Also known as "pano",
hematogenic chronic osteomyelitis,
enostosis, long-bone disease,
and eosinophilic panosteitis

(also known as "pano", hematogenic chronic osteomyelitis, enostosis, long-bone disease, and eosinophilic panosteitis)
by Roger Ross, DVM

This is a sort of mystery disease of young dogs that causes sudden lameness. German Shepherds seem to be most affected but other breeds can also be susceptible.  There's not a whole lot of dependable information about this disease, and unfortunately I'm not going to correct this problem.  But your vet or breeder friend may tell you your dog has "Pano" and hopefully this will give you an idea of what they're thinking.

The Basics:

Sudden pain and or lameness in one or more limbs.  The problem is usually in the "long bones" of the arms and rear legs.  There aren't any fractures, there aren't any torn or stretched tendons or ligaments, but the dog hurts when you pinch the middle of the long bones. (Femur, Tibia, Humorus, Radius, Ulna)

Most dogs recover with rest and time.  Sometimes the disease progresses from one bone to the next though, making recovery drawn out.

It's important to see a vet mainly to rule out other causes of lameness' in young dogs.  (Common examples are elbow and shoulder dysplasias of the front legs and cruciate damage to the rear leg)  Your vet will probably be able to confirm the problem by ruling out other causes on palpation and by radiographs.   With panosteitis the bone surface shows up as milky or fuzzy on radiographs.  I need to warn you though that we often miss the problem on x-rays during the early, most painful, part of the disease.  Bone biopsy confirms the disease.  Whether or not it is worth doing this test is questionable though.

The disease shows up in young growing dogs because the disease involves a problem with the osteoblasts in growing bone.  For this same reason, the disease improves once the bones stop growing.  (The age range seems to be from 7 - 18 months)

The pain and degree of lameness varies a lot from minor to crippling.   It can cause some dogs to panic, snap, and become crazed with anxiety about taking a step.

I can't begin to explain why, but most cases seem to involve "show dogs".  I told you this was known as a mystery disease.  And another thing; it always seems to occur after you paid your non-refundable fee for the show.

The underlying cause and mode of transmission is basically unknown.  Genetics and diet are frequently sited but not proven. Feeding lower protein and lower calorie diets seems to reduce the symptoms though.  Too little or too much calcium are frequently mentioned.  My own unsubstantiated opinion revolves around sex hormones (puberty) as being a factor.  That might explain why it's seen in show dogs more, since show dogs aren't castrated.   Maybe certain individuals of certain breeds produce more or slightly different  levels of testosterone than others leading to bone growth changes that cause inflammation.  Speaking of breeds:

Other breeds besides German Shepherds that have been found to have this disease are the Rottweiler, Airedale, Irish Setter, German Shorthaired Pointer, Doberman Pinscher, Great Dane, Basset Hound, and Saint Bernard.   And apparently some small breed dogs have been reported with the disease.

Here's something interesting I didn't know but picked up during my research for this very article: Males are 4 times more likely to be affected by panosteitis and the clinical signs are more severe .

Early in the U.S. space program it was discovered that women could withstand the stress of G-forces (acceleration) better than men. 

The U.S. Army determined that female dogs can run 26% longer and swim 46% longer than males. 

As a man, I feel I should interject something here in favor of the males, but I don't seem able to think of anything right at the moment.

Treatment Options

1.  Symptomatic or Palliative.  There is no known reliable treatment and as a consequence, every vet has their favorite. Typical choices are prednisone, buffered aspirin, Vitamin C,  Mineral supplementation, Anti-oxidants, and the new non-steroidal pain medications.  All of these treatments have potential side effects and none of them work well for every case.

2.  Time.  Most cases get better on their own after 1-4 weeks.  Meanwhile, we make them as comfortable as possible.

DURLACTIN   a new nutriceutical used to reduce the chronic inflammation associated with either arthritis or soft tissue injury.  See below:

NSAIDs and corticosteroids have been relied on for years for the short- and long-term control of inflammatory conditions such as osteoarthritis. While effective in managing inflammation and pain, these methods may have undesirable side effects which can limit their use.


Research has identified compounds in a special patented milk derivative with natural anti-inflammatory properties. Recent advancements in modification of the cellular response provide a new class of neutrophil-suppressing compounds processed from milk of hyperimmunized cows. Duralactin contains MicroLactin, a patented, milk-derived, high protein product from hyperimmunized cows that contains factors that appear to inhibit neutrophil participation in the inflammatory response.

Duralactin is not a drug or steroid, but is considered an immuno-nutritional aid. Duralactin helps to relieve clinical signs associated with inflammation.

Duralactin is derived from milk and has demonstrated no toxicity in human and animal studies.

DURALACTIN affects the ability of neutrophils to attach and migrate to the injury site. This reduces inflammation and helps prevent subsequent tissue damage caused by excessive neutrophil infiltration. By working at this level, DURALACTIN stops inflammation earlier in the process and avoids inhibiting protective COX-1 activity.

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