Panosteitis

What is Panosteitis?

Panosteitis is a fairly common condition of long bones in the large breeds of young dogs such as Basset Hounds and German Shepherds. The disease causes severe lameness which is usually self-limiting and leaves no permanent damage. As such, intensive investigations of the various stages of the disease are lacking and many contraindications exist as to its clinical features.

The cause of panosteitis is unknown though many factors have been postulated, including infection, metabolic problems, endocrine dysfunction, allergy, parasites, hereditary factors and even auto-immune problems. Nevertheless, viral infection appears to be the most likely factor.

What are the Signs of the Disease?

We usually see a healthy dog (especially male dogs) with an acute onset of lameness but no history of trauma. The lameness is very noticable even to the degree of 'leg carrying' in some cases, and can last for a few days up to several weeks. Over 50% of cases show 'shifting lameness' where other limbs become involved. These bouts of shifting lameness usually subside by the time the dog reaches 2 years of age (although the disease has been detected in dogs up to 5 years of age).

How is the Disease Detected?

Acute pain is detected when the affected area of long bone is palpated. Dogs react differently to palpation. Some will cry out whilst others will wince, pull the leg away or snap at the examiner. Occasionally affected dogs will also present with other signs such as fever, muscle withering, reduced activity and/or inappetance.

The affected leg(s) are X-rayed for confirmation once panosteitis is suspected. Three phases of panosteitis can be viewed from X-rays.

Early phase: Some cases show few if any signs. Blurring or accentuation of the bone structure is seen towards the ends of the bone in the medullary cavity in X-rays. A few granular densities are seen in some cases as well.

Middle phase: Patchy thick looking densities are seen around the areas of main blood supply to the bone. Thickening of the outer bone covering becomes involved in approximately one third of cases.

Late phase: During recovery the medulla starts to attain its normal density. However, the bone cortex remains thicker than normal if the outer bone covering has been affected.

In general the lesions affect the centre of the radius, the top third of the ulna, the bottom of the humerus, the top of the tibia, and the centre and top of the femur.

What Other Diseases can Present Smilarly to Panosteitis?

Hip dysplasia, hip luxation, osteochondritis dissecans, cruciate disease, fracture, rheumatoid arthritis and lupus.

How is Panosteitis Treated?

Treatment is symptomatic and aims at relieving pain by using anti-inflammatories. Treatment is continued until the condition resolves by 'itself'.