RESUMO
A two-year-old male entire border collie dog was evaluated for a short history of mixed bowel diarrhoea, coughing, vomiting and stranguria. Physical examination revealed dyspnoea with increased ventral lung sounds and a flaccidly distended bladder. Neurological examination revealed poor pupillary light reflexes, an absent gag reflex and a poor anal tone. Thoracic radiography was consistent with megaoesophagus and aspiration pneumonia. Clinicopathological testing revealed an elevated muscular nicotinic acetylcholine receptor antibody titre. The dog was euthanased because of clinical deterioration. Cerebrospinal fluid (CSF) collected immediately post-mortem revealed macrophagic pleocytosis. Post-mortem histopathological examination was consistent with dysautonomia. This is the first report of coexisting autoimmune myasthenia gravis and dysautonomia in a non-human species. The concomitant diseases may suggest a common immunopathological aetiology.
Assuntos
Doenças Autoimunes do Sistema Nervoso/veterinária , Doenças do Cão/diagnóstico , Miastenia Gravis/veterinária , Disautonomias Primárias/veterinária , Animais , Doenças Autoimunes do Sistema Nervoso/complicações , Doenças Autoimunes do Sistema Nervoso/diagnóstico , Líquido Cefalorraquidiano/química , Líquido Cefalorraquidiano/citologia , Doenças do Cão/fisiopatologia , Cães , Eutanásia Animal , Masculino , Miastenia Gravis/complicações , Miastenia Gravis/diagnóstico , Disautonomias Primárias/complicações , Disautonomias Primárias/diagnósticoRESUMO
The presence of a recessive inherited muscle disease in Old Danish Pointing Dogs has been well known for years. Comparisons of this disease with myasthenic diseases of other dog breeds and humans have pointed toward a defect in the synthesis of the neurotransmitter acetylcholine possibly due to decreased activity of the enzyme choline acetyltransferase. We sequenced exons 5-18 of the gene encoding choline acetyltransferase (CHAT) in 2 affected and 2 unaffected dogs and identified a G to A missense mutation in exon 6. The mutation causes a valine to methionine substitution and segregates in agreement with the inheritance of the disease. The mutation was not detected in 50 dogs representing 25 other dog breeds. A DNA test has been developed and is now available to the breeders of Old Danish Pointing Dogs.