Research Digest Short Cuts
Research Digest Selected highlights from other journals Overcoming the placebo effect when investigating pain relief in cats M. E. Gruen, E. Griffith, A. Thomson, W. Simpson, B. D. X. Lascelles In trials of treatments for cats, owners are often asked to report whether the treatment has affected the cat’s behaviour or physical condition. Owner-based assessment tools include the feline musculoskeletal pain index and the client-specific outcome measures assessment. Previous studies have indicated that placebo effects may occur when such tools are used to assess degenerative joint disease (DJD)-associated pain in cats, with owners of cats in the placebo group likely to report that the clinical signs have diminished. This study aimed to test a novel trial design that incorporates a ‘washout period’ and assess whether it could overcome the placebo affect seen in a group of cats with DJD-associated pain by their owners. Sixty-six ‘indoor only’ cats with DJD that had been presented to primary care veterinarians at practices in the USA were included in the study. On the first day of the trial, all owners completed several subjective evaluations relating to their cats’ condition. For the first two weeks after enrolment, all cats received a volume-matched placebo in order to acclimatise them to the daily medication regime. Cats were then randomised to receive either meloxicam or a volume-matched placebo administered via injection for three weeks. Following this, all cats underwent a three-week washout period in which they received a placebo, to which the owners were blinded. Owner assessments were completed after the period of acclimatisation and after each threeweek ‘treatment’ period. During the treatment period in which some cats were given meloxicam and others were given a placebo, both groups of owners reported a significant improvement in clinical signs compared with baseline, but following the second period in which all cats were given a placebo, the owners of cats that had previously been receiving meloxicam were more likely to report a deterioration in their cat’s condition compared with owners of cats in the placebo group. The authors conclude that studies that include a washout period following treatment may be better able to detect the effects of treatment and that this may also be of use in trials involving people where the placebo effect is particularly strong. Journal of Veterinary Internal Medicine (2014) 346-350 doi: 10.1111/jvim.12312
Average roaming and dispersal distances in badgers A. W. Byrne, J. L. Quinn, J. J. O’Keeffe, S. Green, D. P. Sleeman, S. W. Martin, J. Davenport Badgers (Meles meles) are a wildlife reservoir of Mycobacterium bovis, a pathogen that has serious economic implications for the cattle industry. Badger movements can facilitate the spread and maintenance of M bovis in badger populations. This study aimed to investigate the movement patterns of a medium-density badger population in a region of Ireland. A mark-release-recapture programme was undertaken in an area of County Kilkenny in the north-west of the Republic of Ireland.
Between September 2009 and June 2012, all badger setts were visited six times. At each active sett, trapping was undertaken for eight nights. Captured badgers were anaesthetised and, when first captured, implanted with a transponder and tattooed with a unique number. The animals were then released. Distances between capture/recapture points for each badger were calculated. A total of 1395 capture events were recorded, with 963 individual badgers identified. Around half of recaptures occurred at the same location where the badger had been caught previously. Mean movement distance was 1.67 km, with 43 per cent of movements less than 1 km. One movement of 22.08 km was also recorded, which the authors describe as ‘exceptionally long’. Five per cent of movements were over 7.28 km. Of the movements of over 1 km, 68 per cent were seen in male badgers. The authors conclude that the results have implications for disease transmission and suggest that buffer zones of more than 7.3 km may be required to confine disease to specific areas in vaccination or culling field trials. Journal of Animal Ecology (2014) doi: 10.1111/1365-2656.12197
Prevalence of obesity in UK horses and ponies S. L. Giles, S. A. Rands, C. J. Nicol, P. A. Harris Equine obesity is of increasing concern in developed countries. It has been found to be a risk factor for laminitis, osteoarthritis and insulin resistance. This study aimed to investigate the prevalence and risk factors for obesity in leisure horses in an area of the UK. A total of 96 horses and ponies living in north Somerset were included in the final analysis. All of the animals lived in groups of two or more and were owned by local riding club members or charitable organisations. Body condition measurements were taken from February to March 2011, and a second set of measurements were taken from July to September 2011. At the end of winter (February to March) the prevalence of obesity in the sample population was 27 per cent, while at the end of the summer (July to September), the prevalence was 35 per cent. In total, 42 per cent of the horses and ponies were found to be obese on at least one occasion during the study period. There was no significant differences in the prevalence of obesity between horses and ponies and the authors suggest that this finding challenges a ‘common myth’ that ponies are more likely to be obese than horses. Horses that sustained a new injury between the end of winter and the end of summer were 5.5 times more likely to be obese than uninjured horses. Native cobs were 13.6 times more likely to be obese than horses of lightweight breeds. The authors suggest that this may be because native breeds have evolved to be particularly ‘thrifty’ and able to survive on sparse, fibrous grasses, and that this puts them at higher risk of excess weight gain when fed certain diets. They conclude that more research is needed to investigate the metabolic implications of seasonally fluctuating versus stable body condition in horses and ponies. PeerJ (2014) 2, e299 doi: 10.7717/peerj.299 doi: 10.1136/vr.g2511 April 5, 2014 | Veterinary Record | 353
Copyright of Veterinary Record: Journal of the British Veterinary Association is the property of BMJ Publishing Group and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use.
