Depigmentation of dog's nose

[babykat]

Lately, I noticed that my 10-month old Shih Tzu's nose has some areas that are turning from black to a lighter color (sort of pinkish brown). Area affected is just under her right nostril up to her lips.  The areas are not extensive but I'm worried as to what might be causing this.

Aside from this lightening of a portion of her nose, she is her usual self.  After the hairball incident mentioned in my previous post, she is back to her normal ways.  She has good appetite, has been drinking water, her urine and poop are ok.  She loves to play.  She was also previously diagnosed with fungal infection of the skin and that was what was causing her to have brittle hair and itchy skin.  She was given an anti-fungal shampoo and although her hair still isn't as it used to be, she has been shedding less and itching less.  I switched her food from Royal Canin to Canidae recently

[Ghilly]

In the absence of plastic bowls, it's difficult to say what could be responsible for a bleaching of your dog's nasal planum.  There is a condition called vitiligo that is responsible for the bleaching of pigmented areas.  It occurs when the melanocytes, the cells responsible for producing color, die or do not function for some reason.  Possible causes include but are not limited to autoimmune conditions, viruses, it could be genetically carried.  Your vet may be able to offer some other suggestions, but as long as your dog is behaving normally in every other respect or there are sudden, dramatic changes in the nose or in the dog's general demeanor, I would think that this is something that could wait to be discussed at the dog's next well-puppy visit.  Just keep a close eye on it and make sure there are no ulcerations or other changes (besides the color) in the nose leather until your vet gets the opportunity to examine it.

Ghilly

[babykat]

Thanks.  I don't use plastic bowls when feeding her.  Her bowl is made from stainless steel.  As far as I know, she hasn't had any scratches or wound on her nose, and it's not even the top or bridge of the nose that has changed color, but the area starting from the nostril going to the lips.  It's only on one side of her nose.  When she drinks from her water feeder, that side almost always gets wet from the water dripping.

[Ghilly]

What kind of bowls do you feed her from?  If you are feeding her from plastic bowls, there is something called plastic bowl dermatitis that can be responsible for the black on the nose leather turning pink.  It's not serious, and the pigment will usually return once you stop using plastic bowls.

The problem with plastic bowls is that from the dog's teeth and from dry food scraping on them, eventually they get scratches in them.  These scratches can be very small, hardly noticeable to the eye, but they are still there and they begin to harbor bacteria.  Even though you may scrub her bowls after each meal you can't get every bit of food from the scratches, and the bacteria that build up in the scratches can and do sometimes cause a problem.  Some dogs lose the pigment in their nose leather.  Others have what appears to be an acne-like thing going on around their lips, kind of like doggie cold sores.  And even without the microscopic scratches, plastic just by itself is porous and can harbor bacteria even if not scratched up.

Now, if she isn't eating from plastic bowls, noses can turn pink from injuries like scrapes or cuts.  It could also be from the fungal infection, although it's more likely that it would have turned pink while she had the infection and not after it's gone.  Although you did say that while she is better, she is still not 100% after the fungal infection, so that could also have something to do with it.  

I wouldn't worry too much about it.  Unless the nose starts to ulcerate or show more signs that there's something wrong, I would just bide my time and wait for the pigment to return.  It mostly always does.  

Ghilly