can an infection cause a dog to shake?

I have a 9 year old mastiff, for a few years he has had an infection between his legs, he has been on antibiotics for it, it will clear up and come back. Recently though he has been shaking and not acting right, he has become scared of our washer and dryer which he never was before but worse than that he has been shaking and just not been himself. Could it be caused by the infection?

Shaking in a dog is a sign of pain. You said that he's been treated more than once for his infection and it keeps coming back? To me, your vet doesn't really know what is going on with your dog and is throwing antibiotics at the problem. My dog was misdiagnosed by his last vet twice with having a UTI yet when given the steroids and antibiotics he would recover for a few days and then get sick again. I took him to my sons vet and he told me that my dog never had a UTI. He had a spinal injury. Now he is fine. A little arthritis but, it's manageable. My suggestion to you is to get a second opinion from a different vet. Not all vets are good ones. Your dog should not keep having this infection coming back after treatment. Get him a proper diagnosis from a different vet. A new vet may be able to diagnose your dog properly and end this cycle.