My dog mated a bitch 2 weeks ago.  Yesterday he needed to  go out more often  and sometimes when he wee'd he seemed  to crouch down rather than  lifting his leg, (but not a puppy boy wee either). and this morning I have gort up to a couple of wees in the kitchen and  there seems to be  blood in one of them. Very unlike him to wet inside.
I will be taking him to the  vets  later  as I presume he has some sort of urinary infection but just wondered  if he could have caught somethiung from the bitch?

Yes they can and do.

Yes there are: http://www.vetinfo.com/sexually-transmitted-disease-dogs.html

We are fortunate that we don't appear to have the virulent and notifiable Canine Brucellosis in the UK.  Certainly it is an issue in other countries and the lady whose dog I am using in USA has her dog tested before he has any' lady' visit him.

This might be another reason that so many people in the US prefer to do a fresh AI rather than allow natural service, as this bacteria can make a dog sterile.

http://www.vetinfo.com/dencyclopedia/debrucel.html