Welcome! My name is Dr. Andy. I am a 2003 graduate from UC Davis, and currently a Medical Director of a veterinary hospital.
I am sorry to hear about this concern for Oscar.
First, record it!
If he doesn't do it all the time, best to get a recording, as you may need to show it to a neurologist or orthopedic specialist for guidance.
Front legs being splayed could be a result of a past injury you may not have seen, a neurologic problem, growing pains (panosteitis), or confirmation problems in the shoulders or elbows.
Another condition that can cause it, although uncommon and he seems a bit old for it, is swimmer's syndrome (doesn't mean he must swim).Swimmer's syndrome
This is another differential to consider that would suggest a developmental cause. Definitely, worth a veterinary evaluation to see if a specialist should be consulted or not.
I hope that information has been helpful.
Please remember to select Reply to Expert, if for any reason you need further clarification, have more questions, or were expecting a different type of answer. Prior to leaving a feedback rating, which I greatly appreciate so I am recognized by Justanswer for responding, my goal is to provide you the best answer possible.