Myopathy (various types)

Myopathy is a general term referring to any disease that primarily affects muscle tissue, causing weakness, pain, or dysfunction. In cats, myopathies represent a diverse group of conditions with varying causes, presentations, and outcomes. These muscle disorders can be inherited, acquired through immune-mediated processes, result from metabolic disturbances, or develop secondary to toxins or nutritional deficiencies. Understanding that myopathy is an umbrella term encompassing many specific conditions is important for cat owners facing a diagnosis, as the specific type of myopathy significantly influences treatment options and prognosis.

The causes of feline myopathies span a broad range of mechanisms that damage or impair muscle function. Inherited myopathies result from genetic mutations that affect muscle cell structure or function, with certain breeds showing predisposition to specific forms. Inflammatory myopathies involve immune system attack on muscle tissue, causing inflammation and damage. Metabolic myopathies result from defects in energy production pathways that muscles rely upon. Endocrine disorders such as hyperthyroidism and hypothyroidism can cause secondary muscle dysfunction. Nutritional deficiencies, particularly of certain vitamins and minerals, can impair muscle function. Toxic myopathies develop from exposure to substances that damage muscle tissue.

The impact of myopathy on affected cats varies dramatically depending on the specific type and severity. Some myopathies cause mild weakness that minimally affects daily life, while others result in severe disability or life-threatening complications. Generalized weakness affecting mobility is common across many myopathy types. Some myopathies selectively affect certain muscle groups, leading to specific functional deficits. Muscle pain may accompany inflammatory forms, affecting the cat's comfort and behavior. In severe cases, respiratory muscles may be involved, creating life-threatening breathing difficulties. The progressive versus stable nature of symptoms depends on the underlying cause.

Treatment and prognosis for feline myopathies vary significantly based on the specific diagnosis. Some acquired myopathies respond well to treatment and may resolve completely, while inherited forms are generally permanent but may be managed to maintain quality of life. Early accurate diagnosis is crucial for optimal outcomes, as specific treatments exist for certain myopathy types while others require supportive care. Veterinary evaluation should be sought for any cat showing signs of muscle weakness or dysfunction, as prompt diagnosis allows appropriate treatment and management planning.

The primary causes of myopathies in cats fall into several categories based on the underlying mechanism of muscle damage. Inherited myopathies result from genetic mutations affecting proteins essential for normal muscle structure or function. These include muscular dystrophies, congenital myopathies, and metabolic myopathies caused by enzyme deficiencies. Inflammatory myopathies occur when the immune system attacks muscle tissue, with polymyositis being the most common form in cats. Infectious agents including Toxoplasma gondii can cause inflammatory muscle disease. Endocrine myopathies develop secondary to hormonal imbalances, particularly hyperthyroidism and hyperadrenocorticism. Drug-induced and toxic myopathies result from exposure to substances that directly damage muscle cells.

Genetic and hereditary factors play a significant role in certain feline myopathies. Hereditary myopathy in Devon Rex and Sphynx cats is a well-documented autosomal recessive condition causing progressive muscle weakness. Hypokalemic myopathy in Burmese cats results from an inherited tendency toward low blood potassium. Muscular dystrophy has been reported in certain cat populations, involving mutations in genes encoding structural muscle proteins. Glycogen storage diseases affecting muscle are rare inherited metabolic disorders. The mode of inheritance varies by specific condition, with most being autosomal recessive, meaning both parents must carry the defective gene for offspring to be affected.

Environmental and lifestyle factors contribute to some acquired myopathies in cats. Nutritional myopathies can develop from diets deficient in essential nutrients such as vitamin E, selenium, or taurine. Cats fed certain types of fish-based diets may develop steatitis (inflammation of fat) that can affect muscle. Sedentary lifestyle does not directly cause myopathy but may unmask mild weakness that would otherwise go unnoticed. Exposure to certain toxins, medications, or plants can cause toxic myopathy. Severe physical trauma can damage muscle tissue. Environmental conditions that promote certain infectious agents may increase risk of infectious myopathy.

Risk factors for developing myopathy depend on the specific type. For inherited myopathies, belonging to an affected breed or having affected relatives constitutes the primary risk factor. Advanced age increases risk for some acquired myopathies. Cats with other autoimmune conditions may be at higher risk for inflammatory myopathy. Underlying metabolic or endocrine diseases predispose to secondary myopathy. Outdoor cats may have higher exposure to infectious agents causing myositis. Cats on certain long-term medications may be at risk for drug-induced myopathy. Feeding inappropriate diets increases risk of nutritional myopathy.

