Highlights of recent clinically relevant papers

Abstract

colleagues in the USA, Canada and Australia have recently published the findings of their retrospective case series which aimed to identify epidemiological trends in cutaneous neoplasms affecting equids in central North America and compare them with previously reported trends.A total of 3351 cutaneous biopsy specimens from 3272 equids with a neoplastic diagnosis were examined. Diagnostic reports from 2 diagnostic laboratories (Colorado State University and Prairie Diagnostic Services Inc) were reviewed for frequency of specific lesions and epidemiological trends. Variables included in analyses (if known) were age, sex, breed, geographic location, date of diagnosis, location of neoplasm on the body and presence or absence of ulceration.Sarcoid, squamous cell carcinoma (SCC) and melanoma were the 3 most common tumours diagnosed. Tumours associated with UV radiation (SCC, SCC in situ, haemangioma, haemangiosarcoma) were 2.3 times as common in biopsy specimens received by Colorado State University than in specimens received by Prairie Diagnostic Services Inc. Appaloosa horses and American Paint horses, respectively, were 7.2 and 4.4 times as likely as other breeds to have tumours associated with UV radiation. Thoroughbreds were predisposed to cutaneous lymphoma, whereas Arabians were more likely to have melanomas. Draught and pony breeds were 3.1 times as likely as other breeds to have benign soft tissue tumours. Morgans and pony breeds more commonly had basal cell tumours. Tumours in the perianal region were significantly more likely to be SCC or melanoma while tumours on the limbs were more likely to be giant cell tumour of soft parts. The authors concluded that signalment, anatomic location of the mass, and geographic location of the horse can be used to help equine practitioners formulate differential diagnoses for cutaneous masses. Further research is necessary to identify the biological basis for the development of many equine cutaneous neoplasms. Antimicrobial resistanceAdele Williams and colleagues in the UK have recently published the findings of their study to determine whether hospitalisation of horses leads to increased antimicrobial resistance in equine faecal Escherichia coli isolates.Escherichia coli were cultured from faecal samples of horses on admission and after 7 days of hospitalisation; antimicrobial susceptibility was determined for 8 antimicrobial agents. Resistance profiles of E. coli isolates were grouped into clusters, which were analysed to determine resistance patterns. Resistance to 7/8 antimicrobial agents and multi-drug resistance (MDR; resistance to Ն3 antimicrobial classes) were significantly higher after 7 days of hospitalisation. Forty-eight resistance profiles were identified; 15/48 were present on Day 0 only, 16/48 on Day 7 only and 17/48 at both times of sampling. There was a significant association between Day 7 profiles and resistance detected to an increased number of antimicrobial agents. Hospitalisation of horses for 7 days resulted in alterations in equine faecal E. coli an...