Evaluation of radiometric faecal culture and direct PCR on pooled faeces for detection of Mycobacterium avium subsp. paratuberculosis in cattle     

Eamens GJ  Whittington RJ  Turner MJ  Austin SL  Fell SA  Marsh IB 《Veterinary microbiology》2007,125(1-2):22-35

Dilution rates for pooled faecal culture (PFC) and direct IS900 polymerase chain reaction (D-PCR) tests were evaluated on faecal samples from infected cows mixed with uninfected faeces in dilutions from 1 in 5 to 1 in 50. PFC was performed by radiometric culture, with confirmation by IS900 PCR and restriction endonuclease analysis (PCR/REA) on growth, and by mycobactin dependency testing on solid medium. Using 37 culture positive faecal samples from 12 subclinical cows, 83.8% and 94.6% of samples were confirmed positive in the PFC assay at dilutions of 1 in 50 and 1 in 30, respectively. Lower dilutions (1 in 5 to 1 in 20) provided only marginally better sensitivity, and confirmation of PFC growth by PCR/REA was significantly more sensitive than mycobactin dependency. D-PCR had significantly lower sensitivity than PFC confirmed by PCR/REA, with pools of 1 in 50, 30, 10 and 5 yielding positive results in 64.9%, 70.3%, 78.4% and 83.8% of samples, respectively. Cattle considered to be shedding 1.5 x 10(6) viable M. avium subsp. paratuberculosis (Map)/g faeces (on the basis of estimated losses in processing and growth rates in radiometric broth) were positive at dilutions up to 1 in 50 in the PFC and D-PCR. Those shedding 5 x 10(5) viable Map/g were positive in the PFC at dilutions up to 1 in 40, but required a 1 in 10 dilution or less for D-PCR. The results suggest that for cattle shedding relatively high concentrations of Map in faeces (>2 x 10(5) viable Map/g), maximal dilutions of 1 in 30 for PFC and 1 in 10 for D-PCR would be applicable.  相似文献   

Successful treatment of a squamous cell carcinoma in a white rhinoceros, Ceratotherium simum     

Goodman G  Rhind S  Meredith A 《Veterinary dermatology》2007,18(6):460-463

A captive 33-year-old male white rhinoceros with seasonal dermatitis was diagnosed with a malignant squamous cell carcinoma on the right flank. Staphylococcus aureus was cultured from the skin lesions. No fungal or yeast was isolated. The dermatitis was treated with a combination of oral antibiotics (trimethoprim-sulphadiazine) and topically with weekly chlorhexidine washes and a mixture of a zinc oxide, balsam peru and bismuth oxide cream. Under azaperone and butorphanol anaesthesia, the skin tumour was surgically removed. The tumour was excised with wide margins and allowed to heal by secondary intention as primary wound closure was not possible. A post-mortem performed 2 years later for an unrelated condition revealed no metastases or recurrence of the skin tumour. It was presumed that chronic irritation or trauma may have contributed to the development of the skin tumour. This is the first detailed report of the successful treatment of a squamous cell carcinoma not associated with the horn in a rhinoceros.  相似文献   

Incidence and effects of West Nile virus infection in vaccinated and unvaccinated horses in California     

Gardner IA  Wong SJ  Ferraro GL  Balasuriya UB  Hullinger PJ  Wilson WD  Shi PY  MacLachlan NJ 《Veterinary research》2007,38(1):109-116

A prospective cohort study was used to estimate the incidence of West Nile virus (WNV) infection in a group of unvaccinated horses (n = 37) in California and compare the effects of natural WNV infection in these unvaccinated horses to a group of co-mingled vaccinated horses (n = 155). Horses initially were vaccinated with either inactivated whole virus (n = 87) or canarypox recombinant (n = 68) WNV vaccines during 2003 or 2004, prior to emergence of WNV in the region. Unvaccinated horses were serologically tested for antibodies to WNV by microsphere immunoassay incorporating recombinant WNV E protein (rE MIA) in December 2003, December 2004, and every two months thereafter until November 2005. Clinical neurologic disease attributable to WNV infection (West Nile disease (WND)) developed in 2 (5.4%) of 37 unvaccinated horses and in 0 of 155 vaccinated horses. One affected horse died. Twenty one (67.7%) of 31 unvaccinated horses that were seronegative to WNV in December, 2004 seroconverted to WNV before the end of the study in November, 2005. Findings from the study indicate that currently-available commercial vaccines are effective in preventing WND and their use is financially justified because clinical disease only occurred in unvaccinated horses and the mean cost of each clinical case of WND was approximately 45 times the cost of a 2-dose WNV vaccination program.  相似文献   

