Suppression of ovarian progesterone production in dairy cows using an implant of GnRH-agonist (deslorelin) for the purpose of evaluating progesterone metabolism     

AR RABIEE  KL MACMILLAN  F SCHWARZENBERGER  D THALLER  MJ RATHBONE  TE TRIGG 《Australian veterinary journal》2001,79(10):690-694

OBJECTIVE: To evaluate the potential of an implant of a GnRH-agonist (deslorelin) to create a progesterone free animal suitable for studying progesterone (P4) metabolism in intact cows by measuring blood P4 and faecal P4 metabolites. METHODS: Experiment 1: Eighteen non-lactating cycling Holstein-Friesian cows, 4 to 7 years old, were allocated to one of three groups to study plasma P4 concentrations preceding an intravaginal insert. These groups comprised: i) a deslorelin group (GnRH-agonist implanted); ii) a PGF group receiving two injections of prostaglandin (PGF2alpha) 12 days apart; and, iii) an ovariectomised (OVX) group. An intravaginal device (CIDR) was inserted into the vagina of each animal and left in place for 11 days. Plasma P4 concentrations were measured during the study period. Experiment 2: Twelve non-lactating cycling Holstein-Friesian cows, 4 to 7 years old, were allocated to two groups: i) a deslorelin group (GnRH-agonist implanted); and ii) an ovariectomised group. Plasma P4 and faecal P4 metabolites (20-oxo-pregnanes, 20alpha-OH and 20beta-OH) were monitored for a period of 5 weeks. RESULTS: Experiment 1: Average plasma P4 concentration did not differ between the three groups (1.28, 1.43 and 1.55 ng/mL for deslorelin, OVX and PGF cows, respectively, P = 0.8) during the period of supplementation. Experiment 2: There was no difference in plasma P4 (mean plasma P4 < 0.02 ng/mL, P = 0.9) and faecal P4 metabolites between deslorelin and OVX cows 2 weeks after the implantation (P = 0.7). CONCLUSIONS: These data showed that a GnRH-agonist (deslorelin) implant may be used as an alternative to ovariectomy to create a progesterone free animal suitable for studying the metabolism of administered P4.  相似文献   

Correlations between ultrasonography findings and hormonal profiles at oestrus in pure Spanish breed mares     

JC ILLERA  MJ ILLERA  G SIL VAN  M ILLERA 《Australian veterinary journal》1993,70(7):273-275

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An evaluation of a live Toxoplasma gondii vaccine in Tammar wallabies (Macropus eugenii)     

MJ LYNCH  DL OBENDORF  P STATHAM  GL REDDACLIFF 《Australian veterinary journal》1993,70(9):352-353

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Retrospective Evaluation of the Effect of Heart Rate on Survival in Dogs with Atrial Fibrillation          下载免费PDF全文

B. Pedro  J. Dukes‐McEwan  M.A. Oyama  M.S. Kraus  A.R. Gelzer 《Journal of veterinary internal medicine / American College of Veterinary Internal Medicine》2018,32(1):86-92

Background

Atrial fibrillation (AF) usually is associated with a rapid ventricular rate. The optimal heart rate (HR) during AF is unknown.

Hypothesis/Objectives

Heart rate affects survival in dogs with chronic AF.

Animals

Forty‐six dogs with AF and 24‐hour ambulatory recordings were evaluated.

Methods

Retrospective study. Holter‐derived HR variables were analyzed as follows: mean HR (meanHR, 24‐hour average), minimum HR (minHR, 1‐minute average), maximum HR (maxHR, 1‐minute average). Survival times were recorded from the time of presumed adequate rate control. The primary endpoint was all‐cause mortality. Cox proportional hazards analysis identified variables independently associated with survival; Kaplan‐Meier survival analysis estimated the median survival time of dogs with meanHR <125 bpm versus ≥125 bpm.

Results

All 46 dogs had structural heart disease; 31 of 46 had congestive heart failure (CHF), 44 of 46 received antiarrhythmic drugs. Of 15 dogs with cardiac death, 14 had CHF. Median time to all‐cause death was 524 days (Interquartile range (IQR), 76–1,037 days). MeanHR was 125 bpm (range, 62–203 bpm), minHR was 82 bpm (range, 37–163 bpm), maxHR was 217 bpm (range, 126–307 bpm). These were significantly correlated with all‐cause and cardiac‐related mortality. For every 10 bpm increase in meanHR, the risk of all‐cause mortality increased by 35% (hazard ratio, 1.35; 95% CI, 1.17–1.55; P < 0.001). Median survival time of dogs with meanHR<125 bpm (n = 23) was significantly longer (1,037 days; range, 524‐open) than meanHR ≥125 bpm (n = 23; 105 days; range, 67–267 days; P = 0.0012). Mean HR was independently associated with all‐cause and cardiovascular mortality (P < 0.003).

