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Time of separation from the litter effect on behavior
A D VA N C E S
PAG E 3
Procedure Seventy adult dogs separated from their dam and littermates and adopted between the ages of 30 and 40 days were compared with 70 adult dogs that had been taken from the litter for adoption at 2 months. Owners were asked to complete a questionnaire on whether their dog exhibited potentially problematic behaviors when in its home environment.
TIME OF SEPARATION FROM THE LITTER EFFECT ON BEHAVIOR Background There is often an inheritable component to the development of anxiety and fear, noise phobia, impulse and control aggression, conspecific aggression, predatory aggression, and obsessive-compulsive disorder in dogs. Although these conditions may appear at between 1 and 2 years of age, signs of irrational fear in puppies may become evident as early as 3 months of age. It is the interplay between genetics, environment, and experience that contributes importantly to the development of most aspects of behavior. The combination of these factors may affect the behavior of puppies throughout life. Adverse early life experiences may have a negative impact on behavior later in life. However, surprisingly little about the relationship between behavioral problems and a dog’s early experience has been objectively investigated. The exposure to environmental stimuli is fundamental in regulating individual responses. It is generally accepted that dogs go through an early socialization period, during which social experiences and stimuli have a greater effect on the development of their temperament and behavior than if they occur in later life. This critical period ranges between the end of the neonatal period, at 2½ to 3 weeks to some time between 12 and 14 weeks. However, others suggest that the effective period may be significantly shorter. Many social and behavioral deficits observed in adult dogs may be affected by removing puppies too early from the dam and littermates.
Objectives To evaluate whether and how early separation of puppies from their litter during the socialization period could affect their behavior as adults.
Results The odds of displaying destructiveness, excessive barking, fearfulness on walks, reactivity to noises, toy possessiveness, food possessiveness, and attention-seeking were significantly greater for the dogs that had been removed from the litter earlier during the socialization period. In addition, dogs purchased from a pet shop at 30 to 40 days of age were reported to exhibit some of the listed behavioral problems with a significantly higher frequency than dogs purchased from a pet shop at 2 months. No significant differences were observed with dogs obtained from other types of sources. The dogs in the youngest age group (18 to 36 months) had a higher probability of displaying destructiveness and tail chasing.
Author Conclusion Compared with dogs that remained with their social group for 60 days, dogs that had been separated from the litter earlier were more likely to exhibit potentially problematic behaviors, especially if they came from a pet shop.
Inclusions One figure, 5 tables, 45 references.
Editor Annotation There are few data on the effects of anxiety on learning in dogs, but we know from studies on rodents and children that chronic glucocorticoid excess-at any time, including pre- and peri-natally interferes with learning at the cellular level. Such chronic glucocorticoid exposure also appears to affect the structural development of the hippocampus (the brain region responsible for associational learning and its further integration into cortical function) and the amygdala (the region responsible for developing and modulating fear). Chronic elevation in cortisol production appears to act as a translational gene regulator that interferes with acquisition and
PAG E 4
A D VA N C E S
consolidation of task learning in regions of the hippocampus. Prenatal stress and chronic ongoing stress in rats leads to lower levels of extinction of cue-conditioned fear, causes shrinkage of the hippocampus, leading to memory impairment, and facilitates fear conditioning in the amygdala, especially for consolidation of auditory fear conditioning. These effects may be more pronounced in some genetic makeups. These studies suggest potential mechanisms for the Pierantoni et al. findings that puppies separated early experienced more fearfulness on walks, reactivity to noises, and overall enhanced reactivity as adults than did those allowed to stay longer with their dams and littermates. One has to wonder whether those humans willing to rush pups out the door act on any concept of providing the best environment for the bitch, and hence the pups, during pregnancy. If early adoption occurs in addition to less-than-optimal breeding and pregnancy practices, pups can have real behavioral problems. Prenatal exposure to maternal stress causes epigenetic methylation of promoter regions on glucocorticoid receptors, which causes hyperreactivity in rodents and humans. In rodents, hippocampal expression of the glucocorticoid receptor gene and behavioral responses to stress are modulated by the amount of care mothers give young in first few days of life. This process is likely to also occur in dogs. These studies show that task learning can be enhanced when stress and distress are mitigated. Raising puppies with their siblings and dam through their first 70 days, a time when most brain myelination is complete but when neuronal remodeling should be rapidly ongoing, provides such mitigation. These emergent, complex neurobiological findings can be distilled to a few simple guidelines for breeding and raising pups. Considering the enhanced risk of relinquishment, abandonment, and euthanasia for dogs with any behavioral concerns, welfare and behavioral standards should mandate that puppies remain with their litters in the home of and with access to the dam through 8 weeks of age. Puppies, bitches, and dams should be exposed to humane conditions that minimize the risks of excess stress and fear. Such guidance would preclude practices so prevalent in puppy mills and help breeders to focus adequate nutrition for the bitches and the in utero pups, adequate
social maturation with dams and littermates, and hopefully, a humane start. Simply by caring for puppies developing brains, we spare them the risk of debilitating, tragic, and often lethal behavioral problems and avoid lives marked by profound fear reactivity. (KLO) Pierantoni L, Albertini M, Pirrone F. Prevalence of owner-reported behaviours in dogs separated from the litter at two different ages. Vet Record 2011;10:1-6.
