Panosteitis

Summary

Panosteitis is a relatively common orthopedic condition seen primarily in young, rapidly growing, large breed dogs. In panosteitis, the superficial layer of the bone known as the periosteum becomes painfully inflamed. Simultaneously, rapid growth within the bone makes way for additional discomfort.

While the cause of the disease remains a mystery, we speculate that mineral oversupplementation (through the diet), infections and genetic factors play a role. High calcium intake, in particular, is associated with this disease.

Dogs between the ages or 6 and 18 months are the most likely patients, though the official range is between 2 months and 5 years. Interestingly, males are more at risk, comprising 70% of all cases. In the case of our female patients, the onset of this disease can be associated with their first heat.

The symptoms of panosteitis vary widely in severity. Some dogs will be almost imperceptibly affected while others experience moderate pain. In rare instances, the pain may be so severe that the dogs must be humanely euthanized for lack of effective pain control.

Thankfully, panosteitis is a self-limiting condition, meaning that the symptoms resolve by themselves in a matter of days or weeks, though a significant percentage may be affected for months at a time.

Symptoms and Identification

In all cases, the long bones of the limbs are painful. One or more bones may be affected. Dogs may limp, but others may simply appear lethargic or display a decreased appetite. A "shifting leg" lameness is common for these dogs. In other words, one day they may limp on the hind limb, another day on the front.

Palpating (pressing on) the middle of the shaft of the long bones of the limb, thereby eliciting pain, is a necessary part of the physical exam for all suspected sufferers. X-rays then provide confirmation when a telltale brightness is seen within the core of the affected bones. Note that some dogs may need to be sedated or even anesthetized for best results on the X-rays.

Affected Breeds

Panosteitis is most often seen in the following breeds, listed in order of prevalence (note that some smaller breeds are included, as well):

• Great Pyrenees

• Mastiffs

• Basset Hounds

• Chinese Shar Peis

• Giant Schnauzers

• German Shepherds

• Bernese Mountain Dogs

• English Springer Spaniels

• Saint Bernards

• Dalmatians

• Great Danes

• Irish Wolfhounds

• American Staffordshire Terriers

• Neapolitan Mastiffs

• Rhodesian Ridgebacks

• Afghan Hounds

• Bulldogs

• Doberman Pinschers

• English Setters

• Newfoundlands

• Weimaraners

• Akitas

• Boxers

• Chesapeake Bay Retrievers

• Chow Chows

• West Highland

• Bull Terriers

• German Shorthaired Pointers

• Labrador Retrievers

• Golden Retrievers

• Rottweilers

• Shih Tzus

• American Cocker Spaniels

Treatment

Treatment for this self-limiting condition primarily revolves around pain relief. Treatment is largely supportive, consisting of pet-specific pain medications, including NSAIDs (like meloxicam and carprofen) and non-narcotic opiates (like tramadol).

Unfortunately, the sometimes unbearably severe pain means that dogs may be euthanized in lieu of treatment.

Veterinary Cost

Because most dogs "grow out of it," treatment with medications lasts only a few days to weeks. Sometimes only intermittent treatment is necessary, based on the symptoms and their severity. This can range from a manageable low-hundreds condition (including the cost of diagnosis) to a higher hundreds rate for those who require more expensive medications and lengthier treatment regimens (though this is relatively rare).

Prevention

Prevention of panosteitis is best achieved through careful attention to nutrition. Large breed dogs should take care to receive diets that do not provide an excess of calcium. Slower growth is key--meaning that lower concentrations of protein and fats should be administered. "Large breed" diets are now widely available commercially and these are perhaps the go-to diets for natural growth in larger breed dogs.

Because heritability of this disease is a very real problem, affected dogs and parents of affected dogs should be spayed and neutered to prevent hereditary transmission of this trait.