What is panosteitis
Panosteitis (pan-all, oste-bones, itis-inflammation) commonly referred to as pano is an orthopedic condition primarily affecting large dog breeds, though also seen in smaller dogs and other animals like cats and horses. Characterized by pain, inflammation and sudden lameness, it occurs in the long bones of the limbs, mainly the humerus. Other bones commonly affected include the ulna, radius, tibia, and femur [1, 3, 6].
Causes and pathophysiology
It occurs when there is a rise in the activity level of the bone-synthesizing cells, osteoblasts, and collagen-synthesizing cells, fibroblasts present in the bone marrow, periosteum (outer bone membrane) and endosteum (thin membrane covering the inner surface). Because of the high level of activity, there is an increased accumulation of connective tissues in the central part of the bone marrow. [1, 4]. However, the causes behind this increase in activity levels are yet to be found.
Why is panosteitis more common in dogs
Researches are going on to find out the causes of its high incidence rate in dogs.
Some studies perceive it to be genetic in nature, particularly among German Shepherds, who majorly suffer from this condition [1,3]. To test its contagious nature, German Shepherds with a history of the condition were cross-bred with healthy pointers. It was seen that the latter remained unaffected while the next generations of GSDs continued to develop it .
Bacterial infection is also speculated to be one of the prime reasons though sufficient evidence is unavailable to confirm it .
To determine if a virus is the cause of this condition, the bone marrow of the affected breeds was infused into the healthy dogs’ bones, with the result being that the latter contracted this disease .
Other possibly responsible factors include stress, autoimmune components, metabolism, infection, high protein or calcium diet, and stages of rapid growth [1, 8].
Canine panosteitis at a glance
|Other names||Eosinophilic panosteitis, growing pain, eopan, enostosis, juvenile osteomyelitis, endosteal proliferation in new bones and wandering lameness |
|Most affected breeds||Large breeds like the German Shepherd, Golden Retriever, Doberman, Great Dane, Rottweiler and Basset Hound, Belgian Malinois, Akita, Chesapeake Bay Retriever, Neapolitan Mastiffs, Newfoundland, English Springer Spaniel, Rhodesian Ridgeback [1,6]. Smaller breeds like American Cocker Spaniel and Shih-Tzu may also be affected by it .|
|Which sex gets it the most||Males|
|Common symptoms||Painful inflammation, lameness, limping, fever, weight loss, depression, loss of appetite [1,3]|
|Treatment||Analgesics or anti-inflammatory medicines to relief pain |
When do the symptoms occur
This condition is majorly seen in young dogs when they are 5 to 14 months old, while the symptoms may show up as early as at 2 months or even delay to 18 months . It has a cyclic nature where the symptoms may come and go . With the pain shifting from leg to leg, the lameness may also affect more than one leg [1, 2].
Each bout of a panosteitis attack may last for a few days or weeks while the gap between the episodes may approximately be a month or more .
How is it diagnosed
If your dog experiences pain when the vet exerts pressure on the affected bone, then panosteitis may be suspected. Radiographs or X-rays of the affected limbs are taken for confirmation. Sometimes X-rays are also conducted on the unaffected limbs for comparing the changes [1, 3, 7, 8].
At times, the deformity may not be detected on X-ray for about 10 days from when the lameness starts. In such cases, it may be done again after one or two weeks to look for patchy white densities in the cavities of the bone marrow [1,9].
Stages of diagnosis
First phase: Subtle increase in the density of the middle part of the diseased bone is detectable.
Second phase: The bones acquire a spotted and patchy look, whereas the outer surface gets rough.
Third phase: The spotted appearance of the bones persist, but otherwise seems to attain normalcy gradually .
Treatment and management
Though this condition has no remedy, medications to relieve pain including NSAIDs (Non-steroidal anti-inflammatory drugs) , like carprofen [6, 12, 13], and meloxicam [6, 11], may be recommended by your vet. In the case of severe and unbearable pain, steroids may be prescribed.
To relieve your dog from the inflammation and pain, natural or herbal remedies or homeopathic treatment can be opted for, after consulting the doctor .
How long does it last
Panosteitis is usually a self-limiting condition with a positive outlook, gradually going away once the puppies become 18 to 24 months old. However, if the episodes prolong for more than 4 to 5 weeks, the growing pain may indicate other orthopedic disorders like an elbow or hip dysplasia, osteochondritis and hypertrophic osteodystrophy [1, 14].
How to prevent panosteitis
There are still no preventive measures available. However, since genetic factors are said to influence it, breeders should take precautions to ensure the dogs they are breeding with are not carrying this condition.
Since large-breed puppies need adequate calcium and proteins in their regular diet to grow properly, it is important to make sure they do not get any more than the amount they actually need of these nutrients.