The biggest thing to watch out for is dehydration, especially when hunting with the dogs during autumn when the weather can be still quite warm. Dehydration in dogs occurs when the body loses more fluid than it’s taking in. It is normal for a dog’s body to gain and lose water throughout the day. Panting, breathing, urinating, defecating, and evaporation through the paws (dogs do not sweat in the same way humans do); this all contributes to normal water loss, which your dog compensates for by eating and drinking.
If you suspect your dog is dehydrated, first make sure he drinks fresh, cool water. Do not let them drink from puddles or drink too much in one go as this can make them vomit and this in turn this will dehydrate them even more.
There are a number of rehydrating solutions available and it is a good idea to carry a bottle or two just in case, as many of these will be more palatable to the dog and therefore encourage them to drink. The best way to protect your dog from dehydration is to make sure he doesn’t reach that condition in the first place. Now, depending on the weather and temperature, as well as the activity level of your dog, it will need more water on some days than others.