Research Digest Selected highlights from other journals Overcoming the placebo effect when investigating pain relief in cats M. E. Gruen, E. Griffith, A. Thomson, W. Simpson, B. D. X. Lascelles In trials of treatments for cats, owners are often asked to report whether the treatment has affected the cat’s behaviour or physical condition. Owner-based assessment tools include the feline musculoskeletal pain index and the client-specific outcome measures assessment. Previous studies have indicated that placebo effects may occur when such tools are used to assess degenerative joint disease (DJD)-associated pain in cats, with owners of cats in the placebo group likely to report that the clinical signs have diminished. This study aimed to test a novel trial design that incorporates a ‘washout period’ and assess whether it could overcome the placebo affect seen in a group of cats with DJD-associated pain by their owners. Sixty-six ‘indoor only’ cats with DJD that had been presented to primary care veterinarians at practices in the USA were included in the study. On the first day of the trial, all owners completed several subjective evaluations relating to their cats’ condition. For the first two weeks after enrolment, all cats received a volume-matched placebo in order to acclimatise them to the daily medication regime. Cats were then randomised to receive either meloxicam or a volume-matched placebo administered via injection for three weeks. Following this, all cats underwent a three-week washout period in which they received a placebo, to which the owners were blinded. Owner assessments were completed after the period of acclimatisation and after each threeweek ‘treatment’ period. During the treatment period in which some cats were given meloxicam and others were given a placebo, both groups of owners reported a significant improvement in clinical signs compared with baseline, but following the second period in which all cats were given a placebo, the owners of cats that had previously been receiving meloxicam were more likely to report a deterioration in their cat’s condition compared with owners of cats in the placebo group. The authors conclude that studies that include a washout period following treatment may be better able to detect the effects of treatment and that this may also be of use in trials involving people where the placebo effect is particularly strong. Journal of Veterinary Internal Medicine (2014) 346-350 doi: 10.1111/jvim.12312
Average roaming and dispersal distances in badgers A. W. Byrne, J. L. Quinn, J. J. O’Keeffe, S. Green, D. P. Sleeman, S. W. Martin, J. Davenport Badgers (Meles meles) are a wildlife reservoir of Mycobacterium bovis, a pathogen that has serious economic implications for the cattle industry. Badger movements can facilitate the spread and maintenance of M bovis in badger populations. This study aimed to investigate the movement patterns of a medium-density badger population in a region of Ireland. A mark-release-recapture programme was undertaken in an area of County Kilkenny in the north-west of the Republic of Ireland.
Between September 2009 and June 2012, all badger setts were visited six times. At each active sett, trapping was undertaken for eight nights. Captured badgers were anaesthetised and, when first captured, implanted with a transponder and tattooed with a unique number. The animals were then released. Distances between capture/recapture points for each badger were calculated. A total of 1395 capture events were recorded, with 963 individual badgers identified. Around half of recaptures occurred at the same location where the badger had been caught previously. Mean movement distance was 1.67 km, with 43 per cent of movements less than 1 km. One movement of 22.08 km was also recorded, which the authors describe as ‘exceptionally long’. Five per cent of movements were over 7.28 km. Of the movements of over 1 km, 68 per cent were seen in male badgers. The authors conclude that the results have implications for disease transmission and suggest that buffer zones of more than 7.3 km may be required to confine disease to specific areas in vaccination or culling field trials. Journal of Animal Ecology (2014) doi: 10.1111/1365-2656.12197
Prevalence of obesity in UK horses and ponies S. L. Giles, S. A. Rands, C. J. Nicol, P. A. Harris Equine obesity is of increasing concern in developed countries. It has been found to be a risk factor for laminitis, osteoarthritis and insulin resistance. This study aimed to investigate the prevalence and risk factors for obesity in leisure horses in an area of the UK. A total of 96 horses and ponies living in north Somerset were included in the final analysis. All of the animals lived in groups of two or more and were owned by local riding club members or charitable organisations. Body condition measurements were taken from February to March 2011, and a second set of measurements were taken from July to September 2011. At the end of winter (February to March) the prevalence of obesity in the sample population was 27 per cent, while at the end of the summer (July to September), the prevalence was 35 per cent. In total, 42 per cent of the horses and ponies were found to be obese on at least one occasion during the study period. There was no significant differences in the prevalence of obesity between horses and ponies and the authors suggest that this finding challenges a ‘common myth’ that ponies are more likely to be obese than horses. Horses that sustained a new injury between the end of winter and the end of summer were 5.5 times more likely to be obese than uninjured horses. Native cobs were 13.6 times more likely to be obese than horses of lightweight breeds. The authors suggest that this may be because native breeds have evolved to be particularly ‘thrifty’ and able to survive on sparse, fibrous grasses, and that this puts them at higher risk of excess weight gain when fed certain diets. They conclude that more research is needed to investigate the metabolic implications of seasonally fluctuating versus stable body condition in horses and ponies. PeerJ (2014) 2, e299 doi: 10.7717/peerj.299 doi: 10.1136/vr.g2511 April 5, 2014 | Veterinary Record | 353
Copyright of Veterinary Record: Journal of the British Veterinary Association is the property of BMJ Publishing Group and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use.
