Hyperthyroidism in Cats: What It Means and How to Help 🌈
Love & Toe Beans | Healthy Cat Diaries | Greater Brisbane Region | Brisbane, Moreton Bay, Redland Bay, Logan & Ipswich
Love & Toe Beans provides gentle in-home pet euthanasia, quality of life consultations, pet cremation, and grief support across the Greater Brisbane Region including Brisbane, Logan, Redland Bay, Ipswich and Moreton Bay.
A note from Dr Emma:
Hyperthyroidism is one of those conditions that can sneak up on families . Your cat might seem hungrier than ever, maybe even a bit more vocal or restless, and yet they are losing weight. It can almost look like the opposite of illness at first glance, like your cat has more energy, not less, but underneath all that extra appetite and activity, their body is working overtime, and they need our help to slow back down. 🧡
If your cat has recently been diagnosed, or if something about their eating, weight or energy has started to feel different, this blog is for you.
🌸🐈 What Is Hyperthyroidism?
Hyperthyroidism happens when the thyroid gland, a small gland in the neck, becomes enlarged and starts producing too much thyroid hormone. In the vast majority of cats, this is caused by a benign change in the thyroid tissue rather than cancer. Thyroid hormone affects almost every system in the body, so when there is too much of it circulating, the whole body's metabolism speeds up.
It is one of the most common hormonal conditions seen in middle aged and older cats, and it is very treatable once identified.
🔍💛 Signs to Watch For
Because thyroid hormone touches so many body systems, the signs of hyperthyroidism can show up in a lot of different ways. Some of the most common include:
🧡 Weight loss, often despite a normal or increased appetite
💛 A noticeably increased appetite, sometimes described as ravenous
💚 Increased thirst and urination
💙 Restlessness, hyperactivity or increased vocalisation, particularly at night
💜 Vomiting or diarrhoea
🩷 A patchy, greasy or unkempt coat
🤍 A fast heart rate that may be irregular
Weight loss alongside a hearty appetite is one of the more distinctive combinations that can point toward this condition, and it is often what prompts families to bring their cat in for a check up.
🩺 How Is It Diagnosed?
Diagnosis usually involves a physical exam alongside blood testing to measure thyroid hormone (T4) levels. Your vet will also check kidney function at the same time, since these organs are closely tied to how hyperthyroidism is managed.
💛 A Note on Kidney Disease
This is an important one, and something we will be exploring further in an upcoming blog. Hyperthyroidism can actually mask underlying chronic kidney disease. The increased thyroid hormone drives the heart to beat faster and stronger, which increases blood flow to the kidneys. This can make kidney function look better on bloodwork than it truly is.
Once hyperthyroidism is treated, that extra blood flow to the kidneys settles back down, and in some cats, this is when underlying kidney disease becomes visible for the first time. It does not mean the treatment caused the kidney disease. It simply means the kidney disease was quietly there all along, hidden behind the hyperthyroidism. This is exactly why your vet will want to monitor kidney values closely before and after treatment begins.
🩵 A Note on the Heart
Hyperthyroidism can also affect the heart. The increased metabolic rate can lead to a faster heart rate, high blood pressure, and thickening of the heart muscle. During a physical exam, your vet may listen for a heart murmur or an extra heart sound called a gallop rhythm, which can be a sign that the heart is working harder than it should. We will be covering this in more detail in a future blog too, as it is closely linked to how we manage hyperthyroidism safely, particularly in cats who may also have underlying heart disease.
💊 Treatment Options
The good news is that hyperthyroidism is one of the more manageable conditions we see in cats, and there are several paths to treatment. Your vet will help you choose the option that best suits your cat and your circumstances.
Medication (methimazole) - taken daily to reduce thyroid hormone production. This is often the first step, and can also help confirm whether any kidney changes are related to hyperthyroidism before committing to a more permanent treatment
Prescription diet - a therapeutic iodine restricted diet can help control thyroid hormone levels for some cats, provided no other food is eaten
Radioactive iodine therapy - a highly effective treatment that destroys the overactive thyroid tissue without affecting the rest of the body. It usually requires a short hospital stay while the radioactive iodine clears from the body, and often resolves the condition permanently
Surgery - removal of the affected thyroid tissue, sometimes used in combination with a period of medication beforehand to help stabilise the cat and check how the kidneys and heart respond first
Whichever path is chosen, ongoing monitoring of thyroid, kidney and heart health is an important part of care, since these systems are all closely connected. Your regular vet or specialist vet can help guide you through your treatment options to help you decide which pathway is best for your cat.
🌿💛 Quality of Life Considerations
Most cats with hyperthyroidism go on to live full, comfortable lives once the condition is under control. But for older cats, or those with more complex or advanced disease alongside other conditions like kidney disease or heart disease, quality of life becomes an important ongoing conversation with your vet.
Some things worth reflecting on:
🌸 Is their appetite and weight stabilising with treatment?
💛 Are they comfortable, settled and behaving like themselves?
🩵 Are any other conditions, like kidney or heart disease, being well managed alongside the hyperthyroidism?
🌿 Are they still enjoying the things that matter to them?
🧡🐾 How We Can Help
At Love & Toe Beans, we understand that a diagnosis like this can bring up a lot of questions and worry, especially if there are other health conditions layered on top. We are here to support you and your cat through every stage of this journey.
If you are ever unsure about your cat's quality of life, we offer free phone Quality of Life consultations, as well as in-home consultations for $198 across the Greater Brisbane Region. When the time comes to say goodbye, we offer gentle in-home euthanasia for cats across Brisbane, Logan, Ipswich, Redland Bay and Moreton Bay, along with pet cremation services and grief support for families navigating this time.
We are here from the very first worried question all the way through to the final goodbye, and everything in between. 🧡
📞 1800 823 267 🌐 www.loveandtoebeans.com.au
Coming soon in this series: how hyperthyroidism can unmask hidden kidney disease, and what a gallop rhythm means for your cat's heart health.
🌸🌿🌼 Related Reading
💛 FAQ: Knowing When It Is Time
💜 When Their Eyes Still Light Up
🌈🐾
Love & Toe Beans provides Quality of Life consultations, gentle in-home pet euthanasia, pet cremation, and grief support across the Greater Brisbane Region including Brisbane, Logan, Redland Bay, Ipswich and Moreton Bay.