I don't really know what to do about it. He'd been acting weird, but he was always a weird dog, I just thought he was being a slightly odder version of himself. Turns out he was dying. I sat next to his body for hours thinking he was just asleep - I even commented to my wife in a video call about how still he was being. I should have realized, but I didn't know he was gone until I reached down to pet him. I don't even know what happened and we're having him cremated so I never will.
Fortunately my wife and kid are out of town so my kid didn't have to see his body and my in-laws helped with all the physical stuff so I didn't have to struggle with that. It feels wrong to have all of these emotions days later but there they are. I keep expecting to see him every time I turn a corner and, while sitting in my recliner, I keep starting to reach over to scratch his head or pet him.
We had to put our dog down on monday too. Our 8 year old was always a bit temperamental specially with new people and there was few cases where he tried to bite strangers who got too close for his comfort but we let that slide, just thought that he didn't like those persons and nothing serious happened. And these cases have been more and more frequent lately and he showed aggressive responses even towards myself and my wife few times if he didn't immediately recognize who was holding him back or touching on a 'wrong moment'.
At sunday we had a family party and he was really angry right from the start. Growling to people, showing teeth and even managed to bite my sister and sister-in-law during the party (only small scratch but still). At first we thought that it was just a stress from a lot of people around, hot weather and being held on a running rope but even after a party and a multi-hour break he was still unpredictable. Our kids was always been "protected" by him, but now there was growling, showing teeth and generally unpredictable behavior.
So, we did the shittiest (but correct) decision in ages and decided to put him down. The trust was gone and we didn't want to wait until something more than few scratches happened. I guess it's a part of owning a pet, but it still was a sad day and now he's gone. We suspect that maybe he had a tumor or ilness or something which caused the sudden change in behavior since the dog we used to have would've never been angry to our 'pack'. We didn't bother to make any tests, as in the end it doesn't really matter.
And the whole family sees him around the corner all the time and checks if the water bowl is filled or if he needs to get to outside. And we listen for familiar sounds of paws and claws wandering around the house, hopping on the couch, drinking water and making a mess around the bowl and so on. And the whole house feels a bit empty.
It sucks. I'm sorry for your loss and I know what you're feeling. All of the feelings are valid, specially after just few days. Even if they are not humans they're still a part of family and have been around for years and years, of course their absense leaves an empty space.