
Hi Nikki
welcome to the forum :)
Any chance your little lad has eaten somehting he shouldn't have? Pups are notorious for scavenging on all things disgusting in the garden, out on walks, etc and of course often steal things off the kitchen counter like butter, cheese, left overs and what not. Anything like this could have caused his system to get over active and produce sloppy motions.
I'd starve him for 12 hours then give him some steamed white fish or chicken. If he copes OK with that add some over cooked rice to this and keep him on that for a further 24-36 hours providing he's showing improvement. Then gradually, very gradually, reintroduce his original diet and by the end of the week he should hopefully have settled completely.
Providing you are happy with his health otherwise this should be sufficient. Is he drinking normally, playing, happy in himself otherwise? If you have doubts about anything then better to have him checked by your vet but if he seems to be OK in the main then a brief fast and bland diet is usually the most effective way to get things back on track.
HTH, best wishes,
Teri :)