2002 - 71 (5)

This paper reports on a choroid plexus hyperplasia in an adult cow suspected of having BSE. The cow was a seven-year-old Belgian Blue with a history of progressive ataxia in the front and hind limbs. No improvement was observed after treatment. On macroscopic examination of the brain, several grayish red masses were found dorsally between the cerebrum and the cerebellum. Histopathology revealed a benign proliferative process of the choroid plexus. This abnormality of the choroid plexus can be added as support for the possible differential diagnosis of bovine spongiform encephalopathy.

Although the genetic defect schistosomus reflexus is not exceptionally rare, literature on this defect is scant. This case report describes a female twin calf, that was born from a seven-year-old fifth calf cow of the Belgian White and Blue breed. The first calf (a bull) was extracted per vias naturales, the schistosomus reflexus was delivered by caesarean section.

Eighty tracheal washings were collected from 80 untreated calves of 28 herds in Flanders, suffering from acute respiratory distress. Thirty-five (44%) of the samples were bacteriologically positive. Identification of the strains resulted mainly in Pasteurella multocida (68%). Other bacteria were Mycoplasma bovirhinis (14%), Mannheimia haemolytica (11%), Mycoplasma bovis (11%), Haemophilus somnus (3%), and α-hemolytic streptococci (3%). In 14 % of the positive samples more than one pathogen was isolated. Mostly Mycoplasma spp. were involved. Antimicrobial resistance patterns of the strains identified as Pasteurella multocida (n = 24; 14 farms) revealed 100% susceptibility for amoxicillin+clavulanate, enrofloxacine, ceftiofur and florfenicol, 96% susceptibility for tetracycline and ampicillin, and 92 % susceptibility for the combination trimethoprim/sulphonamides. In one strain only (4%) resistance against two antimicrobials was found. In contrast with surveys in neighbouring countries, the prevalence of Pasteurella multocida in bovine respiratory disease was high in Belgium and antimicrobial resistance was low. Possibly, these differences can be explained partially by the fact that in the neighbouring countries necropsy strains prevailed in the collections studied.

Impulsive, disinhibited behavior in dogs, which comes to expression as aggression, has a major impact on public health. Measures taken without a real understanding of the underlying pathology are unlikely to be effective. It would therefore be not only of pathophysiological but also of clinical relevance to develop a research paradigm to investigate this aberrant behavior in dogs. The first aim of this article is to review the literature concerning functional-anatomical and biochemical research on animal impulsivity. On the basis of this research, a hypothesis involving the prefrontal serotonin-2A receptor in the frontal cortex is generated and the feasibility of quantifying the 5-HT2A receptor with Single Photon Emission Computed Tomography (SPECT) and the highly selective receptor radioligand 123I-5I-R91150 is presented in a pilot study. If confirmed, this hypothesis may lead to the development of an in vivo research tool for investigating behavioral disorders and a modality for monitoring the effects of pharmacologic interventions and behavior therapy.

To regain the SPF status of a contaminated but genetically valuable rabbit breeding unit, embryos from the contaminated does were transferred into SPF recipient females. Embryos were collected on day 3 of gestation by flushing uterine horns. All usable embryos were frozen, and a portion of them were preserved in liquid nitrogen to form a stock of highly valuable genotypes. Thirty-two stimulated does produced 893 embryos, 821 (92%) of which had an intact zona pellucida and were cryopreserved. Of this stock, 478 embryos were thawed, 466 were recovered (97.5%) and 417 were of good quality (87.2%). In 30 does, 10 to 18 embryos were surgically transferred per recipient doe and 24.9% (104/417) of them developed to term after transfer. This corresponds to an average number of 3.47 (104/30) live newborns per recipient. Health screenings performed on sanitized rabbits confirmed the disappearance of pathogenic agents.