If you suspect your dog has a broken leg, restrain it and tried to calm it down. A broken limb will dangle below the break. Do not look for swelling since it may not be evident immediately following the break.
If help is available, have someone sit with the dog and keep it calm; immobilize the leg (or keep the dog from thrashing his leg), while you look for proper splinting material.
Splinting materials: wire coat hangers, wooden stakes, cardboard tubing, and other semi rigid, non-pointed material will work. You will also need gauze, tape, and ice.
Before you splint your dog’s leg, muzzle it first. When you handle your dog’s leg, the pain may cause it to strike at you, even if your dog is usually docile. Then check the area around the wound, looking for signs of blood, which may indicate a compound fracture. This is very serious, and you must immobilize the leg, not allowing it to move. The jagged ends of the bones can possibly sever major veins and arteries, if it has not already done so. If there is severe bleeding, priority must be taken to stop the bleeding. After that is accomplished, proceed with the splinting.
When you splint the leg, try to leave it in a neutral position (not straight, not at a sharp angle), and then bend the wire coat hanger, or other semi rigid material, to conform to the angle of your dog’s leg. Carefully place the hanger against the leg, and gently but firmly wrap the gauze around the leg and the hanger. Anchor the ends with tape, making sure that you do not apply the tape onto your dogs fur. Secure the splint by taping both ends of the splint, and then at least two other places, with at least one immediately below, and the other immediately above the break. Apply ice to the area around the break to reduce swelling.
Take your dog immediately to your vet or the nearest emergency pet hospital. If there is someone available to drive, it will allow you to hold your dog, calming it down, and allow you to immobilize your dog’s leg as much as possible. If you have to transport your dog by yourself, it is vital that you place your dog in its crate, securing it to the seat with the seatbelt or bungee cords. Do NOT place your dog in your lap, or next to you on the seat!
Note: make sure you have either your credit cards, cash, or checkbook with you since many vets, and emergency pet hospitals, will require payment before they treat your dog.