Haven Lake Animal Hospital

300 Milford Harrington Highway
Milford, DE 19963





Haven Lake Animal Hospital is one of only two pet care providers in Delaware that can treat hyperthyroidism—a common feline cancer—with I-131 radioiodine therapy. If your precious cat has been diagnosed with feline hyperthyroidism, make an appointment today. Your cat’s condition does not have to become a terminal illness.

What’s Happening in Your Kitty?

Hyperthyroidism is caused by cancer of the thyroid, which is typically benign. But it’s still harmful, because it elevates metabolism to levels that can cause heart failure, vomiting, diarrhea, behavioral changes, and kidney problems.


How Can We Help?

Just one treatment of I-131 radioiodine therapy cures 95% of hyperthyroidism in cats. No other organs or systems are affected by the I-131 treatment, and normal thyroid function will return in one to three months.

If you are a veterinarian that would like to refer a patient for our I-131 treatment please submit our Referral Form.

Referral Form


White Cat

First Things First

Proper treatment of hyperthyroidism begins with proper testing and analysis. Haven Lake Animal Hospital performs and/or reviews the following before treating your cat with I-131 radioiodine therapy:

  • Chest X-rays
  • CBC/profile
  • T4

T4 level must be taken when off Tapazole (methimazole) for at least two weeks. Cats must be off Tapazole at least two weeks prior to treatment.


Treatment Overview

Your cat will stay at our facility for a minimum of 96 hours after administration of the I-131 radioiodine therapy. This allows us to care for your cat properly while the isotope is in their system.

When you pick up your pet, you will be given a set of written instructions on limiting your cat’s activities and collecting/storing/removing feces, urine, and other body fluids.

Consent Form


Payment Details

The cost of this procedure includes the I-131 treatment as well as your cat’s care while hospitalized. The cost does not include therapy for concurrent illnesses or follow-up after treatment.



Puppy & Kitten Care

Senior Care


Cancer Care


Diagnostic Services

End of Life Care

I-131 Therapy



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