Panosteitis

From Dog
Panosteitis[1]

Panosteitis (Enostosis, eosinophilic panosteitis) is an idiopathic, painful bone disease of young and growing dogs, particularly German Shepherds[2].

Speculated causes include oversupplementation of calcium and other minerals; viral, bacterial, or other infectious causes; and genetic predispositions. German shepherds are most commonly affected by panosteitis, and Great Dane puppies with high calcium intake, specifically during the preweaning period, can develop radiographic signs of the disease.

Some evidence suggests that protein or amino acid metabolism is affected in dogs with panosteitis. The general view is that an 'osseous compartment syndrome' occurs as a result of excessive protein accumulation within the medulla of bone, leading to increased intramedullary pressure and compression of blood vessels. Subsequent osseous ischemia leads to local inflammation. The disease is aggravated excessive physical activity[3].

Clinically affected dogs present with acute lameness, pain surrounding the region, fever and anorexia. Male large-breed dogs dogs appear to be more commonly affected, and in females is frequently associated with the first estrus.

Diagnosis is suggested by clinical presentation of shifting-leg lameness and pain on digital palpation of the diaphysis.

Supportive radiographic evidence includes evidence of a generalized inflammatory bone disease with diffuse osteosclerotic appearance of long bone diaphyses. Additionally radiographic findings include increased opacity of the medullary canal, elevation and thickening of the periosteum, thickening of the bone cortices and increased intramedullary bone density[4].

Bone scintigraphy has also been used to assist a definitive diagnosis[5].

A differential diagnosis would include osteomyelitis, polyostotic bone cysts, hypertrophic osteodystrophy, osteochondrosis, Legg-Calve-Perthes disease, hip dysplasia[6], and infectious causes such as Toxoplasma spp and Neospora spp.

Treatment usually involves supportive care, a carefully regimented protein restriction diet and judicious use of non-steroidal anti-inflammatory drugs such as carprofen (2.2 mg/kg orally twice daily) or meloxicam (0.1 mg/kg orally once daily).

Most cases resolve after 1 - 2 months and prognosis is guarded in severe refractory cases where morbidity and mortality can be high.

References

  1. Vet Surgery Central
  2. Corbee RJ et al (2012) Composition and use of puppy milk replacers in German Shepherd puppies in the Netherlands. J Anim Physiol Anim Nutr (Berl) 96(3):395-402
  3. Schawalder P et al (2002) Canine panosteitis: an idiopathic bone disease investigated in the light of a new hypothesis concerning pathogenesis. Part 1: Clinical and diagnostic aspects. Schweiz Arch Tierheilkd 144(3):115-130
  4. Johnson KA & Allan GS (1982) Panosteitis in a cocker spaniel dog. Aust Vet J 58(4):153-155
  5. Schwarz T et al (2004) Bone scintigraphy in the investigation of occult lameness in the dog. J Small Anim Pract 45(5):232-237
  6. Demko J & McLaughlin R (2005) Developmental orthopedic disease. Vet Clin North Am Small Anim Pract 35(5):1111-1135