While we are often concerned about our dogs becoming overweight, some canines start to lose weight as they age into their senior years. In this blog post, our Stanwood veterinarians discuss weight loss in senior dogs and when you should be concerned.

Why Your Old Dog May Be Losing Weight

If you notice that your older dog is losing weight, it may happen gradually, with subtle differences in their body, or suddenly, with a more significant drop in weight. Regardless of the pace of the weight loss, it is crucial to determine the underlying cause.

Sometimes, weight loss or muscle mass reduction in senior dogs may indicate an underlying health issue that could be serious. Therefore, it is essential to catch the problem early to manage the disease or illness and ensure that your older dog maintains the best possible quality of life during their golden years.

As you see your furry companion every day, it is easy for you to monitor any subtle changes, even if they seem insignificant at the time. Remember that every little change could be relevant to your vet. As your dog ages, it is especially important to watch for noticeable shifts in weight or appetite.

In this post, we will discuss some common causes of weight loss in dogs, when you should be concerned, how a dog can lose weight even if it eats, what to feed an old dog that is losing weight, and how to help your senior dog gain weight.

What Could Cause Weight Loss in Older Dogs?

It is important to have your dog diagnosed and treated by a veterinarian for any of these issues. Most of these health problems also have other symptoms that can accompany weight loss. If your senior dog is losing weight, the best thing you can do is to observe them for any other symptoms and inform the vet promptly.

The symptoms that can come with each condition are as follows:

Liver/gallbladder disease

      • Lethargy
      • Increased thirst
      • Vomiting/diarrhea
      • Fever
      • Pain 
      • Pale or yellow gums
      • Yellowing of skin/eyes


      • Dry gums 
      • Lethargy 
      • Sunken eyes
      • Loss of skin elasticity
      • Less urination
      • Dark urine

Dental Issues

      • Excessive drooling
      • Difficulty eating/chewing
      • Bad breath
      • Swollen or bleeding gums

Kidney disease

        • Increased thirst
        • Excessive urination (may contain blood)
        • Vomiting
        • Loss of appetite
        • Pale gums
        • Lethargy

Heart disease

      • A chronic cough
      • Tires easily
      • Exercise intolerance
      • Excessive panting
      • Irregular heartbeat
      • Restlessness


      • Excessive thirst
      • Excessive urination
      • Increased appetite
      • Lethargy
      • Repeated urinary tract infections


      • Lethargy
      • Unusual bleeding
      • Lumps, bumps, or swelling
      • Distended abdomen
      • Limping or lameness
      • Unusual urination – frequency or amount


      • Wobbling
      • Lameness
      • Scuffing the toes
      • Incontinence

If you notice that your senior dog is losing weight gradually, we recommend that you contact us to schedule a physical exam. However, if the weight loss is sudden and accompanied by other symptoms, it is crucial to take your dog to the veterinarian immediately to rule out any potential diseases or illnesses. Additionally, your veterinarian can develop a diet plan to counteract the weight loss and ensure that your dog is receiving the necessary nutrients and could possibly gain weight back.

Why Your Dog May Lose Weight if They're Still Eating

If your dog doesn't exhibit the aforementioned causes and symptoms, you may be perplexed as to why they're losing weight despite eating normally or exhibiting a normal appetite. Different justifications for this include:

  • Changes in diet - either the brand of food your senior dog is eating or its ingredients (i.e., sometimes kibble companies will change their recipe and the number of calories per serving) 
  • Liver disease
  • Maldigestion disorders that disrupt the body's ability to break food down into nutrients 
  • Malabsorption disorders such as inflammatory bowel disease 
  • Diseases such as diabetes, which can cause loss of weight and muscle mass

What To Feed an Old Dog That Is Losing Weight

If your vet can’t find an underlying health concern that could be causing your senior pup's weight loss, it's time to reconsider your dog's dietary needs. Speak to your vet about your dog's current diet and the amount of protein, fat, and fiber they are getting. Your vet can provide recommendations on what to feed an old dog that is losing weight.

Dietary changes may even be as simple as changing how often or how much you feed your dog each day, or your vet might recommend a different food to help meet your senior dog's nutritional needs. Veterinarians can also precisely calculate the number of calories your dog needs each day to stay healthy. This means that they can tell you exactly how much food to feed your dog at each meal and how often your pup should be fed to help them achieve a healthy weight.

Many reputable brands offer senior foods that are formulated to meet the precise needs of your aging pooch. Some of these foods can even help address age-related diseases such as arthritis and kidney disease.

Note: The advice provided in this post is intended for informational purposes and does not constitute medical advice regarding pets. For an accurate diagnosis of your pet's condition, please make an appointment with your vet.

If your senior dog is losing weight, contact our Stanwood vets right away to schedule an appointment for your dog.