Environmental risk factors in puppies and kittens for developing chronic disorders in adulthood: A call for research on developmental programming

Abstract

Many dogs and cats are affected by chronic diseases that significantly impact their health and welfare and relationships with humans. Some of these diseases can be challenging to treat, and a better understanding of early-life risk factors for diseases occurring in adulthood is key to improving preventive veterinary care and husbandry practices. This article reviews early-life risk factors for obesity and chronic enteropathy, and for chronic behavioral problems, which can also be intractable with life-changing consequences. Aspects of early life in puppies and kittens that can impact the risk of adult disorders include maternal nutrition, establishment of the gut microbiome, maternal behavior, weaning, nutrition during growth, growth rate, socialization with conspecifics and humans, rehoming and neutering. Despite evidence in some species that the disorders reviewed here reflect the developmental origins of health and disease (DOHaD), developmental programming has rarely been studied in dogs and cats. Priorities and strategies to increase knowledge of early-life risk factors and DOHaD in dogs and cats are discussed. Critical windows of development are proposed: preconception, gestation, the suckling period, early growth pre-neutering or pre-puberty, and growth post-neutering or post-puberty to adult size, the durations of which depend upon species and breed. Challenges to DOHaD research in these species include a large number of breeds with wide genetic and phenotypic variability, and the existence of many mixed-breed individuals. Moreover, difficulties in conducting prospective lifelong cohort studies are exacerbated by discontinuity in pet husbandry between breeders and subsequent owners, and by the dispersed nature of pet ownership.

Relative Impact of Birth Weight and Early Growth on Neonatal Mortality in Puppies

“…This suggests that birth weight is not only related to very early neonatal mortality but can also impact later life, in this case, with a midterm impact. This result is in line with that of Gaillard et al [ 48 ] and Mugnier et al [ 49 ], suggesting long-term consequences of reduced intrauterine growth in the canine species.…”

Identifying the target population and preventive strategies to combat feline obesity

“…[56][57][58][59][60] This hypothesis identifies that preventing and treating childhood obesity is essential to reducing obesity risks and prevalence in adulthood. These studies were conducted in humans; however, similar results have been observed in cats, 8,24,55,[61][62][63] such that rapid growth in kittens was a predictor of obesity in the adult life stage. 24 Feline growth can be broken down into five stages (Table 2).…”

“…Early development has previously been identified as a key life stage for preventing various diseases and disorders, such as obesity, in cats. 55 In humans, poor nutrition during fetal development and childhood overweight or obese condition are associated with health complications into adulthood, such as obesity and diabetes mellitus; this is known as the Barker hypothesis. [56][57][58][59][60] This hypothesis identifies that preventing and treating childhood obesity is essential to reducing obesity risks and prevalence in adulthood.…”

“…11,67 Although further research is necessary to understand the influence of different communication strategies on the health outcome of pets, effective communication between the owner and the veterinary team is likely to have a positive impact on feline health. Meaningful Table 2 The risk for obesity onset at the stages of growth for kittens 55,[64][65][66] discussion surrounding weight management could also play a key role in ensuring the prevention of obesity during the growth phase, and thereafter into adulthood. 68,69 Additional strategies that can be implemented by the owner, including regular monitoring of growth and appropriate feeding practices, can also aid in successful obesity prevention.…”

Association between Birth Weight and Subcutaneous Fat Thickness at Adulthood in Dogs

“…In contrast to the differences with mouse, rabbit and human, evidence of maternal programming in the canine species is lacking [ 41 ]. This work provides the demonstration of an association between birth weight (endpoint of embryofetal growth) and adiposity at adulthood in dogs.…”