Mycobacterium paratuberculosis detection in bovine feces is improved by coupling agar culture enrichment to an IS900-specific polymerase chain reaction assay.

The feasibility of coupling an agar culture enrichment step with gene amplification (ACE-PCR) as a means to improve turnaround time and detect Mycobacterium paratuberculosis (Mpt) in the presence of contaminants was investigated. Fecal samples from 463 Pennsylvania dairy cows were cultured in duplicate sets. One replicate from each set was processed and interpreted according to standard culture (SC) protocol, whereas cultures from the second replicate were harvested at 6 weeks postinoculation; DNA extracts from the harvested material were evaluated by a polymerase chain reaction (PCR) test for the Mpt-specific IS900 gene. One hundred seventy-six of 463 culture sets were positive by either method. One hundred sixty-five of these (94%) were ACE-PCR positive, and 151 (86%) were positive by SC. Eleven SC-positive samples were ACE-PCR negative, and 9 ACE-PCR-positive samples were negative by SC; these discrepancies could be a consequence of a low organism burden (< or = 5 organisms/g) or slow growth rate of Mpt in cultures of these samples. One hundred thirty-nine of 463 culture sets (30%) were reported as inconclusive because of culture contamination according to SC protocol; 16 of these (11.5%) were ACE-PCR positive. Seventy-four ACE-PCR-positive sets (42% of all positives) were negative or inconclusive by SC at 6 weeks postinoculation. Agar culture enrichment prior to IS900 PCR testing significantly improves Mpt culture turnaround time and sensitivity.     

Laminectomy for 34 dogs with thoracolumbar intervertebral disc disease and loss of deep pain perception

The case details and the results of treatment of 34 dogs with thoracolumbar intervertebral disc disease, without deep pain perception, that had been treated by laminectomy and fenestration, are presented. The association of a number of potential prognostic factors with the neurological outcome is examined. Twenty-one dogs (62 per cent) recovered neurological function, seven (21 per cent) failed to recover neurological function and three (9 per cent) developed progressive myelomalacia postoperatively, while three dogs (9 per cent) were euthanized intraoperatively because of diffuse myelomalacia. Twenty of the dogs that recovered neurological function showed a return of deep pain perception within two weeks of decompressive surgery. Statistical analysis showed significant differences in the outcome between dogs that took less than one hour to lose the ability to ambulate and dogs with a longer duration of onset of inability to ambulate. The extent of spinal cord swelling determined by myelography was not found to be a useful prognostic indicator.     

Mesenchymal chondrosarcoma in a young German shepherd dog

An 18-month-old, entire male German shepherd dog was presented with signs indicative of a caudal abdominal space-occupying mass. A needle-core biopsy of this mass failed to establish a definitive diagnosis, but identified a prominent round-cell component. The dog's condition worsened and euthanasia was performed on humane grounds. Histopathology of the mass revealed a mesenchymal chondrosarcoma.     

Dynamics in the membrane organization of the mammalian sperm cell and functionality in fertilization

The capacitation process of sperm cells involves complex changes in the composition and orientation of molecules at the surface of the sperm cell. Here we focus on the lipid architecture in the sperm plasma membrane and demonstrate that the sperm plasma membrane is not static but is an extremely dynamic structure. Advanced fluoroscopic techniques enabled continuous monitoring of lipid organization in living cells and extremely rapid lipid movements were observed. The orientation of lipids in the sperm plasma membrane changed under capacitative treatments, was found to be sensitive for temperature and also changed upon binding of sperm cells to the zona pellucida. The changes in membrane properties coincided with an activation of protein kinases resulting in tyrosine phosphorylation of specific plasma membrane proteins. The detected membrane changes relate to intrinsic membrane properties such as fluidity, permeability, adhesiveness and fusibility. We think that these results may provide a physiological basis for new assays, able to discriminate between functional and non-physiological sperm cells.     

Attaching and effacing lesions in the large intestine of an eight-month-old heifer associated with Escherichia coli O26 infection in a group of animals with dysentery

Escherichia coli O26:K60, with genetic attributes consistent with a potentially human enterohaemorrhagic E. coli was isolated from the faeces of an eight-month-old heifer with dysentery. Attaching and effacing lesions were identified in the colon of a similarly affected heifer examined postmortem, and shown to be associated with E. coli O26 by specific immunolabelling.     

A new isolate of the nematophagous fungus Duddingtonia flagrans a biological control agent against free-living larvae of horse strongyles

An experiment was carried out in 1997 to test the efficacy of an isolate of the microfungus Duddingtonia flagrans against free-living stages of horse strongyles under conditions in the field and to assess the eventual effect of the fungus on the normal degradation of faeces. Faecal pats were made from faeces of a naturally strongyle infected horse, which had been fed fungal material at a dose level of 106 fungal unit/kg bwt. Control pats without fungi were made from faeces collected from the same animal just before being fed fungi. Faecal cultures set up for both groups of faeces to monitor the activity of the fungus under laboratory conditions showed that the fungus significantly reduced the number of infective third-stage larvae (L3) by an average of 98.4%. Five faecal pats from each batch of faeces were deposited on pasture plots at 3 times during spring-summer. The herbage around each pat was sampled fortnightly to recover L3 transmitted from faeces. The results showed that the herbage infectivity around fungus-treated pats was reduced by 85.8-99.4%. The remaining faecal material at the end of each sampling period was collected, and the surviving L3 were extracted. Significantly fewer larvae were recovered from the fungus-treated pats. Analysis of wet and dry weight of the collected pats, as well as their organic matter content, were performed to compare the degradation of faeces of both groups. The results indicated that the presence of the fungus did not alter the degradation of the faeces.     

Investigating the Link between Particulate Exposure and Airway Inflammation in the Horse

Inhalant exposure to airborne irritants commonly encountered in horse stables is implicated in the pathogenesis of inflammatory airway disease (IAD) and recurrent airway obstruction (RAO), non‐infectious, inflammatory pulmonary disorders that impact the health and performance of horses across all equine disciplines. IAD and RAO have overlapping clinical, cytological, and functional manifestations of the pulmonary response to organic dust and noxious gases encountered in the barn environment. Study of these diseases has provided important but incomplete understanding of the effect of air quality upon the respiratory health of horses. In this review, the principles of particulate exposure assessment, including health‐related aerosol size fractions and size‐selective sampling, the factors influencing air quality in equine environments, and the effect of air quality on the equine respiratory tract are discussed. The objective of this review is to provide the reader with a summary of the most common chronic inflammatory airway diseases in the horse and the principles of air sampling that are essential to the planning, interpretation, and assessment of equine respiratory health‐related exposure studies.