Hand-rearing puppies is an exhausting task, requiring a great deal of commitment from clients. There are also behavioural implications so clients may require guidance or professional behavioural advice to achieve the best outcome for their puppy.
Clients may be faced with the prospect of hand-rearing puppies if the dam is unwell or unable to feed them adequately. This is the “best case” of hand-rearing scenarios as the puppies may still be cared for and have physical contact with the dam even if supplemental feeding is required. If the dam has died or has rejected the puppies there are behavioural implications, but the puppies will still have the benefit of siblings. The most concerning situation is where a puppy is left without a dam or siblings, and these orphaned singletons are at risk of significant behavioural issues and need a great deal of help and support.
Puppies raised without a dam are behaviourally disadvantaged as it has been shown that the level of maternal care, particularly nursing and licking, affects the temperament of adult offspring in terms of engagement, anxiety and aggression (Tiira and Lohi, 2015; Foyer et al., 2016). Puppies who are removed from their mother too soon are more likely to develop a variety of behavioural issues as adults and show high levels of stress (Slabbert and Rasa, 1997; Pierantoni et al., 2011).
The best-case scenario for orphaned puppies is, without question, to foster either with a post-partum dam or with a canine foster parent who has not had puppies.
Websites and online groups are available that can match orphaned puppies with a post-partum dam. Care must be taken to ensure that legal aspects of ownership are covered and that the dam is vaccinated, wormed and in good health. It is also important to ensure that any remaining puppies are of similar size and age, and that the puppy will be safely accepted. It can be hard to find a foster dam if the puppy is in rescue and parentage is unknown as many matching groups will not accept puppies who are in rescue.
Canine foster families
If a post-partum dam cannot be found, then an alternative option is for the puppy to be raised with a canine foster family: with adult dogs who are gentle and kind to puppies. Breeders may have access to other suitable adult dogs, and many adult bitches and some adult dogs will accept and nurture orphaned puppies, acting as “aunt” and “uncle” figures (Figure 1).
The use of “allomothers” – other female dogs who help care for puppies – is common in free-living dogs (Pal et al., 2021). Raising a singleton puppy without a suitable adult dog in the household is to be avoided at all costs due to the behavioural implications of raising a puppy without appropriate canine exposure. In lab studies, puppies who have been hand-reared in isolation from other dogs were observed to show behavioural deficits and a lack of normal social behaviour both around people and dogs (Fox and Stelzner, 1967).
Raising a singleton puppy without a suitable adult dog in the household is to be avoided at all costs due to the behavioural implications of raising a puppy without appropriate canine exposure
Understanding normal maternal care
To understand why hand-rearing has behavioural impacts we must consider what normal maternal care is. Maternal behaviour includes physical contact, nursing, licking and grooming, play, thermoregulation, movement of puppies and the teaching of appropriate skills.
Licking and grooming
Licking may be one of the most important behaviours that impacts a puppy’s behavioural development. Maternal licking in rats is crucial in behavioural responses to stress in later life, including reduced fearfulness in response to novelty (Caldji et al., 2000). Maternal behaviour also “programmes” the hypothalamic–pituitary–adrenal axis’s responses to stress in the offspring (Liu et al., 1997).
Without a dam to lick and groom the puppy, the human foster carer must stimulate the puppy to urinate and defecate (until around three weeks old) by wiping the anogenital region. In addition, “grooming” of the body with moist warm cotton wool may be advantageous as it mimics grooming by the dam to some extent. In an ideal foster situation, a canine foster mother would assist by licking and grooming puppies, and many canine foster parents will happily do so (Figure 2).
Hand-reared puppies may be at risk of a suboptimal gut microbiome as this is usually acquired not only by exposure to the dam during birth but also when nursing and via licking. This has behavioural implications, as in dogs the gut microbiome is linked to aggression, anxiety-based disorders and phobias (Mondo et al., 2020). If singleton puppies are raised with other adult dogs, then microbiome impacts could potentially be mitigated by the dogs’ grooming of the puppy, restoring normal gut flora.
Nursing is so much more than just nutrition as it can impact puppies at a neurological level: during nursing, oxytocin activates areas of the brain concerned with mother–pup bonding (Febo et al., 2005).
Puppies would normally be nursed by the dam, and though hand-raised puppies’ nutritional needs may be met by the bottle, their emotional needs may not. It has been shown that human contact, gaze and stroking can boost oxytocin levels in dogs so close contact by the human caregiver, although it can in no way replace the care of a natural dam, may be beneficial (Handlin et al., 2012; Nagasawa et al., 2015).
