PANO (for short) - leg pain and treatment
Panosteitis, sometimes known as PANO, occurs in rapidly growing large or giant breed puppies. It occurs in the shaft of the bone not the joint. The fatty marrow inside the shaft of the long bones degenerates and is replaced with bone cells. When this occurs, the marrow becomes congested causing inflammation and pain. Eventually, the new bone cells are resorbed and normal marrow structure is reestablished. Once an area in the bone has been affected, it is unlikely to be affected again, but each leg has 3 long bones.
PANO can affect different bones at different times, so frequently the lameness will “shift” from leg to leg. The cycles of lameness may last 2-3 weeks for each bone. Often, there will be periods of no lameness. It usually affects dogs between 5 and 12 months of age, but dogs don’t read the rules, so sporadic cases occur at other ages.
Like many other orthopedic problems, PANO may be difficult to diagnosis due to its shifting nature. During a physical exam, a dog with PANO will usually be painful when the affected bone is squeezed by the veterinarian. X-rays are necessary for a conclusive diagnosis.
The good news about PANO is most dogs recover without any permanent effects. Unfortunately, the condition can linger for months, during which time the dogs are very painful, lose weight, lose muscle mass and have a fever. Treatment consists of exercise as tolerated and pain relievers as needed. Your veterinarian has several possible medications to keep your puppy comfortable.
The cause of PANO has not been determined. Some veterinary nutritionists think calorie intake is related to the severity of the symptoms and recommend a 25% reduction in food. Stress has also been implicated as a contributing factor. Likewise there is no known prevention of PANO.
Ó 2005 BKramerDVM1/10/06