Comparison of indirect fluorescent antibody test and enzyme linked immunosorbent assay in the detection of exposure of cattle to Theileria parva in Kenya.

Appraisal of the indirect fluorescent antibody test (IFAT) and antigen enzyme linked immunosorbent assay (ELISA) serological tests as carried out to detect cattle exposed to Theileria parva at the National Veterinary Research Centre, Muguga (NVRC), Kenya is reported. Using sera from T. parva naive cattle and cattle experimentally exposed to T. parva, the two tests were appraised in terms of their sensitivity and specificity. IFAT and ELISA had the same sensitivity of 90% while ELISA had a higher specificity (90%) than IFAT (80%). A comparison was also made of the capability of the two tests to detect exposure of dairy cattle to T. parva prior to immunization against East Coast fever (ECF). The positive outcome from the IFAT was significantly higher (chi 2 = 30.36; P < 0.001) than that from the ELISA. The agreement between the two tests was low (Kappa = 0.21). The two tests indicated a higher risk of ECF in the study area than was expected. Indications are that the ELISA has been effectively adopted at NVRC.     

Evaluation of the efficacy of Salmonella enteritidis oil-emulsion bacterin in an intravaginal challenge model in hens.

The efficacy of Salmonella enteritidis (SE) oil-emulsion bacterin (a commercially available vaccine) was evaluated in an intravaginal challenge model in hens producing a high rate of SE-contaminated eggs. Hens were vaccinated at 38 wk of age. A second (booster) bacterin injection was administered 4 wk later. Two weeks after the second vaccination, all hens were challenged intravaginally with 10(7) colony-forming units of SE. After challenge, 36 of 189 eggs (19.0%) in the vaccinated hens were positive for SE, and this contamination rate was significantly (P < 0.01) lower than that in the unvaccinated hens (61 of 165 eggs, 37.0%). SE was highly recovered from the cloacal and vaginal swabs of the unvaccinated and vaccinated hens, but the number of SE from the cloaca of the vaccinated hens was significantly (P < 0.05) lower than that in the unvaccinated hens at 7 days post-challenge (PC). The recoveries of SE from the spleen and ovary in the vaccinated hens were significantly (P < 0.05) lower than those in the unvaccinated hens at 7 days PC. At necropsy, SE was recovered from 2 of 15 forming eggs (13.3%) taken from the oviducts of the unvaccinated hens, whereas no SE was recovered from 17 forming eggs in the vaccinated hens. After vaccination, serum antibodies for SE in the vaccinated hens were significantly higher than those in the unvaccinated hens. Antibodies from the oviductal washing, especially immunoglobulin G isotype, in the vaccinated hens were higher than those in the unvaccinated hens after challenge. This intravaginal challenge model produced frequent contaminated eggs and clearly demonstrated the ability of the bacterin to protect against egg contamination. The present model may be a useful tool for further studies to evaluate the protective effect against SE contamination of eggs by potential vaccine candidates.     

Functional significance of musculature of the external nose in swine (Sus scrofa f. domestica)

The origin and attachments of the muscles of the external nose were examined in 17 pigs comprising both sexes and different age groups. The modification of the porcine nasal apex to the snout-disc leads to different functional aspects of the muscles of the external nose. Accordingly, all these muscles are attached to the snout-disc. Only the nasolabial levator and caninus muscles are also attached to the upper lip. In addition, the snout-disc includes an intrinsic muscle, the nasal muscle. With regard to morphological and functional aspects, the nostrils can be divided into two parts. The superficial part consists of muscle and connective tissue and is dilated by the cooperative contraction of all muscles of the external nose. In contrast, the second and cartilaginous part of the nostrils dilates less readily, through contraction of the rostrally located deep fibres of the levator nasolabial muscle. As an adaptation for rooting, a special supportive system for muscles of the external nose has developed in pigs, including osseous (eminentia canina) and muscular (muscular slip of the m. levator labii superioris attached to the nasal bone, species-specific development of the m. levator nasolabialis) structures. The observed cartilaginous connection between the ventral lateral nasal and the vomeronasal cartilages suggests another transport mechanism for odours into the vomeronasal organ. Due to this connection, movement of the snout-disc and the cartilages of the external nose could imply passive movement of the vomeronasal cartilage and therefore of the vomeronasal organ.     

