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September 10, 2020 – We all can relate to and understand the extreme sense of loss and grief when we, our friends  and family members lose a beloved companion animal. Less understood is whether or not our pets grieve after a similar loss. But many people who own multiple pets report changes in the behavior of remaining animals following the loss of a companion animal in the home.

In a recent Morris Animal Foundation-funded study, Australian and New Zealand researchers surveyed 279 owners, investigating changes in behavior in dogs and cats that had recently lost a companion animal in their household. The survey helped document owner-perceived behavioral changes in 414 surviving pets, split evenly between cats and dogs. Behavior categories include changes in affection, feeding, sleeping, vocalization, elimination, aggression, and territoriality.

While many of the reported changes in behaviors were similar between dogs and cats, there were some key differences. For example, cats were more likely to increase vocalizations than dogs and dogs were more likely to change their eating patterns following the death of a pet in the home.

The team’s findings include:


Increases in affection were by far the most reported observation by owners, with 74% of dogs and 78% cats in the survey displaying more affectionate behaviors with their owners. These behaviors included a need to be closer to, or demanding more affection from, their owners. But for a few pets, just the opposite happened. About 10% of dogs and 15% of cats sought less attention from their owners.


While some dogs and cats reduced their consumption of food after the death of a companion animals, dogs were more likely than cats to increase consumption of food. Interestingly, dogs that lost another companion dog were more likely to slow down the speed at which they ate food, not necessarily the amount eaten, than dogs that lost a cat companion.


More dogs than cats experienced changes in sleep patterns. Surveyed owners reported about 42% of dogs experienced changes in sleep behavior, with 81% of those sleeping more. 


Cats seemed to be more prone to changing how they vocalized, both in frequency and volume, than dogs after the death of a companion animal. Vocalization patterns usually returned to normal in about two months or less for most cats.


Most cats and dogs in the survey did not show any changes in the location of elimination or toileting, suggesting this may not be a key behavior change following a loss of a household companion animal.


Few pets in the survey exhibited increased aggression following a loss of a companion animals. The ones that did were more often cats showing increased aggression toward other animals within the house. Studies show that aggressive behavior is one of the most obvious signs of stress in cats. These findings leave the door open to debate if increased aggression is a hierarchical or territorial behavior, and if cats are just setting up new boundaries in the household.


Sixty percent of dogs and 63% of cats displayed a change in territorial behavior, of which 50% of these dogs and 56% of these cats sought out the deceased pet’s favorite hangouts. This behavior usually resolved itself in about two months or less. 

Reactions to Deceased Body

Many owners believe seeing the deceased body will help their surviving pets understand that a loss has occurred. Owners surveyed reported 58% of dogs and 42% of cats viewed the deceased body of their companion animal. No distinct behavioral differences were noted by owners between the animals that saw the deceased body and those that did not. However, many of the animals that saw the deceased body of their companion were prone to sniff and investigate.

Behavior and Grief

The researchers note the behavioral changes observed in this study parallel similar behaviors observed in separation anxiety. The behavior changes tended to resolve at different times, with changes in affection subsiding between two to six months following the death of a household pet, for both dogs and cats and most other behaviors gradually stopping within two months of the loss.

The team hopes these findings open the door to more discussions on how animals cope following the loss of a household companion animal and maybe signs to watch for and discuss with your veterinarian. It is important to note that many of the grief behaviors described in the study, including changes in sleeping, food consumption, vocalizations, also can be associated with health issues.

Morris Animal Foundation has funded more than 50 behavior studies over the years, from our first studies on behavior changes due to aging to our two most recent proposal calls for horse and cat behavior studies in relation to the health and welfare of these species. As animals can’t directly talk to us, owners need to watch for both subtle and extreme behavior changes in their pets after the loss of a household companion. Understanding what is expected behavior can help ease both owners and surviving pets through the grief process.



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