Iran is a diverse place and the level of religiosity differs significantly from one town to the one right next to it. I only knew of one other family that kept dogs in our small shahrestan, but they kept their dog in their "baagh" outside the city limit. I can't imagine having a dog in a place like Astaneh in Gilan even today. In Lahijan it's probably much better these days. Rasht never had a problem to begin with, neither does Anzali most likely. I've lived in Tehran and knew lots of people there who had dogs and had little to no problems. This is all like 18-20 years ago. As discussed, dehaat is a whole different story. Half of my family is dehati, so I'm well aware of how much they need and value dogs. In general, anyone who has a dog loves it. It's impossible not to. It's funny, over the years we had hardcore religious people working for us who in the beginning would complain "najiste, najiste(sic)" but would later form a seemingly closer bond with our dog than what we had with him. Overall, without the negative attitude I think both dog owners and more importantly dogs themselves would suffer a lot less in a place like Iran.
Regarding how much religion influences the level of violence, I think a lot. Just look at Hindus. It seems to make a lot of difference there. It really depends on what the religious prescriptions are for dealing with animals.
Also, I don't think anyone is trying to excuse mistreatment of animals in non-muslim countries. Even when it comes to dogs, there are puppy mills here with absolutely horrid conditions, but nobody is trying to be an apologist for what goes on there the way some people want to excuse certain disgusting practices in Muslim countries. There are so many organizations dedicated to just that cause in the west. Saying nothing can be done in Muslim countries in the immediate future is plain stupid. It wasn't long ago that people were consuming "bareh too deli" in Iran, but that's almost gone because people started to recognize how disgusting that was. I disagree with others. I think its exactly on this day that we have to post pictures like this, just to raise more awareness. Saying this is offensive is just being an apologist. We have changed, and we can change again, Muslim or not Muslim.