Cephalosporins – pharmacological basis of clinical use in veterinary dermatology

Cephalosporins form a large group of β-lactam antibiotics which are used extensively in human medicine and to a lesser extent in domestic animals. In veterinary dermatology, the principle use for the cephalosporins is the clinical management of canine pyoderma associated with Staphylococcus intermedius . In practice, the use of orally administered first generation cephalosporin drugs to affected dogs is well tolerated and highly efficacious. Bacterial drug resistance appears to occur rarely.     

Morphometric Study of the Equine Navicular Bone: Age-Related Changes and Influence of Exercise

Navicular bones from the four limbs of 95 horses, classified in 9 categories, were studied. The effects of age on navicular bone morphometry and histomorphometry were estimated, after adjustment of the data to even out the effects of front and rear limbs, morphometrical type, sex, weight, and size.All the external measurements of the navicular bone decreased significantly with increasing age. From the histomorphometrical data, cortical bone volume decreased with age in most horses, whereas cancellous bone volume and, in particular, the marrow spaces increased. The increase in the cancellous bone volume could have resulted from tunnelling of the internal part of the cortex, which converted it progressively into a porous trabecular-like structure. Trabecular bone volume also decreased with age and the trabecular lattice changed dramatically to become disconnected in aged horses. These observations corresponded closely to those reported for ageing of the skeletal system in humans.However, in sporting horses, the navicular cortical bone volume increased with age and the cancellous bone volume decreased. Exercise appeared to have decreased bone resorption and increased bone formation at the endocortical junction. The cancellous bone architecture was also improved, in that the trabecular lattice and trabecular bone volume remained unchanged in aged sporting horses. Our findings confirmed that exercise may be good practice to prevent age-related bone loss.     

Factors Influencing the Bioavailability of Peroral Formulations of Drugs for Dogs

The oral route is presently the preferred route of drug delivery. Poor oral bioavailability results in variable concentrations of drugs in the plasma and variable pharmacological responses, in addition to higher product costs. The unique canine physiology, anatomy and biochemistry makes designing canine dosage forms a challenging exercise. This article reviews the physicochemical, physiological, pharmacokinetic, pharmacological and formulation factors that can influence the drug availability of the oral formulations in dogs in an effort to provide a source of data to aid development of canine drug products with superior bioavailability.     

In situ hybridization for the detection and localization of swine Chlamydia trachomatis

Gnotobiotic piglets were inoculated intralaryngeally with swine Chlamydia trachomatis strain R33 or orally with swine C. trachmatis strain R27. Archived formalin-fixed, paraffin-embedded tissues from piglets euthanatized 4-7 days postinoculation were examined by in situ hybridization for C. trachomatis nucleic acid using a nonradioactive digoxigenin-labeled DNA probes that targeted specific ribosomal RNA or omp1 mRNA molecules of the swine C. trachomatis strains. Positive hybridization signals were detected in bronchial epithelial cells, bronchiolar epithelial cells, pneumocytes, alveolar and interstitial macrophages, and jejunal and ileal enterocytes. Chlamydia-infected cells had a strong signal that was confined to the intracytoplasmic inclusions. Positive hybridization signals were not detected in tissue sections from an uninfected control piglet or in C. psittaci-infected sheep placenta. The morphology of host cells was preserved despite the relatively high temperature required in parts of the incubation procedure. The data indicate that in situ hybridization can be used to detect swine C. trachomatis in formalin-fixed, paraffin-embedded tissue specimens.