Hypertrophic osteodystrophy

Hypertrophic osteodystrophy (HOD) is a bone disease in young large and giant breed dogs. It may occur between the ages of 2 and 7 months.cite book|author=Thrall, Donald E.|title=Textbook of Veterinary Diagnostic Radiology|edition=2nd ed.|publisher=W.B. Saunders Company|year=1994|id=ISBN 0-7216-3143-6] HOD is characterized by decreased blood flow to the metaphysis (the part of the bone adjacent to the joint) leading to a failure of ossification (bone formation) and necrosis and inflammation of cancellous bone. [cite web | title = Hypertrophic Osteodystrophy | work = The Merck Veterinary Manual | date = 2006 | url = http://www.merckvetmanual.com/mvm/index.jsp?cfile=htm/bc/91504.htm | accessdate = 2007-02-06 ] The disease is usually bilateral in the limb bones, especially the distal radius, ulna, and tibia.cite journal |author=Miller C |title=Hypertrophic osteodystrophy in a Great Dane puppy |journal=Can Vet J |volume=42 |issue=1 |pages=63–6 |year=2001 |pmid=11195528]

peculated causes of HOD

Causes have been speculated to include decreased Vitamin C uptake, increased vitamin (other than C) and mineral uptake, and infection with canine distemper. Decreased Vitamin C uptake has been dismissed as a cause, but excessive calcium supplementation remains a possibility.cite journal | last = Wehrenberg | first = Aaron | coauthors = Elkins, A.D. | title = Juvenile Orthopedics | journal = Veterinary Forum | volume = 23 | issue = 9 | pages = 22–28 | publisher = Veterinary Learning Systems | date = Sept. 2006 ] There is no evidence over-feeding is a significant cause.cite book|author=Ettinger, Stephen J.;Feldman, Edward C.|title=Textbook of Veterinary Internal Medicine|edition=4th ed.|publisher=W.B. Saunders Company|year=1995|id=ISBN 0-7216-6795-3] There may be a link to recent vaccination with a modified live vaccine, but no specific vaccine has been implicated. [cite journal |author=Crumlish P, Sweeney T, Jones B, Angles J |title=Hypertrophic osteodystrophy in the Weimaraner dog: lack of association between DQA1 alleles of the canine MHC and hypertrophic osteodystrophy |journal=Vet J |volume=171 |issue=2 |pages=308–13 |year=2006 |pmid=16490714 |doi=10.1016/j.tvjl.2004.11.015] It has been recommended that Weimaraners receive killed virus vaccines instead of modified live or separate vaccines for canine distemper, parvovirus, and adenovirus to prevent the possibility of vaccine-induced HOD. [cite journal |author=Demko J, McLaughlin R |title=Developmental orthopedic disease |journal=Vet Clin North Am Small Anim Pract |volume=35 |issue=5 |pages=1111–35, v |year=2005 |pmid=16129135 |doi=10.1016/j.cvsm.2005.05.002]

ymptoms, diagnosis, and treatment

Symptoms include firm swelling of the metaphysis, pain, lameness, depression, loss of appetite, and fever. It may progress to angular limb deformity. Most dogs recover within several days, but some relapse. X-rays show a dark line at the metaphysis, which can progress to new bone growth on the outside of that area. This represents microfractures in the metaphysis and bone proliferation to bridge the defect in the periosteum. Treatment includes pain medication (usually NSAIDs) and supportive care. Supplementation of Vitamin C is contraindicated due to an increase in calcium levels in the blood, possibly worsening the disease. [cite journal|author=Bennett, David;Clements, Dylan J.|title=Letters to the Editor|journal=Journal of the American Veterinary Medical Association|year=2004|volume=225| issue=1|pages=29|url=http://avmajournals.avma.org/doi/abs/10.2460/javma.2004.225.28|accessdate=2006-05-11|doi=10.2460/javma.2004.225.28] The disease is usually self-limiting.

Breeds at increased risk for HOD

*Boxer
*Chesapeake Bay Retriever
*German Shepherd Dog
*Golden Retriever
*Great Dane
*Irish Setter
*Labrador Retriever
*Weimaraner [cite journal |author=LaFond E, Breur G, Austin C |title=Breed susceptibility for developmental orthopedic diseases in dogs |journal=J Am Anim Hosp Assoc |volume=38 |issue=5 |pages=467–77 |year=2002 |pmid=12220032]

References