A cross-sectional survey on wounds in horses in New Zealand

AIM: To determine the frequency and type of skin wounds encountered by New Zealand veterinarians in their equine patients, the duration and estimated costs of treatment as well as the expected outcomes for these wounds.

METHODS: An online survey was sent to all veterinarians registered with the New Zealand Equine Veterinary Association. The survey comprised questions on the location and experience of respondents, the number of wound-related cases in relation to the total equine caseload, the type and anatomical location of wounds treated, the frequency, duration and costs of treatments, the outcome of wound treatment and an estimate of the most common causes of death or euthanasia in their equine patients.

RESULTS: The survey response rate was 110/262 (41.9%). The median number of equine cases seen by respondents was 20 (interquartile range (IQR) 6–60) per month; of these, five (IQR 2–10) were wound related. Wounds ranked third after lameness and respiratory disease for the relative frequency with which respondents encountered them. Of 102 respondents 59 (58%) reported that their clients frequently treated wounds incurred by their horse without consulting a veterinarian. Wounds on the distal limb, whether involving only the skin or also deeper structures, were reported by 86/101 (85%) respondents as the most frequently encountered. Wounds in this location also incurred the longest treatment period and were the most prone to develop complications. Finally, wounds ranked second, after colic, as the most common cause of death/euthanasia in the veterinary respondents’ equine patients.

CONCLUSIONS: The data obtained via the survey indicate that skin wounds, particularly on the distal limb, are a common occurrence in horses in New Zealand and, when they involve structures underlying the skin, are costly and time-consuming to manage and may lead to decreased performance, retirement or euthanasia. Consequently, we recommend that more effort be devoted to the education of equine veterinarians and owners, and that appropriate research funds be allocated to help improve patient outcomes.     

Sheep pox: experimental studies with a west african isolate

Under conditions of a maximum security laboratory, four cross-bred sheep were inoculated intradermally only or intradermally and intratracheally with a West African isolate of sheep pox virus. All sheep had increased temperature and depression by the fourth or fifth day after infection. Nasal and lacrimal discharge and coughing occurred in all sheep but were more severe in sheep receiving the virus via the tracheal route. From the fifth day after infection, numerous papular erythematous skin lesions developed at the inoculation sites. These were 3-7 mm in diameter and gradually became nodular. Some of these lesions healed and others coalesced to form tumorlike masses. In one sheep, euthanized 14 days after intradermal and intratracheal inoculation, nodular lesions were found in the skin around the eyes, nostrils, oral and perianal regions, the mucosa of the rumen and throughout the lungs. Histologically, skin nodules were characterized by ischemic necrosis, vasculitis, microvesicualtion, eosinophilic cytoplasmic inclusions in the dermal epithelial cells and vacuolar nuclear degeneration. The pulmonary lesion was that of proliferative alveolitis with occasional cytoplasmic inclusions in the alveolar cells and macrophages. Ultrastructurally, large cuboidal virus particles were found both in the skin lesion and inoculated tissue cultures. The sheep pox virus structure was easily distinguished from contagious ecthyma virus, a parapoxvirus which causes sporadic disease in Canada. Serum neutralizing antibodies developed in all the sheep by 14 days postinfection.

The clinical and pathological characteristics of experimental sheep pox produced with this West African isolate were similar to those caused by Neethling virus of lumpy skin disease in cattle.

     

Water/nutrient interactions affecting the productivity of stands of Pinus radiata

The accumulation of above-ground biomass and the seasonal patterns of leaf-area development, foliar nutrient concentrations and tree and soil water-status have been measured for fertilised, irrigated, and control stands of Pinus radiata D. Don growing on a low-productivity site, average annual precipitation of 790 mm, near Canberra in southeastern Australia. In the second growing-season after treatments commenced, projected leaf-area index reached peak values of 7 on the irrigated/fertilised stands compared with approximately 5 on the other stands. Average canopy nitrogen concentration (dry-weight basis) varied across the treatments from 9 to 17 mg g⁻¹. Measurements of soil and tree water-status over a 2-year period indicated that stands which were not irrigated experienced summer droughts of up to 4 months duration.

Annual volume production measured over the 2-year period ranged from 17 to 45 m³ ha⁻¹. The extent to which this variation could be attributed to differences in leaf area, rats of photosynthesis, duration of the period of positive net photosynthesis, and hence growth, was analysed in terms of a process-based model of stand growth dependent on climate and soil water-balance.

Annual canopy net photosynthesis simulated by the model ranged from 18 t carbon ha⁻¹ for the control stand to 38 t ha⁻¹ for the irrigated/fertilised stands. Simulations indicated that 67% of this difference could be attributed to the role of irrigation in extending the period of active growth. The additional leaf area carried by the irrigated/fertilised stands contributed a further 23%, while differences in rates of photosynthesis, related to nitrogen nutrition, explained the remaining 10%.     

A fine-scale chimpanzee genetic map from population sequencing

To study the evolution of recombination rates in apes, we developed methodology to construct a fine-scale genetic map from high-throughput sequence data from 10 Western chimpanzees, Pan troglodytes verus. Compared to the human genetic map, broad-scale recombination rates tend to be conserved, but with exceptions, particularly in regions of chromosomal rearrangements and around the site of ancestral fusion in human chromosome 2. At fine scales, chimpanzee recombination is dominated by hotspots, which show no overlap with those of humans even though rates are similarly elevated around CpG islands and decreased within genes. The hotspot-specifying protein PRDM9 shows extensive variation among Western chimpanzees, and there is little evidence that any sequence motifs are enriched in hotspots. The contrasting locations of hotspots provide a natural experiment, which demonstrates the impact of recombination on base composition.