The mechanisms of muscle damage vary by myopathy type but ultimately result in impaired muscle cell function or death. In inflammatory myopathies, immune cells infiltrate muscle tissue and attack muscle fibers, causing necrosis and replacement with fibrous tissue. Inherited myopathies involve defective structural proteins that compromise muscle fiber integrity or metabolic enzymes that impair energy production. Metabolic myopathies prevent muscles from generating adequate energy for contraction. Endocrine myopathies alter protein metabolism, leading to muscle protein breakdown. Toxic myopathies may directly damage muscle cell membranes or interfere with cellular processes. Understanding these mechanisms helps guide appropriate treatment approaches.

Early warning signs of myopathy in cats can be subtle and easily attributed to other causes or normal aging. Mild exercise intolerance, where the cat tires more quickly during play, may be an early indicator. Subtle changes in gait, such as a slight stiffness or awkwardness in movement, can precede obvious weakness. Cats may show reluctance to jump or climb, preferring to stay at floor level. Slight changes in posture when sitting or lying down may reflect muscle discomfort or weakness. Decreased activity level that owners might attribute to laziness could indicate developing muscle problems. Because cats naturally hide illness, early myopathy signs are frequently missed until more obvious symptoms develop.

Common symptoms of myopathy include generalized muscle weakness that affects the cat's ability to perform normal activities. Affected cats often have difficulty jumping, climbing stairs, or walking for extended periods. A stiff, stilted, or choppy gait is characteristic of many myopathies. Muscle wasting (atrophy) may be visible, particularly over the hindquarters, spine, and shoulders. Some cats develop a plantigrade stance, walking flat on their hocks rather than on their toes. The classic ventroflexion of the neck, where the cat cannot hold its head up normally, occurs in certain myopathies, particularly those associated with potassium deficiency. Muscle pain may cause cats to vocalize or resist being touched.

Behavioral changes associated with myopathy reflect the cat's physical limitations and potential discomfort. Affected cats typically become less active and may spend increased time resting or sleeping. Play behavior diminishes, and cats may show little interest in toys or activities they previously enjoyed. Appetite may decrease, particularly if the cat experiences pain or has difficulty accessing food and water. Some cats become withdrawn or hide more than usual. Irritability or aggression when touched may indicate muscle pain. Changes in grooming behavior occur if weakness or pain makes self-grooming difficult. Altered litter box habits may develop if the cat has difficulty getting in and out of the box.

Physical signs of myopathy extend beyond obvious weakness to include several characteristic findings depending on the specific type. Muscle atrophy gives the cat a thin, bony appearance with prominent skeletal landmarks. Some myopathies cause muscle enlargement (pseudohypertrophy) where muscle is replaced with fat or fibrous tissue. Tremors or twitching of affected muscles may be visible. The cat may have difficulty maintaining normal postures, tending to sit or lie down frequently. Respiratory abnormalities including rapid, shallow breathing may indicate respiratory muscle involvement. In some inflammatory myopathies, muscle swelling and firmness may be palpable. Skin changes may accompany certain myopathy types, particularly dermatomyositis.

Symptom progression in myopathies varies considerably by type. Inherited myopathies often follow a predictable progressive course, with symptoms worsening over months to years. Some inflammatory myopathies can develop acutely over days to weeks, while others have a more chronic course. Metabolic and endocrine myopathies may fluctuate with the underlying condition. Drug-induced myopathies typically improve when the offending medication is discontinued. Nutritional myopathies improve with appropriate dietary correction. Some cats experience episodic weakness with periods of relative normality between episodes. Understanding the expected progression helps owners and veterinarians plan appropriate management.

Emergency symptoms requiring immediate veterinary attention include severe respiratory distress, which may indicate respiratory muscle failure. Sudden collapse or inability to stand represents a critical situation. Severe neck ventroflexion preventing the cat from eating or drinking is an emergency. Signs of severe pain such as continuous vocalization or aggression require urgent evaluation. Dark brown or red-colored urine may indicate rhabdomyolysis (severe muscle breakdown) releasing muscle proteins into blood and urine. Rapid progression of weakness over hours to days warrants emergency care. Any cat showing difficulty breathing due to suspected muscle disease needs immediate veterinary attention.

