Why Does My Dog Look Weak? Causes Of Dog Muscle Atrophy

Why Does My Dog Look Weak? Causes Of Dog Muscle Atrophy

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Is your dog suddenly losing muscles? Does it look thinner and frail… Well, muscle atrophy might be the reason behind it. Muscle atrophy is a serious condition in which dogs start losing muscles triggered by various issues. So the question arises- Can muscle atrophy in dogs be reversed? And How? 

Well… The best way to reverse muscle atrophy is to find its root cause and fix the issue. It can be inactivity, not eating enough, or, in serious cases, due to underlying chronic health issues or injuries. So, Let’s find out what all can be the reason behind muscle atrophy in dogs. 

Genetic Causes behind Muscle Atrophy

Due to their genetic structure, different breeds are more prone to a few conditions. Muscle atrophy in some breeds is more genetically predisposed than others. Let’s look at some genetic disorders that might lead to muscle weakness in dogs. 

In Conditions like Duchenne Muscular Dystrophy (DMD gene) it leads to a lack of dystrophin in the system. Golden Retrievers and Rottweilers are breeds that are more prone to this condition. 

Other genetic conditions, like Myotonia Congenita, are due to a mutation (CLCN1 gene) affecting muscle cells’ chloride channels. This results in stiffness and loss of muscle mass. This is mainly seen in breeds like Miniature Schnauzers and Australian Cattle Dogs. 

A group of genetic disorders called Congenital Myasthenic Syndromes is caused by gene mutations affecting the neuromuscular system. This condition is identified in breeds like Jack Russell Terriers. 

Hereditary Myopathy of Labrador Retrievers (HMLR), also known as centronuclear myopathy (PTPLA gene).  Collie Eye Anomaly (CEA) with Muscle Atrophy (an eye condition caused by mutations of the NHEJ1 gene), some forms of which can also be associated with muscle atrophy in Collies and Shetland Sheepdogs.

Canine Degenerative Myelopathy (SOD1 gene) is a neurodegenerative condition affecting the spinal cord. It is mainly seen in German Shepherds, Pembroke Welsh Corgis, and Boxers. Spinal Muscular Atrophy (SMN gene) identified in Brittany Sapaniels also affects the spinal cord by degeneration of motor neurons. 

A severe muscle-wasting disorder, X-linked Myotubular Myopathy (MTM1 gene), is seen in Labrador Retrievers and related breeds.

Chronic Diseases Leading To Muscle Loss

Multiple diseases affect the muscular structure of dogs. Let’s find out what the reasons are that can lead to muscle atrophy in dogs. 

Chronic Kidney Disease is a progressive loss of kidney function that leads to malnutrition and toxin buildup. Chronic Heart Disease, like congestive heart failure, might result in reduced blood flow and oxygen delivery to muscles and overall weakness. Chronic liver conditions lead to poor nutrient absorption, metabolic imbalances, and overall systemic weakness.

Chronically high blood sugar levels (Diabetes Mellitus) affect the dog’s protein synthesis and lead to overall metabolic imbalances. Diabetic neuropathy also contributes to muscle atrophy.

An overproduction of cortisol (Cushing’s Disease or Hyperadrenocorticism) due to the adrenal or pituitary gland. Other symptoms might include a pot-bellied appearance, thinning skin, and hair loss.

An underactive thyroid gland (Hypothyroidism) leads to a slow metabolism. This condition leads to muscle weakness, lethargy, and eventually muscle atrophy. It is commonly seen in breeds like Golden Retrievers and Doberman Pinschers.

Chronic neuromuscular disorders, such as myasthenia gravis, affect dogs’ nerves and muscles. Autoimmune disorders like lupus, polyarthritis, or polymyositis cause chronic inflammation, pain, and muscle wasting. It is due to prolonged disease activity and reduced mobility. 

Cancers, particularly those affecting the muscles, bones, or nerves, are one of the other reasons. Cancer cachexia, a syndrome characterized by severe muscle and weight loss, occurs in advanced cancer stages. 

Secondary Causes Behind Muscle Atrophy

Apart from these genetic disorders and chronic diseases mentioned above, secondary reasons might fuel the degeneration of muscles in dogs. These can be: 

Injuries and trauma that might have affected the muscle tissues and nerves directly or indirectly. Accidents might occur due to bites or surgical complications, resulting in a loss of nerve supply. These severe wounds that penetrate muscle tissue cause direct damage to muscle fibers. 

Infections in muscle tissue (myositis) or near joints lead to inflammation, pain, and reduced mobility, contributing to muscle wasting.

Spinal cord injury from trauma like falls, car accidents, or intervertebral disc disease sometimes results in paralysis and loss of muscle below the site of injury. 

Not just the spinal cord, but to heal any broken bone, sometimes immobilization is required. In the same way, ruptured tendons, such as the Achilles tendon or ligament tears, cause loss of function in the associated muscles. This leads to muscle atrophy due to the inactivity of that site. In the same way, Injuries to joints cause pain and reduced movement of the affected limb. These might leave you wondering, is muscle atrophy in dogs painful? The answer is yes in most cases. 

Adequate nutrition is vital for maintaining muscle mass. Protein deficiencies can result to severe consequences. The body breaks down muscle tissue to meet its protein needs. We need to ensure a balanced diet tailored to our dog’s age, weight, and health condition preventing nutritional deficiencies and malnutrition. 

If your dog is not active, that might also lead to muscle loss. Regular exercise is crucial for maintaining muscle tone and mass. Dogs that are sedentary or do not receive sufficient exercise are at a higher risk of developing muscle atrophy. So, providing regular, appropriate exercise routine tailored according to the dog’s breed and health status significantly prevents muscle loss.


There might be various reasons leading to muscle atrophy in dogs. From genetic disorders to chronic diseases. Sometimes, muscle or nerve injury also might play a negative role in your dog’s muscle health. To learn the symptoms of muscle loss and how to reverse muscle atrophy in dogs, visit VetGen Pharmaceuticals.  

References: National Institute of Health