What Are the Causes of Dogs Sleeping Too Much?

The average amount of time a healthy dog generally sleeps is between 12 and 18 hours a day, according to Next Gen Dog, a dog information website. If your dog is sleeping more than he normally does, you should observe him for any other signs of illness. Then, bring him to a veterinarian for evaluation and treatment.

Little girl and dog sleeping together
Boring TV puts everyone to sleep.
credit: Design Pics/Design Pics/Getty Images

Medical Conditions Could Cause Sleepiness

Some medical conditions or medications could cause sleepiness. If you started your dog on a new medicine, and she's sleepier than normal, discuss this with your veterinarian right away.

Hypothyroidism, a common dog disease, could make your dog sluggish. The disease attacks the thyroid gland, which is responsible for metabolism. This disease is treatable with medication.

Diabetes is another common dog disease that could cause your dog to sleep more than she normally does. Instead of using glucose for energy, a dog with diabetes rids the glucose through urination. This results in lower energy levels for the dog. Lethargy is a later sign of diabetes. This disease is treatable.

Other diseases that could cause lethargy in dogs include:

  • Parvovirus
  • Distemper
  • Kennel cough
  • Heartworm
  • Leptospirosis
  • Heart disease
  • Liver disease

Dogs Can Be Depressed

Depression can lead to a dog sleeping too much. Maybe there was a death of a beloved canine or human housemate. Or maybe the absence of a favorite family member who has gone away to school or has been deployed in the armed forces is causing your dog to be depressed. Most dogs typically recover from depression within a few months, according to John Ciribassi, DVM and past president of the American Veterinary Society of Animal Behavior.

Age Plays a Part

Puppies sleep more than adult dogs do. Senior dogs, between 7 and 10 years and up, also need more sleep than younger, adult dogs do. Larger dogs reach senior status and exhibit signs of aging before smaller dogs do. Sometimes senior dogs become restless at night, which makes them sleepier during the day.

Miscellaneous Factors Play a Part

A combination of factors could affect how much any particular dog sleeps. The following are factors to help you determine whether your dog is sleeping a normal amount of time:

  • Larger dogs sleep more than smaller dogs do.
  • Inactive dogs sleep more than active or working dogs do. Inactive dogs often sleep because they are bored. So, if you have an inactive Maltese, for example, she might sleep more than what is typically normal for a small dog.
  • Poor quality dog food can make dogs feel sluggish, causing them to sleep more.

Why Dogs Sleep More than People Do

There are two types of sleep patterns for dogs: slow-wave sleep and rapid eye movement sleep. Rapid eye movement sleep is a deeper sleep, but dogs enter this sleep pattern only between 8 and 12 percent of their sleep time. Because dogs spend only a small percentage of time in deep sleep, they need to nap often to get enough rest, which is the reason you might find your dog napping on and off throughout the day and evening.