This novel approach may be applicable to other nonverbal populations (eg, young children or elderly people with cognitive impairment).

Information gained here may provide improved measurements of clinical change in animal studies that use dogs with naturally occurring chronic pain to evaluate novel human treatment protocols.

Obesity is thought to affect quality of life, but limited objective data exist to support this supposition. The current study aim was to use a questionnaire to determine health-related quality of life (HRQOL) both before and after weight loss, in obese client-owned dogs. Fifty obese dogs were included, and represented a variety of breeds and genders. Prior to weight loss, owners were asked to complete a validated standardised questionnaire to determine HRQOL. Thirty of the dogs successfully completed their weight loss programme and reached target, and owners then completed a follow-up questionnaire. The completed questionnaire responses were transformed to scores corresponding to each of four factors (vitality, emotional disturbance, anxiety and pain), and scored on a scale of 0-6. Changes in the scores were used to explore the sensitivity of the questionnaire, and scores were correlated with responses to direct questions about quality of life and pain, as well as weight loss. Dogs that failed to complete their weight loss programme had lower vitality and higher emotional disturbance scores than those successfully losing weight (P=0.03 for both). In the 30 dogs that completed, weight loss led to an increased vitality score (P<0.001), and decreased scores for both emotional disturbance (P<0.001) and pain (P<0.001). However, there was no change in anxiety (P=0.09). The change in vitality score was positively associated with percentage weight loss (r(P)=0.43, P=0.02) and percentage body fat loss (r(P)=0.39, P=0.03). These results indicate demonstrable improvement in HRQOL for obese dogs that successfully lose weight.

This is the first report of a valid and reliable companion animal health-related quality of life instrument, the contemporary approach to animal welfare measurement, which is presented in a web-based format, with automated production of a health-related quality of life profile. It offers major advantages to dog owners, practitioners and researchers.

Objectives The objective of this study was to develop a valid, reliable web-based, generic feline health-related quality-of-life (HRQoL) questionnaire instrument to measure the affective impact of chronic disease. Methods A large initial item pool, obtained through interviews with cat owners, was reduced using predetermined criteria, survey scores for relevance and clarity, and the ability of individual items to discriminate between healthy and sick cats when owners completed a prototype questionnaire. Using these data, factor analysis was used to derive a scoring algorithm and provide evidence for factorial validity. Validity was demonstrated further in a field trial using a 'known groups' approach (sick vs healthy cats will have a different HRQoL profile, and the HRQoL profile of cats will deteriorate as comorbidities increase). Test-retest reliability was assessed using intra-class correlation coefficients (ICC). Results In total, 165 items were reduced to 20 and, on the basis of a factor analysis that explained 72.3% of the variation in scores input by 71 owners of 30 healthy and 41 sick cats using the prototype, these were allocated to three domains (vitality, comfort and emotional wellbeing [EWB]) with a scoring algorithm derived using item loadings. Subsequently, the owners of 36 healthy and 58 sick cats completed one or two (n = 48) assessments. Median scores (healthy vs sick) for all domains were significantly different ( P <0.001), 78% of cats were correctly classified as healthy or sick and for comorbidities the correlation coefficients were moderate (vitality 0.64; comfort 0.63; EWB 0.50). Test-retest reliability was good (ICC vitality 0.635; comfort 0.716; EWB 0.853). Conclusions and relevance This study provides initial evidence for the validity and reliability of a novel HRQoL instrument to aid the assessment and management of chronic diseases of cats.