Feline calicivirus     

Radford AD  Coyne KP  Dawson S  Porter CJ  Gaskell RM 《Veterinary research》2007,38(2):319-335

Feline calicivirus (FCV) is an important and highly prevalent pathogen of cats. It belongs to the family Caliciviridae which includes other significant pathogens of man and animals. As an RNA virus, high polymerase error rates convey upon FCV a high genome plasticity, and allow the virus to respond rapidly to environmental selection pressures. This makes the virus very adaptable and has important implications for clinical disease and its control. Being genetically diverse, FCV is associated with a range of clinical syndromes from inapparent infections to relatively mild oral and upper respiratory tract disease with or without acute lameness. More recently, highly virulent forms of the virus have emerged associated with a systemic infection that is frequently fatal. A proportion of FCV infected cats that recover from acute disease, remain persistently infected. In such cats, virus evolution is believed to help the virus to evade the host immune response. Such long-term carriers may only represent a minority of the feline population but are likely to be crucial to the epidemiology of the virus. Vaccination against FCV has been available for many years and has effectively reduced the incidence of clinical disease. However, the vaccines do not prevent infection and vaccinated cats can still become persistently infected. In addition, FCV strain variability means that not all strains are protected against equally. Much progress has been made in understanding the biology and pathogenesis of this important feline virus. Challenges for the future will necessarily focus on how to control the variability of this virus particularly in relation to emerging virulent strains and vaccination.  相似文献   

Feline herpesvirus     

Gaskell R  Dawson S  Radford A  Thiry E 《Veterinary research》2007,38(2):337-354

Feline herpesvirus (FHV-1; felid herpesvirus 1 (FeHV-1)) is an alphaherpesvirus of cats closely related to canine herpesvirus-1 and phocine herpesvirus-1. There is only one serotype of the virus and it is relatively homogenous genetically. FeHV-1 is an important cause of acute upper respiratory tract and ocular disease in cats. In addition, its role in more chronic ocular disease and skin lesions is increasingly being recognised. Epidemiologically, FeHV-1 behaves as a typical alphaherpesvirus whereby clinically recovered cats become latently infected carriers which undergo periodic episodes of virus reactivation, particularly after a stress. The primary site of latency is the trigeminal ganglion. Conventional inactivated and modified-live vaccines are available and protect reasonably well against disease but not infection, although viral shedding may be reduced. Genetically engineered vaccines have also been developed, both for FeHV-1 and as vector vaccines for other pathogens, but none is as yet marketed.  相似文献   

Intracranial medulloblastoma as the cause of progressive ataxia in a 6-month-old draft horse cross gelding     

Megan Palmisano  Susan Bender  Amy L. Johnson 《Journal of veterinary internal medicine / American College of Veterinary Internal Medicine》2023,37(1):361-365

We describe the unique clinical presentation of a central nervous system neoplasm in a 6-month-old draft horse cross gelding. Based on the neurologic examination at admission, neurolocalization was most consistent with a mildly asymmetric cervical, multifocal, or diffuse myelopathy. Mild vestibular involvement also was considered, but no cranial nerve deficits were observed. The gelding was negative for Sarcocystis neurona or Neospora hughesi based on paired serum and cerebrospinal fluid (CSF) samples analyzed, with no evidence of cervical compression based on contrast myelography. The horse was euthanized because of progression of clinical signs. At necropsy, a mass was identified associated with the cerebellum, and histopathology was consistent with medulloblastoma, which has not been reported previously in the horse.  相似文献   

Onchocerca sp. in an imported Zangersheide gelding causing suspensory ligament desmitis     

Kara A. Brown  Amy L. Johnson  Susan J. Bender  Thomas J. Nolan  Bianca Pfisterer  JoAnn Slack  Elinor Willis  Emily K. Rule 《Journal of veterinary internal medicine / American College of Veterinary Internal Medicine》2023,37(2):735-739

A 5-year-old imported Zangersheide gelding was evaluated for SC swellings over both forelimbs and lameness localized to the distal metacarpus. Ultrasound examination of the SC masses was compatible with verminous granulomas. Linear hyperechoic foci were present within the suspensory ligament branches of both forelimbs, suggestive of ligamentous parasitic infiltrates. A diagnosis of onchocerciasis was confirmed on biopsy of a SC mass. The gelding was treated with ivermectin and a tapering course of PO dexamethasone but was eventually euthanized. Necropsy confirmed the presence of SC eosinophilic granulomas and degenerative suspensory ligament desmitis, both with intralesional nematodes. Given the location and appearance of the nematode, a diagnosis of Onchocerca sp., most likely O. reticulata, was made. Onchocerciasis should be included as a differential diagnosis for multifocal suspensory ligament desmitis with these sonographic characteristics when paired with SC masses in imported European Warmbloods.  相似文献   

