Afghan Hound hereditary myelopathy

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Afghan hound hereditary myelopathy (hereditary necrotizing myelopathy and myelomalacia) is an autosomal-recessive genetic disease of the Afghan Hound breed[1] characterized by a rapidly progressive symmetrical paraparesis[2].

A similar condition has been described in the Dutch Kooiker breed[3].

Affected dogs usually present at a young age (under 12 months of age) with a bunny-hop gait which rapidly progresses to paraplegia. Some dogs progress to collapse, respiratory distress and death[4][5].

Hematology, diagnostic imaging and CSF analysis are usually unrewarding.

Diagnosis is based on presenting clinical symptoms, breed-predisposition and histological findings of spinal cord tissue[6].

Histologically, a bilaterally symmetrical vacuolation of the spinal cord is evident with myelin loss confined to white mater, usually affecting most of the spine from the cervical to lower lumber regions. Despite extensive spongiform degeneration of myelin that progressed to micro- and macro-cavitation, substantial numbers of axons are preserved[7].

A differential diagnosis would include Leigh syndrome, thiamine deficiency, neonatal encephalopathy, L-2-hydroxyglutaric aciduria and familial cerebellar abiotrophy in Kerry Blue Terriers[8][9] and Bull Mastiffs[10].

There is no treatment for this condition, and the prognosis is poor.

References

  1. Averill DR & Bronson RT (1977) Inherited necrotizing myelopathy of Afghan hounds. J Neuropathol Exp Neurol 36(4):734-747
  2. Targett M & McInnes E (1998) Afghan hound myelopathy. Vet Rec 142(25):704
  3. Mandigers PJ et al (1993) Hereditary necrotising myelopathy in Kooiker dogs. Res Vet Sci 54(1):118-223
  4. Dewey, CW (2008) A practical guide to canine and feline neurology. 2nd Edition. Wiley-Blackwell, Iowa State University Press, Iowa. p:349
  5. LeCouteur, RA & Grandy, VL (2005) Diseases of the spinal cord. pp:842-887. In SJ Ettinger & EC Feldman (eds), Textbook pf Veterinary Internal Medicine, Diseases of dogs and cats (6th edn). WB Saundes Co, Philadelphia, PA
  6. Cockrell, BY et al (1973) Myelomalacia in Afghan Hounds. J Am Vet Med Assoc 162:362-365
  7. Cummings JF & de Lahunta A (1978) Hereditary myelopathy of Afghan hounds, a myelinolytic disease. Acta Neuropathol 42(3):173-181
  8. Montgomery DL & Storts RW (1983) Hereditary striatonigral and cerebello-olivary degeneration of the Kerry blue terrier. Vet Pathol 20:143–159
  9. de Lahunta A & Averill DR (1976) Hereditary cerebellar cortical and extrapyramidal nuclear abiotrophy in Kerry blue terriers. J Am Vet Med Assoc 168:1119–1124
  10. Carmichael S et al (1983) Familial cerebellar ataxia with hydrocephalus in bull mastiffs. Vet Rec 112:354–358