If you have found a dog, or fortunate enough to have your dog returned to you, re-hydrating and vital nutrition is crucial especially if it has been on the run or lost for days or even weeks. it is natural to give a warm welcome but rehydration is important.
The dog is likely to be very thirsty but not allowing it to drink the whole bowl at once is prudent because over zealous drinking will consume air along with the water and could cause bloat, which may be very dangerous.
The solution is to provide water in small amounts every 10-15 minutes and if their gums feel dry or sticky, try electrolytes.
This might sound expensive but there really is no need to go out and buy electrolytes,here is a good cheap homemade recipe :
Two pints of fresh tap water.
1 Tablespoon Honey
1 Teaspoon Salt
Mix it all and store in the fridge, however serve it at room temperature and make a fresh batch daily.
3 Tablespoons for puppies/kittens
5 Tablespoons for pets up to 5 lbs.
¾ cups for pets up to 10 lbs.
¼ cup per 5 lbs. of body weight for pets 15 lbs. and more
When it comes to food, small bits often to ease their stomach back into digestion.
Once they are ready to eat, feed them soft and bland foods such as plain rice and boiled chicken, rice and scrambled egg (without butter or oil) etc.