You might also want to take your dog to a good vet, one who has an interest in allergies. In several of my cats and dachshunds, mine diagnosed blocked tear ducts and/or sinus passages due to allergies. Not sure what the exact med was or the dosage but after giving injections to all my affected critters, the tearing cleared up and hasn't come back except briefly when we get a high pollen count. That was 2 years ago. Well worth the office call and med charges. Once you clear up the problem(s) causing the tearing then the other problems should also pretty much disappear, too.
I've noticed that this doesn't seem to be a problem for my larger dogs, especially my drug detection dog, a chocolate lab who gets into some really funky/weird places when we're on duty.