Pharmacokinetics and pharmacodynamics of alfaxalone after a single intramuscular or intravascular injection in mallard ducks (Anas platyrhynchos)

Pharmacokinetics and pharmacodynamics of alfaxalone was performed in mallard ducks (Anas platyrhynchos) after single bolus injections of 10 mg/kg administered intramuscularly (IM; n = 10) or intravenously (IV; n = 10), in a randomized cross‐over design with a washout period between doses. Mean (±SD) C_max following IM injection was 1.6 (±0.8) µg/ml with T_max at 15.0 (±10.5) min. Area under the curve (AUC) was 84.66 and 104.58 min*mg/ml following IV and IM administration, respectively. Volume of distribution (V_D) after IV dose was 3.0 L/kg. The mean plasma clearance after 10 mg/kg IV was 139.5 (±67.9) ml min^?1 kg^?1. Elimination half‐lives (mean [±SD]) were 15.0 and 16.1 (±3.0) min following IV and IM administration, respectively. Mean bioavailability at 10 mg/kg IM was 108.6%. None of the ducks achieved a sufficient anesthetic depth for invasive procedures, such as surgery, to be performed. Heart and respiratory rates measured after administration remained stable, but many ducks were hyperexcitable during recovery. Based on sedation levels and duration, alfaxalone administered at dosages of 10 mg/kg IV or IM in mallard ducks does not induce clinically acceptable anesthesia.     

禽用活疫苗SPF化现状及对兽用生物制品企业的影响

目前,禽病防疫仍以疫苗免疫接种为主,疫苗安全性直接影响疫病防控效果,优质疫苗能预防疾病,提高家禽的生产性能,创造经济效益。相反,劣质疫苗可能对动物造成伤害,对环境造成污染,乃至威胁人类的健康。因此,选择安全高效的优质疫苗是做好家禽疫病防疫的关键。为保证疫苗质量安全,实行禽用活疫苗SPF化已经势在必行。     

Dam Mycobacterium avium subspecies paratuberculosis (MAP) infection status does not predetermine calves for future shedding when raised in a contaminated environment: a cohort study

Uptake of Mycobacterium avium subsp. paratuberculosis (MAP) by calves in the first days of life from colostrum, milk and faeces is regarded an important moment of transmission. The objective of this study was to quantify the association between the MAP status of dams as determined by the presence of MAP DNA and antibody in colostrum and that of DNA in faeces and the environment with subsequent MAP shedding of their daughters. A cohort of 117 dam-daughter pairs giving birth/being born on eight commercial dairy farms with endemic paratuberculosis was followed where colostrum, faecal and environmental samples (dust) were analysed for the presence of MAP using an IS900 real-time PCR. Antibodies in colostrum were measured by ELISA. Analysis of dust samples showed that on all farms environmental MAP exposure occurred continuously. In significantly more colostrum samples (48%) MAP DNA was detected compared to faecal samples (37%). MAP specific antibodies were present in 34% of the colostrum samples. In total MAP DNA was present in faecal samples of 41% of the daughters at least once during the sampling period. The association between faecal shedding in the offspring and the dam MAP status defined by MAP PCR on colostrum, MAP PCR on faeces or ELISA on colostrum was determined by an exact cox regression analysis for discrete data. The model indicated that the hazard for faecal shedding in daughters born to MAP positive dams was not significantly different compared to daughters born to MAP negative dams. When born to a dam with DNA positive faeces the HR was 1.05 (CI 0.6; 1.8) and with DNA positive colostrum the HR was 1.17 (CI 0.6; 2.3). When dam status was defined by a combination of both PCR outcomes (faeces and colostrum) and the ELISA outcome the HR was 1.26 (CI 0.9; 1.9). Therefore, this study indicates that neither the presence of MAP DNA in colostrum, MAP DNA in faeces nor the presence of MAP antibodies in colostrum of the dam significantly influences the hazard of MAP shedding in their subsequent daughters up to the age of two years when raised in a contaminated environment.     

leptospira interrogans serovar hardjo vaccination against leptospira interrogans serovar balcanica infection

Abstract

Extract

Sir, — Leptospira interrogans serovar balcanica is now recognised as a widespread infection among opossums in New Zealand ⁽²⁾ Hathaway, S. C, Blackmore, D. K. and Marshall, R. B. 1978. The serologic and cultural prevalence of Leptospira interrogans serovar balcanica in opossums (Trichosurus vulpecula) in New Zealand. J. Wild Dis., 14: 345–350. [PubMed], [Web of Science ®] , [Google Scholar] and the possibility of domestic stock acting as accidental hosts has recently been demonstrated. ⁽³⁾ Mackintosh, C. G., Marshall, R. B. and Blackmore, D. K. 1980. Leptospira interrogans serovar balcanica in cattle. N.Z. vet. J., 28: 268–268. [Taylor &; Francis Online], [Web of Science ®] , [Google Scholar] With the recent development of hardjo vaccines ⁽¹⁾ Flint, S. H. and Liardet, D. M. 1980. A Trivalent leptospiral vaccine with emphasis on a Leptospira interrogans serovar hardjo component to prevent leptospiruria. N.Z. vet. J., 28: 263–266. [Taylor &; Francis Online], [Web of Science ®] , [Google Scholar] ⁽⁴⁾ Marshall, R. B., Broughton, E. S. and Hellstrom, J. S. 1979. Protection of cattle against natural challenge with Leptospira interrogans serovar hardjo using a hardjo - pomona vaccine. N.Z. vet. J., 27: 114–116. [Taylor &; Francis Online], [Web of Science ®] , [Google Scholar] for controlling infection with this serovar in the maintenance hosts, stock could be left vulnerable to infection with other prevalent serovars such as balcanica.