Original article(s)

Sixteen adult female pigeons were randomly divided into two groups that were fed either corn or peas. Within each group, four pigeons received a supplement of 2.5 g L-carnitine/l drinking water. After an adaptation period of 7d, all excreta were gathered per bird in a 7d collection period. Coefficients of apparent digestibility of dry matter, organic matter, crude fat, crude fiber and nitrogen-free extract and apparent nitrogen retention were calculated from proximate analyses of feedstuffs and excreta. Blood samples were taken at the end of the trial and plasma samples were analyzed for carnitine and related compounds. Supplementation of L-carnitine did not affect digestibility but it did reduce apparent nitrogen retention in the corn-fed pigeons. Plasma analysis of γ-butyrobetain gave indications for a negative feedback mechanism of high L-carnitine dosage on de novo L-carnitine synthesis.

Severe combined immunodeficiency (SCID) of horses is an inherited autosomal recessive defect carried by pure Arabian horses and their crossbreds. SCID foals have a deficiency in the number and function of mature lymphocytes and are very prone to infectious diseases. The defect is caused by a mutation in the PRKDC gene coding for the catalytic subunit of the DNA activated protein kinase (DNA-PKcs). Identification of the causative mutation made it possible to design a genotyping test for identifying carriers of the defective allele and to use this information in selective breeding against SCID. Here, the first frequency sampling of the SCID allele in the Belgian population of Arabian horses is presented. Four hundred and thirteen animals were genotyped, 25 or 6.05% of which were found to carry the SCID allele. Calculations based on these results showed the SCID allele frequency to be around 3.1% and the occurrence of SCID to be 0.096%.

Fourteen dogs with clinical signs compatible with a spinal arachnoid cyst were presented and examined at the Department of Medicine and Clinical Biology of Small Animals (Ghent University) between November 2000 and September 2004. The typical presentation was a slowly progressive non-painful ataxia. The diagnosis of a spinal arachnoid cyst was made by myelography, in some cases followed by computed tomography. Six dogs were treated surgically. Three dogs underwent durectomy and three dogs durotomy. All dogs were available for short-term follow-up and five out of six dogs were available for long-term follow-up (more than 1 year post surgery). Both the short-term and long-term results were promising.

Caseous lymphadenitis (CL) in goats is manifested by abscesses filled with caseous pus, mainly in the superficial lymph nodes, but also in internal lymph nodes and several organs. Not only because of the direct economic losses, but also because of the zoonotic aspect, the occurrence of the disease can harm the profitability of the goat farm. Because until now no records have been available in Belgium, a prevalence study for CL was performed in the province of East Flanders.

Antibiotic resistance of Brachyspira hyodysenteriae, especially to pleuromutilins, is a matter of concern in several countries. In the present study, the antimicrobial susceptibilities of 30 Belgian B. hyodysenteriae isolates from 24 swine herds were tested and compared with the clinical effect of treatment. In vitro, no resistance to tiamulin was found, but two isolates(6%) were classified as intermediately susceptible. All isolates were susceptible to valnemulin at low concentrations (MIC50: ≤0.03 µg/ml). Higher minimal inhibitory concentrations (MICs) for valnemulin were found in isolates with higher MICs for tiamulin. For lincomycin, 16 (53%) isolates were classified as resistant and 4 (13%) isolates as susceptible. For tylosin, a high percentage of resistance(96%) was recorded. The MICs for 50% of the strains for salinomycin and doxycycline were 0.5 and 4 µg/ml, respectively. Subsequently, the in vitro data obtained were compared with the farm history and clinical efficacies in 23 of the 24 swine herds of origin as judged by the attending veterinarians. The effect of treatment as evaluated in the field was generally in agreement with the in vitro data for these antibiotics. However, a clinical interpretation of certain breakpoints is imperative. A revision of the clinical breakpoint for tiamulin is proposed. Isolates with MIC ≥1µg/ml should be considered as not responding to therapy in vivo. Consequently, the therapeutic use of another compound is indicated. In the third part of this study, the in vitro MIC for lincomycin was compared in detail with the effect of treatment on four farms. Even though in vitro all isolates were classified as resistant, a good response to treatment was observed on two farms. On one of these farms, however, the disease reappeared after treatment was discontinued. It was concluded that in vitro susceptibility testing of B. hyodysenteriae for lincomycin only partially predicted clinical effect of treatment in the field.

