C.A. Wyse

Prevalence of obesity in riding horses in Scotland

OBESITY is a serious and largely underreported equine welfare issue. Obese horses are predisposed to the development of pathological conditions including laminitis, hyperlipaemia and strangulating lipoma ([Watson and others 1992][1], [Treiber and others 2006][2]). Obese horses may also be more

Prevalence, heritability and significance of musculoskeletal conformational traits in Thoroughbred yearlings

REASONS FOR PERFORMING STUDY The assessment of belief that equine conformation is associated with performance and durability is a fundamental concept of horsemanship. Surprisingly, there is almost no quantitative evidence to support these beliefs. OBJECTIVES To assess the prevalence and heritability of conformational traits in Thoroughbred yearlings, and investigate their significance for subsequent turf flat-racing performance and durability. METHODS Nine selected conformational traits were assessed in a consistent, qualitative manner by a single veterinary observer and entered into a database together with details of pedigree and racing records. RESULTS Conformational data were collected from 3916 Thoroughbred yearlings sold at public auction during the 7 year period 1993-1999. Most of the horses (72%) raced in the UK in turf flat races; just 7% of the yearlings failed to race. Prevalence of conformational defects for the UK horses was reported, with turned out feet the most commonly recorded defect (30% of all horses). There was a tendency towards a greater proportion of horses with defects in the group of unraced horses compared with horses that raced, but this was not statistically significant. There were some significant associations between racing performance and conformational defects but these were found to be almost completely explained by an effect of sire. All of the conformational traits showed considerable evidence of genetic influence, with heritability indices ranging 0.16-1.00. CONCLUSIONS AND POTENTIAL RELEVANCE Overall, there were only weak associations between performance and conformation that could not be accounted for by the very strong relationship between pedigree and conformation. Further study of potential association between highly heritable conformation traits and racing durability and racing performance should be undertaken utilising validated, quantitative methods and technology.

Current and future uses of breath analysis as a diagnostic tool

The analysis of exhaled breath is a potentially useful method for application in veterinary diagnostics. Breath samples can be easily collected from animals by means of a face mask or collection chamber with minimal disturbance to the animal. After the administration of a 13C-labelled compound the recovery of 13C in breath can be used to investigate gastrointestinal and digestive functions. Exhaled hydrogen can be used to assess orocaecal transit time and malabsorption, and exhaled nitric oxide, carbon monoxide and pentane can be used to assess oxidative stress and inflammation. The analysis of compounds dissolved in the aqueous phase of breath (the exhaled breath condensate) can be used to assess airway inflammation. This review summarises the current status of breath analysis in veterinary medicine, and analyses its potential for assessing animal health and disease.

Effects of changes to the stable environment on the exhalation of ethane, carbon monoxide and hydrogen peroxide by horses with respiratory inflammation.

The aim of this study was to assess the effects of changes to the stable environment on exhaled markers of respiratory inflammation in six horses with clinical histories of recurrent airway obstruction. The horses were maintained for two weeks under conventional stable management (straw bedding and hay) and for two weeks on a reduced-dust regimen (paper bedding and ensiled grass), in a crossover study design. Exhaled ethane and carbon monoxide (CO) and exhaled breath condensate hydrogen peroxide (H2O2) were measured every three days under each regimen. The presence of clinical signs of airway inflammation (nasal discharge and cough) was monitored daily. The reduced-dust regimen was associated with fewer clinical signs of airway inflammation than the conventional regimen. Exhaled ethane and CO were significantly lower on the reduced-dust regimen and these markers were correlated with clinical signs of respiratory inflammation, but exhaled H2O2 was not affected by the management regimen.

Collection and analysis of exhaled breath condensate hydrogen peroxide in conscious healthy dogs

THE analysis of exhaled breath condensate is a diagnostic technique that is of increasing interest as a non-invasive method for the investigation of respiratory disease in human medicine (Montuschi and Barnes 2002). Various markers of inflammation have been detected in human exhaled breath condensate, including hydrogen peroxide (H2O2) (Sznajder and others 1989), 8-isoprostane (Montuschi and others 2000), leukotrienes and prostaglandins (Montuschi and others 2003) and nitrate/nitrite (Ganas and others 2001). Exhaled breath condensate has been collected from anaesthetised dogs (Sznajder and others 1989, Pietra and others 2003), but the application of the method in conscious dogs has been precluded by the technical difficulty in collecting samples of sufficient volume in small animals. The collection and analysis of breath condensate offers a potential alternative to more invasive methods for the detection of respiratory inflammation, such as the analysis of bronchoalveolar lavage (BAL) fluid; markers of disease are inevitably diluted by the introduction of saline solution into the respiratory tract during the collection of BAL fluid. The collection of samples of exhaled breath condensate does not alter the endogenous dilution of disease markers by respiratory secretions, but other variables, such as the ambient humidity, respiratory rate and body temperature, may have considerable effects on its concentration. Cytological analysis of BAL fluid provides valuable information on the pathophysiology of respiratory inflammation, but the invasive nature of BAL precludes its use for the frequent monitoring of disease progression or response to therapy. In contrast, the collection of breath condensate for analysis is completely non-invasive and can be performed cheaply and using basic laboratory equipment. The aim of the present study was to develop a method for the collection of exhaled breath condensate from dogs and to investigate the variability of an exhaled marker of respiratory inflammation, H2O2, in a group of healthy dogs. To assess inter- and intrasubject variability in exhaled H2O2, samples of breath condensate were collected from 10 healthy dogs (bodyweight range 15 to 36 kg) on two occasions, with at least 15 minutes elapsing between the collection of the two samples. The study was carried out under the approval of the Animal Ethics and Welfare Committee of the University of Glasgow. The dogs remained at rest, in lateral or sternal recumbency, in their kennels during collection of the samples. Breath condensate was collected by allowing the dog to breathe through a plastic mask connected to a con

Ultrasonographic assessment of the rate of solid-phase gastric emptying in dogs

Twelve healthy dogs were used in an ultrasonographic assessment of the effect of the composition of a solid meal on the rate of gastric emptying. The dogs were fasted for nine hours before they were fed either a standard or a high energy density test meal, in a cross-over study design. The gastric antrum was visualised with a 6·5 MHz microconvex transducer, and the area inside the elliptical shape defined by the craniocaudal and ventrodorsal diameters of the stomach was measured. Antral images were acquired at regular intervals for six hours after the ingestion of the test meal. Three indices to describe the rate of gastric emptying were computed: the gastric half-emptying time (t1/2), the time to 50 per cent maximal antral area (t50%), and the time of maximal antral area (tmax). The values of t50% and t1/2 calculated for the high energy density meals were significantly longer than for the standard meals, but there was no significant difference between the tmax values.

A comparison of the rate of recovery of 13CO2 in exhaled breath with 2H in body water following ingestion of [2H/13C]octanoic acid in a dog

The objective of this study was to assess post-gastric processing of octanoic acid (OA) by comparing the rate of recovery of 13C in breath with the rate of recovery of 2H in saliva following ingestion of [2H/13C]OA. A test meal with 100mg [13C]OA and 750 mg [2H]OA was ingested on two separate occasions by one dog. Exhaled breath and saliva samples were collected at set time points for 6h following ingestion of the test meal. Two indices were computed, half recovery time (t(1/2)) and the time of peak excretion (t(max)). Recovery of 2H in saliva was quicker than recovery of 13C in breath as determined by the difference in the indices for each isotope; 1.33 and 1.59 h for t(1/2) and t(max), respectively. These findings suggest that the post-gastric processing of OA imposes a delay on the recovery of 13C in breath in the dog, as occurs in man and in the horse.