Answer

Hi John
If the rash involves the skin surrounding the vagina it is likley to be a contact dermatitis. So she may have sat on something that has caused the reaction. Common causes are plant species, particularly creepers and ground covers. If your dog is mainly indoors it could be a floor detergent or new rug. You should think about where she has been and what changes have been made lately. Sometimes matting of hair can cause it (as you've indicated), particularly if some faecal material or urine has contaminated the coat. Check that she has not developed urinary incontinence (bed wetting) as this can be a big contributor with urine scalding the skin.
Because the coat has now been clipped away this will help clear the rash. If necessary clip any remaining hair that still covers the area or get your groomer to trim it a little shorter. If the skin is moist and weepy you should now bathe it with a saline solution (1 teaspoon salt per pint cool water) and pad it dry with a soft cotton cloth afterwards. If you have an anti-histamine or cortisone cream you should apply that. Otherwise vitamin E cream (from your pharmacy) is very effective. Continue to bathe (whilst it is still moist) and apply the ointment twice a day until it responds.
These rashes sometimes become secondarily infected and can need antibiotics. If it is not responding and in particular if it gets smelly or she seems unwell with it you should have your vet assess it.
Now you said the rash was around the vagina. If it simply involves the vulvar itself and into the fold of skin that surrounds the vulva it may be a vulvar fold dermatitis. In this case bacteria cause an infection within the shelter of this fold. It will be necessary to clean this out well with the saline solution and ensure it is dried well. You must pay attention deep in this fold. So you can understand what the vulvar fold is this link has some pictures
http://www.acvs.org/AnimalOwners/HealthConditions/SmallAnimalTopics/VulvarFoldDermatitis/
Again vulvar fold dermatitis sometimes requires antibiotics but it is also an ongoing problem that requires long term management.
I hope I have been of assistance. Please contact me back if I can help further.
Regards, XXXXX

Expert:	Dr Pete
Pos. Feedback:	100.0 %
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Answered:	1/7/2009

Cat Veterinarian

Bachelor of Veterinary Science (University of Melbourne, Australia)