Original article(s)

The efficacy of spray vaccination against Infectious Bronchitis (IB) in rearing layers, was examined in 12 flocks housed on 2 farms. For this purpose the vaccine was prepared with substantially more water than is commonly used in practice and was carefully sprayed in the direction of the animals. Single vaccination at 2 weeks of age resulted in mean 2log HI titres of only 3 to 4 at the end of the rearing period (16 weeks), whereas two vaccinations yielded titres of 6 to 7. Upon a third vaccination, titres increased up to 7 to 9, individually even reaching 11. These titres are distinctly higher than the mean level in the Netherlands. None of the flocks showed clinical symptoms of IB, neither during rearing, nor in the laying period, except one. For unknown reasons, this flock showed a poor serological response after three vaccinations and subsequently experienced clinical IB at the start of the laying period. It is concluded that administration of live IB vaccines as described in this study, deserves large scale practice, because it will then become clear whether this procedure contributes to a better IB prevention or not.

The treatment of obesity involves dealing with the psychological aspects, manipulating the diet and increasing the activity level. The objectives of the nutritional management are to decrease energy intake, to stimulate satiety and to provide a balanced nutritional intake that is appropriate for the stage of life and/or concomitant disease. The assessment of a diet for weight reduction should take into account the daily nutrient intake in order to avoid underfeeding of essential nutrients. The treatment of obesity will be illustrated with a complicated case of obesity and renal insufficiency in a dog.

In this study, the effect of the insemination dose (250 or 500 x 106 fresh spermatozoa) on pregnancy rate at 35 days post-insemination (PI) in synchronized ewes was analyzed. The 30 days non-return rate was determined by the introduction of an intact ram harnessed with a crayon at 10 days PI. At 35 ± 2 days PI, the ewes were scanned for pregnancy by means of transrectal ultrasonography (7 MHz). Five months PI, the lambing rate and fecundity were recorded. No significant differences (p<0.05) were found in non-return rate, pregnancy or fecundity between 250 and 500 x 106 fresh spermatozoa per insemination dose. Increasing the number of spermatozoa from 250 x 106 to 500 x 106 per insemination dose did however improve the lambing rate (p<0.1). Pregnancy control by transrectal ultrasound (7 MHz) at 35 ± 2 days was at least as reliable as a teaser ram.

Isospora suis causes neonatal coccidiosis in piglets. Clinical signs include diarrhoea in 5 to 14-days-old piglets. The morbidity is high and the mortality low to moderate. Up until now, no I. suis prevalence data have been available in Belgium. Therefore, 30 swine herds (10 litters/farm) were sampled in Flanders during the summer of 2000 to determine the prevalence and the importance of I. suis. On 24 of the 30 examined farms (80%) oocysts were present, with an average of 33% of the litters infected. On 4 of the 5 farms with obvious problems of diarrhoea an average of 47 % of the litters was infected. However, diarrhoea was not significantly correlated with the presence of I. suis infection or with the percentage of infected litters. The cleaning of the farrowing crate and the treatment of the sows (at parturition) with sulfonamids had no apparent effect on the occurrence of the infection, but the disinfection of the farrowing crates however had a significant effect on the percentage of infected litters.

Since April 1, 2002, the European Union has extended the TSE testing in ruminants by including sheep and goats in the survey studies. Like for the bovine species, the diagnostic protocol is performed on a tissue sample of the brain stem collected at the level of the obex. Morphological differences of the brain stem of sheep and goats, in comparison with the bovine species, have required some adjustments to the sampling method and equipment. In this study, the technical aspects of sampling and a number of morphometrical parameters of the ovine brain stem are described. The essential differences, compared to the bovine species, concern the dimensions and the more pronounced caudal narrowing of the brain stem.

In this paper we report the application of a new, non-invasive, objective, painless and sensitive neurological test method in the horse. After transcranial stimulation of the motor cortex of the brain, using a changing magnetic field, the evoked potentials are registered electromyographically and measured. The technique was first applied in eightteen normal horses in order to obtain reference values. Thereafter, the usefulness of transcranial magnetic stimulation was investigated in eight neurological cases, as a complementary and objective diagnostic method in the neurological examination of the horse.We conclude that magnetic transcranial stimulation can put the diagnostic examination of horses with abnormal gait into a new perspective. The method is complementary the clinical neurological examination. In cases of severe ataxia the magnetic potentials determined in the present study correlated well with the clinical signs. In horses with subtle signs of ataxia, or when the nature of the affection as a purely orthopedic problem is not clearly evident, the lesions along the motor tracts can be assessed adequately, even in acute cases. In these cases the neurological lesions can be located with certainty, thus allowing the use of more specific ancillary tests (radiography, serum biochemistry, etc.). A supplementary advantage is that by measuring the onset latency and amplitude, an evolution in time can be followed objectively.

Thirty windsucking horses were admitted in the last eleven years (1990–2000) for a surgical intervention at the Department of Surgery and Anesthesiology of Domestic Animals of the Faculty of Veterinary Medicine in Ghent. Twenty-one horse owners answered the follow-up questionary. The results after surgery (modified operation of Forssell) were good in 71.4% of the cases, with little postoperative complications. There was no predisposition for a certain age or sex although thoroughbreds were more often referred for surgical treatment. The etiology of this stereotypy and its treatments are discussed.

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.