The initial examination for suspected myopathy includes comprehensive physical and neurological assessment. The veterinarian will gather detailed history about symptom onset, progression, diet, medication exposure, and any known family history of muscle disease. Physical examination evaluates overall muscle mass, tone, and any palpable abnormalities such as swelling, firmness, or pain response. Neurological examination distinguishes myopathy from neurological conditions by assessing reflexes, proprioception, and nerve function. Gait analysis reveals characteristic patterns of muscle weakness. The examination helps determine whether weakness is generalized or affects specific muscle groups, guiding further diagnostic testing.

Diagnostic tests for myopathy aim to confirm muscle involvement and identify the specific underlying cause. Blood work includes measurement of muscle enzymes, particularly creatine kinase, which is released from damaged muscle cells and is often markedly elevated in active myopathy. Complete blood count and biochemistry panel screen for underlying conditions that might cause secondary myopathy. Thyroid hormone levels evaluate for hyperthyroidism or hypothyroidism. Electrolyte measurements, especially potassium, are essential as hypokalemia is a common cause of feline myopathy. Specific tests for infectious causes such as Toxoplasma antibodies may be indicated. Acetylcholine receptor antibody testing helps distinguish myasthenia gravis from primary myopathy.

Advanced diagnostics may be necessary to definitively characterize the myopathy. Electromyography records electrical activity in muscles, revealing abnormal patterns characteristic of myopathy and distinguishing muscle disease from nerve disease. Muscle biopsy provides tissue for histopathological examination, allowing visualization of muscle fiber changes, inflammatory infiltrates, and specific features that identify certain myopathy types. Immunohistochemistry on biopsy samples can identify specific protein deficiencies in inherited myopathies. Genetic testing is available for some hereditary myopathies and can provide definitive diagnosis. Advanced imaging such as MRI may visualize patterns of muscle involvement in complex cases.

Differential diagnosis for myopathy must consider the many conditions that can cause muscle weakness in cats. Neurological diseases affecting nerves or spinal cord cause weakness but typically show different examination findings. Myasthenia gravis affects the neuromuscular junction rather than muscle itself and has specific diagnostic tests. Metabolic disorders such as diabetes and liver disease can cause weakness that mimics myopathy. Joint disease may be mistaken for muscle weakness when pain limits movement. Cardiac disease can cause exercise intolerance resembling myopathy. Careful integration of history, examination findings, and diagnostic test results allows accurate diagnosis of myopathy and identification of its specific cause.

Emergency and immediate treatment for myopathy addresses acute crises and stabilizes severely affected cats. Cats with respiratory distress from respiratory muscle weakness require oxygen supplementation and potentially intensive care. Severe hypokalemic myopathy requires careful intravenous potassium supplementation, as dangerously low potassium levels can cause life-threatening muscle weakness including paralysis and cardiac effects. Rhabdomyolysis with myoglobinuria requires aggressive fluid therapy to prevent kidney damage from muscle protein released into the bloodstream. Nutritional support ensures adequate caloric intake in cats too weak to eat normally. Pain management may be needed for painful inflammatory myopathies.

Medical management of myopathy depends entirely on the underlying cause. Inflammatory myopathies typically respond to immunosuppressive therapy, with corticosteroids being the first-line treatment. Prednisone or prednisolone is started at immunosuppressive doses and gradually tapered based on response. For refractory cases, additional immunosuppressive agents such as azathioprine or cyclosporine may be added. Infectious myositis requires appropriate antimicrobial therapy targeted at the causative organism. Hypokalemic myopathy responds to potassium supplementation, either orally for chronic management or intravenously for acute crises. Endocrine myopathies improve with treatment of the underlying hormonal disorder. Drug-induced myopathy typically resolves when the offending medication is discontinued.

Surgical options for myopathy are limited as these are primarily medical conditions. In rare cases where myopathy results from a tumor or other mass requiring removal, surgery may be indicated. Muscle biopsy, while diagnostic rather than therapeutic, is a minor surgical procedure that may be necessary for definitive diagnosis. Some cats with severe muscle contractures may benefit from surgical release procedures, though this is uncommon. The role of surgery in myopathy management is generally minimal compared to medical treatment and supportive care.

