Premium
Suspected mitochondrial myopathy in a Jack Russell terrier
Author(s) -
Olby N. J.,
Chan K. K.,
Targett M. P.,
Houlton J. E. F.
Publication year - 1997
Publication title -
journal of small animal practice
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 0.7
H-Index - 67
eISSN - 1748-5827
pISSN - 0022-4510
DOI - 10.1111/j.1748-5827.1997.tb03346.x
Subject(s) - medicine , oxidative phosphorylation , exercise intolerance , mitochondrial myopathy , pathology , myopathy , nicotinamide adenine dinucleotide , abnormality , muscle biopsy , biopsy , biochemistry , nad+ kinase , biology , enzyme , mitochondrial dna , heart failure , psychiatry , gene
A Jack Russell terrier with a history of progressive exercise intolerance was examined at the age of four months and again 10 months later. Clinical examination revealed a stunted, thin dog with a stilted gait. The dog had raised lactate levels before and after feeding and a raised lactate/pyruvate ratio after feeding, indicating a metabolic abnormality. Histochemical evaluation of muscle biopsies revealed subsarcolemmal accumulation of oxidative activity when stained with nicotinamide adenine dinucleotide tetrazolium reductase and ragged red fibres when stained with modified Gomori trichrome; all fibre types were involved. Ultrastructural examination of the muscle confirmed the presence of subsarcolemmal accumulations of mitochondria. Histochemical staining for the activity of enzymes of the Krebs cycle, oxidative phosphorylation and other metabolic cytosolic enzymes failed to demonstrate an abnormality. In view of the clinical picture and the biochemical and histological findings, a tentative diagnosis of mitochondrial myopathy was made. The difficulties associated with diagnosing mitochondrial disorders are discussed.