The death of a pet can be heartbreaking for owners, yet new research suggests that it may be equally gut-wrenching for other animals in the same household.
Published in the journal Scientific Reports, the study indicates that behavioral and emotional changes exhibited by dogs following the passing of another pooch from the same home could be interpreted as grief.
Grieving has been reported in several species, including elephants, great apes, and birds. Certain animals, like whales and some primates, have even been observed moving the corpses of dead relatives in what the study authors describe as “death rituals.”
Though rare, similar behavior is known to occur in wild dogs. Case studies have described the burial of young pups by wild wolves, while another report details the treatment of a deceased dingo pup by its mother and littermates.
To determine if domesticated dogs are capable of grieving, the study authors interviewed 426 Italians who had owned at least two dogs, one of which had died while the other was still alive. Using a tool called the Mourning Dog Questionnaire, the researchers obtained information about the behavioral and emotional responses of both pets and owners to the loss of a four-legged friend.
Overall, 86 percent of owners reported negative changes in the surviving dog’s behavior. When asked for more details, around two-thirds said their dog became more attention-seeking, while 57 percent reported less playfulness. Increased fearfulness and a tendency to sleep more were observed in 35 percent of bereaved pets, with reduced food intake reported in 30 percent of cases.
Around a third of owners said these changes persisted for two to six months, although a quarter claimed that the effects lasted for more than six months.
A closer look at the data revealed that dogs were 30 percent more likely to engage in “emotional eating” if they had a friendly relationship with the deceased pet, while reduced eating was more common in dogs that had lost a parent or offspring.
Behavioral changes were also more frequent in dogs who had shared food with the departed pet, possibly reflecting the way in which pack animals tend to synchronize their routines with other group members and are therefore susceptible to losing their way when conspecifics die.
The authors also report that “the level of fear in the surviving dog was positively correlated with owners' level of suffering, anger and psychological trauma,” and that pets were more likely to eat less if their owner was grieving. This, they say, may indicate “emotional contagion,” whereby dogs pick up on and adopt the affective state of their owners.
As an alternative explanation, the researchers hypothesize that the dismay of an owner may simply trigger fear insecurity in a dog. Regardless of the underlying processes, though, they conclude that “a dog may show grief-related behavioral and emotional patterns when a close conspecific dies, with aspects of the latter possibly related to the owner’s emotional status.”
Warning against the tendency to anthropomorphize pets, however, they sign off by insisting that “even if we recognize the importance of these results, we still cannot confirm it was grief.”