Original article(s)

During a routine inspection on a pig farm, nortestosterone was found in faecal samples. An intersexual pig held responsible for this finding was slaughtered and further investigated anatomically, histologically and chemically. Macroscopic inspection revealed a mainly female reproductive tract consisting of a vagina, a uterus and on the left side a normal ovary and uterine tube. However, on the right side a hypoplastic testis with an epididymis was found together with a well developed plexus pampiniformis-like structure. Histologically no spermatozoa were found in this testis, but Leydig cells were numerous. Chemical analysis showed the presence of 17--nortestosterone in the urine, fat, kidney and testicular tissue, as well as the precursor noradrenostenedione in the urine, kidney and testis. As intersexuality is a frequent phenomenon in pigs, veterinarians who are responsible for food safety must be aware of this problem which interferes with the inspection on hormonal products in meat.

 In the present study a modified method is described in which coated polyurethane catheters and a titanium vascular access port (VAP) with a silicone membrane were implanted into the femoral artery in forty dogs. This device enabled repeated arterial blood pressure measurement and blood sampling in conscious and anesthetized dogs for an average period of two weeks. The catheter was not removed by any of the dogs themselves, and few clinical problems were observed. An infection with Pseudomonas aeruginosa induced by a contaminated flush solution was diagnosed in four dogs. These dogs recovered rapidly after an appropriate antibiotic therapy The conclusion of the study is that this arterial catheterization technique with vascular access port in place over a two-week period is suitable and technically feasible for experimental protocols in dogs.

During the period of July 1999 through June 2002, carcasses of wild rabbits that had been shot or found dead and livers originating from wild rabbits that had been shot for consumption were collected in Flanders. One hundred and twelve carcasses were suitable for necropsy and histological and bacteriological analysis; histological analysis was possible in 41 livers. Considering the 112 rabbit carcasses only, Rabbit Hemorrhagic Disease (RHD) was found to be present in 33.9% of the cases. RHD was the most prevalent wild rabbit pathology detected in this study, before staphylococcosis (12.5%), and myxomatosis (10.7%). None of the liver samples from rabbits shot for consumption were positive for RHD. Of the 38 histologically RHD positive samples, 24 were analyzed with the hemagglutination (HA) technique, yielding 58.3% positive results. Seven samples that were histologically positive for RHD but HA negative were examined by transmission electron microscopy and were found positive for calicivirus. This proves that HA-negative RHD strains are circulating in the Flemish wild rabbit population.

 A new insemination device (DIUI-pipette) was developed to deposit the semen near the oviduct. In this field study, 4064 cows were inseminated by 12 inseminators to assess the feasibility of the new DIUI-pipette. The cows were inseminated using three different methods: 1) in the uterine body with the classic insemination device, 2) in the uterine body with the DIUI-pipette, and 3) in the top of both uterine horns with the DIUI-pipette. Each insemination was performed with 10-15 x 106 frozen-thawed spermatozoa. The pregnancy rates (PRs) were significantly affected by the insemination technique (p = 0.02), the inseminator (p = 0.01), heifer or multi-parous cow (p < 0.01), and by the insemination number (p < 0.01). Time did not have a significant effect (p = 0.07). Pregnancy rates obtained after insemination with the classic insemination device were significantly better than those obtained after insemination in the uterine body with the DIUI-pipette (p < 0.01), but did not differ significantly from those obtained after deep insemination in both uterine horn tops (p = 0.27). Although the deep intra-uterine insemination method is more time consuming and requires more experience than the classic insemination method, it can be concluded that the DIUI-pipette is suitable for the insemination of dairy cattle under field conditions. Whether the new DIUI-pipette is also suitable for insemination with lower insemination doses is still to be examined.

Between 1996 and 2000 79 Belgian blue donor cows were submitted to OPU-IVF. They all had a history in classical embryo transfer programs with disappointing results. Two different in vitro embryo production protocols were used. Between 1996 and 1998 (period A), oocytes were matured in M199 and Epidermal Growth Factor (EGF) and Foetal Calf Serum (FCS) were added. Subsequently, the oocytes were cultured in a granulosa co-culture system in a Synthetic Oviduct Fluid (SOF) medium. From 1998 until 2000 (Period B), M199, FCS, equine chorionic gonatrophin (eCG) and a granulosa cell co-culture were used for in vitro maturation.Zygotes were subsequently cultured in SOF with a co-culture of bovine oviduct epithelial cells (BOEC). During period A, 531 OPU-IVF sessions were performed, collecting 2111 cumulus oocyte complexes (COCs), of which 928 (44 %) were of good morphological quality. The In vitro maturation (IVM), fertilization (IVF) and culture (IVC) resulted in 241 transferable embryos. When fresh embryos (n=88) were transferred, a pregnancy rate of 27 % was obtained, whereas the transfer of frozen embryos (n=18) resulted in 29 % pregnant recipients. During period B, 1519 OPU sessions were performed, collecting 7027 COCs, with 2157 (31%) of them being of good quality. Following IVM-IVF-IVC, we cultured 1120 transferable embryos of which 438 were transferred fresh, resulting in a pregnancy rate of 39%. The transfer of frozen embryos (n=139) yielded a pregnancy rate of only 5 %. The overall results improved over the years, while individual donor variability was one of the main factors that have an influence on the OPU-IVF success rate. At the end of the second period, an average of 0.8 embryos were obtained per OPU session. Since freezing of in vitro derived bovine embryos is still problematic, the transfer of fresh embryos remains the best option. However, in our circumstances the availability of good quality recipients appeared to be the limiting factor.

