats adjust quickly to the environment, especially with familiar food and calming routines.
Wednesday: Discharge & Aftercare
On Wednesday morning, we’ll evaluate your cat’s radiation levels. If they’re within the safe range, you’ll receive a call with a pickup time and instructions.
At discharge, we’ll review everything you need to know for your cat’s transition home, including:
Radiation safety tips for your household
Handling guidelines for the first few days
A printed and verbal aftercare plan tailored to your cat
You’ll also receive updates throughout the stay:
Monday evening (post-admission)
Tuesday morning (mid-stay check-in)
Wednesday (final update and discharge details)
Get Your Questions Answered
Want to know more about aftercare, radiation safety, or how the treatment works? Watch our short videos and step-by-step explanations covering both appointments, at-home care, and how I-131 works.
We know it’s not easy to be away from your cat while they receive treatment, but we’re here to make this process smooth and reassuring every step of the way.
