Cut feet and pads are something of an occupational hazard for dogs and although prevention is best, injuries cannot always be avoided.

There are two main considerations with an open wound on the foot

Bleeding and longer term healing.

First aid should be focused on stemming the bleeding. If that can be done whilst also cleaning the wound then that is best but if cleaning is not practical or possible in the first instance then controlling bleeding should always be the priority.

In the short term wound contamination is not an immediate problem and it can be addressed later whereas uncontrolled bleeding can obviously be very dangerous and needs to be controlled as soon as possible.

Bleeding is best controlled by applying pressure to the area for several minutes, you can do this by pressing a wad of material against the bleeding wound or just the pressure of your fingers and thumb if nothing else is available.

As soon as possible apply a bandage dressing to the wound. Apply the dressing to the whole foot as the toes may swell if they are left out. Try to apply even pressure with the bandage to keep the wound from bleeding.

If the bleeding is controlled this way then have your vet examine the wound as soon as practical within the next 24h and monitor your dog closely in the meantime. 

If the blood continues to come through the dressing then you should contact an emergency vet for veterinary attention as soon as possible.

If there is to be a delay before the vet can see your dog then take care to remove and replace the dressing every few hours to prevent the risk of the pressure bandage preventing effective circulation of blood to the foot and toes.

A tight bandage applied for too long can cause irreversible tissue damage.

If you remove the dressing temporarily and the bleeding is stopped then you could attempt some gentle cleaning with cool boiled salty water either rinsing the wound with a syringe if available or immersing the foot in a pan or bowl and gently cleaning.

Suturing of wounds to the foot is not always necessary, many will heal naturally without stitches. Your vet will advise you on the best course of action depending on the position and severity of the wound.