Rabies oral vaccination of foxes during the summer with the VRG vaccine bait

The vaccination of foxes by distributing vaccine baits in the environment was initiated in France in 1986. Two campaigns per year were carried out: one in the spring and one in the autumn. After the spring campaigns, only 22-52% of fox cubs consumed vaccine baits compared to 75% of the adults and 70-80% of the adults or fox cubs after autumn campaigns. In order to reduce the period of time during which fox cubs do not have access to baits and are not immunised, a vaccination campaign was organised during the summer of 1992 over a contaminated area of 25,748 km2 where vaccines had never previously been given. Vaccine bait stability was assessed during the same summer in the field and their appetence tested on captive foxes. The efficacy of the campaign was evaluated by the relative decrease in rabies incidence and the rate of bait uptake by foxes compared to those from neighbouring areas vaccinated for the first time with the same vaccine during the spring or autumn. Summer vaccination significantly increased (P < 0.01) bait uptake by fox cubs (71%) compared with spring vaccination (39%), but no significant difference was observed for adult foxes. Moreover, the decrease in rabies incidence, measured during the 6-month period following the campaigns was less pronounced after summer vaccination (49% decrease) than when the first vaccination was carried out during the spring or autumn (79 and 72% decrease, respectively). Three campaigns led to an apparent elimination of rabies when the first campaign was performed in the spring or autumn, but only to a 76% decrease in rabies incidence density index when the first campaign was performed during the summer. The high thermostability of the Raboral VRG bait permits its use during the summer for an emergency campaign. For routine vaccination plans, however, the classical calendar of spring and autumn vaccination campaigns should continue to be preferred.     

Detection of papillomavirus-DNA in mesenchymal tumour cells and not in the hyperplastic epithelium of feline sarcoids

Abstract We examined 12 formalin-fixed paraffin-embedded feline skin tumours which had the histopathological features of fibropapillomas for the presence of papillomavirus (PV) DNA using touchdown polymerase chain recation (PCR), DNA sequencing and nonradioactive in situ hybridization. Nine of the tumours contained a 102-bp PCR product demonstrated using consensus PV primers that amplify a portion of the L1 gene. The nucleotide sequences are closely related, but not identical to that of ovine PV type 2, rabbit oral PV and reindeer PV. The deduced amino acid sequences had strong homologies with the major capsid protein L1 of deer PV, bovine papillomavirus (BPV) 1 and BPV 2, and European elk PV. Although PV antigens were not detected in any of the tumours by immunohistochemistry, PV DNA was demonstrated in individual mesenchymal cells or cell nests of 4/12 tumours by in situ hybridization. A nonproductive infection of mesenchymal fibroblast-like tumour cells with a papillomavirus would explain the lack of PV antigen expression and the absence of PV DNA in the hyperplastic epithelium. Because these tumours and their pathogenesis are similar to equine sarcoids, we suggest that they should be reclassified as 'feline sarcoids' instead of fibropapillomas.     

Gastric ulcers in standardbred racehorses: prevalence,lesion description,and risk factors

This study was performed to estimate the prevalence of gastric ulcers in Standardbred racehorses, to describe the lesion score and location, and to identify potential risk factors. Two hundred seventy-five (275) Standardbred horses from 5 training centers and 2 racetracks in Quebec, Canada, were studied. Historical data for the 2 months before examination were recorded for each horse, and the presence of gastric ulcers was determined by gastroscopy. A previously reported scoring system that used grades 0-3 for gastric lesions was used. Overall, 121 horses (44.0%; 95% CI, 38.1-50.1%) had gastric ulcers. The prevalence of gastric ulcers was significantly higher (P < .0001) in actively racing horses (63.3%; 95% CI, 54.7-71.2%) than in horses at rest. Multivariate analysis defined that horses in racing (OR = 9.29; 95% CI, 3.55-24.3) were significantly more likely to have gastric ulcers than horses at rest and that trotters (OR = 2.23; 95% CI, 1.28-3.86) were more likely to have gastric ulcers than pacers. The number of lesion sites (P < .0001) and poor body condition (P < .0001) were significantly associated with lesion scores. Gastric ulcers are highly prevalent in Standardbred racehorses. Furthermore, actively racing horses and trotters are more likely to have gastric ulcers. Also, poor body condition in Standardbred racehorses may be an indication that gastric ulcers are present and that lesion scores are high. The cause-and-effect relationship between poor body condition and the presence of gastric ulcers is unclear.     