PAG E 3
Procedure Seventy adult dogs separated from their dam and littermates and adopted between the ages of 30 and 40 days were compared with 70 adult dogs that had been taken from the litter for adoption at 2 months. Owners were asked to complete a questionnaire on whether their dog exhibited potentially problematic behaviors when in its home environment.
TIME OF SEPARATION FROM THE LITTER EFFECT ON BEHAVIOR Background There is often an inheritable component to the development of anxiety and fear, noise phobia, impulse and control aggression, conspecific aggression, predatory aggression, and obsessive-compulsive disorder in dogs. Although these conditions may appear at between 1 and 2 years of age, signs of irrational fear in puppies may become evident as early as 3 months of age. It is the interplay between genetics, environment, and experience that contributes importantly to the development of most aspects of behavior. The combination of these factors may affect the behavior of puppies throughout life. Adverse early life experiences may have a negative impact on behavior later in life. However, surprisingly little about the relationship between behavioral problems and a dog’s early experience has been objectively investigated. The exposure to environmental stimuli is fundamental in regulating individual responses. It is generally accepted that dogs go through an early socialization period, during which social experiences and stimuli have a greater effect on the development of their temperament and behavior than if they occur in later life. This critical period ranges between the end of the neonatal period, at 2½ to 3 weeks to some time between 12 and 14 weeks. However, others suggest that the effective period may be significantly shorter. Many social and behavioral deficits observed in adult dogs may be affected by removing puppies too early from the dam and littermates.
Objectives To evaluate whether and how early separation of puppies from their litter during the socialization period could affect their behavior as adults.
Results The odds of displaying destructiveness, excessive barking, fearfulness on walks, reactivity to noises, toy possessiveness, food possessiveness, and attention-seeking were significantly greater for the dogs that had been removed from the litter earlier during the socialization period. In addition, dogs purchased from a pet shop at 30 to 40 days of age were reported to exhibit some of the listed behavioral problems with a significantly higher frequency than dogs purchased from a pet shop at 2 months. No significant differences were observed with dogs obtained from other types of sources. The dogs in the youngest age group (18 to 36 months) had a higher probability of displaying destructiveness and tail chasing.
Author Conclusion Compared with dogs that remained with their social group for 60 days, dogs that had been separated from the litter earlier were more likely to exhibit potentially problematic behaviors, especially if they came from a pet shop.
Inclusions One figure, 5 tables, 45 references.
Editor Annotation There are few data on the effects of anxiety on learning in dogs, but we know from studies on rodents and children that chronic glucocorticoid excess-at any time, including pre- and peri-natally interferes with learning at the cellular level. Such chronic glucocorticoid exposure also appears to affect the structural development of the hippocampus (the brain region responsible for associational learning and its further integration into cortical function) and the amygdala (the region responsible for developing and modulating fear). Chronic elevation in cortisol production appears to act as a translational gene regulator that interferes with acquisition and
PAG E 4
A D VA N C E S
consolidation of task learning in regions of the hippocampus. Prenatal stress and chronic ongoing stress in rats leads to lower levels of extinction of cue-conditioned fear, causes shrinkage of the hippocampus, leading to memory impairment, and facilitates fear conditioning in the amygdala, especially for consolidation of auditory fear conditioning. These effects may be more pronounced in some genetic makeups. These studies suggest potential mechanisms for the Pierantoni et al. findings that puppies separated early experienced more fearfulness on walks, reactivity to noises, and overall enhanced reactivity as adults than did those allowed to stay longer with their dams and littermates. One has to wonder whether those humans willing to rush pups out the door act on any concept of providing the best environment for the bitch, and hence the pups, during pregnancy. If early adoption occurs in addition to less-than-optimal breeding and pregnancy practices, pups can have real behavioral problems. Prenatal exposure to maternal stress causes epigenetic methylation of promoter regions on glucocorticoid receptors, which causes hyperreactivity in rodents and humans. In rodents, hippocampal expression of the glucocorticoid receptor gene and behavioral responses to stress are modulated by the amount of care mothers give young in first few days of life. This process is likely to also occur in dogs. These studies show that task learning can be enhanced when stress and distress are mitigated. Raising puppies with their siblings and dam through their first 70 days, a time when most brain myelination is complete but when neuronal remodeling should be rapidly ongoing, provides such mitigation. These emergent, complex neurobiological findings can be distilled to a few simple guidelines for breeding and raising pups. Considering the enhanced risk of relinquishment, abandonment, and euthanasia for dogs with any behavioral concerns, welfare and behavioral standards should mandate that puppies remain with their litters in the home of and with access to the dam through 8 weeks of age. Puppies, bitches, and dams should be exposed to humane conditions that minimize the risks of excess stress and fear. Such guidance would preclude practices so prevalent in puppy mills and help breeders to focus adequate nutrition for the bitches and the in utero pups, adequate
social maturation with dams and littermates, and hopefully, a humane start. Simply by caring for puppies developing brains, we spare them the risk of debilitating, tragic, and often lethal behavioral problems and avoid lives marked by profound fear reactivity. (KLO) Pierantoni L, Albertini M, Pirrone F. Prevalence of owner-reported behaviours in dogs separated from the litter at two different ages. Vet Record 2011;10:1-6.