Soloxine for Dogs

Soloxine is a common medication given to dogs with hypothyroidism and has few lasting side effects. Since hypothyroidism is the most common autoimmune disease affecting dogs, many dogs will need this medication at some point in their lives.

Why Give Soloxine

Soloxine is the most common medication given to dog suffering from hypothyroidism, which means that the body doesn't produce enough thyroid hormones to perform all the functions a dog requires. The thyroid is involved in many bodily functions, including the stimulation of metabolism, growth, development and differentiation of certain tissues.

A dog with hypothyroidism may be difficult to detect because the symptoms are so subtle.

Symptoms of hypothyroidism include:

  • sudden weight gain
  • lethargy
  • dull coat
  • oily skin
  • skin lesions 
  • hair loss or excessive shedding

Soloxine replaces thyroid hormones, allowing your dog's body to keep up with the demands on the thyroid. If given the proper dosage, these symptoms should begin to subside in a few days.

How Soloxine Works

Soloxine is made of levothyroxine, also known as T4, the inactive thyroid hormone naturally produced in your dog's body. Studies have shown that in most cases, this is the hormone lacking in hypothyroidism.

T4 is then converted to the active form of the hormone, liothyronine (T3). In studies conducted on hypothyroid patients, doctors have found that once supplemented with T4, the patients have no problem converting T4 into T3. Thus, Soloxine supplements the body with the T4 hormone that may then be converted.

Soloxine is absorbed in the gastrointestinal tract and enters the blood stream, allowing your dog's body to begin conversion into active thyroid hormones.

Proper Dosage

There are eight dosage strengths of Soloxine, ranging from 0.1 to 0.8mg. The strength of the dosage depends on a variety of factors, including your dog's age, breed, size and level of hypothyroidism.

Studies have shown that 0.1mg of Soloxine produces the same results as one grain of dried out thyroid. Thus, the initial recommended dosage is 0.1mg per 10 pounds of your dog's body weight. However, initial dosage varies depending on your veterinarian's diagnosis and is usually determined by a thorough blood test that examines levels of thyroid hormones in your dog's blood stream.

Initially, monthly blood tests will help determine the correct dosage. These tests will be required annually after the first year on the medication.

Soloxine is given in pill form twice daily, at least an hour prior to mealtime to allow for proper absorption. Your dog will likely be on the medication for the remainder of his life.

Side Effects and Precautions

Dogs with heart disease or hypertension should only take Soloxine with veterinary supervision as the increased metabolic rate may be harmful.

There are few side effects associated with Soloxine, but if given an improper dose, your dog may experience symptoms of hyperthyroidism (overproductive thyroid), which include sudden weight loss, increased appetite, increased energy and skin problems.

In rare cases, your dog may experience an allergic reaction or more severe symptoms, such as difficulty sleeping, personality changes or fever. Your dog may also experience:

  • diarrhea
  • vomiting
  • skin rash
  • dizziness
  • loss of appetite