Characteristics of Haemophilus pleuropneumoniae Isolates and Some Epidemiological Findings on Porcine Haemophilus Pleuropneumonia in Saskatchewan

Thirty isolates of Haemophilus pleuropneumoniae from clinical and slautherhouse cases of porcine Haemophilus pleuropneumonia in Saskatchewan as well as six isolates from British Columbia and Ontario were subjected to cultural, biochemical, serological and antibiotic sensitivity tests. All strains were Gram-negative pleomorphic rods or coccobacilli which grew only in the presence of V factor and all produced porphyrin from delta-aminolaevulinic acid. Biochemically, the organism was positive for urease, O-nitrophenyl-β-D-galactopyranosidase and the fermentation of sucrose, mannitol, dextrose, lactose and xylose, but was usually negative for indole. Most strains of H. pleuropneumoniae were sensitive to chloramphenicol, furamazone, carbenicillin and ampicillin, but only about 50% were sensitive to tetracycline. Serotype 5 was more common than serotype 1 or the untyped strains among Saskatchewan isolates. In addition, serotype 3 was identified from British Columbia.

Retrospective epidemiological studies showed that Haemophilus pleuropneumonia occurred and recurred on farms in the Saskatoon and adjoining districts, serviced by the diagnostic laboratories of the Western College of Veterinary Medicine and that the disease was more common among three month old pigs during the fall-winter season.

     

Use of exfoliative cytology for diagnosis of transmissible venereal tumour and controlling the recovery period in the bitch

Transmissible venereal tumour (TVT) is a rare vaginal tumour that can be treated surgically or cryosurgically as well as by radiotherapy or chemotherapy. Vincristine has been found to be very effective for treating TVT. Since vaginal secretion or discharge may contain neoplastic cells, the cytological identification of TVT cells is possible. The present study was carried out in 12 bitches. Vaginal smears were obtained with cotton swab from the anterior vagina and TVT suspected structures. The smears were stained according to Papanicolaou and assessed by light microscopy. Additionally the general condition of the patients was evaluated by haematological and radiographic examinations. In bitches with TVT vincristine sulphate was administered intravenously at weekly intervals. The total treatment period was three to six weeks until no atypical cells were found in the smear. This was the case after an average of 3.2 +/- 1.3 applications. Tumour masses became smaller and by this non-visible from the rima vulva after 4.2 +/- 0.7 applications. During the treatment, two of the 12 bitches (16.7%) suffered from vomiting and diarrhoea while three (25%) showed neutropenia. Twelve months after completion of treatment, the bitches were examined again and vaginal smears were taken in order to control the recovery process or a possible recurrence of TVT. No atypical cells were found in any vaginal smear. By this exfoliative cytology has proved to be a safe and easy method for TVT diagnosis and for observing the recovery process.     

The effects of food withdrawal and darkening on lipid peroxidation of laying hens in high ambient temperatures

The aim of this study was to investigate the effects of feed withdrawal and darkening on the antioxidative status of laying hens in high ambient temperatures between 30-40 degrees C. We determined vitamins A and E, lipid peroxidation as thiobarbituric-acid reactive substances (TBARS), glutathione peroxidase (GSH-Px) and reduced glutathione (GSH) in the serum, liver and muscle. Sixteen week old hens (Ross Brown) were divided into 3 groups of 30 hens each. The first group was used as a control. Hens in the second (feed withdrawal) group were subjected to feed removal between 14-18 h during the summer. Hens in the third (darkening) group were subjected to darkening of the hens house with black curtains between 14-18 h. At the end of 16 weeks, blood serum, liver and breast muscle samples were taken from all animals and analysed. Vitamins A and E levels in serum and liver were significantly (P < 0.05, P < 0.01) higher in feed withdrawal and darkened groups than in control group whereas the serum levels of the darkening group were highest. GSH-Px activity and GSH level in liver and muscle were also significantly (P < 0.05, P < 0.01) higher in feed withdrawal and the darkening group than in control. However, TBARS levels in liver and muscle were significantly (P < 0.05, P < 0.01) lower in feed withdrawal and darkening groups compared with control group, whereas the level of the darkening group was the lowest. In conclusion, we observed that feed withdrawal and darkening of hens in high temperatures during summertime resulted in an increase of antioxidant enzymes and vitamins levels and in a decrease of lipid peroxidation.     

Comparison of the trotting gaits of Labrador Retrievers and Greyhounds

OBJECTIVE: To compare the trotting gaits of Labrador Retrievers and Greyhounds to determine whether differences in locomotion are attributable to differences in their manner of moving or to body size and shape differences between these 2 breeds. ANIMALS: 8 healthy 5-month-old Greyhounds and 5 healthy Labrador Retrievers between 6 and 18 months old. PROCEDURE: A series of 4 force platforms was used to record independent ground reaction forces on the forelimbs and hind limbs during trotting. Values of stride parameters were compared between breeds before and after normalization for size differences. Standard values of absolute and normalized stride period and stride length were determined from linear regressions of these parameters on relative (normalized) velocity. Forces were normalized to body weight and compared at the same relative velocity. RESULTS: Greyhounds used fewer, longer strides than the Labrador Retrievers to travel at the same absolute speed. After normalization for body size differences, most measurable differences between breeds were eliminated. Subtle differences that did persist related to proportion of the stride that the forefoot was in contact with the ground, timing of initial hind foot contact relative to initial forefoot contact, and distribution of vertical force between the forelimbs and hind limbs. CONCLUSIONS AND CLINICAL RELEVANCE: Results suggest that apparent differences in the trotting gait between Labrador Retrievers and Greyhounds are mainly attributable to differences in size, and that dogs of these 2 breeds move in a dynamically similar manner at the trot.     

