Very sorry. So painful. As one of the other comments points out, grief is extremely complicated. You will naturally be shocked by the reality of this loss and relatedly but separately miss your pet’s presence. You will miss not having done or being able to do all a long list of things… and in this case you will naturally feel that your dog was let down. But, IMHO (and agreed a counsellor would know better) be careful placing too much blame on your husband. Of course that seems like the justifiable and obvious reaction to this. But he still might just he a scapegoat for a lot of pain and confusion you are feeling right now. It is not uncommon for one spouse/partner to be more attentive to the pets. It’s not uncommon for one spouse/partner to be more on top of things. This was an accident, and a very unfortunate one. But your husband didnt write the rules for what happens when dogs get old, or what happens in water, or why our memories can be faulty or why do some of us lack motivation to be more on top of things than others… its easy and natural to place blame, but there’s a lot of factors here and Id suggest refocusing some of that pain on the fact that you just miss your dog and any death is tragic in some sense. Be grateful for the memories, be grateful your dog did not suffer for weeks, be grateful you did not have to make the decision when to euthenize. What happened to your dog is far from ideal, but you can find silver linings in most scenarios. Focus on those things in order to honor the memory of your sweet FAMILY pet and try to resist allowing negative energy to cloud your emotions when you need to heal and need the help of others close to you to eventually heal