Intraocular pressure development after cataract surgery: a prospective study in 50 dogs (1998-2000)

Objective To study the course of intraocular pressure (IOP) after cataract surgery in 50 dogs. Design Prospective study. Animals Fifty dogs without preoperative ocular hypertension were selected for cataract surgery. Methods All dogs underwent cataract surgery: 25 by manual extracapsular extraction and 25 by phacoemulsification. For each dog, intraocular pressure was measured before surgery, and 1, 3, 5, 18 h, 1 week and 1 month post surgery. Results No significant difference of mean intraocular pressure between the two surgical methods was observed for each time measurement. Nine dogs had postoperative hypertension (IOP > 25 mmHg) during the first 5 hours post surgery. Incidence of postoperative hypertension was not significantly different with manual extracapsular extraction (16%) vs. phacoemulsification (20%). A decrease of mean IOP was observed 1 h after surgery (8.49 mmHg vs. 10.91 mmHg), then an increase 3 and 5 h post surgery (12.3 and 13.32 mmHg, respectively). At 18 h, 1 week and 1 month post surgery, mean IOP decreased. Mean IOP was 10.38, 10.38 and 8.84 mmHg, respectively. Conclusion In this study incidence of POH is not high. However, a follow‐up of IOP in the first hours after cataract surgery is required to avoid complications of the retina and optic nerve and to administer hypotensive treatment if necessary.     

Field efficacy of ivermectin plus praziquantel oral paste against naturally acquired gastrointestinal nematodes and cestodes of horses in North America and Europe

The efficacy of an oral formulation of ivermectin plus praziquantel in the reduction of nematode and cestode egg counts in horses was assessed in 273 horses under field conditions at 15 sites in North America (n = 6) and Europe (n = 9). Horses were confirmed by fecal examination to have natural infections of strongyles (100%) and tapeworms (76%). Replicates of four horses were formed at each site, and in each replicate three animals received ivermectin (0.2 mg/kg body weight) plus praziquantel (1 mg/kg body weight) oral paste and one animal remained untreated or received vehicle paste. Fecal samples were collected for fecal nematode and cestode egg counting before and 7, 8, 9, 14, 15, and 16 days after treatment. Horses treated with ivermectin plus praziquantel oral paste had significantly (P <.01) lower posttreatment strongylid and cestode egg counts (reductions of 98% or more) than controls. Combined site analyses revealed that 95% or 96% of the horses positive for cestode eggs before treatment that were treated with ivermectin plus praziquantel were negative for cestode eggs at each posttreatment fecal examination. No adverse reactions attributable to ivermectin plus praziquantel oral paste treatments were observed. The results of the studies demonstrated that ivermectin plus praziquantel paste was highly effective in reducing egg shedding by gastrointestinal nematodes and cestodes, and no adverse reactions were observed in horses treated under field conditions.     

Learning performances of honeybees (Apis mellifera L) are differentially affected by imidacloprid according to the season

To establish the sublethal concentrations domain, acute and chronic oral tests were conducted on caged honeybee workers (Apis mellifera L) using imidacloprid and a metabolite, 5-OH-imidacloprid, under laboratory conditions. The latter showed a 48-h oral LD50 value (153 ng per bee) five times higher than that of imidacloprid (30 ng per bee). Chronic feeding tests indicated that the lowest observed effect concentrations (LOEC) of imidacloprid and of 5-OH-imidacloprid on mortality of winter bees were 24 and 120 microg kg(-1) respectively. Behavioural effects of imidacloprid and 5-OH-imidacloprid were studied using the olfactory conditioning of proboscis extension response at two periods of the year. Winter bees surviving chronic treatment with imidacloprid and 5-OH-imidacloprid had reduced learning performances. The LOEC of imidacloprid was lower in summer bees (12 microg kg(-1)) than in winter bees (48 microg kg(-1)), which points to a greater sensitivity of honeybees behaviour in summer bees, compared to winter bees.     

