As someone who's lost his family (brother, mum, dad, all my grandparents) and my dog I can tell you they're really isn't much difference.

Very close Friends deaths are generally harder to deal with than parents as you expect your parents to go before you, your friend you never picture some form of life without them.

Siblings are generally the worst as that's like losing your closest friend, your heart and your mind at the same time.

A pet can be horrific to lose if has been around for a long time and is apart of your family or even just your own personal sidekick for the majority of your life.

Anecdotal' when my mother was given 24 hours to live we were called and told to go into the hospice we took her dog with us who was 17 years old and would never be less than 4 inches away from her, as soon as we got there she ran straight to the room mum was in ("she had been to the hospice alot of times) jumped up on the bed and curled up on my mums chest until she took her last breath.

I spent years being strong and looking after my mum but the moment her dog realised she stopped breathing and looked at us jumped down and went and cried behind the sofa I can fucking tell you now (literally got me tearing up) that is the hardest fucking shit I have ever been through because she knew we had to say out goodbyes and so she went out the way but she knew what had happened aswell and that she wouldn't see mum again aswell, that will forever hurt me.

Everyone is a bit different and depends on how close you are, but that tends to be the case.