right to your husbands points frfom my experience (which I wouldnt change for the worls) my dh didnt want a dog but is now as passionate a dog owner as me and in fact dog 2 was mainly his driving.
Responsibility, there is a lot, if you are saying you will take it all on that means you could never go away for the weekend and leave dh, he has to agree to some if you want a dog in your shared home.
Smelly house, my house doesnt smell, however I have yankee candles on the go all the time, the windows open all the time and the dogs get bathed if they start to get whiffy, some dogs breeds are smellier than other, my spaniel is a stink bomb.
Tieing you down, it really does, more than yoou can imagaine. we nearly cancelled our family holiday this year as I didnt want to leave the dogs, we cant go to places for the weekend, a few weeks ago we had a late night party and managed to get babysitters, had to get some one to check in on dogs, come home after 4 hours and stay up for an hour with them rather than falling into bed.
The house will be ruined, no it wont, but you have to do a lot of training to ensure this, and stuff will get ruined, like my brand new £60 shoes, and my 20 year old biker boots which are ireplacable and the kitchen cupboard and the skirting boards etc, you get the picture, however we dont mind because we love the dogs more tha anything.
Poo all over hte garden is ridiculous, unless you are a scruff, you pick up poo as the dog doees it, twice a day when they are older, who would want their garden covered in poo.
Cats, they can live together fine, mine have however left hme and now reside next door to be returned most evenings, but that is more down to nutty neighbour than the cats, whiole other story.
What I would say is you really do need him on board for a puppy, they are fantastic, love my dogs to death and they are my company when the kids are at school, they keep me kit, and stop me getting depression (infact got me over depression thats why we got dog 1) but there will be times when you wonder what you have done and if dh is against you this is when poor puppy is likely to end up being a problem. Would your dh consider an older dog? what breeds are you thinking off? this can make a huge difference to everything.