Rhabdomyolysis is breakdown of muscles resulting in the release of muscle fiber contents into the bloodstream. The death of a muscle has potentially life-threatening consequences. Shock and kidney failure may occur when a large amount of fluid moves from the blood into the necrotic muscle, reducing the fluid volume in the body and blood flow to the kidneys. When myoglobin muscle pigment breaks down, it releases harmful compounds that may block the structures of the kidney, causing acute tubular necrosis and kidney failure. Muscular trauma is the most common cause of rhabdomyolysis. Less common causes include muscle carnitine deficiencies and glycogen storage diseases. Rhabdomyolysis is a potentially life-threatening condition that must be suspected in all patients with a history of any circumstance that can result in damage of skeletal muscle.
Patients affected by rhabdomyolysis often have a familial history of the disease. The main hereditary causes of rhabdomyolysis are due to inborn errors of metabolism affecting carbohydrate and fat metabolism within the muscle. They are often precipitated by brief, intense exercise or fasting. Extreme muscle exertion, even in well-conditioned individuals, may cause rhabdomyolysis. The nonhereditary causes of rhabdomyolysis include large amounts of tissue damage, such as burns and crush injuries, medications, electrolyte abnormalities (hypokalemia, hypophosphatemia), sepsis, and snake or insect venom. Rhabdomyolysis also can develop as a complication of babesiosis or heat stroke, but the most frequent cause is crush injuries. Weakness, muscle pain and tea-colored urine are the main clinical manifestations. Often animals are unwilling or unable to move due to severe pain. Vomiting is often present, while a drop in urine output is a sign of impending kidney failure. Exertional rhabdomyolysis is common in sled dogs and in animals with high energy expenditures that consume high fat (60% of ingested calories) diets, especially in dogs that retire during the initial 500 miles of a long-distance race, compared with dogs that complete the race.1,2
Exertional rhabdomyolysis is common in sled dogs
The treatment is focused on removing the offending agent and supportive care. One of the major consequences of rhabdomyolysis is acute kidney failure, and the treatment of this syndrome is directed at preventing this complication. Aggressive intravenous hydration is indicated to improve the solubility of by-products and urine flow.4
- Piercy RJ, Hinchcliff KW, Morley PS, DiSilvestro RA, Reinhart GA, Nelson SL Jr, Schmidt KE, Craig AM. Vitamin E and exertional rhabdomyolysis during endurance sled dog racing. Neuromuscul Disord. 2001 Apr;11(3):278-86.
- Hinchcliff KW, Shaw LC, Vukich NS, Schmidt KE. Effect of distance traveled and speed of racing on body weight and serum enzyme activity of sled dogs competing in a long-distance race. J Am Vet Med Assoc. 1998 Sep 1;213(5):639-44.
- Jacobson LS, Lobetti RG. Rhabdomyolysis as a complication of canine babesiosis. Small Anim Pract. 1996 Jun;37(6):286-91.
- Lisa Marcucci, Elizabeth A Martinez. Avoiding Common ICU Errors