a very uncomfortable subject and embarrasing is this premature ejaculation and unfortunately there arent much good help out there for it i speak from experience ,observation, and many friends who experienced it. it's the same for all animals and human. what i noticed by getting infected to pinworms mostly (maybe other parasites as well) a very healthy male suddenly manifests this uncomfortable condition other symptoms of infections are nail biting picking the fingueres skin and nervesness exessive saliva. pinworms effect the nerves somehow.1 should be completely free of them for at least 2 weeks to notice normal intercourse again. sorry for my bluntness but i thought it will help some1 somewhere. most doctors have no clue what causes premature ejaculation. it might be the mindset for a small percentage but what i just wrote is the main cause. good luck. be safe.