Are you a cat parent curious about hypothyroidism in cats? Well, you’ve come to the right place! In this article, we’ll explore the causes, symptoms, and treatment options for this rare condition. So, let’s dive in and learn more about hypothyroidism in our feline friends.
What Is Hypothyroidism in Cats?
Hypothyroidism in cats occurs when there is a lack of thyroid hormone in their bodies. This condition is quite rare and can be categorized into two types: congenital (present at birth) and acquired. The most common scenario is when a cat with hyperthyroidism (overactive thyroid) receives treatment that overcorrects the problem, leading to acquired hypothyroidism.
Congenital Hypothyroidism
Congenital hypothyroidism is a rare form of the condition that is present in kittens at birth. The thyroid hormone plays a crucial role in the development of their nervous and skeletal systems. Kittens lacking this hormone may exhibit symptoms such as mental dullness and smaller-than-normal proportions.
Acquired Hypothyroidism
Acquired hypothyroidism in cats is a lack of thyroid hormone that occurs in adult cats, which is also very rare. Acquired hypothyroidism can further be divided into three categories: primary hypothyroidism, secondary hypothyroidism, and iatrogenic hypothyroidism. Each type has a different cause.
- Primary hypothyroidism is thought to result from an immune-mediated disorder or thyroid gland atrophy, where the gland does not function properly.
- Secondary hypothyroidism has only been reported in cats that have experienced head trauma, which leads to a decrease in the production of thyroid-stimulating hormone (TSH).
- Iatrogenic hypothyroidism can occur in cats being treated for hyperthyroidism. Surgery or radioactive iodine therapy may leave cats with low levels of thyroid hormone, causing irreversible hypothyroidism. However, it can be managed with proper care.
Your cat may also develop iatrogenic hypothyroidism if they are being treated with methimazole. However, this is generally reversible after finding the right dosage.
Symptoms of Hypothyroidism in Cats
The symptoms of hypothyroidism in cats vary depending on the type of the condition they have.
Congenital Hypothyroidism
Kittens with congenital hypothyroidism may display the following symptoms:
- Mental dullness
- Small size compared to littermates
- Abnormal body proportions, such as a large head, enlarged tongue, and short limbs
- Lethargy
- Wobbly, drunken gait (ataxia)
- Dry skin
- Thin fur
Acquired Hypothyroidism
Cats with acquired hypothyroidism may exhibit the following signs:
- Lethargy
- Excessive weight gain
- Lack of appetite
- Dry, dull coat
- Hair loss
- Scaly skin
Causes of Hypothyroidism in Cats
The causes of hypothyroidism in cats depend on the type of the condition.
Congenital Hypothyroidism
Causes of congenital hypothyroidism can be divided into goitrous and nongoitrous forms. Goitrous congenital hypothyroidism refers to the enlargement of the thyroid gland.
- Goitrous congenital hypothyroidism is thought to be caused by an inherited defect or dietary issues during the pregnancy of the mother cat or in newborn kittens.
- Nongoitrous congenital hypothyroidism is usually caused by incomplete thyroid organ development. This condition has been observed in domestic shorthair cats as well as Abyssinian cats.
Acquired Hypothyroidism
Adult-onset acquired hypothyroidism is most commonly caused by iatrogenic hypothyroidism. This occurs when a cat’s treatment for hyperthyroidism results in an underactive thyroid. Finding the right balance and anticipating the cat’s response to therapy can be challenging.
How Vets Diagnose Hypothyroidism in Cats
Diagnosing hypothyroidism in cats involves a specific blood test called a thyroid panel. This panel consists of multiple measurements to determine the thyroid hormone levels.
A cat with hypothyroidism usually has low total T4 levels. However, additional testing may be required as certain medications and other factors can also lower total T4 levels. This additional testing may include measuring free T4, T3, and TSH levels.
In kittens with congenital hypothyroidism, X-rays may reveal bony changes due to the essential role of the thyroid hormone in normal skeletal and nervous system development. Other tests, such as a complete blood count and chemistry panel, may also be conducted to assess any associated issues.
Treatment for Hypothyroidism in Cats
The primary goal of treatment for hypothyroidism in cats is to restore normal levels of thyroid hormone in their blood. This is usually achieved by administering an oral thyroid medication supplement in liquid or tablet form.
The drug sodium levothyroxine is commonly prescribed and is typically given twice daily. Some cats may require a second medication called synthetic sodium liothyronine (L-T3).
Cats with congenital and acquired hypothyroidism will require lifelong medication. However, cats with acquired iatrogenic hypothyroidism caused by an excessive dose of oral or transdermal methimazole can usually be treated by adjusting the dose.
Recovery and Management of Hypothyroidism in Cats
The goal of oral medication for hypothyroidism in cats is to improve the clinical signs of the disease. Regular follow-up bloodwork is crucial to monitor the absorption and appropriate dosing of medication.
It is important to avoid overdosing the medication as it can have significant consequences. Monitoring your cat’s blood levels of T4 is therefore essential for proper regulation.
For cats with acquired iatrogenic hypothyroidism resulting from hyperthyroidism treatment, additional follow-up testing is recommended. This includes a complete blood count, serum biochemistry, and urinalysis.
In some cases, hypothyroidism can be reversed when the ideal dosage of long-term hyperthyroid medication for your cat is found. However, for cats treated with permanent treatments like surgery or radioactive iodine, long-term oral thyroid hormone medication will be necessary.
Hypothyroidism in Cats: FAQs
Q: Can hypothyroidism in cats be cured?
A: Hypothyroidism in cats cannot be cured, but it can be successfully managed with proper medication and follow-up care.
Q: Is hypothyroidism in cats common?
A: No, hypothyroidism in cats is relatively rare compared to hyperthyroidism.
Q: Can I prevent my cat from developing hypothyroidism?
A: While there is no guaranteed prevention, maintaining a healthy lifestyle and regular veterinary check-ups can help detect and manage any potential health issues, including hypothyroidism.
Q: Is hypothyroidism a life-threatening condition for cats?
A: In most cases, hypothyroidism in cats is not life-threatening. However, proper diagnosis and treatment are crucial for ensuring your cat’s well-being.
For more information about hypothyroidism in cats and how to care for your feline friend, visit Katten TrimSalon.
Remember, as a responsible cat parent, it’s essential to be aware of any changes in your cat’s behavior or appearance. If you suspect your cat may have hypothyroidism or any other health concerns, consult with your veterinarian for appropriate care and guidance.