You hate being overly cautious but what you describe are symptoms of an obstruction....There is "care credit" if you don't have the money to pay for the visit....it is credit available on the spot at animal ERs.
With little pups things can go south very quickly.
NAPWDA Certified Cadaver Dog
Waiting at the Bridge (italics
=GSDs) (hemangiosarcoma=blue):Grim , Cyra, Toby
, Rainbow, Linus, Oscar
, Arlo & Waggles