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Is your old dog losing weight and muscle mass? It's true that many dogs lose weight as they age, but weight loss can also signify an underlying health problem. Today's post looks at why senior dogs lose weight and what to do.

How Weight Affects Your Dog's Health

Much like people, our canine companions often change weight as they enter their senior years. Although it's often the case that dogs will put on extra pounds as they age, some dogs actually begin to lose weight as they age. So, why is your old dog losing weight but eating normally?

The possible reasons for weight loss in senior dogs fall into two categories, either your pup has an underlying condition that is resulting in weight loss or your dog’s aging process naturally results in your dog slimming down.

When To Be Concerned About Your Senior Dog Losing Weight

If your old dog is losing weight due to a health concern, there is a good chance the weight loss is related to one of eight conditions: liver/gallbladder disease, dehydration, dental issues, kidney disease, heart disease, diabetes, cancer, and arthritis. Each one of these health concerns needs to be diagnosed and addressed by your vet as early as possible to avoid further unnecessary decline in your pup's overall health.

Besides weight loss, if your dog has an underlying health concern you are likely to notice other symptoms as well. Contact your vet to make an appointment, then monitor your senior dog carefully and watch for other symptoms so that you are able to provide your veterinarian with as many details as possible about your dog's condition. Below are a few of the symptoms commonly associated with different health conditions.

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

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.

Sudden Unexplained Weight Loss

Sudden, notable weight loss is a serious cause for concern and shouldn't be ignored. If your dog has lost weight suddenly make an appointment with your vet right away to book an examination for your dog.

If you are concerned about your dog's weight in general, bring it up with your veterinarian at your senior dog's bi-annual routine exam.

Note: The advice provided in this post is intended for informational purposes and does not constitute medical advice regarding pets. Please make an appointment with your vet to accurately diagnose your pet's condition.

Concerned about your senior dog's weight loss? Contact our Windsor vets today to book an examination for your aging pup.

Looking for a vet in Windsor? We're accepting new patients!

Contact (860) 688-8400