My dog refuses to go up the stairs
My family and I have a 4 years old German Shorthair Pointer who is all of a sudden refusing to go up the stairs.
We usually have to put a leash on him and drag him up, but even then he stands by the bedroom door wanting to get out. We cannot leave him downstairs because we just got new furniture and he has a nasty habit of wanting to pee on everything.
He is a bit skittish and gets freaked easily by things such as our vacuum, but it's always with his first encounter with the object. He has climbed these stairs countless times without any problems and we can not figure out why he is afraid of them now.
Dragging him is probably not making him feel any happier about this... can you isolate him from the new furnishings (in the kitchen, for example, or in his crate if you've gotten him used to considering the crate "his room") overnight?
If you are in the habit of dragging your dog by the collar, PLEASE STOP. Please get a harness suitable to your dog's size. Dragging your dog and jerking a collar that is around your dog's neck can cause serious damage. Consider holding (embracing) and picking up your dog to calm them and move them when needed.
All of a sudden = go get him checked by a vet
I can see only two reasons your dog would suddenly refuse to climb the stairs: he got hurt and it is painful for him to walk up the stairs or he had a negative experience and learned to be afraid of the stairs (or a combination of both: he got hurt in the stairs, that's the negative experience and now it's painful as well).
In any case it is worth checking with your vet.
Dragging him with a leash = animal abuse
Why would you do that?
If he's scared you're just reinforcing that fear and you're making the stair and your presence a negative experience.
If he's got a physical problem (might be temporary, a sore muscle for example) you're probably hurting him even more, you're creating a very negative experience and that means that even if its physical problem is temporary, he'll learn to avoid the stairs even when he'll get better.
Of course I can understand that at some point you might need to take him upstairs. Why don't you just carry him up the stairs in your arms? It is definitely possible to do that with a German Shortair Pointer (according to Wikipedia the weight of a male is around 25 kg). If he doesn't let you do that, train him to like it.
Away from the stairs, lift him up and give him some treat, slowly increase the duration and treat.
As for everything training is the key
Now that you had him checked by your vet and that you stopped making things worse, you can start helping him to be confortable with the stairs again.
That kind of training is called counter-conditioning.
The idea is simple but it requires a lot of patience. You simply reward every (tiny) steps taken in the correct direction. If you get your dog interested in some treats, attract his attention and move closer to the stairs, reward him for following you and approaching the stairs. When he won't approach closer, throw a treat away from the stairs, and reward him for coming back, do that little game for a while, and then reward only when he takes one more step. You get the idea.
You can also do the same game elsewhere were he'll agree to climb the stairs. That way you reinforce his efforts and you set him up for success.
At the same time I would suggest to reinforce him for being upstairs. Make upstairs be his favorite place to stay.
You can also reinforce him when you take him up the stairs.
With patience and a combination of these exercices you'll start to see improvements.
I do agree with your answer and gave it my vote, I don't think that using a leash equals animal abuse. I will say that too may people get aggressive because they're ignorant of how to properly correct a behavior and misuse those tools, but there are some issues that you can't treat your way out of. I try to be as positive with my animals as possible and counter condition scary situations with treats, but my dog is never going to be okay with going to the vet and she's never going to enjoy getting her nails trimmed. So while I try to train positively, I will use the leash as a reinforcement.