The intensity of resistance by mature Merino ewes against Haemonchus contortus and Tichostrongylus colubriformis in single-species and combined-species infection     

DB ADAMS  JJ LYNCH†  BH ANDERSON  LR FELL‡  GN HINCH§  RK MUNRO¶ 《Australian veterinary journal》1990,67(12):443-445

Three-year-old, non-lactating and non-pregnant Merino ewes, raised on pasture under a program of strategic treatment with anthelmintic and found to be extremely resistant to "trickle" infection with Haemonchus contortus, were given single-dose infections with either H. contortus or Trichostrongylus colubriformis or both species together. The purpose was to ascertain the intensity of protective immunity against the 2 parasites in sheep with immunity acquired from a presumably slight exposure to infection. To provide a criterion, some infected ewes were immunosuppressed with corticosteroid, dexamethasone. Untreated ewes were extremely resistant to challenge infection with either 15,000 or 150,000 H. contortus or 15,000 T. colubriformis. Surprisingly, when mixed infection was given, egg counts for H. contortus were significantly elevated compared with infection by that species alone. Antibody to antigens from infective larval and adult H. contortus was measured in serum by enzyme-linked-immunosorbent assay (ELISA) during the course of infection. Serum titres against larval antigens were significantly depressed when infections with either H. contortus or T. colubriformis were permitted by immunosuppression with dexamethasone, whereas those against adult antigen were depressed when infection with T. colubriformis was permitted.  相似文献   

Helminth findings in indigenous raccoon dogs Nyctereutes procyonoides (Gray, 1843)     

Thiess A  Schuster R  Nöckler K  Mix H 《Berliner und Münchener tier?rztliche Wochenschrift》2001,114(7-8):273-276

Internal organs of 74 racoon dogs originating from the eastern districts of the Federal Land Brandenburg were subjected to a complete helminthological dissection. In addition, samples of diaphragma muscles from 46 further animals were examined for Trichinella larvae. Altogether 3 trematode- (Alaria alata, Isthmiophora melis, Metorchis bilis), 3 cestode- (Mesocestoides sp., Echinococcus multilocularis, Taenia polyacantha) and 7 nematode species (Capillaria aerophila, C. plica, Trichinella spiralis, Uncinaria stenocephala, Molineus patens, Crenosoma vulpis, Toxocara canis) could be identified. Thereby, the racoon dog has a comparable helminth spectrum as well known in red foxes. Differences in the frequency of the occurrence of helminths in both hosts can be explained by different food preferences.  相似文献   

Optimising spring oral vaccination campaigns of foxes against rabies     

Vos A  Müller T  Selhorst T  Schuster P  Neubert A  Schlüter H 《DTW. Deutsche tier?rztliche Wochenschrift》2001,108(2):55-59

To optimise spring vaccination campaigns the following set of data has been analysed; (i) population dynamics of the red fox, (ii) onset and progress of the reproductive season, and (iii) maternal immunity and the immune response of fox cubs to oral vaccination. The field data originated from foxes caught in Bavaria, Germany. The results of our analysis clearly demonstrate that certain periods during spring are less suitable for bait distribution. If the objective of a vaccination campaign is to reach only the adult foxes, it is suggested to conduct the campaign during the first half of March. If also young foxes are to be vaccinated, baits should not be distributed before the end of May in previously baited areas, because a large segment of the young fox population can not be vaccinated effectively before this date as a result of maternally transferred immunity. In areas vaccinated for the first time, baits can be distributed earlier, since 5 weeks old cubs are already immunocompetent.  相似文献   

Immunogenicity and efficacy of the oral rabies vaccine SAD B19 in foxes     

Neubert A  Schuster P  Müller T  Vos A  Pommerening E 《Journal of veterinary medicine. B, Infectious diseases and veterinary public health》2001,48(3):179-183

Studies on the immunogenicity and efficacy of SAD B19 attenuated rabies virus vaccine in foxes under laboratory conditions were conducted. Twenty-seven foxes (Vulpes vulpes) were offered a vaccine bait containing 10(6.3) FFU/ml SAD B19. Blood samples were collected 60, 110 and 190 days post-vaccination. On day 190 post vaccination the animals and 14 controls were challenged with a canid street rabies virus. Twenty-four of the 26 vaccinated foxes (92.3%) survived the challenge, whereas all the controls died from rabies. The two vaccinated foxes that did not survive the challenge did not show any detectable level of rabies neutralizing antibodies at any time after vaccination. The geometric mean titres (GMT) of foxes that seroconverted after vaccination were 43.5, 33.9 and 43.5 IU/ml 60, 110 and 190 days post-vaccination, respectively. Furthermore, to test the vaccine virus under sub-optimal conditions five naive and nine previously vaccinated vixens received 2 ml SAD B19 (10(6.7) FFU/ml) by direct administration of the vaccine virus into the oral cavity shortly before or during pregnancy. All vixens seroconverted above the threshold of 0.5 IU/ml. No booster effect was observed in the immune response of the previously vaccinated animals.  相似文献   

The effects of duration and concentration of plasma progesterone on the fertility of post-partum cows treated with pregnant mare serum gonadotrophin and intravaginal progesterone     

