摘要:

This review covers some epidemiological aspects that allowBrucellato survive, spread, and maintain itself in the environment. Because the success of maintainingBrucella‐free herds is determined by the efficiency of the serological tests to detect a single infected animal the limitations of the traditional serological tests are emphasized. Serological tests cannot differentiate between cattle infected withBrucellaand cattle infected with microorganisms that serologically cross‐react withB.abortusantigen. These cattle and cattle with ‘natural’ antibodies jeopardize theBrucella‐free status of a herd. Likewise, infected cattle with serologically inconclusive test results or which elude detection are also a hazard toBrucella‐free herds. Since cattle that elude detection with serological tests and the presence of non‐specific serum antibodies in healthy cattle have long been recignized as problems, it is opportune to reconsider the procedures currently used to diagnose brucellosis in individual animals. Use of the skin delayed‐type hypersensitivity test in addition to serological tests will significantly improve the diagnosis of brucellosis. This will limit the financial loss incurred by outbreaks of brucellosis.

ISSN:0165-2176    

DOI:10.1080/01652176.1998.9694845

出版商:Taylor & Francis Group    

年代:1998

数据来源: Taylor

摘要:

Endoscopic ultrasonography (EUS), grey‐scale histogram analysis of EUS images, and transcutaneous ultrasonography (TUS) were done in four dogs with caerulein‐induced pancreatitis. One other dog was subjected to laparotomy and biopsy specimens were collected for histopathology. By EUS, the pancreatic lesions were first detected at 60 minutes after the start of caerulein infusion. They were detected after 120 to 150 minutes when using TUS. EUS findings included swelling, a more distinct lobular pattern, subcapsular hypoechoic areas, and anechoic stripes through the pancreatic tissue. No marked changes in the histogram analysis was seen until 30 minutes. From 30 to 60 minutes, a decrease in the mean brightness of the pancreatic tissue was observed. These changes in mean brightness reflected histopathological findings showing vacuolization of acinar cells and interstitial oedema of the pancreas. These findings indicated that EUS can detect slight and diffuse changes in pancreatic tissue. Furthermore, grey‐scale histogram analysis detects histopathological changes more sensitively than endoscopic ultrasound images.

ISSN:0165-2176    

DOI:10.1080/01652176.1998.9694846

出版商:Taylor & Francis Group    

年代:1998

数据来源: Taylor

摘要:

Type III von Willebrand's disease (vWD) was diagnosed in 38 Dutch kooiker dogs. Ten male and 9 female probands had been referred independently of each other to the Utrecht University Clinic for Companion Animals because of a moderate to severe bleeding tendency. Screening of 717 Dutch kooiker dogs, including 356 puppies, detected vWD in another 19 dogs. Diagnosis was based on non‐detectable amounts (< 1.6%) of von Willebrand factor antigen (vWF:Ag) in plasma by ELISA. Capillary bleeding time (CBT) was prolonged (> 10 min) and polybrene cofactor activity (vWF:PbCo) was not detectable in 11 dogs tested. No distinguishable protein bands were detected by multimer analysis. As in Scottish terriers with type III vWD, factor VIII clotting activity (FVIII:C) in affected Dutch kooiker dogs was decreased but considerably less than in humans with type III vWD. A recessive mode of inheritance was indicated by the normal or subnormal but measurable amounts of vWF:Ag in the plasma of eight pairs of parents of affected dogs. The F1offspring resulting from the experimental mating of two affected dogs consisted of three affected males and four affected females. In 39 obligatory carriers vWF:Ag ranged from 30% to 114% with median and mean vWF values of 64% and 64.2%, respectively, and was subnormal (< 50%) in only 9 animals.

ISSN:0165-2176    

DOI:10.1080/01652176.1998.9694847

出版商:Taylor & Francis Group    

年代:1998

数据来源: Taylor

摘要:

In a case‐control study of risk factors forSalmonella dublinon 126 dairy farms the following variables were significantly associated with infection. Standardized herd size and water surface area showed a positive association. Contact with cows from other herds during exchange was, unexpectedly, preventive forS. dublininfection. Purchase of cows from other herds was a risk factor. More infections occurred when the feed consisted of grass only compared to grass supplemented with maize or silage.S. dublininfection was highly associated with a liver fluke infection.