Supportive care is essential for all cats with myopathy regardless of the underlying cause. Physical therapy helps maintain muscle function and prevent contractures in cats with chronic weakness. Gentle range of motion exercises keep joints flexible. Assisted standing and walking exercises help maintain strength in mobile cats. Environmental modifications make daily activities easier for weak cats, including low-sided litter boxes, elevated food and water dishes, and comfortable resting areas at floor level. Nutritional support through high-quality diet maintains overall health and provides substrate for any possible muscle recovery.

Alternative and complementary treatments for myopathy may supplement conventional management. Acupuncture has been used for pain management and may support muscle function in some cases. Omega-3 fatty acid supplementation may have anti-inflammatory effects beneficial in inflammatory myopathies. Carnitine supplementation may be helpful in certain metabolic myopathies. Coenzyme Q10 supplementation has theoretical benefits for mitochondrial function. Physical rehabilitation including hydrotherapy, when available, supports muscle function and recovery. These complementary approaches should be discussed with the veterinarian and used alongside, not instead of, appropriate medical treatment.

Treatment decisions for myopathy depend on the specific diagnosis, prognosis, and owner circumstances. Acquired myopathies with treatable underlying causes often have favorable outcomes with appropriate therapy. Inherited myopathies generally cannot be cured but may be managed to maintain quality of life for extended periods. The cost of diagnosis can be substantial, particularly if advanced testing such as muscle biopsy is needed. Ongoing treatment costs vary by condition, from relatively inexpensive potassium supplementation to costly immunosuppressive therapy and regular monitoring. Quality of life must be regularly assessed, with honest discussions about prognosis and humane end-of-life decisions when appropriate.

The recovery timeline for myopathy varies dramatically depending on the underlying cause and its treatability. Cats with hypokalemic myopathy often show rapid improvement within days once potassium levels are corrected. Inflammatory myopathies typically respond to immunosuppressive therapy over weeks, with gradual improvement in strength as inflammation subsides. Drug-induced myopathies usually resolve within weeks after the offending medication is stopped. Nutritional myopathies improve over weeks to months with dietary correction. Inherited myopathies do not recover in the traditional sense but may stabilize with appropriate management. Endocrine myopathies improve as the underlying hormonal condition is controlled, though full recovery may take months.

Post-treatment care for cats recovering from myopathy requires ongoing attention to ensure continued improvement and prevent relapse. Medication schedules must be followed carefully, with particular attention to gradual tapering of immunosuppressive drugs rather than abrupt discontinuation. Physical activity should be gradually increased as strength improves, avoiding overexertion that might cause setbacks. Nutritional support continues throughout recovery to provide substrates for muscle rebuilding. Regular monitoring of blood work, particularly muscle enzymes and any parameters related to the underlying cause, tracks recovery progress. Follow-up appointments allow assessment of improvement and medication adjustments.

Prognosis factors for myopathy include the specific underlying cause, severity at diagnosis, response to treatment, and presence of any permanent muscle damage. Treatable acquired myopathies such as hypokalemic myopathy and many inflammatory myopathies generally have favorable prognosis with appropriate therapy. Infectious myopathies often resolve with antimicrobial treatment. Drug-induced and nutritional myopathies typically resolve once the offending factor is addressed. Inherited myopathies have more guarded prognosis, as the underlying genetic defect cannot be corrected. Severity at diagnosis matters, as cats with severe muscle wasting or contractures may never fully recover even if the underlying process is controlled.

The long-term outlook for cats with myopathy depends on achieving and maintaining control of the underlying cause. Many cats with treatable myopathies achieve full functional recovery and return to normal activities. Some cats require ongoing management to maintain remission, such as continued immunosuppressive therapy for inflammatory myopathy or dietary supplementation for metabolic conditions. Inherited myopathies may progress despite management, though the rate of progression varies by specific condition and individual. Regular veterinary monitoring helps detect any deterioration early and allows treatment adjustment. Quality of life assessment should be ongoing, with realistic discussions about long-term expectations based on the specific diagnosis.

Primary prevention of myopathy focuses on avoiding known causes and identifying at-risk individuals. For inherited myopathies, responsible breeding practices are the primary prevention strategy. Breeds with documented hereditary myopathies should have breeding animals tested using available genetic tests, and affected individuals or known carriers should not be bred. Potential buyers of at-risk breeds should inquire about health testing and family history. Prevention of acquired myopathies involves avoiding known causative factors when possible. Feeding complete and balanced commercial diets appropriate for cats prevents nutritional myopathies. Avoiding unnecessary medications and monitoring for side effects when medications are needed reduces drug-induced myopathy risk.

