I would definately (as already suggested) have the dogs anal glands looked at. Have them expressed "properly" by the vet. The vet will express them from the inside instead of squeezing from the exterior. By squeezing from the exterior you can build scar tissue and a dependance on having them expressed in the future. You may also want to discuss diet with your vet. I have never had a dog with anal gland problems, and I have never squeezed any of my dogs butts at any age
I think with proper diet you can help your dog to express their own glands. When you have too many soft bowel movements this is not helping to express the glands naturally. Also, as a side note; some breeds due to thier unnatural conformation have problems expressing their glands due to their conformation. We see this most often in small breeds and expecially in Cocker spaniels (we have no Hairless breeds coming in for grooming
)...so your dog may be predisposed to anal gland problems due to conformation. If you will have to express the glands in the future have your Vet show you how to do it properly.
I do recommend that you have your dog looked at by a Vet...just in case the glands are impacted, if they are impacted they will need to be treated properly for infection.