Cat Hyperthyroidism

A common disease seen in elderly cats is hyperthyroidism. The thyroid gland is a butterfly shaped gland that sits in the throat surrounding the trachea, or windpipe. It is responsible for producing hormones such as T4 or levothyroxine, T3, and TSH, which help regulate growth and metabolism. It also stores iodine in the body. 

If this gland becomes overactive, it starts to overproduce hormones, and can cause signs of illness called hyperthyroidism. The gland often becomes overactive due to a benign (non-cancerous) growth similar to a goiter, but in rare cases there can be an actual cancerous tumor present.

Signs that your cat may have an overactive thyroid include weight loss despite a good appetite, vomiting, and increased activity. Other signs such as increased blood pressure, changes in urination or thirst, or changes in vision can also be present. Since these symptoms can also be seen with other serious diseases such as kidney disease or diabetes amongst others, if your pet is exhibiting any of these signs please schedule an appointment with us as soon as possible. 

An examination may reveal an enlarged thyroid gland, elevated heart rate, changes in the retina of the eyes, or other signs which may make hyperthyroidism a likely culprit. Likely a blood sample will be taken to look at liver and kidney functions, red and white blood cells, and a thyroid or T4 level. Additional bloodwork to look at TSH, free T4, or T3 may be required to get a diagnosis.

If your pet does indeed have an elevated T4 level, a diagnosis of hyperthyroidism will be made. There are many treatment options available including surgical removal of the gland called thyroidectomy, radioactive iodine or I131 treatment, oral medications like methimazole or Tapazole®, and even a diet severely restricted in iodine (Hill’s y/d®). There are pros and cons to each of these treatments, and depending on your pet and your situation we may make different recommendations as to which treatment to pursue, what follow up will be involved, and what outcome we are hoping to achieve. 

Things such as concurrent diseases, multiple pet households, pet demeanor, and owner finances are all factors in deciding which treatment is correct for your pet, so please contact us for more information today.
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12624 Bass Lake Road
Maple Grove, MN 55369
Located just east of highway 494 on Bass Lake Road,
behind Culver's.

Communities We Serve:

Plymouth, Maple Grove, Brooklyn Center, Brooklyn Park, Osseo, Corcoran, Champlin, New Hope, Minnetonka, Minneapolis, Rogers, Robbinsdale and Golden Valley, Minnesota (MN).