{"id":628328,"date":"2024-05-20T12:21:41","date_gmt":"2024-05-20T16:21:41","guid":{"rendered":"https:\/\/www.singlecare.com\/blog\/?p=628328"},"modified":"2024-10-25T09:56:53","modified_gmt":"2024-10-25T13:56:53","slug":"synthroid-for-dogs","status":"publish","type":"post","link":"https:\/\/www.singlecare.com\/blog\/synthroid-for-dogs\/","title":{"rendered":"Synthroid for dogs"},"content":{"rendered":"

Synthroid<\/span><\/a> is a brand-name prescription drug that treats underactive thyroid (hypothyroidism) in people, but it’s not commonly used in dogs. The active ingredient in Synthroid is levothyroxine sodium, a synthetic version of the thyroid hormone thyroxine (T4). Thyroxine regulates many critical functions in the body, including metabolism, energy, oxygen consumption, protein synthesis, blood volume, body temperature, chemical reactions, heart rate, and growth. An underactive thyroid causes several health problems. <\/span><\/p>\n

Like people, dogs commonly experience <\/span>underactive thyroid<\/span><\/a> and are treated with levothyroxine. However, levothyroxine doses are substantially higher in dogs than in people. Synthroid and generic levothyroxine tablets prescribed to humans come in tablets that are too low for most dogs. Veterinarians may prescribe Synthroid to a dog but will more often use higher-dose levothyroxine tablets, which the U.S. Food and Drug Administration approves for use in dogs.<\/span><\/p>\n

RELATED: <\/b>Save up to 80% on Synthroid<\/b><\/a><\/p>\n

What is Synthroid used for in dogs?<\/span><\/h2>\n

Synthroid can treat underactive thyroid in dogs, but veterinarians are more likely to use <\/span>levothyroxine<\/span><\/a> formulated specifically for dogs.<\/span><\/p>\n

Hypothyroidism<\/span><\/h3>\n

The thyroid gland produces two critical hormones: thyroxine (T4) and triiodothyronine (T3). Hypothyroidism is when the thyroid gland does not produce enough thyroid hormones. It is a common medical condition in people and dogs, particularly middle-aged and older dogs between <\/span>four and 10 years of age<\/span><\/a>. Some breeds are more <\/span>predisposed to hypothyroidism<\/span><\/a>, such as Labrador Retrievers, Golden Retrievers, Doberman Pinschers, Beagles, Boxers, and Border Collies. <\/span><\/p>\n

When the thyroid produces too little thyroid hormone in a dog, owners will notice changes in the dog, including lack of energy, decreased activity level, weight gain, hair loss, “rat tail,” poor hair coat quality, dullness, and cold sensitivity (the dog will exhibit heat-seeking behaviors). Low thyroid hormone also causes multiple abnormalities, such as high cholesterol, that can eventually cause serious health issues in the dog.<\/span><\/p>\n

Hypothyroidism has many causes. The problem can be that the thyroid gland does not secrete enough thyroid hormone (primary hypothyroidism) or that the pituitary gland does not secrete enough hormone (<\/span>TSH<\/span><\/a>) to tell the thyroid to produce thyroid hormone (secondary hypothyroidism). No matter what the cause, hypothyroidism is treated in one way: thyroid hormone replacement. Among the possible thyroid hormone supplementation therapies, the standard choice is daily doses of oral levothyroxine. <\/span><\/p>\n

In most dogs, hypothyroidism is a lifelong condition, so pet owners will give the dog levothyroxine tablets every day for the rest of the dog’s life. <\/span><\/p>\n

RELATED: <\/b>How to treat hypothyroidism in dogs<\/b><\/a><\/p>\n

Is Synthroid safe for dogs?<\/span><\/h2>\n

When used at the appropriate dose, Synthroid will only rarely cause problems in a dog. <\/span><\/p>\n

However, Synthroid should never be given to a dog that has recently had a heart attack. Other contraindications are overactive thyroid (hyperthyroidism) and untreated Addison’s disease, a condition in which the adrenal gland does not produce enough cortisol, the body’s primary “stress” hormone. Synthroid should never be given to a euthyroid dog (a dog with healthy thyroid function).<\/span><\/p>\n

Because of potential problems, veterinarians use levothyroxine cautiously in dogs with an overactive adrenal gland, heart disease, or <\/span>diabetes<\/span><\/a>. They will also be careful when using it in senior dogs. <\/span><\/p>\n

Side effects of Synthroid in dogs<\/span><\/h3>\n

When the Synthroid dose is appropriate, dogs rarely experience adverse reactions. Levothyroxine is chemically very similar to thyroxine, a natural hormone always present in a dog’s system.<\/span><\/p>\n

Dogs may experience side effects if the dose is too high, but dogs are more resistant to levothyroxine overdoses than other animals. Symptoms of a levothyroxine overdose closely resemble the symptoms of hyperthyroidism, a condition in which the thyroid gland produces too much thyroid hormone.<\/span><\/p>\n

Interactions of Synthroid with other pet meds<\/span><\/h3>\n

Before giving a dog levothyroxine tablets, tell the prescribing veterinarian about all the drugs, supplements, and foods that the dog takes. Since thyroxine hormones affect nearly every system in a dog’s body, levothyroxine has many significant drug and food interactions. The most significant include:<\/span><\/p>\n