This is what one Hometalker does to keep their carpets smelling fresh
I think the first thing to do would be, keep your little dog clean, with regular bathes. Depending on your local weather, whether cold or warm, if you could take your beautiful dog to a grooming 'salon'. Maybe their fur needs trimming in the hotter months?? I have 2 little dogs - and after their bath - they just love to go and sit in the dirt - while wet. My suggestion would be, is seek some information from your local vet. surgery. And also check out natural (not chemical) solutions for odour control.
ODOBAN works great for animal smells. Carpet should be cleaned first with a Bissell or other professional cleaning machine.
You need an enzymatic cleaner. Then OdoBan, which is a disinfecting deodorizer.