A big sounding word. Some of you may know of this as Pano, or maybe as Growing Pains. Basically it is an inflammation of the outer lining (periosteum) of one or more long bones. It is more common in the front legs but can occur in back legs as well. It often occurs in one bone at a time, sometimes just to get better and then show up in another leg. It occurs most often between 5-15 months but can begin as early as 2-3 months or as late as 18 months. It is most common in large breed dogs.
Not all dogs get this of course, and it seems to be relatively uncommon in Samoyeds. It is not known what causes the episodes of inflammation but rapid growth, stress, or infection may play a role. And high protein and/or calcium diets (the very diets required by large breed puppies) may be a factor. Genetics may also possibly contribute but little is known about this.
The primary symptom is sudden painful limping, most commonly with a front leg. Typically, the affected bone(s) is painful to touch and there may also be fever, poor appetite, lethargy, and even weight loss. Often it is cyclical with an episode of lameness that improves after a few days to weeks and then may recur a month or so later in the same bone or another bone. Spontaneous resolution occurs by 18-24 months of age.
Diagnosis can be confirmed by x-ray which shows typical findings of increased bone density of the affected bone(s). It may take up to 10 days for findings to show up. The density returns to normal once the condition has resolved. As you are aware there are many many causes of lameness in our dogs, and since none of them have read the textbooks, their symptoms may not follow the “rules”. X-rays are important to obtain in order to rule out other more serious conditions.
The condition is self-limiting and will spontaneously resolve with no treatment. But, because it can be very painful, supportive treatment with pain medication and/or anti-inflammatory drugs is required. Exercise should be restricted during times of pain, and hard exercise and long walks should be avoided until the condition has fully resolved at 18-24 months. For dogs who have poor appetite during episodes, supplements may be indicated. If any episode lasts longer than 3-4 weeks, other diagnoses should be considered as the cause.