In this study, the efficacy of intraruminal copper boli in the prevention of molybdenosis in cattle caused by environmental contamination was examined. The efficacy and safety of a high- and a low-dose intraruminal copper bolus were tested. Both treatments maintained copper serum levels within normal limits. The high-dose treatment caused very significant (P<0.001) differences in serum copper levels compared with untreated controls. Significant differences could not be demonstrated in the second trial in which the effects of the high- and the low-dose bolus were compared because an unexpectedly high number of animals had to be excluded from the trial. No abnormal high copper levels or signs of toxicity were observed. In order to prevent excessive copper accumulation in the liver, the lower dose copper bolus may be preferable.

Most variations of the rostral teeth in sheep affect the canine teeth. The present study reports the occurrence of these variations observed in 266 sheep of six different breeds. Unilateral or bilateral absence of the canines was observed in 15.4 % of the cases. This might interfere with the correct determination of the age. Rotation of the canines was observed in 1.1 % of the sheep investigated. Changes of shape or presence of canine teeth in the upper jaw were not observed in the animals of this study.

Clinical navicular disease (CND) is a classification diagnosis defined as a lameness originating in the foot with clinical signs compatible with navicular disease syndrome (ND): the lameness is blocked by distal digital palmar analgesia (DDPA) and no radiographic signs of ND are present. Fifty horses with CND were injected with corticosteroid intra-articularly into the distal interphalangeal (D.I.P.) joint to evaluate the effect of such applications. Follow-up was done by questionnaire, and mean follow-up time was at least one year. Within three to four days after “treatment,” 34% of the horses were sound and remained so for two months and longer. In 66% of the horses, no or insufficient (less than two months) effect was recorded. It is suggested that, in horses with CND, 1/3 might have lameness originating from the palmar compartment of the D.I.P. joint, and 2/3 have pain that might be localized in the bursa (results of previous study).

In this study, the prevalence of PMWS affected pigs was determined in three Belgian farms with a history of PMWS and in four control farms with no suspicion of PMWS. The diagnosis of PMWS was based on the fulfillment of all four of the following criteria: the presence of wasting, gross lesions and histopathological lesions suggestive of PMWS and the presence of high PCV2 titers in the lymphoid organs. In the farms with a history of PMWS, 2% of the piglets died of PMWS during the observation period. In the control farms, 0.1% of the piglets were found to be affected with PMWS. Serological examinations showed that all piglets became infected with PCV2 on all farms and no differences in serological profiles were seen between farms or litters with or without PMWS-affected piglets. PRRSV infections were clearly demonstrated in PMWS-affected and non-affected piglets but no correlation was seen between simultaneous infections with PCV2 and PRRSV and the occurrence of PMWS.

A retrospective study was performed on 100 horses with incarceration of the small intestine through the omental (epiploic) foramen at the Faculty of Veterinary Medicine of Ghent University in Belgium during the period 1994-2001. Preoperative euthanasia was done in 10 horses for different reasons and an explorative laparotomy was performed in 90. Of these ninety horses, 1 died spontaneously during surgical intervention, 10 underwent euthanasia because of the extent of the lesions or a fatal hemorrhage, and surgery was completed on the other 79. A second intervention was necessary in 11 of these 79 horses Simple reduction and reposition of the small intestine was possible in 35 of them, and a resection followed by an intestinal anastomosis was required in the other 44. Forty-four (49%) of the original 90 horses in which surgery was accomplished were discharged from the clinic. Six of these 44 were re-operated. The survival rate in the group of horses that underwent simple reduction was 60% and in the group that underwent resection and anastomosis it was 52%. After discharge from the clinic, 9 of the original 44 horses were lost for follow-up, and the remaining 35 survived for at least 9 months. During the follow-up period (1 to 7 years), 16 horses had one or more bouts of colic, for which reason 5 of them (14%) underwent euthanasia. In this study the mean age of the horses with incarceration of the small intestine through the omental foramen was 9.46 years. Geldings, males and riding horses were clearly more represented. During surgical intervention a medio-lateral incarceration was observed in 98% of the horses. A negative correlation was observed between the survival rate and the length of the incarcerated intestinal segment, on the one hand, and between the survival rate and the distance to the clinic (duration after onset of symptoms) on the other.