Mate - it will cost you a dollar to pick up the phone and call a local vet, just describe the symptoms to them, and they can give you some advice. They may or may not think that coming to physically assess the horse is necessary.
But seriously, it is sheer laziness to not pick up the phone and talk to a vet for 5 minutes. My vet is on speeddile on my phone, the slightest little worry and I call him to discuss. We have a good relationship, and he's not money hungry so won't come out and charge me unless he feels it absolutely necessary.
Just call... it's not going to hurt!