July 17th, 2020
Humans are not the only animals who grieve and mourn the loss of other individuals, family members or friends. Surely, companion animals do as well. There are numerous observations among wild animals such as elephants and wolves and coyotes, various great apes and other non human primates, and even cetaceans, such as dolphins and whales, that they grieve the loss of close friends and family members. We're not the only animals in the grief and mourning arena.
There are a lot of different ways you can know that if your pet is grieving. Look for behavioral changes. In dogs, you'll often see that they become less playful. They may mope around. You can read their body language, their tail position, their ear position, they may stop eating and they may just show a lack of interest in things that used to interest them, such as going for a walk or to a dog park. They may just exhibit a feeling of general malaise.
So, behavioral observations are really critical. When they're correlated with the loss of a close friend, sibling or mate, you can really use those as markers that something's wrong. Another individual is no longer here, there's a change in their daily pattern, there might be the lack of a playmate, or the lack of certain odors, or just the lack of company. You know how dogs and cats and other animals can just like lying next to one another, touching one another.
August 19th, 2020
Yes, pets grieve when another pet or a person in the home dies. There are bonds and love just like humans. I had two cats that were littermates and the boy died and his sister had been mute her entire life until the day he died. I thought there was another cat in my house and it was Olivia meowing and meowing, crying, grieving, looking for her brother Sapphire. It was heartbreaking.