Older dog urinating in one room of the house

I have a four year old sheltie that has been a wonderful dog since I
got her as a puppie but just recently (about two weeks ago) she has
started pooping and urinating in one room of the house every night.
Every time I clean it up very well and apply enzyme treatment but she
returns to the same room the next night. Up to this time, she has never
done anything in the house before. Does anyone have any possible
explanations or suggestions?

Alison...

She still is a wonderful dog , she's just got a bit of a problem.
Get her check by a vet in case there is a medical reason for this.
What is her routine at night? When and where is she let out and where
does she normally sleep?
Could anything have scared her such as a thunder storm, any noises
outside the house. Shelties can be nervy.
Make sure she goes to the toilet last thing, go outside with her or take
her for a short walk.
Alison

Janet B...

vet check is in order. So is blocking access to the room, as part of
behavior modification.

pfoley...

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Have there been any changes in your family lately, i.e, new baby, new job
and dog being left alone for hours, less attention given the dog, etc? I
have heard of some dogs doing that to get more attention. Is the dog
getting out enough? I would take the dog to the vet to eliminate any
physical problems.