Kc if your dog has acidosis or the screws mate in can and is quite serious and can take some getting over, in severe cases it damages internal Organs.
Try and source some Dufalite and use this after very hard work especialy if your dog looks in distress.
Its caused when a dog is not Fit enough for the work being asked of it or and when its hot or a dog is distressed - exited barking ect before or after Hard work.,
If its just happened get it to a Vet and on a Drip, once home put a heat lamp over it at nightime till it starts putting on weight.
Plenty fluids and Rest.
It will take quite a