Toy Poodle Fur Discoloration

Question
QUESTION: Our 8 year old toy poodle was originally dark chocolate brown but faded to a light cafe colour at a young age. Three weeks ago I noticed a small patch of black fur on her lower back about half inch diameter. In three weeks this has spread right up her back. The underlying skin looks normal and isn't causing any irritation. On close examination there are some white hairs but mainly black. We haven't introduced any new foods and she isn't on any medications. Around 18 months ago she had severe poisoning after eating snail bait otherwise completely healthy. Any ideas on the sudden and rapid darkening of her coat?

ANSWER: Hello Tom,
The fading you are talking about is common and normal in a Brown Poodle due to the Fading gene present in the Brown color.  The spots you are talking about aren't as common and can be due to a number of things.  It can be from an injury, scratching, itching, or digging at the skin (which in itself can be due to a number of things), licking or chewing the hair which can cause discoloration when chemicals in the saliva mix with chemicals in the hair, diet, or even the water she is drinking.  
You say that she doesn't have any irritation. So I am assuming no injurys to the skin either.  You also said no food changes, so no allergies or chemicals in her food that would cause this.  Are there any new cleaning products that you may have started using recently?  New shampoos, laundry detergents, household cleaners, etc?   
It could be her water she is drinking.  Do you know of any chemical additions that your city may have added to the drinking water?  I know where we live, they recently started adding Anmonia to the water.  You might check your local Water Treatment Plant to see if they are putting anything new in your water.  Another thing it could be is if your neighbors have treated their yard or plants recently.  Dogs can be allergic to the chemicals sprayed on lawns and the spray can be spread through the air.  Another thing it could be is if you have used a Spot-On flea and tick treatment.  The chemicals in it can change the color of the hair.  
When the skin of a dog is damaged, the hair will grow in in the original color that it started out to be, and will gradually change color over time, (about as long as it took for your dog to turn the color she is now).   Are there any other places where her hair is changing color like this, or is it mainly on her back and lower back?  In between the feet pads and toes, and around the rear/vaginal area tend to be places where the hair can also change color.

I hope this helps you some.  If you have other questions about this, or other Poodle questions in general, please feel free to ask.

Thanks for using AllExperts.com,
Kim

---------- FOLLOW-UP ----------

QUESTION: We recently moved to a new area where ticks are prevelant. For approx 3 months we have employed a tick and flea collar which exudes a powder. The areas of her back which are changing color can't be reached by her mouth / teeth. As the house is brand new there could be new and strong chemicals present such as underfloor termite treatments. The land was virgin land however that does not preclude some sort of contamination from agricultural chemicals. I guess it is looking like some sort of chemical cause. We also have a red toy poodle with a faded coat. She also has a couple of spots on her back which are darker which I'm not sure were there before. Many thanks for your response, it's very much appreciated.

Answer
Hello again,
It is sounding like the collar could be contributing to her hair changing issues.  I really disapprove of the Flea collars because the powder is poison and it has to be deposited on the dogs skin to kill the fleas.  The only fleas it can kill are the fleas that get close enough to touch it, meaning they have to reach the neck.  Your best bet would be to use Advantage II.  The problem is that Advantage doesn't kill ticks, so you would have to get another spot-on treatment for ticks.  Frontline and Frontline plus (including the new product you can get from Walmart) doesn't work any longer.  You can try it, but its about like putting water on your dog.  You can use Advantix, but you need to make sure cats won't come into contact with your dog because Advantix can harm cats.
To the darker spots on her back, could her groomer have nicked her in those areas?  That can cause the hair to grow in darker because it damages the hair follicles, re-booting the hair growth.  

Again, I hope this was helpful to you.  Please feel free to contact me with any other questions.

Thanks again,
Kim