Hyperthyroidism in Cats Diet: What to Feed and Avoid

Is your cat consistently hungry but still losing weight? This could indicate hyperthyroidism, a common hormonal condition in cats. For hyperthyroidism in cats, diet plays a vital role in managing the condition and supporting your feline’s overall health and well-being.

A study published on PubMed found something interesting. It showed that 1 in 10 cats older than 10 years have overactive thyroid glands.

“A proper diet plays a key role in slowing down the effects of hyperthyroidism, helping cats regain weight and maintain their strength.”

In this guide, we will look at the best diet for hyperthyroid cats. We will cover the right nutrients, foods to avoid, and feeding tips to help their health and recovery.

Understanding Hyperthyroidism in Cats

It is the most common hormonal disorder in senior cats. Middle-aged and old cats are at increased risk of developing hyperthyroidism. It occurs due to excessive thyroid hormone production by the thyroid glands, resulting in an increased metabolic rate. If left untreated, it can lead to serious health problems in cats, making early diagnosis and proper management essential.

Common Causes of Hypothyroidism in Cats

The exact cause of too much thyroid hormone is not fully known. However, several factors are thought to play a role in this condition.

• Benign thyroid tumors (the most common cause, which contributes to 98% of cases)
• Malignant Thyroid Tumors (Rare but Serious)
• Dietary & Environmental Factors
• Genetic Predisposition
• Immune System Dysfunction
• Hormonal and Metabolic Changes with Age

Hyperthyroidism in Cats: Symptoms

Hyperthyroidism in cats affects their metabolism, leading to a variety of symptoms. Common symptoms include:

• Weight Loss Despite Increased Appetite
• Increased Appetite (Polyphagia)
• Increased Thirst and Urination (Polydipsia & Polyuria)
• Hyperactivity & Restlessness
• Poor Coat Condition
• Vomiting & Diarrhea
• Rapid Heart Rate (Tachycardia)
• Panting or Difficulty Breathing
• Muscle Wasting & Weakness

Nutritional Needs of Hyperthyroid Cats

In cases of hyperthyroidism in cats, diet is important. It can be the main treatment or support medication.

Hyperthyroidism in cats can result in muscle wasting; to prevent this, a high-protein diet is recommended for cats. To ensure this, the cat’s diet should at least contain 40% high-quality animal protein (dry matter basis).

The most suitable protein sources for this include chicken, turkey, beef, lamb, and fish. Additionally, plant-based diets should be avoided, as cats are obligate carnivores ( like meat meat-based diet).

Hyperthyroid cats need a high-energy diet to support their elevated metabolic rate. Therefore, high-fat diets (moderate levels) can provide extra calories. In addition, wet food is often better than dry kibble because of its high nutrient density.

Iodine is essential for thyroid hormone production. A low-iodine diet is essential to regulate thyroid hormone levels, such as Hill’s Prescription Diet y/d. But if your cat is receiving medications like methimazole, iodine levels should be neither too low nor too high.

Hyperthyroidism in cats’ diets should include additional nutrients to support overall health. These nutrients include taurine, which is important for eye and heart health. Omega-3 fatty acids help reduce inflammation and support skin health. B vitamins are needed for energy metabolism and to prevent deficiency.

As hyperthyroid cats experience increased thirst and urination, to prevent dehydration, wet food is preferred over dry kibble. In addition, encourage water intake in cats by adding water to meals.

Chronic kidney disease (CKD) is commonly seen in cats with hyperthyroidism. In this case, choose a moderate-to-low-level phosphorus diet to protect kidney function.

Best Food Options for Cats with Hyperthyroidism

While considering the best food options for feline hyperthyroidism, you should always keep in mind the above-stated considerations about nutrient needs.

If diet is the sole method of treatment, a low-iodine diet is the only effective approach. If you are relying solely on diet to treat hyperthyroidism in your cat, then make sure it’s low in iodine content. Hill’s Prescription Diet y/d Feline Thyroid Care is the best choice. It limits iodine to reduce thyroid hormone production.

However, it must be fed exclusively, as no other food or treats are permitted. In addition, it’s not suitable for cats on methimazole or radioactive iodine therapy because they require balanced iodine intake.

“The best diet for a hyperthyroid cat is one that prioritizes quality animal protein while limiting excess iodine and unnecessary fillers.”

Cats with hyperthyroidism require a high-protein, high-calorie diet, whether they are undergoing treatment or managing the condition with medication. Some of the best food options include

• Tiki Cat Puka Puka Luau (Chicken)
• Wellness CORE Grain-Free Turkey & Chicken Pâté
• Fancy Feast Classic Pâté
• Weruva Cats in the Kitchen Goldie Lox
• Orijen Cat & Kitten (dry food if needed)

Some cat owners prefer homemade or raw diets. However, they must be nutritionally balanced and iodine-controlled. So, you can use human-grade meat and iodine-rich ingredients. You can also consult a vet or pet nutritionist for balanced recipes.

Foods to Avoid for Hyperthyroid Cats

Avoiding certain foods in case of hyperthyroidism in a cat’s diet can help prevent complications and support the overall health of the cat.

Firstly, you should avoid high-iodine food, especially in cats on a low-iodine diet. So, avoid fish & seafood, dairy products, egg yolk, and iodized salts.

Secondly, avoid low-quality and plant-based proteins. Therefore, avoid foods like soy-based food, legumes, and wheat or corn gluten.

Thirdly, avoid a carbohydrate-heavy diet because it interferes with protein utilization by the cat’s body.

Lastly, avoid fish-based commercial cat foods that contain excessive iodine.

Feeding Tips for Hyperthyroid Cats

Managing a hyperthyroid cat’s diet properly can help maintain weight, prevent muscle loss, and support overall health.

• Always choose the right diet based on treatment.
• Feed smaller and more frequent meals because hyperthyroid cats have increased hunger. Therefore, give 4-6 small meals instead of 1-2 large ones.
• Provide fresh water all the time because hyperthyroid cats are more prone to dehydration due to increased thirst and urination.
• Monitor weight and muscle mass to track progress.
• Gradually transition to a new diet to avoid digestive upsets in cats.

Treating Hyperthyroidism in Cats

Treating hyperthyroidism is very important. If it is not treated, it can cause weight loss, heart disease, and high blood pressure. But thankfully, many result-yielding treatment options are available.

Medications are typically the initial treatment choice for managing hyperthyroidism in cats. Methimazole is a common medicine that stops the production of thyroid hormones. However, you must take it for life. If you stop taking it, your symptoms will come back.

Another treatment option is radioactive iodine therapy (I-131). Radioactive iodine therapy (I-131) is considered the gold standard treatment for hyperthyroidism in cats, with a success rate exceeding 95%.

A single dose of radioactive iodine specifically targets and eliminates hyperactive thyroid tissue. But it requires a hospital stay of a few days until radiation levels are safe.

Lastly, surgical thyroidectomy is a permanent but riskier treatment. In this method, the veterinarian removes the overactive thyroid gland(s) under general anesthesia. But it’s recommended when only one thyroid lobe is affected.

Conclusion

In conclusion, diet plays a crucial role in managing feline hyperthyroidism. In this article, we discussed the basics of hyperthyroidism in cats and its dietary management.

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