When nursing, puppies are exposed to pheromones secreted by the sebaceous glands in the intermammary sulcus, which provide calm and comfort. The synthetic dog appeasing pheromone (DAP) mimics these pheromones and has been shown to reduce anxiety in a variety of stressful situations, which may be beneficial to hand-reared puppies (Mills et al., 2006; Gaultier et al., 2009).
Non-nutritive sucking (NNS) is a need that can be difficult to fulfil in hand-reared puppies. In other mammalian species, NNS stimulates enzymes and hormones that facilitate digestion, providing a calming effect (Pinelli and Symington, 2005). In dogs, NNS starts early in the neonatal period, peaks at around three to five days old and decreases at around three weeks (Scott, 1958). It is thought that puppies deprived of NNS or weaned early may develop oral fixations (Battaglia, 2009). Puppies can be given some outlet for NNS needs by allowing them to suck on bottle teats when not feeding and by providing safe pacifiers or finger teats for them to suck.
Puppy movement and physical contact
Puppies will lie in close physical contact with the dam and move away if they get too hot. Studies in rat pups have shown that being in physical proximity to the mother impacted on the serotonin system in the brain and that separation from the mother could have both immediate and long-term negative impacts on the offspring’s developing brain (Courtiol et al., 2018). In hand-reared puppies, this lack of maternal presence could have long-term consequences. In the absence of the dam, close contact with other safe, friendly adult dogs in the foster home seems essential but must of course be carefully managed (Figures 3 and 4).
Physical contact with siblings also enables the puppy to develop motor skills and physical dexterity as they climb over each other in the whelping pen. The use of safe soft toys of suitable size, some of which can be purchased with a heat pad and “heartbeat” inside, can give the puppy something to climb on and lie against in their bed area (Figure 5). An enriched environment of safe toys, novel objects and different sounds, textures and scents is beneficial to all puppies, but perhaps of extra importance to hand-reared singletons (Figure 6).
Socialisation skills and play
Puppies raised without siblings or a mother risk being deprived of social contact with their own species at a crucial time in their development. The socialisation period from 3 to 12 weeks old is where there is a large focus on the development of the appropriate skills surrounding conspecifics (Scott and Fuller, 1965). If singleton puppies are fostered with stable adult dogs, they can learn how to communicate, play and behave appropriately from these dogs.
Learning how to use their teeth gently and bite without causing harm is a crucial skill that should be learned by puppies when interacting with their littermates and mother (Bekoff, 2001). In the absence of littermates this skill should be learned around kind adult dogs. Ideally, foster dogs should be of a similar size so that puppies can safely mix with them; if there is a large size disparity then all interactions must be very carefully managed to prevent injury.
There is a huge risk that a negative encounter at this crucial age could have a long-lasting impact on the puppy’s emotional development. Protected contact can be useful if puppies are much smaller than the adult dogs, and use of a puppy pen or stairgate, for example, can allow puppies to interact with adult dogs without the risk of physical injury (Figures 7 and 8). All interactions must, of course, be very closely supervised, and the adult dogs must be tolerant and highly skilled.
Puppies can also meet friendly, healthy and fully vaccinated dogs from outside the household as long as infection control measures are in place. It may also be possible to arrange for puppies to meet other puppies of a similar size and age, but care must be taken to ensure that the puppies are not overwhelmed.
In addition to physically meeting other dogs, scent cloths can be used to help accustom a puppy to their own species. Cloths should be washed without detergent, rubbed over other dogs and then put in the pen for the puppy to experience.
Weaning is a topic that clients may require advice about.
Weaning abruptly or too early can cause stress for puppies and may have long-term behavioural implications (Slabbert and Rasa, 1993; Kikusui and Mori, 2009). Recent studies have shown that the natural weaning age is later than anticipated at around 11 to 13 weeks in free-living dogs (Pal et al., 2021). There is no need to rush or to wean suddenly, and if the hand-reared singleton needs additional bottle feeds, they can continue and gradually be decreased over time to enable as natural a weaning process as possible, without stress.
Early help by qualified and accredited trainers and behaviourists may also be advantageous as behaviour issues are common in singletons, even with the best care and attention. Puppies who have been hand-reared may be best suited to behaviourally aware and experienced homes, with existing stable dogs, to help mitigate for the deficiencies of their start in life.