Exercise Intolerance in Dogs

You may not even notice that your dog is having exercise intolerance if your dog spends a lot of time outdoors. That is why it is a good idea to exercise your dog every day, even if he has been outside all day. This can be going for a walk, playing fetch, or taking him to the dog park. If you do this, you will always know if your dog is not feeling his best. With EIC, your dog will likely collapse during extreme physical play such as an intense game of fetch or while hunting. They may become wobbly before they collapse. Some of the causes of exercise intolerance include heart disease, diabetes, myasthenia gravis, hypothyroidism, infection, anemia, and pulmonary disease.

Most healthy dogs are active and do not refuse or have any difficulty with getting up and going anywhere. Therefore, if your dog suddenly does not want to exercise or seems to tire much easier and sooner than usual, this is considered exercise intolerance. Some of the signs of this condition include general listlessness, sleeping more than usual, refusing to play, not running to greet you when you come home, weakness, and similar signs of being tired. If you notice any of these signs that last longer than 24 hours, you should call your veterinary care provider. A more severe case of exercise intolerance is exercise induced collapse (EIC), which usually affects Labrador Retrievers more than any other breed. In EIC, the dog will collapse after five or ten minutes of exercise for no obvious reason. You should get your dog to a veterinary care provider right away if your dog collapses.

The symptoms of exercise intolerance are different in every dog and may be difficult to notice in mild cases. Depending on the condition, the symptoms may get more noticeable with time. Some of the most commonly noticed symptoms are:

• Not wanting to play
• Laying around more than usual
• Sleepiness or tiredness
• Depression
• Weakness
• Panting or breathing heavy while exercising
• Wobbly gait (EIC)
• Increased body temperature (EIC)
• Collapse (EIC)

Types

• Exercise intolerance can involve any breed of any sex and age and has many different causes
• Exercise induced collapse (EIC) usually affects Labrador Retrievers, Pembroke Welsh Corgis, German Wirehaired Pointers, Curly-coated Retrievers, Chesapeake Bay Retrievers, and Boykin Spaniels

Genetics, as in Labrador Retrievers, Pembroke Welsh Corgis, German Wirehaired Pointers, Curly-coated Retrievers, Chesapeake Bay Retrievers, and Boykin Spaniels

• Heart disease such as heart failure, cardiomyopathy, or congenital heart disease
• Diabetes is common in older dogs
• Myasthenia gravis is an immune related disease that weakens the nerve impulses to the muscles
• Infections such as parvovirus or bronchial infection
• Anemia, which is caused by reduced red blood cells and iron
• Pulmonary diseases like pneumonia, chronic obstructive pulmonary disease (COPD), and bronchitis

You will need to provide your veterinary care provider with your dog’s immunization and medical history. In addition, tell the veterinarian when the symptoms started, if they have been progressive, and if you have seen any other abnormal behavior. Also, tell the veterinarian if you have given your dog any medications since this can affect diagnosis and treatment. A complete physical will be done along with a lameness analysis and vitals check. Your veterinarian will palpate and auscultate your dog’s vital organs and muscles. A neuromuscular examination will be performed next, checking your dog’s reflexes and other muscle functions.

The veterinarian may also want to hook your dog up to an electrocardiograph machine to check for possible heart malfunctions. The laboratory tests needed typically include urinalysis, fecal examination, blood count and culture, chemistry panel, and blood glucose level. The most important tests may be radiographs (x-rays), ultrasound, CT scan, and MRI. These can show any abnormalities in the muscles, bones, and vital organs. EIC can also be detected by a DNA test, but this is usually only done after all other causes are eliminated.

Your dog’s treatment plan depends on the examination and test results. If your veterinarian finds an underlying illness, that will need to be treated, which will usually take care of the exercise intolerance. Some of the treatments may include:

Heart Disease

Depending on the type of heart problem, this may be treated with medication or, in some cases, surgery to repair abnormalities.  

Diabetes

Diabetic dogs are treated with insulin shots that can be given by the owner on a daily basis or as needed. A special diet and daily exercise regimen are also necessary to keep blood sugar levels under control.

Myasthenia Gravis

This condition is treated with phenobarbital and special exercise training.

Infections

Depending on the type of infection, treatment is usually either an antibiotic or antiviral medication.

Anemia

The veterinarian may give your dog a blood transfusion if he is really anemic. Otherwise, a strict diet and regular check-ups are indicated.

Pulmonary Disease

These disorders can be treated with bronchodilators to clear the lungs and dilate the airways. In some cases, antibiotics and oxygen therapy are needed.

Your dog’s prognosis depends on the cause of the exercise intolerance. Overall, the outlook is good with treatment and followups. It is important to bring your dog back as directed for repeat laboratory tests.