Hypertrophic osteodystrophy

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Hypertrophic osteodystrophy in a 10-week-old Australian shepherd, showing a radiolucent line in the metaphyseal region of the distal ulna and radius bilaterally[1]

Hypertrophic osteodystrophy (metaphyseal osteopathy) is an immune-mediated developmental disorder of young dogs characterized by malformations at the metaphyses of growing bones and associated immunodeficiency syndrome.

A breed predisposition has been noted in the Great Dane, Weimeraner and Australian Shepherd[2]. Most cases are sporadic, but entire litters of Weimaraners have been affected.

In the Weimeraner, the disease appears to affect functionality of the dog leukocyte antigen[3].

Affected dogs are usually young large-breeds with rapid growth rates and is unlikely to be related to overnutrition[4] or vitamin C deficiency[5]. Male puppies are 2.3 times more likely to develop the disease than are female puppies[6].

Recent studies have shown a link between recent vaccination with a modified live virus and the onset of HOD, particularly in Weimaraner dogs[7][8].

Dogs usually present with painful, swollen joints, reluctance to stand and pyrexia. In addition to bone pain, there are variable general signs including fever, lethargy, depression and loss of appetite.

The disease in some puppies is preceded with canine juvenile cellulitis[1]. The onset of clinical signs has been reported as early as two months and relapses have occurred as late as 8 months, but not after growth plate closure[9].

Dogs that are suspected of having hypertrophic osteodystrophy should be monitored closely for evidence of septicemia, particularly Escherichia coli[10] and the administration of prophylactic antibiotics may be advisable.

Radiographs usually show irregular lucent zones in the metaphysis of the proximal humerus, tibia or femur, parallel and adjacent to the physis[11].

A differential diagnosis would include panosteitis, osteochondrosis, Legg-Calve-Perthes disease, hip dysplasia, elbow dysplasia and hypertrophic osteoarthropathy.

Treatment is usually conservative, with correction of any nutritional deficiencies, exercise restriction and anti-inflammatory drugs such as aspirin.

References

  1. 1.0 1.1 Wentzell, ML (2011) Hypertrophic osteodystrophy preceding canine juvenile cellulitis in an Australian shepherd puppy. Can Vet J 52(4):431–434
  2. Bellah JR (1993) Hypertrophic osteopathy. In: Bojrab MJ, Smeak DD, Bloomberg MS, editors. Disease Mechanisms in Small Animal Surgery. 2. Lea & Febiger; Philadelphia, USA. pp:858–864
  3. Safra N et al (2011) Expanded dog leukocyte antigen (DLA) single nucleotide polymorphism (SNP) genotyping reveals spurious class II associations. Vet J 189(2):220-226
  4. Lenehan TM & Fetter AW (1985) Hypertrophic osteodystrophy. In: Newton CD, Nunamaker DM, eds. Textbook of Small Animal Orthopedics. Philadelphia: Lippincott. pp:597-601.
  5. Miller C (2001) Hypertrophic osteodystrophy in a Great Dane puppy. Can Vet J 42(1):63-66
  6. Munjar TA et al (1998) Comparison of risk factors for hypertrophic osteodystrophy, craniomandibular osteopathy and canine distemper virus infection. Vet Comp Orthop Traumatol 1:37-43
  7. Crumlish PT et al (2006) Hypertrophic osteodystrophy in the Weimaraner dog: lack of association between DQA1 alleles of the canine MHC and hypertrophic osteodystrophy. Vet J 171(2):308-313
  8. Harrus S et al (2002) Development of hypertrophic osteodystrophy and antibody response in a litter of vaccinated Weimaraner puppies. J Small Anim Pract 43(1):27-31
  9. Bellah JR (1993) Hypertrophic osteopathy. In: Bojrab MJ, ed. Disease Mechanisms in Small Animal Surgery. Philadelphia: Lea & Febiger. pp:858-864
  10. Schulz KS et al (1991) Escherichia coli bacteremia associated with hypertrophic osteodystrophy in a dog. J Am Vet Med Assoc 199(9):1170-1173
  11. Franklin MA et al (2008) Hypertrophic osteodystrophy of the proximal humerus in two dogs. J Am Anim Hosp Assoc 44(6):342-346