Hypertrophic osteodystrophy is a terribly painful disease affecting mostly puppies. The long bones of a puppy’s legs have what are called “growth plates”, which are responsible for the bone growing. In HOD the bones are fragile and fracture just above those growth plates, twisting, bowing, and excessively elongating as they heal. So puppies who are refusing to stand or whose joints are horribly swollen should be immediately x-rayed. As with most illnesses, the longer it goes untreated, the more deformity will occur. Below is an xray of the bowing and breakage of the bones.
There are two primary factors in HOD, which not all “experts” agree on, but are certainly on everyone’s concern list: diet and possible vaccine reactions. Diet, just as with hip dysplaysia, is a tricky business for giant dogs. The ratio of calcium to phosphorous, and the relative amount of protien and calories has little room for error with a dog that grows almost 3 feet in one year! And there is some evidence that Vitamin C supplementation can make it far worse (links below, and Feeding page to right). Prevention is the best cure!
Vaccine reactions in Danes has become enough of a problem that the Great Dane club of America has funded research into protocols used by veterinarians. Some 5200 cases have been evaluated, but it is highly probable that there are many more that have been misdiagnosed as nutritional HOD. Before you accept a diagnosis of nutritional HOD, have a blood test done to rule out septic infections, vaccine reactions, and other arthritic conditions. As an aside, some vets will skip the blood tests and go straight to antibiotics for treating the problem. Insist on the blood test, and be very careful about antibiotics–some will cause even more problems with Danes. Check it out at http://www.greatdanelady.com/articles/vaccine_reactions_in_great_danes.htm to find out which antibiotics to avoid.
HOD can be an almost cyclical disease, with periods of quiet between the flare ups. Sometimes the disease just never quits and can cause the most horrific of disabling deformities. Treatment is sometimes corticosteroids as anti-inflammatories and pain medicines, but the steroids are falling out of favor because of the viral or bacterial possible cause. And they have potentially severe side effects. My Taj had HOD (past loves page), and all the side effects of corticosteroids used to treat him. Recent research points to the effectiveness of antibiotics and whatever pain medicine is needed to give comfort.
As for my Taj, I couldn’t stand to see him suffer, and he was 23 months old when I put him to sleep. When he didn’t “snap out of it”, and all the steriods had done damage to the rest of his body, I knew it was cruel to keep him alive just so I could avoid the grief of his death. So don’t play games with HOD–your puppy is walking around on 4 broken legs and he cannot take himself to the vet.