"Hyperthyroidism in Cats: A Guide to Symptoms, Diagnosis, and Treatment"
What is Feline Hyperthyroidism?
Hyperthyroidism is a condition where the thyroid gland causes an excess production of the hormone thyroxine. It can typically be caused by a benign tumor in the thyroid. The thyroid is Important as it helps regulates a cats metabolism and can have an impact on their overall weight and appetite.
Prevalence and Risk Factors
hyperthyroidism appears to be very common in cats and the most common hormonal disease for them. Its often found in middle to older aged kitties like draco (15), but can occur in cats as young as 4 years old. The average age of Diagnosis is 13 however. as far as research goes there is no direct genetic link to why cats get it, it just happens.
Common Clinical Signs
Draco giving a big roar (i mean yawn)
Cats with Hyperthyroidism typically show an increased metabolic rate with symptoms that are typically shown as extreme hunger (very ravenous for food) while still losing weight over time. Other symptoms you might see but not readily associate with hyperthyroidism can be anxiety, vomiting, Diarrhea, and increased urination and thirst. In the case of my kitty Draco, he is very hungry all the time and within the past two years he has went from 17 pounds down to 15.2 pounds. Additionally he has gotten a bit more vocal over time as well which is often another sign. As I know Draco is 15 years old, I assumed the increased vocalization was due to his age and Cognitive decline that is a gradual process with senior cats as he otherwise acted perfectly healthy and shown no signs of pain or discomfort.
Less Common/Subtle Symptoms
Other symptoms outside of the ones previosuly mentioned include:
unkempt appearance (fur coat)
poor body condition
rapid breathing or difficulty breathing
hear murmurs (rapid rate or abnormal rate)
Hyperactivity and restlessness
agression
an enlarged thyroid gland that feels like a lump on the throat
thickened nails
Diagnosis: How Veterinarians Confirm Hyperthyroidism
To Diagnose a cat with Hyperthyroidism there is typically a blood test that would show high levels of the thyroid hormone (t4 or tT4) along with the general signs of increased hunger and weight loss with the symptoms mentioned above. as the signs can often be similar to renal failure and Diabetes mellitus, further testing may be needed on the thyroid to rule them out.
Kidney disease is also a diagnosis that tags along with hyperthyroidism that would also require treatment for that specific condition. in dracos case, he showed no negative signs on his blood tests indicating a kidney issue. as far as we know, it is only the hyperthyroidism for now thankfully.
What causes it?
Draco and Pancakes blending in with the floor
some potential causes have been linked to flame Retardants in furniture, organic Pollutants and exposure to high levels of dietary Iodine that can make cats more susceptible to developing it. these are only hypothesized at this time and more studies need to be conducted to find a causal link but it is most commonly a combination of genetic and environmental causes.
Treatment Options for Feline Hyperthyroidism
Medication
There are a few different options for treatment for our kitties, the most common one being daily medication of methimazole. methimazole can come in pill form or in a compounded formula that is then applied as a transdermal gel on the inside of the ear twice a day. i have opted to do the transdermal gel for draco at this time, as he is not a cat who enjoys to be held and cuddled. if i were to choose the pill we could crush it in food, but that runs the risk of the food tasting bad and him avoiding his food that would further lead down to more weight loss. if i choose to pill him he would most likely fight and squirm which could cause him more undue stress in an already unpleasant condition.
Radioactive Iodine Therapy
Family photo - Draco (left), dr chocolate (right) & pancakes (back)
radioactive iodine therapy is a treatment that often cures cats of the condition after the first session. during this procedure the cats diseased thyroid tissue is treated Radioactively with iodine in a highly controlled medical Facility. during this treatment the cat may spend a few weeks at the facility to ensure the radioactive materials have left their body before going home. even after coming home there may be some additional precautions when it comes to their stools and urine that you may have to store it for a certain duration of time before tossing in the trash for the radioactive elements and exposure risk. depending on the cats age of diagnosis, the iodine therapy for younger cats would most likely be the best approach over using the daily medication when it comes to costs over time.
Surgical Thyroidectomy
another option for treating hyperthyroidism is to remove the thyroid gland that is diseased. this is typically best done when only one side of the thyroid is diseased and the other is healthy to ensure the cat does not obtain hypothyroidism. the opposite of hyperthyroidism in this case. some issues that can occur from the surgery include Paralyzation of their voice box and the development of low blood Calcium levels.
Prescription Diet (Iodine-Restricted Diet)
Restricting iodine from your cats diet is the fourth method of managing the condition. however it would also be a lifetime Commitment like the medication route but you would also need to ensure any other cats in the house are also on this diet but adding in additional vitamins and minerals to ensure they have their daily nutrition needs of iodine or being Extremely methodical and strict to ensure the kitty with the condition does not get their fur families food. additionally the kitty with the condition would not be able to have any sort of human food or cat treats on this diet which would be Disappointing in my case as draco loves to clicker train and learn new tricks.
Managing and Living with a Hyperthyroid Cat
Draco showing off his chewy box
Monitoring & Follow-up Care
When it comes to monitoring, routine follow ups every 3-6 months will be needed to ensure the kitties thyroid levels look good but to also monitor kidney function as that can often be found once the hyperthyroidism is treated. it is said about 25% of cats also have kidney disease alongside the hyperthyroidism. the routine follow up would consist of checking their blood levels and general check up care of their vitals.
Potential Complications
possible complications can be seen with a potential allergy to the Medication ingredients and other co morbidities such as kidney disease and hypertension.
Prognosis & Quality of Life
Once treatment begins, many cats can enjoy many more happy years with a fulfilling life. Although I initially feel very anxious about this medication routine and how to keep my other cats from licking Draco’s ear for two hours after each application, it still gives me hope that he’ll live many more years and remain the happy-go-lucky kitty he’s always been.
