Spinal ganglioneuroma in a dog.

A 10-year-old mixed-breed dog was examined because of lameness and mutilation of the left hind limb. Neurologic examination revealed ataxia, conscious proprioceptive deficit, muscle atrophy, lack of withdrawal reflex, and hyperreflexia of the patella of the left hind limb. Epidurography revealed right-sided deviation of the dye column at the sixth to seventh lumbar vertebrae. Laminectomy with cytoreduction was performed, and histologic examination revealed ganglioneuroma. Twelve months after surgery, clinical signs recurred and surgery was repeated. The dog's clinical signs were again palliated. The specific type of ganglioneuroma identified in this dog is amenable to surgical resection, unlike many types of spinal cord neoplasia.

Electron microscopic studies of bovine progressive degenerative myeloencephalopathy in brown Swiss cattle.

Selected peripheral nerves from animals affected with Bovine Progressive Degenerative Myeloencephalopathy (BPDME) were examined by transmission electron microscopy. Changes in axons were both degenerative and reactive in nature and included axonal swelling in conjunction with accumulation of altered organelles and various forms of vesicles. Affected axoplasm was often vacuolated and shrunken, with loss of microtubules and microfilaments and separation of the axoplasmic membrane from the myelin sheath. Segmental disorganization of the normal lamellar pattern of myelin sheaths was observed. Affected myelin sheaths exhibited intramyelinic vacuoles or myelin bubbles often in association with concurrent axonal changes. Schwann cells occasionally contained swellen and vacuolated mitochondria and membrane-bound vesicles. Axonal and myelin changes were considered similar, if not identical, to those described in the central nervous system of affected animals reported in the literature. Collectively, the changes described in the axons and myelin sheaths of the peripheral nerves studied were considered to be compatible with the "dying back" process described in various distal axonopathies. A metabolic defect in the enzyme systems associated with axonal transport was postulated to explain these peripheral nerve lesions.

Salmonella enteritidis infection in two species of psittaciformes.

In 1990, Salmonella enteritidis phage type 4 was recovered from two young (less than 20-week-old) lilac-crowned Amazon parrots (Amazona finschi Schlater), one in Tennessee and one in Kansas. The parrot from Tennessee was treated for a plugged naris and anorexia before the S. enteritidis infection was discovered. The parrot from Kansas exhibited signs of septicemia and died within 24 hours of examination. An apparently healthy green-cheeked conure (Pyrrhura molinae) on the same premises as the parrot from Tennessee was positive for S. enteritidis phage type 4 on a cloacal swab. These are the first reported cases of avian infection with S. enteritidis phage type 4 in the United States. Because several infectious agents were present simultaneously in the Amazon parrots, it was difficult to determine the precise role of S. enteritidis phage type 4 in the clinical presentations.

Histochemical and morphometric studies of peripheral muscle in bovine progressive degenerative myeloencephalopathy of brown Swiss cattle.

Histochemical and morphometric analysis of selected skeletal muscles was performed on 14 pure bred, Brown Swiss cattle. Nine cattle were clinically affected with bovine progressive degenerative myeloencephalopathy (BPDME) while five served as controls. Statistically significant trend differences were not observed for the parameters of mean cross sectional area, and mean fiber type percentages for types, I, IIA, and IIB fibers between affected and control test groups. In general, patterns of hypertrophy or atrophy, fiber type grouping, fiber type predominance, or fiber cross sectional profile alteration were not observed in the muscles examined from affected cattle. The findings suggest that BPDME, or weaver syndrome, is not a muscular dystrophy and that muscle pathology is not a primary part of the syndrome nor would muscle pathology be expected to contribute significantly to the clinical signs of the disease.

A combination histochemical stain for equine muscle.

The purpose of this study was to find a combination histochemical staining technique for the evaluation of equine skeletal muscle that is reliable and effective, while offering a substantial reduction in the labor and cost involved with currently used individual histochemical methods. Several combinations under varying conditions of pH were studied. The most uniform results were obtained using an acid preincubation step at an optimal pH of 4.2 followed by reduced nicotinamide adenine dinucleotide-tetrazolium reductase (NADH-TR) and the remainder of the acid-ATPase procedure.

A rapid and reliable sequential staining method for bovine muscle.

Various different combinations of histochemical stains at differing pH levels on single sections of bovine skeletal muscle were evaluated. The staining sequence that was the most consistent and reliable of those studied included an initial NADH-TR (reduced nicotinamide adenine dinucleotide-tetrazolium reductase) followed by an acid ATPase stain at pH 4.15. This staining combination resulted in easily discernable type I, II A, and II myofibers. Thus, a marked saving of expended time, labor and materials was realized.