Cocker spaniel pregnancy?

Question
I have a 6 1/2 year old female cocker. An unknown breed of dog jumped 6 foot fence and joined with her. Can you give advice about the best way to deal with this. What are the chances of her being pregnant? Is she too old to have a litter? Would it be better to have her de-sexed and when is the best time?

Answer
That would depend on what part of her heat cycle she was in. Most of the time when a dog is receptive they are at their fertile period.
So the chances are very good that she is pregnant.
I don't know how long ago this happened but some vets can give them an injection that is like the morning after pill if it's within 24 hours.
However, the best thing you can do for her is get her spayed and get it done next week or tomorrow.
Yes it would be better to neuter her and you might even save her the pain of having future mammary tumors from not being spayed for 6 yrs.
So the best way to proceed is to make the appointment tomorrow to get her spayed.