Conclusions and Clinical Importance

Holter‐derived meanHR affects survival in dogs with AF. Dogs with meanHR <125 bpm lived longer than those with meanHR ≥ 125 bpm.  相似文献   

Primary tonsillar mast cell tumour in a dog          下载免费PDF全文

CC Shekell  MJ Thomson  RI Miller  JT Mackie 《Australian veterinary journal》2018,96(5):184-187

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Detection and genetic diversity of porcine rotavirus A,B and C in eastern Australian piggeries     

B Genz  J Gerszon  Y Pollock  B Gleeson  R Shankar  MJ Sellars  RJ Moser 《Australian veterinary journal》2023,101(4):153-163

Rotaviruses (RV) have a high prevalence in piggeries worldwide and are one of the major pathogens causing severe diarrhoea in young pigs. RV species A, B, and C have been linked to piglet diarrhoea in Australian pig herds, but their genetic diversity has not been studied in detail. Based on sequencing of the structural viral protein 7 (VP7) RVA G genotypes G3, G4 and G5, and RVC types G1, G3, G5, and G6 have been identified in Australian piggeries in previous studies. Although occurrence of RVB was reported in Australia in 1988, no further genetic analysis has been conducted. To improve health management decisions in Australian pig herds, more information on RV prevalence and genetic diversity is needed. Here, 243 enteric samples collected from 20 pig farms within Eastern Australia were analysed for the presence of RV in different age groups using a novel PCR-based multiplex assay (Pork MultiPath™ enteric panel). RVA, RVB, and RVC were detected in 10, 14, and 14 farms, respectively. Further sequencing of VP7 in selected RV-positive samples revealed G genotypes G2, G5, G9 (RVA), G6, G8, G14, G16, G20 (RVB), and G1, G3, G5, G6 (RVC) present. RVA was only detected in young (<10 weeks old) pigs whereas RVB and RVC were also detected in older animals (>11 weeks old). Interestingly, RVB and RVC G-type occurrence differed between age groups. In conclusion, this study provides new insights on the prevalence and diversity of different RV species in pig herds of Eastern Australia whilst demonstrating the ability of the Pork MultiPath™ technology to accurately differentiate between these RV species.  相似文献   

Early harvest and ensilage of forage sorghum infected with ergot (Claviceps africana) reduces the risk of livestock poisoning     

BJ Blaney  MJ Ryley  BD Boucher 《Australian veterinary journal》2010,88(8):311-312

Sorghum ergot produces dihydroergosine (DHES) and related alkaloids, which cause hyperthermia in cattle. Proportions of infected panicles (grain heads), leaves and stems were determined in two forage sorghum crops extensively infected 2 to 4 weeks prior to sampling and the panicles were assayed for DHES. Composite samples from each crop, plus a third grain variety crop, were coarsely chopped and half of each sealed in plastic buckets for 6 weeks to simulate ensilation. The worst-infected panicles contained up to 55 mg DHES/kg, but dilution reduced average concentrations of DHES in crops to approximately 1 mg/kg, a relatively safe level for cattle. Ensilation significantly (P = 0.043) reduced mean DHES concentrations from 0.85 to 0.46 mg/kg.  相似文献   

Genetic characterisation of protective vaccine responses in sheep using multi-valent Dichelobacter nodosus vaccines     

Raadsma HW  McEwan JC  Stear MJ  Crawford AM 《Veterinary immunology and immunopathology》1999,72(1-2):219-229

Protective vaccine responses to nine distinct serogroups of Dichelobacter nodosus (serogroups A-I) can be readily measured by serogroup-specific K-agglutinating antibody titres. On the basis of a large quantitative genetic experiment (1200 progeny from 129 sire groups), it was shown that variation in antibody responses following vaccination with a multi-valent pilus antigen D. nodosus vaccine (serogroups A-I) is, in part, under genetic control and thus heritable. Based on the genetic relationships between antibody responses to all nine antigens, results suggested that both genes for a broad-based and genes for serogroup-specific response contributed to genetic variation in vaccine response. Furthermore, preliminary data in 389 progeny showed that polymorphism within the ovine major histocompatibility (MHC) based on serological classification accounted for a significant proportion of the variation in vaccine responses. In subsequent experimentation, we examined the importance of genetic polymorphism within the ovine MHC, and the possibility of genes outside the MHC for their involvement in antigen-specific and broad-based vaccine response. Within two large half sib families(131, and 143 progeny), four MHC haplotypes were investigated and found to be associated with differential antibody responses to six out of eight distinct vaccine-antigens presented to the host in a multi-valent vaccine. The model used here shows how well characterised immunogens, quantitative genetic experimentation, and molecular gene mapping tools can be used to unravel genetic differences in host responses to commercial vaccines.  相似文献   

"Gammaglobulin" levels in suckled calves     

E W Fisher  I E Selman  A D McEwan 《The Veterinary record》1971,89(26):695-696

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Diagnostic features, confirmation and disease progression in 28 cases of lethal acrodermatitis of bull terriers     

McEwan NA  McNeil PE  Thompson H  McCandlish IA 《The Journal of small animal practice》2000,41(11):501-507

Lethal acrodermatitis (LAD) is a genetically determined metabolic disease of bull terriers first described in the USA in the 1980s. In this study, the largest so far reported, 28 bull terriers born in the UK were diagnosed as suffering from LAD, and the clinical findings and the progression of the disease with time are described. The main characteristics of LAD are stunting, splayed digits, eating difficulties, skin disease of the face and feet, and increased susceptibility to microbial infections. In older dogs, paronychia, nail disease and hyperkeratosis of the footpads develops, becoming severe in dogs over six months of age. A diagnosis of LAD can be strongly suspected in any bull terrier showing a combination of the aforementioned signs from an early age. Dermatohistopathological demonstration of marked parakeratotic hyperkeratosis is strongly supportive of the diagnosis of LAD and, in association with the typical clinical findings, is sufficient to confirm a diagnosis. Although many of the clinical signs and the pathology of this condition suggest zinc deficiency, the measurement of blood zinc levels as a diagnostic aid is of limited value.  相似文献