Use of a three-drill-tract technique for arthrodesis of the distal tarsal joints in horses with distal tarsal osteoarthritis: 54 cases (1990-1999)

OBJECTIVE: To assess the long-term clinical outcome of horses with distal tarsal osteoarthritis (OA) in which a 3-drill-tract technique was used to induce arthrodesis of the affected joints, identify any preoperative or operative factors associated with outcome, and describe any complications associated with the technique. DESIGN: Retrospective study. ANIMALS: 54 horses. PROCEDURE: Medical records were reviewed for information on signalment, use, history, physical and lameness examination findings, surgical technique, and postoperative care. Radiographs were examined, and severity of OA was graded. Follow-up information was obtained through telephone interviews with owners at least 13 months after the procedure. RESULTS: 32 (59%) horses had a successful outcome, 6 (11%) improved but were not sound after surgery, and 16 (30%) did not improve following surgery. Outcome was negatively associated with the previous use of intra-articular injections. Few postoperative complications were evident. CONCLUSIONS AND CLINICAL RELEVANCE: Results suggest that distal tarsal OA in horses can be successfully treated by means of distal tarsal arthrodesis with a 3-drill-tract technique. Horses with advanced distal tarsal OA are likely to have poorer outcomes, and the procedure will likely be of minimal benefit in horses with concomitant causes of hind limb lameness prior to surgery and in horses with preexisting proximal intertarsal joint disease.     

Effect of dietary fat sources on systemic and intrauterine synthesis of prostaglandins during early pregnancy in gilts

The present experiment was conducted to determine the influence of dietary fatty acids C18:2n-6 and C18:3n-3 on the modulation of intrauterine synthesis of prostaglandin E2 (PGE2) and F2alpha (PGF2alpha) during early pregnancy in pigs. Prostaglandin E2 in uterine fluid has been previously reported to be associated with embryo survival and development. Thirty-two Yorkshire-Landrace nulliparous gilts were randomly allocated to four diets containing 5% supplemental fat. The four dietary treatments were: HT, hydrogenated tallow (26.5% C16:0 and 54.8% C18:0); SO, sunflower oil (61.3% C18:2n-6); LO, linseed oil (50.4% C18:3n-3); and SO(CLA), a mixture of sunflower oil and conjugated linoleic acids to provide 20% CLA. Treatments started 2 d after the first pubertal estrus (d -21) and lasted for 36 d (slaughter), which was 15 d after the second estrus (d 0; insemination). Fatty acids and PGE2 were measured in the peripheral blood plasma on d -19, d -7, d 0, and d 14. Fatty acids in endometrial tissues and PGE2 and PGF2alpha in the uterine fluid collected on d 15 were also measured. Concentrations of fatty acids in the plasma reflected the content of fatty acids in the diet as early as d -7. From d -7, PGE2 concentrations in the plasma were higher in gilts fed SO compared with HT (P < 0.05). Plasma PGE2 concentrations were lower (P < 0.01) on d 14 in gilts fed LO compared with HT. Total PGF2alpha contents in the uterine fluid of gilts fed LO were more than 70% lower (P < 0.05) than for the HT group. A similar trend was observed for total PGE2 content and for the ratio PGF2alpha:PGE2, but the effect (LO vs HT) was less marked (P < 0.07 and P < 0.10, respectively). There was no effect of SO or SO(CLA) on total PGE2 contents in the uterine fluid. Dietary enrichment in C18:2n-6 and/or C18:3n-3 for early pregnant gilts can influence fatty acids in plasma and endometrial tissue and can modulate circulatory and intrauterine prostaglandins.