Of 97 dogs which were castrated at the Faculty of Veterinary Medicine, Ghent University between 2003 and 2005 for different indications such as unwanted sexual behavior, prostatic problems, testicular tumors and cryptorchidism; both testicles were examined macroscopically and then submitted for histopathological examination of testicular parenchyma. Thirty eight different breeds were represented in the examined population. Bilaterally normal testicles were found in 46% of the patients. Testicular tumors were found in 29% of the cases and usually occurred in older dogs (mean age 10.9 years). Testicular neoplasms could be subdivided into seminomas (39%), Sertoli cell tumours (14 %), Leydig cell tumors (29%) and mixed tumors (18 %). Testicular neoplasm was incidentally found in 19% of the 27 dogs presented for routine castration. No other testicular pathologies were present in this group. Besides testicular tumors, testicular atrophy (20 %) was the most frequently observed testicular pathology in the population which was examined, whereas inflammation of the testis was very rarely diagnosed (5%).

The PrP genotyping of sheep for selection from the population of individuals with scrapie resistant genotypes has become a very important component of the scrapie eradication strategy. However, a limited number of sheep did not seem to possess a standard “two allele” genotype, but rather three or more PrP (prion protein) alleles (complex genotypes). One hypothesis is that these animals are blood chimerisms, due to exchange of blood with their co-twin during gestation. In this study, blood from sheep with different genotypes was deliberately mixed (mimicking chimerism in vitro) and genotyped using real-time Polymerase Chain Reaction (PCR) and Restriction Fragment Length Polymorphism – Denaturating Gradient Gel Electrophoresis (RFLP-DGGE). At certain mixture ratios, complex genotypes were detected. This experiment shows that if the complex genotypes diagnosed in vivo are due to blood chimerism, they can to a certain extent be detected by these techniques.

Swine dysentery is causing severe economic losses in affected herds. In the present study an elimination protocol without depopulation was developed and evaluated on three farrow-to-finish farms using fecal examination. The elimination protocol consisted of stringent rodent control, hygienic measures and an elimination treatment of the sows using tiamulin 10 mg/kg BW or valnemulin 4 mg/kg BW for 3 weeks, followed by a 3 week treatment at half the dose. On day 10 of antimicrobial supplementation, treatment was accompanied by washing of the sows and cleaning of the environment. Once treated and washed according to this protocol, the sows were considered clean. Thus the piglets born from these sows in a clean environment were considered clean and were kept separated from the rest of the piglets and fatteners. For the piglets and fatteners born before the elimination treatment, no elimination treatment was done. Only pigs showing clinical symptoms were treated, in combination with hygienic measures to prevent spreading. Fecal samples from sows and clean pigs were monitored monthly until one year after the start of the treatment program. In two herds, elimination of the disease was successful: no clinical signs were seen and fecal samples remained negative until the end of the testing period. In one herd, clinical symptoms reappeared in the fatteners. The findings of this study confirm the potential usefulness of the elimination protocol described in single-site, farrow-to finish herds. In addition, the results of the prolonged follow-up strongly indicate that the causal bacterium itself, Brachyspira hyodysenteriae, can be eliminated at the farm level when this elimination protocol is applied.

Swine dysentery is causing severe economic losses in affected herds. In the present study an elimination protocol without depopulation was developed and evaluated on three farrow-to-finish farms using fecal examination. The elimination protocol consisted of stringent rodent control, hygienic measures and an elimination treatment of the sows using tiamulin 10 mg/kg BW or valnemulin 4 mg/kg BW for 3 weeks, followed by a 3 week treatment at half the dose. On day 10 of antimicrobial supplementation, treatment was accompanied by washing of the sows and cleaning of the environment. Once treated and washed according to this protocol, the sows were considered clean. Thus the piglets born from these sows in a clean environment were considered clean and were kept separated from the rest of the piglets and fatteners. For the piglets and fatteners born before the elimination treatment, no elimination treatment was done. Only pigs showing clinical symptoms were treated, in combination with hygienic measures to prevent spreading. Fecal samples from sows and clean pigs were monitored monthly until one year after the start of the treatment program. In two herds, elimination of the disease was successful: no clinical signs were seen and fecal samples remained negative until the end of the testing period. In one herd, clinical symptoms reappeared in the fatteners. The findings of this study confirm the potential usefulness of the elimination protocol described in single-site, farrow-to finish herds. In addition, the results of the prolonged follow-up strongly indicate that the causal bacterium itself, Brachyspira hyodysenteriae, can be eliminated at the farm level when this elimination protocol is applied.

In 56 dogs and 1 cat a diagnosis of suspected fibrocartilaginous embolism was made based on the history, the typical clinical presentation, and the absence of specific abnormalities on radiography and myelography. None of the diagnoses was confirmed by histopathological examination; since none of the patients was euthanized at the time of diagnosis. Therapy consisted of supportive care, with additional physio and/or hydrotherapy in a quarter of the cases. Short- and long-term results (more than 1 year after diagnosis) were better than earlier reported.