Hypertrophic Osteodystrophy (HOD)

Hypertrophic osteodystrophy causes lameness and extreme pain in younggrowing dogs, usually of a large breed. Great danes, German shepherds,dobermans, retrievers and weimaraners are examples of breeds that may beaffected by this condition. It appears to occur in weimaraners as a vaccinereaction and this may also affect mastiffs and great Danes. In this case,it usually occurs a few days after vaccination and may appear to be worsethan the "average" case on radiographs.

HOD usually shows up as an acute lameness, often seeming to affect allfour legs simultaneously. Affected dogs may stand in a "hunched up" stanceor refuse to stand up at all. They may have a fever but this is not consistentlypresent. They usually have painful swellings around the lower joints onthe legs. Some puppies will die from this disease, some suffer permanentdisability but many recover later. The disease is so painful that manyowners elect to euthanize the puppy rather than watch it suffer, despitethe reasonably good chance for recovery, long term. Affected dogs may beso ill that they refuse to eat.

X-rays confirm this diagnosis in most cases. There are very typicalX-ray changes, although it can look a little like bone infection from aseptic condition. There is some evidence at this point that viral or bacterialinfections may underlie some cases of HOD as canine distemper virus hasbeen found in the affected areas in some dogs. There can be high whiteblood cell counts and the alkaline phosphatase level in the blood streamis often elevated.

There is also a theory that this condition may occur with excessive dietary levels of calcium or protein. I am not sure what the current statusof this theory is.

Treatment usually consists of analgesic medications such as aspirinor carprofen (Rimadyl Rx). Since a viral or bacterial agent may be involvedin this problem the use of corticosteroids is questionable. Many peopletry switching to a diet that is lower in calcium (the puppy foods for largedogs may be a good choice now that they are available. Previously manypeople switched to adult dog foods which didn't always result in lowertotal calcium in the diet). Even more potent pain relief medications maybe indicated in some puppies. Hydrocodone and aspirin may be a more effectivecombination than either one alone. Antibiotics are often given for thiscondition. There is a persistent rumor that vitamin C supplementation isbeneficial in dogs with HOD. This appears to be a false rumor and thereis some evidence that vitamin C may actually promote abnormal calcificationin these puppies. It is not a good idea to supplement vitamin C.

Hypertrophic osteodystrophy may resolve spontaneously in as short atime as a week or so. It can be a recurrent, cyclic infection that goeson for a long time, too. If there are severe secondary bone changes, surgicalcorrection of these may be necessary for normal future function of thelimbs.

There is no reason not to control pain as effectively as possible withthis condition. That definitely needs to a primary goal of treatment.