Using midday stem water potential for scheduling deficit irrigation in mid–late maturing peach trees under Mediterranean conditions     

José Manuel Mirás-Avalos  Francisco Pérez-Sarmiento  Rosalía Alcobendas  Juan José Alarcón  Oussama Mounzer  Emilio Nicolás 《Irrigation Science》2016,34(2):161-173

Irrigation techniques that reduce water applications are increasingly applied in areas with scarce water resources. In this study, the effect of two regulated deficit irrigation (RDI) strategies on peach [Prunus persica (L.) Batsch cv. “Catherine”] performance was studied over three growing seasons. The experimental site was located in Murcia (SE Spain), a Mediterranean region. Two RDI strategies (restricting water applications at stage II of fruit development and postharvest) based on stem water potential (Ψ_s) thresholds (?1.5 and ?1.8 MPa during fruit growth and ?1.5 and ?2.0 MPa during postharvest) were compared to a fully irrigated control. Soil water content (θ_v), Ψ_s, gas exchange parameters, vegetative growth, crop load, yield and fruit quality were determined. RDI treatments showed significantly lower values of θ_v and Ψ_s than control trees when irrigation water was restricted, causing reductions in stomatal conductance and photosynthesis rates. Vegetative growth was reduced by RDI, as lower shoot lengths and pruning weights were observed under those treatments when compared to control. However, fruit size and yield were unaffected, and fruit quality was slightly improved by RDI. Water savings from 43 to 65 % were achieved depending on the year and the RDI strategy, and no negative carryover effect was detected during the study period. In conclusion, RDI strategies using Ψ_s thresholds for scheduling irrigation in mid–late maturing peach trees under Mediterranean conditions are viable options to save water without compromising yield and even improving fruit quality.  相似文献   

Measured and estimated water use and crop coefficients of grapevines trained to overhead trellis systems in California’s San Joaquin Valley     

Larry E. Williams  Matthew W. Fidelibus 《Irrigation Science》2016,34(6):431-441

The use of overhead trellis systems for the production of dry-on-vine (DOV) raisins and table grapes in California is expanding. Studies were conducted from 2006 to 2009 using Thompson Seedless grapevines grown in a weighing lysimeter trained to an overhead arbor trellis and farmed as DOV raisins for the first two years and for use as table grapes thereafter. Maximum canopy coverage for the two lysimeter vines across years was in excess of 80 %. Seasonal (15 March–31 October) evapotranspiration for the lysimeter vines (ET_Lys) was 952 mm in 2007 (farmed as DOV raisins) and 943 and 952 mm (when farmed as table grapes). The maximum crop coefficient (K _cLys) across all 4 years ranged from 1.3 to 1.4. These maximum values were similar to those estimated using the relationship where K _c is a function of the amount of shaded area measured beneath the canopy at solar noon (K _c = 0.017 × percent shaded area). Covering the lysimeter’s soil surface with plastic (and then removing it) numerous times during the 2009 growing season (1 June–14 September) reduced ET_Lys from an average of 6.4 to 5.6 mm day^?1 and the K _c from 1.07 to 0.93. A seasonal basal K _c (K _cb) was calculated for grapevines using an overhead trellis system with a 13 % reduction in the K _cLys across the growing season.  相似文献   

Crop response of drought-tolerant and conventional maize hybrids in a semiarid environment     

Ryan B. Mounce  Susan A. O’Shaughnessy  Brock C. Blaser  Paul D. Colaizzi  Steven R. Evett 《Irrigation Science》2016,34(3):231-244

In the High Plains, corn (Zea mays L.) is an important commodity for livestock feed. However, limited water resources and drought conditions continue to hinder corn production. Drought-tolerant (DT) corn hybrids could help maintain high yields under water-limited conditions, though consistent response of such hybrids is unverified. In this two-year study, the effects of three irrigation treatments were investigated for a DT and conventional maize hybrid, Pioneer AQUAMax P0876HR and Pioneer 33Y75, respectively. In 2013, the drier of the 2 years, irrigation amounts and crop water use (ET_c) were greater for the conventional hybrid, but grain water use efficiency (WUE) and harvest index were significantly greater for the DT hybrid. In 2014, grain yields and WUE were not significantly different between hybrids. However, irrigation amounts, ET_c and biomass yields were greater for the conventional hybrid. Results from both years indicate that the DT hybrid required less water to maximize grain yield as compared to the conventional hybrid. Producing relatively high yields with reduced amounts of water may provide a means for producers to continue corn production in a semiarid environment with declining water supplies.  相似文献