Felimazole challenge test, Kidney problems and high blood pressure

In cats with hyperthyroidism, kidney problems can be masked by hypertension. High blood pressure increases the glomerular filtration rate (GFR) in the kidneys, leading to enhanced renal clearance. Administering radioactive iodine treatment to a cat with underlying kidney issues can be fatal. Therefore, we recommend conducting the Felimazole challenge test, also known as the ‘anti-thyroid challenge test,’ for cats with questionable kidney function. This test should be performed by you as the referring veterinarian before the cat is referred to us for radioactive iodine treatment. If the kidney values are within the normal range, the challenge test is not necessary. For any concerns related to abnormal kidney values or questions about a specific patient, we kindly request further intercollegiate consultation with a member of our staff.

Veterinarians
Previous information is meant for referring veterinarians. Are you the owner of a cat with thyroid problems, we would like to refer you to the following page.