ISSN:0165-2176    

DOI:10.1080/01652176.1998.9694848

出版商:Taylor & Francis Group    

年代:1998

数据来源: Taylor

摘要:

In horses reproductive performance is usually expressed as the foaling rate. This rate ranges from 40% to 80%. Three major factors contribute to this variation namely, the stallion, the mare and management. In this study, the performance of Shetland ponies kept in three different breeding systems was investigated retrospectively. In one breeding system, the stud farmer travelled with his stallion (n = 9) to the mare (system 1) while in another system, the stallion (n = 3) stayed at the studfarm and the mares came to the stallion (system 2). The last system was pasture breeding (system 3; n = 9). Each stallion participated in only one system. The average number of cycles per mare used for breeding did not differ significantly between systems 1 and 2. However, the number of matings per cycle was higher in system 2 than in system 1. The average number of mares serviced per stallion was 91, 50, and 17 for systems 1, 2 and 3, respectively. Mares mated in pasture had a 2.8‐fold higher chance (p < 0.05) of having a foal the next season than the mares mated under systems 1 and 2. The foaling rate per season was 58%, 48%, and 80% for systems 1, 2 and 3, respectively. Management aspects play an important role in the relatively low foaling percentages of systems 1 and 2.

ISSN:0165-2176    

DOI:10.1080/01652176.1998.9694849

出版商:Taylor & Francis Group    

年代:1998

数据来源: Taylor

摘要:

The incidence of patentToxocara canisinfection as result of reactivation of somatic larvae with subsequent tracheal migration was investigated by faecal examination during 23 oestrous cycles of 15 bitches. Blood samples were collected for determination of total and differential leukocyte counts, prolactin concentration, andToxocaratitre. Five pregnant dogs were used as controls.

ISSN:0165-2176    

DOI:10.1080/01652176.1998.9694850

出版商:Taylor & Francis Group    

年代:1998

数据来源: Taylor

摘要:

This study included 190 lactating cows from eight dairy farms and was designed to investigate the sensitivity and specificity of a milk test (Ketolac) for detecting subclinical ketosis in dairy cattle. Blood and milk samples were collected between 38 and 50 days post partum. At a beta‐hydroxybutyric acid concentration in blood of 1.2 mmol/L, the prevalence of ketosis was 14%. A Response Operator Characteristic curve was drawn for two milk test values: 100 μmol/L and 200 μmol/L. Assessment of several beta‐hydroxybutyric acid cut‐off values in blood showed that when 100 μmol/L on the Ketolac milk test was defined positive, the most desirable sensitivity‐specificity combination was achieved. This milk test can be routinely used to screen a herd for subclinical ketosis.

ISSN:0165-2176    

DOI:10.1080/01652176.1998.9694851

出版商:Taylor & Francis Group    

年代:1998

数据来源: Taylor

摘要:

The German waspVespula germanica(Fabr.) (Hymenoptera: Vespidae) has been observed to injure dairy cows teats, causing lesions which can lead to mastitis. The number of dairy herds in Israel reported to be affected in this way has increased from five prior to 1989 to 32 from 1989 to 1993. Likewise, the geographical distribution of the colonies of these wasps has expanded from the Galilee to the northern Negev. Most cases of mastitis appeared during August and September when the wasps were most active; the predominant organism isolated wasStreptococcus dysgalactiae. Apparently the wasps served as a vector in spreadingS. dysgalactiaeinfection in the herds. More adult cows than first‐calving cows were affected. The teats of the front quarters were more affected than those of the hind quarters.

ISSN:0165-2176    

DOI:10.1080/01652176.1998.9694852

出版商:Taylor & Francis Group    

年代:1998

数据来源: Taylor

ISSN:0165-2176    

DOI:10.1080/01652176.1998.9694853

出版商:Taylor & Francis Group    

年代:1998

数据来源: Taylor