ISSN:0425-1644    

DOI:10.1111/j.2042-3306.1988.tb01532.x

出版商:Blackwell Publishing Ltd    

年代:1988

数据来源: WILEY

ISSN:0425-1644    

DOI:10.1111/j.2042-3306.1988.tb01533.x

出版商:Blackwell Publishing Ltd    

年代:1988

数据来源: WILEY

ISSN:0425-1644    

DOI:10.1111/j.2042-3306.1988.tb01534.x

出版商:Blackwell Publishing Ltd    

年代:1988

数据来源: WILEY

摘要:

SummaryVariable interval (VI) reinforcement scheduling is a specific type of operant conditioning that is sensitive to drug effects even when overt clinical signs of the drug have diminished. Six horses were conditioned to break a light beam with a head‐bobbing movement and this behaviour was reinforced with a reward of clean oats (approximately 30 mg/reinforcement). Initial training procedures included familiarisation with the behavioural equipment and fixed‐ratio reinforced scheduling. To establish baseline rates of behaviour, the horses were converted to a variable interval (60 sees) reinforcement schedule and kept on this schedule for the remainder of the study. A within subjects cross‐over design was used with three treatments counterbalanced with the six horses. Detomidine (40 μg kg body weight, xylazine (1.1 mg/kg bodyweight) and saline (10 ml) were administered intravenously on Monday mornings with VI responding rates measured during a routine 30 min session each day from Monday to Friday. Responses and reinforcements were recorded and dispensed by use of an electromechanical relay system wired to an electric eye, an automatic feeder and a programming and recording system. Xylazine produced a small decrease in responding rates at 1 h post dose, while detomidine treated horses showed a dramatic decrease in responding rates after 1 h and a lingering effect at 24 h. No long range effects were seen with either treatment and all horses returned to baseline responding rates by 48 h pos

ISSN:0425-1644    

DOI:10.1111/j.2042-3306.1988.tb01535.x

出版商:Blackwell Publishing Ltd    

年代:1988

数据来源: WILEY

摘要:

SummaryDetomidine was administered throughout 10 pregnancies in eight mares. An intravenous injection of 20 pg/kg bodyweight was given weekly from Day 14 to Day 60 of gestation and thereafter every four weeks until parturition. One mare suffered torsion of the large colon and was destroyed on Day 86; the foetus was normally developed. A further mare aborted at 167 days. The remaining eight pregnancies continued to full term. One foal was delivered by caesarean section because of torticollis and, of the seven foals born spontaneously, one had bilateral upward patellar fixation at one month old. Therefore, although only six of the 10 foals developed normally, the other four cases showed no pathological similarities to suggest a common cause. Although these data were based on a small number of mares, they did not suggest that the repeated administration of detomidine had specific adverse effects on the pregnancies.

ISSN:0425-1644    

DOI:10.1111/j.2042-3306.1988.tb01536.x

出版商:Blackwell Publishing Ltd    

年代:1988

数据来源: WILEY

ISSN:0425-1644    

DOI:10.1111/j.2042-3306.1988.tb01537.x

出版商:Blackwell Publishing Ltd    

年代:1988

数据来源: WILEY

摘要:

SummaryDetomidine was administered twice to six foals (14 to 94 days old) using three different doses (10, 20 and 40 μg/kg bodyweight intravenously) in a double blind trial. Sedation, analgesia, heart rate and clinically observed side‐effects were recorded. Detomidine showed strong sedative effects at all doses tested. Sedation deepened very little by increasing the dose from 10 to 40 μg/kg bodyweight, but the duration of the effect was longer. Analgesia was considered good with the largest dose (40 μg/kg), and moderate or non‐existent with the lower doses. Detomidine caused a decrease in heart rate at all doses and other observed side‐effects included ataxia, heavy breathing, arrhythmia, sweating and frequent urination. No adverse effects were

ISSN:0425-1644    

DOI:10.1111/j.2042-3306.1988.tb01538.x

出版商:Blackwell Publishing Ltd    

年代:1988

数据来源: WILEY

ISSN:0425-1644    

DOI:10.1111/j.2042-3306.1988.tb01539.x

出版商:Blackwell Publishing Ltd    

年代:1988

数据来源: WILEY

摘要:

SummaryThe effects of administration of one of four opiates (pethidine 1 mg/kg bodyweight (bwt), morpine 0.1 mg/kg bwt, methadone 0.1 mg/kg bwt, and butorphanol 0.05 mg/kg bwt) given intravenously to horses and ponies already sedated with detomidine (10 μg kg bwt) were investigated. Behavioural, cardiovascular and respiratory effects of the combinations were compared with those occurring with detomidine alone. Addition of the opiate increased the apparent sedation and decreased the response of the animal to external stimuli. At doses used, butorphanol produced the most reliable response. Side effects seen were increased ataxia (greatest following methadone and butorphanol) and excitement (usually muzzle tremors and muscle twitching). Following pethidine, generalised excitement was sometimes seen. Marked cardiovascular changes occurred in the first few minutes after morphine or pethidine injection, but within 5 mins cardiovascular changes were minimal. Following morphine or pethidine there was a significant increase in arterial carbon dioxide tension. Fourteen clinical cases were successfully sedated using detomidine/butorphanol combinations

ISSN:0425-1644    

DOI:10.1111/j.2042-3306.1988.tb01540.x

出版商:Blackwell Publishing Ltd    

年代:1988

数据来源: WILEY

摘要:

SummaryTissue specimens obtained from equine herpesvirus‐1 (EHV‐1), subtype 1‐infected aborted foetuses were analysed for the presence of virus DNA by means of Southern blot and dot blot hybridisations. The specificity of the methods was confirmed although the sensitivity was inferior to classical techniques such as virus isolation. However, the possibility of detecting the state of the virus DNA and the ability to distinguish between subtypes were important features, and the dot blot method was shown to have potential for a rapid diagnostic test. This report demonstrates some potential practical applications of hybridisation methods for studying the pathogenesis and epidemiology of EHV‐1 but also reveals limitations of the tec

ISSN:0425-1644    

DOI:10.1111/j.2042-3306.1988.tb01541.x

出版商:Blackwell Publishing Ltd    

年代:1988

数据来源: WILEY