Muscle Loss in Senior Dogs: How to Preserve and Rebuild Muscle Mass

Subtle muscle loss is one of the earliest signs of ageing that I see in my patients. It often begins long before an owner notices any obvious change in their dog's weight, mobility or strength.

Once a dog has lost a significant amount of muscle, it can be very difficult to rebuild—particularly when there are other chronic health conditions to manage at the same time. It is much better to recognise the change early and start protecting muscle mass while your dog is still younger, active and well.

Muscle supports the joints, protects mobility and helps dogs remain physically independent as they age. Maintaining it is far easier than trying to rebuild it once a significant amount has gone.

Muscle loss begins before mobility changes

Dogs do not begin losing muscle at a particular age. Larger dogs tend to age earlier than smaller dogs, and health, activity level and genetics all influence how quickly muscle changes occur. A 2025 review of nutrition and ageing in dogs found that there is no reliable starting age or annual rate of muscle loss that applies to every dog.

We do know that older dogs tend to carry less lean tissue than younger dogs. A 2012 study found that healthy Labrador Retrievers over eight years of age had less muscle beside the spine than younger Labradors. A separate 2015 study also found less lean body mass in geriatric dogs.

This change may be well underway before your dog develops hind-leg tremors, slips on the floor or has difficulty rising. Body weight may remain stable because muscle is being lost while body fat increases.

How to check your dog's muscle condition

Body weight, body condition and muscle condition measure different things.

Body condition scoring mainly assesses fat. Muscle condition scoring looks at muscle. An overweight dog can still have moderate muscle loss hidden beneath the fat, which is why the number on the scale never gives the full picture.

The WSAVA muscle condition assessment involves looking at and feeling the muscles over:

• The skull
• The shoulder blades
• Both sides of the spine
• The pelvic bones

Run your hands slowly over these areas rather than relying only on what you can see. Healthy muscle should feel full and rounded. As muscle is lost, the bones underneath become easier to feel and the surrounding areas may appear flatter or hollowed.

Although formal scoring uses those standard areas, I often notice early changes over the gluteal muscles across the hindquarters and the triceps at the back of the upper front legs. Comparing both sides can also reveal uneven muscle loss caused by pain or reduced use of one limb.

As muscle loss becomes more advanced, you may notice:

• Taking longer to rise from the floor
• Hind legs trembling while standing
• Slipping more often
• Difficulty climbing stairs or getting into the car
• Becoming reluctant to jump
• Walking more slowly or tiring sooner
• Shifting weight away from one leg
• Losing confidence on uneven ground

These changes can also be caused by pain, joint disease or neurological problems, so they should not automatically be blamed on ageing.

When muscle loss may be caused by illness

Health conditions can cause inappropriate and accelerated loss of muscle mass. These include kidney disease, heart disease, cancer, chronic inflammation, joint pain and neurological disease.

Please bring your dog to your vet if the muscle loss:

• Appears suddenly or progresses quickly
• Is much more obvious on one side
• Occurs alongside unintentional weight loss
• Is accompanied by reduced appetite
• Causes weakness, falling or dragging of the feet
• Occurs with new pain or lameness
• Is accompanied by reduced exercise tolerance or difficulty breathing
• Develops alongside vomiting, diarrhoea or other signs of illness

Depending on the rest of the examination, your vet may recommend blood and urine tests, imaging, a joint or neurological assessment, or a review of your dog's diet.

How to preserve and build muscle

Maintaining muscle relies on three things working together: adequate nutrition, regular movement and good pain control. Medical conditions that contribute to muscle loss also need to be identified and managed.

Feed enough protein and calories

Healthy older dogs should not automatically be placed on a low-protein diet. Protein supplies the amino acids needed to maintain and repair muscle. As dogs age, they may also become less efficient at using dietary protein, so the amount that was adequate when they were younger may no longer be enough.

As a rough guide, many healthy adult and older dogs need at least around 2.5 grams of protein per kilogram of body weight each day. Some will need more depending on their age, activity level, calorie intake and health. A healthy 10-kilogram dog would therefore need at least approximately 25 grams of protein each day.

Protein requirements do not scale perfectly with body weight, so this is only a practical starting point. For an overweight dog, protein needs should be considered against their healthy target weight rather than their current weight.

The percentage printed on a food label can be misleading. A food described as 25% protein cannot be compared directly with another food unless moisture and calorie density are considered. To work out how much protein your dog is actually receiving, calculate the grams of protein in the amount of food they eat each day.

Protein quality depends on digestibility and the balance of essential amino acids, not simply whether a particular meat appears on the ingredient list. A complete and balanced diet is generally a better foundation than adding large amounts of meat, eggs or protein powder to an otherwise balanced food.

