Increased risk of chronic wasting disease in Rocky Mountain elk associated with decreased magnesium and increased manganese in brain tissue

Chronic wasting disease (CWD) is a transmissible spongiform encephalopathy (TSE) of Rocky Mountain elk in North America. Recent studies suggest that tissue and blood mineral levels may be valuable in assessing TSE infection in sheep and cattle. The objectives of this study were to examine baseline levels of copper, manganese, magnesium, zinc, selenium, and molybdenum in the brains of Rocky Mountain elk with differing prion genotypes and to assess the association of mineral levels with CWD infection. Elk with leucine at prion position 132 had significantly lower magnesium levels than elk with 2 copies of methionine. Chronic wasting disease-positive elk had significantly lower magnesium than control elk. The incorporation of manganese levels in addition to magnesium significantly refined explanatory ability, even though manganese alone was not significantly associated with CWD. This study demonstrated that mineral analysis may provide an additional disease correlate for assessing CWD risk, particularly in conjunction with genotype.     

Phase II open‐label study of single‐agent hydroxyurea for treatment of mast cell tumours in dogs*

This prospective study evaluated the efficacy and safety of hydroxyurea (HU) in dogs with measurable mast cell tumours (MCTs). Dogs were treated with HU at 60 mg kg^?1per os q24h for 14 days then 30 mg kg^?1 q24h thereafter or until MCT recurrence. Forty‐six dogs were enrolled. The overall response rate was 28%. Two dogs had a complete response (CR) for 256 and 448 days, respectively. Eleven dogs had a partial response for a median duration of 46 days (range, 28–189 days). Grade 2 to 4 neutropenia occurred in eight dogs and grade 4 thrombocytopenia in two. Grade 3–4 anaemia occurred in seven dogs; overall, there was a significant decrease in haematocrit after treatment with HU. The median drop in haematocrit was 10%. This study demonstrated that HU has activity in the treatment of MCTs with mild anaemia being the primary adverse event.     

Precipitation Regulates the Response of Net Ecosystem CO2 Exchange to Environmental Variation on United States Rangelands

Rangelands occupy 50% of Earth’s land surface and thus are important in the terrestrial carbon (C) cycle. For rangelands and other terrestrial ecosystems, the balance between photosynthetic uptake of carbon dioxide (CO₂) and CO₂ loss to respiration varies among years in response to interannual variation in the environment. Variability in CO₂ exchange results from interannual differences in 1) environmental variables at a given point in the annual cycle (direct effects of the environment) and in 2) the response of fluxes to a given change in the environment because of interannual changes in biological factors that regulate photosynthesis and respiration (functional change). Functional change is calculated as the contribution of among-year differences in slopes of flux-environment relationships to the total variance in fluxes explained by the environment. Functional change complicates environmental-based predictions of CO₂ exchange, yet its causes and contribution to flux variability remain poorly defined. We determine contributions of functional change and direct effects of the environment to interannual variation in net ecosystem exchange of CO₂ (NEE) of eight rangeland ecosystems in the western United States (58 site-years of data). We predicted that 1) functional change is correlated with interannual change in precipitation on each rangeland and 2) the contribution of functional change to variance in NEE increases among rangelands as mean precipitation increases. Functional change explained 10–40% of the variance in NEE and accounted for more than twice the variance in fluxes of direct effects of environmental variability for six of the eight ecosystems. Functional change was associated with interannual variation in precipitation on most rangelands but, contrary to prediction, contributed proportionally more to variance in NEE on arid than more mesic ecosystems. Results indicate that we must account for the influence of precipitation on flux-environment relationships if we are to distinguish environmental from management effects on rangeland C balance.     

A survey of aged horses in Queensland, Australia. Part 2: Clinical signs and owners' perceptions of health and welfare

Objective To describe the prevalence and risk factors for clinical signs of disease and owner-reported health or welfare issues of aged horses in Queensland, Australia. Methods Owners of horses were contacted via an equestrian organisation in Queensland and asked to complete a questionnaire about their horses aged 15 years and older, to gain information about clinical signs observed in the horse and disease history. Owners were asked to identify health or welfare issues they felt were important in aged horses. Results Owners were able to identify many clinical signs of disease, with 83% of horses having at least one reported clinical sign of disease. Muscle stiffness (33%), lameness (28%), ocular discharge (22%), change in hair coat (22%) and skin problems (21%) were the most commonly reported signs. Increasing age was a risk factor for the presence of clinical signs of disease. Ponies had an increased risk of both laminitis and hirsutism, whereas Thoroughbreds had an increased risk of stereotypies, wounds, weight loss and musculoskeletal signs. Owners reported a known disease or disorder in their horses less frequently than the clinical signs of disease. Owners reported weight loss (28%), arthritis/lameness (24%) and teeth/dental care (18%) as the most important health issues, followed by welfare issues (8%). Conclusion Owners demonstrated concern for the health and welfare of their aged horses, but the lack of appropriate recognition of the significance of clinical signs and limited veterinary care suggest a need for increased client communication and veterinarian–client interaction.     