Environmental prevention strategies for myopathy focus on reducing exposure to causative factors. Keeping cats indoors reduces exposure to infectious agents that can cause myositis, including Toxoplasma from hunting infected prey. Avoiding exposure to known muscle toxins protects against toxic myopathy. Maintaining a low-stress environment may help reduce risk of some immune-mediated conditions. Providing regular opportunities for moderate exercise maintains overall muscle health. Environmental enrichment encourages activity that supports muscle conditioning. For cats with known risk factors, careful monitoring allows early detection of developing problems.

Dietary prevention of myopathy centers on providing complete and balanced nutrition. Commercial cat foods formulated to meet established nutritional standards provide all necessary nutrients for muscle health. Home-prepared diets should be formulated with veterinary guidance to ensure nutritional completeness. Taurine deficiency, once a common cause of feline health problems including myopathy, is prevented by feeding appropriate diets. Vitamin E and selenium at appropriate levels support muscle health. Avoiding certain fish-based diets that can cause steatitis prevents this specific nutritional problem. For breeds with metabolic myopathies, specific dietary modifications may help manage the condition.

Health maintenance through regular veterinary care supports prevention and early detection of myopathy. Annual wellness examinations allow assessment of muscle mass, strength, and any developing abnormalities. Screening blood work can detect electrolyte abnormalities, thyroid dysfunction, and other conditions that might lead to secondary myopathy before muscle symptoms develop. Prompt attention to any signs of weakness or movement abnormalities allows early diagnosis and treatment. Monitoring cats on long-term medications for signs of drug-induced myopathy enables early intervention. Keeping vaccinations current and managing parasite prevention supports overall health.

Early intervention when myopathy is suspected improves outcomes for many types. Recognizing early signs of weakness, gait changes, or decreased activity and seeking veterinary evaluation promptly allows diagnosis before severe muscle damage occurs. For treatable myopathies, early treatment typically produces better outcomes than delayed intervention. For inherited myopathies that cannot be cured, early diagnosis allows implementation of supportive management and realistic planning. Owners of at-risk breeds should be educated about symptoms to watch for. When myopathy is diagnosed in a breeding animal, responsible breeders should modify breeding programs to reduce disease transmission.

Daily management of a cat with myopathy requires adaptation to the cat's capabilities while maintaining quality of life. Medication administration must be consistent, particularly for cats on immunosuppressive therapy or supplements for metabolic conditions. Monitoring for changes in strength, mobility, and overall condition should be part of the daily routine. Feeding appropriate diet, potentially modified for the specific myopathy type, supports muscle health. Activity should be encouraged within the cat's capabilities, as complete inactivity leads to further muscle weakening. Rest periods should be respected when the cat tires, avoiding pushing beyond comfortable limits.

Home environment modifications make daily life easier and safer for cats with myopathy. Ramps or pet stairs provide access to favorite elevated spots without requiring jumping that weak muscles may not support. Litter boxes with low sides or cut-out entries allow easy access for cats with mobility limitations. Food and water should be placed at comfortable heights and locations to minimize effort required to eat and drink. Non-slip surfaces help cats with weak limbs maintain footing. Comfortable, padded bedding supports weakened muscles during rest. Warm, draft-free resting areas are particularly important as muscle weakness can affect temperature regulation.

Maintaining quality of life for cats with myopathy involves finding the balance between accommodation of limitations and continued enjoyment of life. Gentle interactive play appropriate to the cat's strength level provides mental stimulation and maintains some muscle activity. Environmental enrichment such as window perches, interesting scents, and safe outdoor viewing areas keeps cats engaged with their environment. Regular grooming assistance maintains coat health if the cat has difficulty self-grooming. Social interaction with family members supports emotional wellbeing. The goal is to help the cat enjoy life as fully as possible within the constraints imposed by the disease.

Monitoring and ongoing care require regular assessment of the cat's condition and prompt response to changes. Regular evaluation of muscle mass, strength, and function tracks disease progression or improvement. Weight monitoring ensures adequate nutrition. Observation for signs of pain or discomfort allows adjustment of pain management if needed. Watching for respiratory changes is important in myopathies that may affect breathing muscles. Regular veterinary visits allow professional assessment and treatment adjustments. Keeping a log of observations helps identify trends and provides valuable information for veterinary consultations.

