AVC Blog

Weight Loss in Dogs

My dog is losing weight and I don’t understand why?
Weight loss in dogs may be associated with many normal and abnormal conditions. Weight loss is considered to be clinically significant when it exceeds ten percent of the normal body weight and when it is not associated with fluid loss or dehydration. For example, a healthy Golden Retriever weighing a breed-normal seventy pounds would have to lose over seven pounds before the weight loss would be considered clinically significant. Changes in diet, environment, or stress levels, including the addition of new pets, may lead to weight loss that is rarely permanent or significant.
Weight Loss in Dogs004
What causes my dog to lose weight?
Weight loss is the result of insufficient caloric intake relative to the body’s requirement. This may be caused by:

  • High energy demand associated with excessive physical activity or a hypermetabolic state
  • Inadequate or poor quality diet
  • Insufficient quantity of food intake associated with anorexia, swallowing disorders or regurgitation
  • Malabsorption and/or maldigestion disorders
  • Excessive loss of nutrients or fluid from vomiting, diarrhea, or excessive urination

What other signs should I look for?
Weight loss can affect any of the body’s organ systems. Questions that may provide insight into the cause of your dog’s weight loss include:

  • Is your dog’s appetite normal, increased or decreased?
  • Does your dog have a fever?
  • What kind, when, where and how much dog food are you feeding your dog?
  • How and where do you store your dog food?
  • How often do you administer your dog’s heartworm preventive and what type of preventative do you use?
  • Have you observed any regurgitation or vomiting, diarrhea or loose stools, or changes in water consumption or urination?
  • What color and consistency are your dog’s stools?
  • Has your dog been spayed or neutered?
  • Have you noticed your dog having any trouble swallowing?

What can be done to diagnose the cause of my dog’s weight loss?
A thorough medical history and physical examination will help your veterinarian determine the most useful diagnostic tests to perform. Blood and urine tests and radiographs are the most commonly recommended diagnostic tests.

What are some of the common diseases that cause weight loss?
There are many diseases that can cause weight loss. In fact, most chronic diseases will result in weight loss at some time during the course of the disease. However, some of the more common conditions associated with weight loss include:

  • Anorexia due to a behavioral condition or disease
  • Pseudoanorexia caused by loss of smell, inability to grasp or chew food, swallowing disorders, vomiting or regurgitation
  • Malabsorptive disorders that inhibit the body’s ability to absorb nutrients from the intestinal tract such as infiltrative and inflammatory bowel disease, lymphangiectasia, or severe intestinal parasitism
  • Maldigestive disorders that interfere with the body’s ability to break down food into usable nutrients. The most common condition is exocrine pancreatic insufficiency.
  • Metabolic disorders such as diabetes mellitus, hypoadrenocorticism (Addison’s disease), hyperthyroidism (rare in dogs, common in cats), and cancer.
  • Diseases involving the major organs (heart, liver or kidney)
  • Neuromuscular disease resulting in weakness or paralysis
  • Swallowing disorders
  • Central nervous system disease causing depression, anorexia or pseudoanorexia.
  • Increased caloric demand associated with excessive physical activity, prolonged exposure to cold, hyperthyroidism, pregnancy or lactation, fever, infection, inflammation and cancer.

What can be done to treat my dog’s weight loss?
Treatment will be determined by the specific cause of your dog’s weight loss. Once a specific diagnosis is made, treatment to improve your dog’s quality of life will be immediately initiated.

What is the prognosis for my dog’s weight loss?
The prognosis ranges from grave to excellent depending on your dog’s specific diagnosis. A thorough medical history, complete physical examination and appropriate diagnostic testing will assist your veterinarian in determining the best course of treatment for your pet.

This client information sheet is based on material written by Ernest Ward, DVM.
© Copyright 2005 Lifelearn Inc. Used with permission under license. December 30, 2008