A trial was conducted to compare the efficacy of intranasal vaccination in protecting goats against pneumonic pasteurellosis with intramuscular vaccination using an oil adjuvant vaccine, and a combination of the two methods. Forty goats were divided into four equal groups. Group 1 was vaccinated twice intranasally with formalin-killed Pasteurella haemolytica A2, group 2 was vaccinated twice intramuscularly with an oil adjuvant vaccine containing P haemolytica A7, and group 3 was initially vaccinated intranasally with the formalin-killed P haemolytica A2 followed by intramuscular vaccination with the oil adjuvant vaccine. In each group the two vaccinations were carried out four weeks apart. Group 4 was the unvaccinated control group. All goats were challenged intratracheally with 4 ml of an inoculum containing live P haemolytica A2 at a concentration of 1.3 x 10(7) colony forming units/ml two weeks after the last vaccination and were killed 14 days after the challenge. Although group 2 showed the highest clinical score following the challenge, deaths were observed only in group 3. Three goats in group 1 had pneumonic lung lesions, compared with six goats in group 2 and all the goats in groups 3 and 4. The lung lesions in group 1 were significantly (P < 0.05) less severe than in groups 3 and 4. Similarly, the lesions in group 2 were markedly less severe than in groups 3 and 4, although the differences were not significant. The difference between the extent of the lung lesions in the goats in groups 1 and 2 was not significant. Antibody against P haemolytica A2 in group 1 reached peak levels and was significantly (P < 0.01) higher than in the control group one week after the second vaccination, before declining.
An experimental oil emulsion Newcastle disease vaccine was evaluated for its efficacy in broiler chickens. A group of chickens vaccinated at one day old with a live lentogenic Newcastle disease vaccine and subsequently revaccinated at three and eight weeks old with the experimental oil emulsion vaccine showed satisfactory haemagglutination inhibition antibody response which persisted for 18 weeks. Between 90 and 100 per cent of the vaccinated chickens were protected when challenged with the velogenic viscerotropic Newcastle disease virus. Although the vaccinated chickens were protected against clinical disease, virus could be isolated from a number of birds. By day 10 to 12 after challenge all the chickens were free from Newcastle disease infection.
House crows (Corvus splendens) in Selangor, Malaysia were examined for the presence of Campylobacter species, Salmonella species, Mycoplasma gallisepticum and Mycoplasma synoviae by serology, culture and pcr. For the detection of Campylobacter and Salmonella species swabs were taken either from the intestine or cloaca. For the detection of mycoplasmas, swabs were taken either from the choanal cleft or trachea for culture and pcr and serum samples were tested by the rapid serum agglutination (rsa) and monoclonal antibody-blocking elisa (mbelisa) for antibodies to M gallisepticum and M synoviae. For campylobacter, 25.3 per cent of the crows were positive by culture, and the species identified were Campylobacter jejuni and Campylobacter coli. No Salmonella species were isolated. Four of 24 swabs were positive for M gallisepticum dna but none gave positive results for M synoviae dna. No M gallisepticum or M synoviae antibodies were detected by rsa but 60 per cent of the sera gave positive reactions for M gallisepticum and 13 per cent gave positive reactions for M synoviae by mbelisa.
Quarter milk samples were taken from 150 cows from three dairy farms in south-east Queensland at drying off, two, four and six weeks after drying off, at calving, and one, two and three weeks after calving. In each of the herds, the cows were randomly allocated to three groups of approximately equal size. One group had all the quarters of all the cows treated at drying off with a dry cow antibiotic infusion containing cloxacillin; the second group was given no treatment, and the third group had selected quarters treated on the basis of their high activity of N-acetyl-beta-D-glucosaminidase at drying off. Dry cow treatment resulted in a marked reduction in the number of infected quarters at two and four weeks after drying off, so that the comprehensively treated group had significantly less infected quarters at these times (P<0.02). Twelve dinical cases of mastitis were detected two weeks after drying off in the untreated groups, 10 in the untreated quarters of the selectively treated groups, and no cases in the comprehensively treated groups. These cases were due mainly to Streptococcus uberis and Streptococcus dysgalactiae. The number of infected untreated quarters increased markedly between drying off and two weeks later, but in all three groups there was a marked decrease in the number of infected quarters between six weeks after drying off and calving, suggesting that the mammary glands were more able to overcome infections at this time.
