Investigating the behavioural and welfare effects of intensive commercial breeding on dogs

Abstract

Large-scale Commercial dog Breeding Establishments (CBEs) are one of the main suppliers of pet dogs in a growing market. The report of intensive breeding practices within CBEs has raised societal and ethical concerns about the welfare of dogs maintained in these facilities. However, extensive knowledge gaps still exist as direct scientific studies within the CBE environment are still scarce. The main aim of my research was to investigate how different aspects of the intensive commercial breeding environment affected the behaviour and welfare of CBE dogs, particularly focusing on breeding dams. In the first study, I developed a behavioural ease of whelping (EoW) index to characterise parturition difficulty in CBE dams. I further investigated the relationship between EoW, intrinsic and environmental factors, early maternal behaviour and puppy perinatal mortality. Parturition difficulty (EoW index) was significantly affected by season of whelping, litter size and the origin of the dam (whether the dam was born and reared within the CBE or brought in). Increasing parturition difficulty was linked to the dams’ spending more time in contact with their puppies during the first 24 hours postpartum. Early maternal behaviour was also affected by breed group (classified according to size/weight) and the origin of the dam. In the second study, using an attention bias test and a stranger approach test, I explored the effect of a four-week positive human interaction enrichment protocol on affective states and human sociability of breeding dams. In the attention bias test, compared with a control group, dams receiving the enrichment treatment interacted for longer with a rewarding stimulus and looked less frequently towards a threatening stimulus —indicating a more positive affective state. Moreover, enriched dams displayed increased affiliative behaviour and were less fearful towards an unfamiliar person in the stranger approach test. Next, I investigated how a similar enrichment protocol conducted during the last four weeks of gestation affected maternal behaviour and the welfare of breeding dams during the first three weeks postpartum. There were no significant differences the duration of mother-puppy interactions between control and enriched mothers. However, as litter size increased, enriched dams had significantly lower hair cortisol 2 concentration (HCC) levels compared to dams in the control group, suggesting that the gestational enrichment treatment mitigated the dam’s stress response towards caring for larger litters. Lastly, I explored the effect of maternal prenatal enrichment on behavioural development of eight-week-old puppies. A subset of litters from the previous study was tested in an isolation test, a novel object test, and a human greeting test. Prenatal enrichment affected puppies’ behavioural response in a sex- dependent way. In the isolation test, exploration and activity levels were reduced in males but not in female puppies as a result of the maternal enrichment treatment. In the novel object test, prenatal enrichment was associated with an increase in confidence in females, whilst the same trait decreased in male puppies. Exploration levels were reduced in male puppies from enriched dams but not in females. There were no significant differences in the human greeting test between puppies reared by control and enriched mothers. However, puppies’ affiliative behaviour towards an unfamiliar human was associated with the level of maternal care provided to the litter. These findings provide evidence about factors which can influence the welfare of commercial breeding dams, and highlights the importance of positive human interaction for improving their psychological and physiological wellbeing.

Date of Award	Jul 2023
Original language	English
Awarding Institution	Queen's University Belfast
Sponsors	National Council of Science and Technology of Mexico
Supervisor	Gareth Arnott (Supervisor) & Grace Carroll (Supervisor)