hair discloloration turning coarse

Question
our poodle had a dark spot appear on his lower back, hair turned kind of coarse, now it has spread down his whole back, the hair is thicker then the rest of his hair, not in any pain rub the area no problem, got him groomed his back looks like he has a dark line going up his back hope you can help us, might have to take him to the vet if can't get answers. Thank you for your help

Answer
Hello Rafael and Cheryl,
I wish I had a better answer for you, but without being able to see your dog I can only guesstimate as to what is going on with him.  Dark spots on dogs can come from a number of things from Medications to Allergies and even diet.  
You didn't say how old your dog is, but if he is over 4 yrs old, then he has already gone through his coat change.  Poodle puppies will have a softer more wavy hair that turns curly and coarse around 1-2 yrs of age.  Older dogs can get age spots just like older people sometimes get and this can also cause the hair to be more coarse.  
You didn't mention if he was scratching or biting at the dark spots, or if his eyes are runny.  If so, this could be a sign of allergies.  Now is the time that dogs will start to get allergy symptoms, so this could be what is bothering your dog.  I would go ahead and at least call your Vet to see if they think this is something that needs to be looked at or not, just to be on the safe side.  

I hope this helps you some.  If you have other questions for me, please feel free to ask me.

Thanks for using AllExperts.com,
Kim