In order to treat your cat with I-131 we require recent lab work (cbc, blood chemistry, urinalysis) from your referring veterinarian.
Because we are often working with a geriatric population, concomitant diseases are not uncommon. Cats with concomitant kidney disease often have blood going through the kidneys at a much faster rate, making the kidney values on bloodwork inaccurate.
When the thyroid hormone is dropped to normal the blood going through the kidneys is also dropped to normal and can subsequently "unmask" the kidney disease. Most often, this kidney disease is mild or moderate but in rare instances treatment of hyperthyroidism can even lead to acute kidney failure, which can be deadly. It is important to note that it does not matter how the thyroid disease is treated. The difference is that medication can be adjusted up or down depending on what the kidneys are doing but permanent treatments such as surgery or I-131 cannot be undone.
Kidney disease can be discovered by first regulating your cat on medication for approximately 2 months prior to I-131 treatment. Because of this, we recommend this "methimazole trial". If your cat does not tolerate methimazole for those 2 months we will be glad to give you a phone consult to decide if your cat is a good candidate for I-131 treatment. If your cat cannot go through a methimazole trial, please have your veterinarian get a current urinalysis to let us better assess kidney function prior to treatment of I-131.
Anyone interested in pursuing I-131 for their cat feel free to phone us at (509)535-6369 and please have all records with pre, post and current bloodwork included (CBC, Chemistry, thyroid level and urinalysis).
The Cat's Meow Feline Veterinary Clinic and Hyperthyroid Treatment Center
1017 South Perry Street
Spokane, WA 99202
(7:30 drop off)