RK MUNRO 《Australian veterinary journal》1989,66(2):43-45

The effects of duration of insertion of progesterone releasing devices (PRIDs) on the concentrations of plasma progesterone (plasma P4) and the relationship of these with fertility were examined respectively in ovariectomised and intact Bos taurus cattle. In experiment 1, ovariectomised cows (n = 14) were treated with PRIDs to produce high and low plasma P4 for 7 or 14 days giving 4 treatment groups designated H7, H14, L7 or L14. Mean plasma P4 in the H14 and L14 groups were 6.6 and 6.0 ng/ml respectively, during the first week and 5.4 and 3.8 ng/ml respectively, during the second. Mean plasma P4 of 6.3 and 4.2 ng/ml were observed in H7 and L7. In experiment 2, suckled cows (n = 171) received the same PRID treatments as cows in experiment 1, plus either 375 or 750 iu pregnant mare serum gonadotrophin, and subsequent calving rates were recorded. These were significantly lower after L7 than the other treatments (12% v 38%, P less than 0.025). These results showed that fertility after oestrus was closely related to plasma P4 observed before oestrus and indicated that treatment with progesterone for as little as 1 week can produce normal fertility providing plasma P4 attain a critical threshold during treatment.  相似文献   

Effects of suckling on oestradiol benzoate induced LH release in post-partum, ovariectomised cows     

RK MUNRO 《Australian veterinary journal》1990,67(9):313-315

Twelve suckling and 12 non-lactating post-partum cows were treated with a progesterone-releasing pessary for 7 or 14 d followed by an injection of 500 micrograms oestradiol benzoate (ODB) 24 h after pessary removal or no injection. Suckling had no significant effect on plasma progesterone concentrations (plasma P4) or plasma luteinising hormone concentrations (plasma LH) during pessary insertion. After pessary removal plasma LH rose in response to ODB. The extent of the rise was similar in suckling and non-lactating cows treated with progesterone for 14 d but was significantly lower in non-lactating than suckling cows (P less than 0.025) treated for 7 d. These findings indicate that suckling increases the responsiveness of plasma LH in post-partum cows following progesterone and oestrogen treatment compared to non-lactating cows and that extended treatment with progesterone can remove this difference.  相似文献   

Gestielte Spermatophoren bei Labidostomiden (Acari, Trombidiformes)     

Schuster B. und I. J. Schuster 《Journal of pest science》1970,43(10):158

Ohne Zusammenfassung  相似文献   

The effect of fish meal content in trout food on water colour in a closed recirculating aquaculture system     

C. Schuster 《Aquaculture International》1994,2(4):266-269

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Effect of maternal immunity on the immune response to oral vaccination against rabies in young foxes.     

T F Müller  P Schuster  A C Vos  T Selhorst  U D Wenzel  A M Neubert 《American journal of veterinary research》2001,62(7):1154-1158

OBJECTIVE: To determine effect of maternal antibodies on immune response to oral vaccination against rabies in young foxes. ANIMALS: 250 cubs from 48 vixens. PROCEDURE: Sera were obtained from cubs of 36 vaccinated (maternally vaccinated [MV+]) and 12 nonvaccinated (MV-) vixens between 23 and 71 days of age and tested for neutralizing antibodies. Seventy-one MV+ cubs and 33 MV-cubs were vaccinated orally with modified-live virus vaccine SAD B19. Geometric mean titer (GMT) was determined in these cubs approximately 21, 39, and 57 days after vaccination. In a subsequent experiment, 10 vaccinated MV+ cubs, 6 vaccinated MV- cubs, and 6 control cubs were challenge inoculated with virulent rabies virus approximately 100 days after vaccination. RESULTS: Serum GMT of nonvaccinated MV cubs (0.23 U/ml) was significantly greater than that of non-vaccinated MV- cubs (0.15 U/ml). The GMT of vaccinated MV+ cubs 21, 39, and 57 days after vaccination were 2.85, 2.11, and 0.79 U/ml, respectively, and were significantly less than those of vaccinated MV- cubs (12.19, 6.76, and 4.02 U/ml, respectively). All challenge-inoculated cubs with GMT < 0.5 U/ml succumbed to rabies. CONCLUSION AND CLINICAL RELEVANCE: Partially impaired immune response in cubs < 8 weeks old from vaccinated vixens causes insufficient protection against rabies. Inhibition of the immune response persists longer than the period during which maternal antibodies are detectable. Thus, oral vaccination campaigns for young foxes in areas where vaccination has been performed need to be reconsidered.  相似文献   

Animal health monitoring and surveillance in Switzerland     

KDC STÄRK 《Australian veterinary journal》1996,73(3):96-97

Switzerland has traditionally used a passive disease reporting system for all notifiable diseases. This type of system is not suitable for the documentation of very low prevalences (freedom from disease), sub-clinical cases and non-notifiable diseases. In order to meet the high international standards for animal health surveillance and to fulfil the general need for sound animal health data, Switzerland has evaluated the feasibility of modern monitoring and surveillance concepts. In general, the principle of active surveillance has been acquired and is now being applied whenever possible. In this paper, several examples of Swiss surveillance systems are presented and discussed. They include systematic testing of random population samples, carcase screening at abattoirs and sentinel herd monitoring.  相似文献