In Malaysia, where vaccination campaigns against foot-and-mouth disease and haemorrhagic septicaemia are routinely carried out, it was desirable to determine whether it was safe and efficacious to administer both vaccines simultaneously. A trial group of 104 cattle was divided into three groups; group 1 animals received both vaccines simultaneously, group 2 animals received only foot-and-mouth disease vaccine and group 3 animals received only haemorrhagic septicaemia vaccine. The serological response to vaccinations was monitored at 0, 21 and 35 days by the virus neutralisation test for foot-and-mouth disease and the mouse-protection and indirect haemagglutination tests for haemorrhagic septicaemia. The simultaneous administration of the two inactivated vaccines produced no adverse effects and the serological response did not differ from the response to either vaccine given separately, thus indicating that cattle may be safely and effectively vaccinated simultaneously in this way.
The liver fluke Fasciola hepatica is a parasitic trematode that has a major impact on livestock production and human health. Control of F hepatica is difficult and relies on anthelmintics, particularly triclabendazole, due to its efficacy against both adult and juvenile stages of the parasite. Emergence of triclabendazole-resistant F hepatica populations has been reported in a number of countries, including the UK, but the overall prevalence and distribution of triclabendazole resistance is unknown. In this study, the authors established the presence of reduced efficacy of triclabendazole in sheep flocks in England and Wales, using a validated composite faecal egg count reduction test. Seventy-four sheep farms were sampled from Wales, southwest, northwest and northeast England between Autumn 2013 and Spring 2015. F hepatica eggs were detected in samples from 42/74 farms. Evidence of a lack of efficacy of triclabendazole was detected on 21/26 farms on which the faecal egg count reduction test was completed, with faecal egg count reductions ranging from 89 per cent to 0per cent. Regression analysis suggested that both prevalence of F hepatica and lack of efficacy of triclabendazole were spatially correlated, with higher faecal egg counts and lower percentage reductions on farms located in the northwest of England, and Wales. Overall, the results show that reduced efficacy of triclabendazole is present across England and Wales, with a complete lack of therapeutic efficacy observed on 9/26 farms.
The efficacy of an intranasal haemorrhagic septicaemia vaccine containing live gdhA derivative Pasteurella multocida B:2 was tested in buffaloes in Sabah. Sixty buffaloes, kept grazing in the field with minimal human intervention were devided into three groups of 20 buffaloes per group. Buffaloes of group 1 were exposed intranasal to 5 ml vaccine containing 10(6) CFU/ml of live gdhA derivative P multocida B:2. Buffaloes of group 2 were not exposed to the vaccine but exposed to PBS and were allowed to commingle and graze in the same field as the buffaloes of group 1 while buffaloes of group 3 were similarly exposed to PBS and were grazing separately. Booster was on group 1, two weeks later. Twelve months after the first vaccination, three buffaloes from each group were brought into the experimental house and challenged subcutaneously with 10(9) CFU/ml of live wild-type P multocida B:2. All challenged buffaloes of groups 1 and 2 survived with only mild, transient signs while all control unvaccinated buffaloes developed severe signs of haemorrhagic septicaemia and were euthanased between 28 hours and 38 hours postchallenge with signs and lesions typical of haemorrhagic septicaemia. These data showed that the gdhA mutant strain, given intranasally as two doses two weeks apart, successfully induced systemic immunity in exposed buffaloes and also led to spread of vaccine strain to the in-contact animals, where it acted as an effective live vaccine to protect both exposed buffaloes and in-contact buffaloes against challenge with the virulent parent strain.
Fourteen goat kids of the local indigenous breed naturally infected with Eimeria species were divided into two equal groups. The first group was superinfected with 500,000 Eimeria species oocysts and the second group was treated with amprolium. Sixty days later both groups were infected with 5000 third-stage caprine Haemonchus contortus larvae. The goats experimentally superinfected with eimeria shed more H contortus eggs and gained weight more slowly.