Myxedema and Myxedema Coma in Dogs
Myxedema coma is an uncommon condition in dogs characterized by an underactive thyroid gland (hypothyroidism). Dogs affected by myxedema exhibit symptoms such as feeling cold, extreme weakness, and mental dullness or depression. These animals experience a decrease in metabolism, oxygen production in their cells, and calorie production. This illness carries a high mortality rate, with affected animals potentially deteriorating from a depressed state to comatose and ultimately succumbing to the condition in a short period. Successful treatment hinges on early detection of the disorder and immediate, appropriate medical intervention.
The term myxedema refers to the swelling above the eyes and in the jowls observed in these patients. This swelling occurs due to an increase in dermal ground substances in their skin, which is the jelly-like material where collagen bundles are based.
Myxedema coma has been most frequently documented in Doberman pinschers.
Symptoms
- Weakness
- Lack of energy
- Low body temperature
- Low heart rate
- Slow breathing rate
- Collapse
- Swelling (myxedema) of the face and jowls
- Itchy skin or a poor hair coat
- Possible bluish-purple gums
- Mental dullness/depression
- Occurs as a result of severe hypothyroidism
Causes
- Severe primary hypothyroidism
- Infectious diseases
- Respiratory disease
- Depressants affecting the central nervous system or respiratory system (such as anesthetics and tranquilizers)
- Heart failure
- Hypovolemia (insufficient blood in the vessels, leading to low blood pressure)
- Exposure to cold environmental temperatures
Diagnosis
Your veterinarian will conduct a comprehensive physical examination of your pet, including a chemical blood profile, a complete blood count, a urinalysis, and an electrolyte panel. A specific blood test to measure thyroxine levels (the thyroid gland hormone that regulates metabolic rate) will help determine, along with clinical signs, whether your pet is experiencing myxedema. Providing a detailed history of your pet’s health, including the onset of symptoms, is crucial.
Additionally, chest and abdominal x-rays will be performed to check for effusion (excess fluid) and swelling in your pet’s lungs.
Treatment
Your veterinarian will use blankets to gently warm your pet and gradually raise its body temperature to a healthy level, taking care not to warm it too quickly, as this could pose a risk to its health. Fluid therapy may be administered as well. If your pet is experiencing difficulty breathing, it may be placed in an oxygen cage. However, if it has been deprived of oxygen for an extended period, it may require assistance from a respirator. Medications will be provided to boost your pet’s metabolism, and your veterinarian will likely prescribe antibiotics as part of the treatment plan.
Living and Management
Myxedema coma typically carries a serious prognosis. In many cases, patients who succumb to this condition have passed away within a day of initiating treatment, despite apparent improvement in their vital signs.