In vitro detection of equine arteritis virus from seminal plasma for identification of carrier stallions

Equine arteritis virus (EAV) was readily isolated in RK-13 cell monolayers by plaque assay from seminal plasma of experimental carrier stallions when they contained high titers of virus regardless of the presence of non-viral cytotoxicity in the seminal plasma. The cytotoxicity interfered with virus isolation from seminal plasma which contained virus at titers less than 10 PFU/ml. However, it was possible to detect the virus in seminal plasma pretreated with PEG (#6000). EAV was consistently identified by RT-PCR from crude seminal plasma which contained virus at titers of more than 10(2.7) PFU/ml. In vitro detection of EAV by virus isolation supplemented with RT-PCR using seminal plasma was proved to be an effective alternative to the standard test mating as a diagnostic method for carrier stallions.     

Prevalence of Salmonella in beef feeder steers as determined by bacterial culture and ELISA serology

Results are presented for monitoring Salmonella infection by bacteriological culture and immune response (enzyme linked immunosorbent assay (ELISA) and haptoglobin) testing of samples collected from beef cattle at a single feedyard sampled over time. A total of 120 beef steers were examined on entry to the feedyard and at days 30, 60, and at time of slaughter (120-150 days). Isolations of Salmonella decreased over time from 40% of the steers sampled at day 0 to 0% at slaughter, whereas serological results varied by serogroup. Seropositivity increased for Salmonella group B up to day 60, and subsequently decreased to about half of the 60-day positivity rate at the time of slaughter. No significant changes in seropositivity were detected during the course of the study for the four other Salmonella serogroups (C1, C3, D1, and E1). Haptoglobin measurements were not a good indicator of Salmonella infection status. Sequential Salmonella testing either by culture, ELISA, or both could be used to monitor pathogen control practices.     

Effects of clomipramine hydrochloride on heart rate and rhythm in healthy dogs

OBJECTIVE: To determine the effects of clomipramine hydrochloride on heart rate and rhythm in dogs. ANIMALS: 17 healthy Beagles. PROCEDURES: In experiment 1, 8 dogs received placebo or clomipramine (20 mg/kg of body weight, q 24 h, PO) for 7 days in a 2-way crossover design. In experiment 2, 9 dogs were evaluated for 48 hours before and 24 hours after oral administration of clomipramine (4 or 12 mg/kg) in a 2-way crossover design. Electrocardiogram and heart rate were monitored continuously by use of telemetry. RESULTS: A significant diurnal rhythm in heart rate was detected; minimum values were recorded at night. Administration of 20 mg of clomipramine/kg induced a significant reduction in heart rate, with peak effect achieved approximately 12 hours after dosing. Administration of 4 or 12 mg of clomipramine/kg did not result in significant changes in heart rate. Sinoatrial and second-degree atrioventricular block and ventricular escape beats were observed during periods of slow heart rate in more dogs that received clomipramine (3 to 4 of 8 dogs), compared with dogs that received placebo (1 to 2 of 8 dogs), but this difference was not significant. CONCLUSIONS AND CLINICAL RELEVANCE: Short-term administration of clomipramine induced benign cardiovascular effects in dogs rather than the potentially dangerous arrhythmias or tachycardia reported following administration of tricyclic antidepressants to humans. Precautions regarding cardiovascular effects may not be needed for the use of clomipramine in healthy dogs.     

A case study on Salmonella enteritidis (SE) origin at three egg-laying farms and its control with an S. enteritidis bacterin

In the early 1990s, three egg-laying farms (farms S, T, and B) were thought to have the possibility of Salmonella enteritidis (SE) contamination because positive liquid egg samples originated from those farms. The present study was therefore conducted. The first clarification for SE contamination was the study on the origin of SE contamination including its vertical transmission. The results of SE contamination profiling with dust and manure, food materials, dead embryos, and residual yolks on hatch day in regular monitoring over a few years were clearly negative. Therefore, we concluded the SE transmission/infection was attributed to horizontal infection in the egg-laying farms but not vertical transmission from parental stock, hatcheries, growth, or food materials during a 7-yr experimental period. Second, we attempted to clarify if administration of an SE bacterin (Layermune SE) to growth flocks for the egg-laying farms could reduce SE incidence in liquid egg samples from each egg-laying farm. In the first experiment, we compared SE incidence in liquid egg samples from vaccinated and nonvaccinated flocks (similar age flocks). SE incidence from vaccinated and nonvaccinated flocks showed negative and <2 most probable number (MPN)/100 ml for farm B, <2 and >1600 MPN/100 ml for farm S, and negative and >1600 MPN/100 ml for farm T, respectively. In the second experiment, we compared the SE isolation incidence in the liquid egg samples from nonvaccinated and newly replaced vaccinated flocks in the same chicken houses from each of the three egg-laying farms. SE incidence in the liquid egg samples was similar to that in the first experiment. Therefore, the SE bacterin may play an important role in reducing the SE incidence of liquid egg samples.     

Surgical treatment of coenurosis (gid) in sheep

During the past six years 623 cases of coenurosis (gid) in sheep have been treated surgically. Cysts were removed successfully from 573 of them (92 per cent) and 517 (83 per cent) were able to return to their flocks, although 36 showed no clinical improvement In 37 cases, the cyst could not be localised, and postmortem examinations showed that in nine cases the cyst was in the brainstem, and in 28 cases it was in the cerebellum. Fifty-six cases deteriorated gradually after surgery and in these cases more than one cyst was found postmortem. Thirteen cases died during surgery.