Muscle Wasting During Injury Recovery: Why It Happens—and How to Get Ahead of It

Muscle wasting is a common yet frequently underestimated consequence of injury and orthopedic surgery in companion animals. While recovery protocols often prioritize pain control, tissue healing, and return to function, loss of lean muscle mass can significantly delay rehabilitation and negatively impact long-term mobility if not addressed proactively.

Understanding the mechanisms behind muscle loss—and intervening before and after surgery—allows veterinary teams to better preserve strength, support mobility, and improve overall recovery outcomes.

Why Muscle Wasting Occurs During Injury and Recovery

Muscle loss during injury recovery is driven by multiple overlapping physiological processes and can begin within days of reduced activity.

1. Disuse Atrophy

Pain, lameness, or post-surgical confinement results in decreased mechanical loading of skeletal muscle. Reduced muscle contraction leads to downregulation of muscle protein synthesis and increased proteolysis, resulting in rapid loss of lean mass.

2. Inflammatory and Catabolic Signaling

Injury and surgical intervention initiate both local and systemic inflammatory responses. Pro-inflammatory cytokines (including TNF-α and IL-6) promote catabolic pathways while suppressing anabolic signaling, creating an environment that favors muscle breakdown even in patients receiving adequate calories.

3. Metabolic Stress and Anabolic Resistance

During recovery, many patients experience a state of anabolic resistance, where normal nutritional intake alone is insufficient to stimulate muscle protein synthesis. This is particularly relevant in aging patients and those recovering from orthopedic trauma or surgery.

4. Age and Concurrent Disease

Senior animals and patients with chronic conditions are inherently more susceptible to muscle loss and often have a reduced capacity to rebuild muscle once it has been lost. In these cases, recovery-related muscle wasting may be more pronounced and less reversible without targeted intervention.

Why Muscle Preservation Matters

Loss of lean muscle mass has direct clinical consequences beyond visible atrophy, including:

• Delayed return to function and weight-bearing
• Increased biomechanical stress on joints and compensatory limbs
• Reduced stability and endurance during rehabilitation
• Prolonged recovery timelines and risk of incomplete functional recovery

Preserving muscle should be considered an integral component of injury and surgical recovery, not a secondary concern.

Getting Ahead of Muscle Loss Before Surgery

When surgery is planned—particularly for orthopedic conditions—there is a critical opportunity to support muscle health before periods of enforced rest or reduced activity begin.

Preoperative Muscle Support

Optimizing muscle condition prior to surgery can help mitigate the degree of post-operative atrophy. This is especially important in:

• Senior patients
• Animals with chronic lameness or joint disease
• Patients already showing signs of muscle asymmetry or weakness

Prehabilitation strategies that focus on muscle preservation can improve resilience during recovery and support better post-surgical outcomes.

Supporting Muscle Health After Surgery

Early and Ongoing Intervention

Muscle loss progresses rapidly during confinement and restricted activity. Interventions aimed at muscle preservation should begin early in the recovery process and continue throughout rehabilitation.

Effective post-operative muscle support may include:

• Adequate pain management to facilitate safe movement
• Gradual, controlled rehabilitation when appropriate
• Targeted support of muscle protein synthesis to counteract disuse atrophy

Fortetropin®: Targeted Support for Muscle Protein Synthesis

Fortetropin®, the bioactive compound found in MYOS® products, has been shown to stimulate muscle protein synthesis through pathways distinct from conventional nutritional approaches.

Importantly, Fortetropin® supports muscle health without relying on increased dietary protein intake, making it a valuable option for:

• Senior patients
• Patients with limited activity or prolonged confinement
• Animals where excessive protein intake may be undesirable

By helping to support muscle protein synthesis during periods of reduced activity, Fortetropin® can be incorporated both before and after surgery to help preserve muscle mass and support functional recovery.

A More Proactive Approach to Recovery

Muscle wasting during injury recovery is predictable, rapid, and clinically significant—but it is also modifiable. By identifying at-risk patients early and implementing targeted muscle-support strategies, veterinary teams can improve recovery trajectories and long-term mobility outcomes.

Preserving muscle should be viewed as a foundational element of recovery. Early intervention—before surgery and throughout rehabilitation—can make a meaningful difference in patient strength, mobility, and quality of life.