Your dog also needs enough calories. If they are eating too little overall, some dietary protein will be used for energy instead of maintaining muscle. Reduced appetite, dental pain, nausea and digestive disease need to be addressed rather than trying to compensate with a supplement.

If your dog has kidney disease

Kidney disease does not make muscle unimportant, but it does make nutrition more complicated.

Protein, phosphorus, calorie intake, appetite, kidney values and the stage of disease need to be considered together. Excessive protein restriction can contribute to muscle loss, while simply adding extra meat to a renal diet may increase phosphorus and unbalance the food.

If your dog has kidney disease and declining muscle condition, their diet should be reviewed individually with your vet or a veterinary nutritionist. The plan may involve adjusting the amount of food, treating nausea, changing the diet or checking whether another health condition is contributing.

Keep your dog moving

Protein provides the building material, but muscles still need to be used.

Canine research is more limited than human research, but the available findings support regular physical activity. In a small 2024 study, dogs completing eight weeks of jogging and strength exercises maintained their body weight while their thigh circumference increased. The study did not include a control group or advanced imaging of muscle, so the result is encouraging rather than conclusive.

Appropriate exercise for an older dog may include:

• Regular controlled walks
• Shorter walks more frequently if stamina is limited
• Gentle slopes
• Slow sit-to-stand exercises
• Carefully controlled stepping over low obstacles
• Swimming or underwater treadmill work where appropriate

Strength exercises should be slow and controlled. Three good sit-to-stands on a non-slip floor are more useful than ten rushed repetitions with your dog twisting, slipping or pushing unevenly through their legs.

Exercise should use the muscles without leaving your dog noticeably stiffer, more painful or more tired later that day or the following morning. Dogs with significant arthritis, heart or respiratory disease, spinal problems or neurological weakness may need a plan designed by their vet or a veterinary rehabilitation professional.

Manage pain early

A painful dog moves less. As activity falls, the muscles supporting the painful joint become weaker. The joint then has less support, making movement even more difficult.

Pain relief may be what allows your dog to walk properly, use the affected limb and participate in rehabilitation. Management may include medication, weight control, physiotherapy and changes around the home.

Non-slip flooring, ramps, supportive bedding and a well-fitted harness can make a considerable difference. A dog cannot rebuild much muscle if every attempt to stand begins with their feet sliding apart.

Can lost muscle be rebuilt?

Some muscle can often be rebuilt, particularly when the loss is mild and the cause can be corrected. Improvement becomes more difficult when muscle loss is advanced, mobility is severely limited or several health conditions are present.

Progress is usually gradual. Watch for practical changes such as rising more smoothly, walking with better control, standing without trembling and regaining some fullness over previously bony areas. Photographs taken from the same angle can help you follow changes, although feeling the muscles remains more useful than appearance alone.

If your dog continues to lose muscle despite eating well and exercising, the plan needs to be reassessed. Increasing exercise is not always the answer. Pain, poor nutrient absorption, hormonal disease, cancer, kidney disease, heart disease and neurological problems may all interfere with progress.

Do muscle-building supplements help?

Most dogs do not need a protein powder or muscle-building supplement if their diet, calorie intake, exercise and pain control are appropriate.

Many supplements are marketed using evidence taken from people or laboratory studies. Evidence that they meaningfully rebuild muscle in ordinary senior dogs is still limited. Omega-3 fatty acids may be useful for some dogs with arthritis or inflammatory disease, but they do not replace adequate protein and regular movement.

Before adding a supplement, check whether your dog is receiving enough protein and calories and whether there is a medical reason for the muscle loss.

What to Do This Week

Run your hands slowly over your dog's skull, shoulder blades, spine and pelvis, and compare both sides. Note how full or bony each area feels so you have a baseline. At your dog's next check-up, ask your vet to assess body weight, body condition and muscle condition separately. Once you know what your dog's normal muscle condition feels like, you will be far more likely to notice a small change before it begins to affect their mobility.

When to See a Vet Urgently

See your vet promptly if muscle loss appears suddenly, progresses quickly, is clearly worse on one side, or occurs with unintentional weight loss, reduced appetite, weakness, falling, dragging of the feet, new pain or lameness, difficulty breathing, or vomiting and diarrhoea.

This article is for educational purposes only and does not replace professional veterinary advice. If your dog is unwell, please consult your veterinarian.

Muscle is one of seven areas that matter most for supporting a longer, healthier life.

About the Author

Dr Kelly Yeo graduated from the University of Melbourne in 2009 and has extensive experience in companion animal medicine, with a special interest in geriatric care, chronic disease management, palliative care, and canine longevity.

Her work focuses on helping dogs live longer, healthier, and more comfortable lives through early detection, thoughtful nutrition, practical preventive care, and compassionate support for owners.