Caregiver support is important for owners managing a cat with chronic muscle disease. The physical demands of caring for a mobility-impaired cat can be significant, particularly if lifting or carrying becomes necessary. The emotional impact of watching a beloved pet struggle with weakness requires acknowledgment and support. Financial planning helps manage ongoing costs of medications, special supplies, and veterinary care. Connecting with other owners of cats with muscle diseases provides practical advice and emotional support. Open communication with the veterinary team about concerns and quality of life helps guide ongoing decisions. Discussing end-of-life considerations in advance prepares owners for difficult decisions if the cat's condition deteriorates despite management efforts.

High-risk breeds for myopathy include those with documented inherited muscle diseases. Devon Rex and Sphynx cats have well-characterized hereditary myopathy caused by a mutation in the dystrophin-related protein gene, inherited in an autosomal recessive pattern. Affected cats develop progressive muscle weakness beginning at a young age. Burmese cats have increased risk of hypokalemic myopathy due to inherited tendency toward potassium regulation abnormalities. Certain lines of other breeds may carry mutations causing muscular dystrophy or other inherited myopathies, though these are less well characterized. Breeders of high-risk breeds should be aware of these conditions and utilize health testing when available.

Moderate-risk categories for myopathy include various groups that may be more susceptible to certain types of muscle disease. Senior cats of any breed have increased risk for acquired myopathies, including those secondary to endocrine disorders and cancer-associated muscle wasting. Outdoor cats face higher exposure to infectious agents that can cause myositis. Cats receiving certain long-term medications may be at risk for drug-induced myopathy. Cats with other autoimmune conditions may have predisposition to inflammatory myopathy. Cats fed nutritionally incomplete diets are at risk for nutritional myopathy. Mixed breed cats can develop any acquired myopathy and may carry genes for inherited forms present in their ancestry.

Screening recommendations for myopathy vary by type and breed risk. Breeders of Devon Rex and Sphynx cats should have breeding animals tested using genetic testing for the hereditary myopathy mutation and should not breed affected cats or known carriers. Burmese breeders should monitor for signs of hypokalemic myopathy and consider potassium level monitoring. For cats of any breed, routine wellness examinations provide opportunities to assess muscle mass and function. Senior cats should have blood work including thyroid levels and electrolytes to screen for conditions that might cause secondary myopathy. Any cat showing weakness or gait abnormalities should be evaluated promptly rather than waiting for obvious deterioration.

Commonly co-occurring conditions with myopathy depend on the specific type and underlying cause. Cats with inflammatory myopathy may have concurrent autoimmune conditions affecting other organ systems. Hyperthyroidism-induced myopathy occurs alongside the other manifestations of thyroid excess including weight loss, increased appetite, and cardiac changes. Diabetes-associated myopathy accompanies the metabolic derangements of uncontrolled diabetes. Infectious myositis may occur with systemic infection affecting other organs. Cancer-associated myopathy presents alongside the primary malignancy. Recognizing and managing these concurrent conditions is essential for optimal outcomes in affected cats.

Conditions with similar symptoms to myopathy include other causes of weakness and mobility impairment in cats. Neurological diseases affecting the brain, spinal cord, or peripheral nerves cause weakness that may be mistaken for myopathy but typically shows different examination findings. Myasthenia gravis affects the neuromuscular junction rather than muscle itself and has specific diagnostic tests. Joint disease causes reluctance to move that may mimic muscle weakness. Cardiac disease can cause exercise intolerance resembling myopathy. Severe systemic illness from any cause can produce general weakness. Accurate diagnosis through appropriate testing ensures cats receive correct treatment.

Potential complications of myopathy depend on the specific type and affected muscle groups. Respiratory failure from respiratory muscle weakness is the most serious potential complication and can be life-threatening. Aspiration pneumonia may occur if pharyngeal or esophageal muscles are affected, leading to difficulty swallowing. Severe muscle wasting leads to mobility impairment and difficulty performing normal activities. Muscle contractures may develop if joints are not regularly moved through their range of motion. Rhabdomyolysis with myoglobinuria can cause kidney damage in acute severe myopathy. Secondary complications from immobility, including pressure sores and urine scalding, may develop in severely affected cats. Close monitoring and proactive management help minimize complications.