A survey of aged horses in Queensland, Australia. Part 1: management and preventive health care

Objective To describe management practices and routine preventive care of aged horses in Queensland, Australia, including effects of owner characteristics, affiliation to an equestrian group and retirement of the horse. Methods Owners of horses were contacted via Equestrian Australia (EA) and asked to complete a questionnaire about their aged horses (e.g. age, breed, sex and colour); their use and management, including preventive health care; and use of equine healthcare providers. Results Horses aged 15 years or greater represented one-third of the total horses owned in the population sample. The median age of the horses was 20.7 years (range 15–44 years). Basic husbandry and preventive health care varied depending on demographic region, age of the horse and its use. Affiliation with EA was associated with the breed and use of the horse, but not with management or preventive health care other than frequency of hoof care visits. Retired horses had reduced basic husbandry and preventive health care compared with non-retired horses. There was reduced preventive health care in rural compared with urban areas. The majority (61%) of horses in the current study had not been visited by a veterinarian in the previous 12 months. Conclusion Aged horses constitute a large subgroup of the Australian horse population. Although basic management is at a high level for most aged horses, it appears to be reduced following the horse's retirement and in the more rural areas. There was limited veterinary involvement in preventive healthcare strategies for aged horses, especially in rural areas.     

Quambalaria eucalypti a pathogen of Eucalyptus globulus newly reported in Portugal and in Europe

The Eucalyptus pathogen Quambalaria eucalypti has been reported from several subtropical and tropical countries of the Southern Hemisphere. During the course of a nationwide monitoring programme aimed at the detection of pathogens in commercial eucalypt plantations in Portugal, Q. eucalypti was found affecting Eucalyptus globulus. The identity of the pathogen was confirmed by sequence analyses of the internal transcribed spacer (ITS) region of the rDNA operon, as well as morphological characteristics. Quambalaria eucalypti is widespread throughout the eucalypt‐producing areas of Portugal. Pathogenicity studies revealed that different host genotypes showed various degrees of susceptibility to the pathogen. To our knowledge, this is the first report of Q. eucalypti on Eucalyptus spp. in Portugal and in the Northern Hemisphere.     

United States Department of Agriculture-Agricultural Research Service stored-grain areawide integrated pest management program

The USDA Agricultural Research Service (ARS) funded a demonstration project (1998-2002) for areawide IPM for stored wheat in Kansas and Oklahoma. This project was a collaboration of researchers at the ARS Grain Marketing and Production Research Center in Manhattan, Kansas, Kansas State University, and Oklahoma State University. The project utilized two elevator networks, one in each state, for a total of 28 grain elevators. These elevators stored approximately 31 million bushels of wheat, which is approximately 1.2% of the annual national production. Stored wheat was followed as it moved from farm to the country elevator and finally to the terminal elevator. During this study, thousands of grain samples were taken in concrete elevator silos. Wheat stored at elevators was frequently infested by several insect species, which sometimes reached high numbers and damaged the grain. Fumigation using aluminum phosphide pellets was the main method for managing these insect pests in elevators in the USA. Fumigation decisions tended to be based on past experience with controlling stored-grain insects, or were calendar based. Integrated pest management (IPM) requires sampling and risk benefit analysis. We found that the best sampling method for estimating insect density, without turning the grain from one bin to another, was the vacuum probe sampler. Decision support software, Stored Grain Advisor Pro (SGA Pro) was developed that interprets insect sampling data, and provides grain managers with a risk analysis report detailing which bins are at low, moderate or high risk for insect-caused economic losses. Insect density was predicted up to three months in the future based on current insect density, grain temperature and moisture. Because sampling costs money, there is a trade-off between frequency of sampling and the cost of fumigation. The insect growth model in SGA Pro reduces the need to sample as often, thereby making the program more cost-effective. SGA Pro was validated during the final year of the areawide program. Based on data from 533 bins, SGA Pro accurately predicted which bins were at low, moderate or high risk. Only in two out of 533 bins did SGA Pro incorrectly predict bins as being low risk and, in both cases, insect density was only high (> two insects kg(-1)) at the surface, which suggested recent immigration. SGA Pro is superior to calendar-based management because it ensures that grain is only treated when insect densities exceed economic thresholds (two insects kg(-1)). This approach will reduce the frequency of fumigation while maintaining high grain quality. Minimizing the use of fumigant improves worker safety and reduces both control costs and harm to the environment.