Polydactyly in Dogs

While this condition can be quite common in cats, it doesn’t often happen in dogs except in a few breeds where it is encouraged through breeding (Great Pyrenees and Australian Shepherd dogs). It is also quite rare to have both the fore and hind limbs affected although, again, there are exceptions such as the Norwegian Lundehund. Most of the time the extra toe is not jointed and is mostly soft tissue with some bone. It only becomes a problem if it catches on things causing injury.

Polydactyly is a rare occurrence where your dog is born with an extra toe or toes. It’s not considered a problem unless it catches on things.

• Most breeds of dogs have four main toes and one dew claw on the front limbs, with four toes on the back
• If your dog has more than the normal number they are considered polydactyl (poly meaning many, and dactyl meaning digits)
• Often just considered an unremarkable trait, it is not really a problem unless it hinders other toes or the leg of your dog 
• The polydactyl digit is usually located up higher on the leg from the other toes 

Interestingly, the condition of having extra digits or toes is not confined to just dogs and cats, mice moles and even humans can sometimes have these additional appendages. 

Types  

• There are two types of polydactyly in dogs; those that are bred intentionally to exhibit this trait while in others it is the result of a rare autosomal recessive genetic condition that results in the extra toes 
• The Norwegian Lundehund is a small dog that is a true polydactyl with six toes (instead of the usual four) with all of them fully formed, jointed and muscled. This dog is adapted to climb narrow cliff paths in Vaeroy where it originally hunted the Puffin bird
• With breeds of dogs that work on snow or uneven ground it is considered an advantage to have extra toes

• In both dogs and cats, limb formation occurs from the 23rd day of gestation and is an intricate process which involves the formation of the limb bud, limb elongation, and the formation of the toes, bone and joints 
• Some animals that vary in the number of toes such as your dog, are considered a ‘throwback’ to an ancestral form
• Mutations of certain genes or the way the genes are expressed are often a cause of this unusual condition
• Polydactyly in your dog is often considered to be caused by a genetic variation

Usually this condition is noticeable from birth. Often the paws with the extra toes give the new puppy a ‘big foot’ look. If you have chosen a pup with this condition, unless your new friend has trouble walking or is limping, then there is nothing to worry about. You can have your pet checked by a veterinarian who may suggest an x-ray to see how the extra toe or toes are attached. Most people consider their pets with extra toes as ‘special’.  The physical examination should be sufficient in this case; however, if there are other health concerns, then a full lab workup may be ordered.

Often the extra toe on the hind limb is situated higher than the other toes and doesn’t come into contact with the ground when your puppy or dog runs and plays. This extra toe is often called a dewclaw. It is only considered a problem if the nail on that toe is not clipped often enough and starts getting caught on things when your dog moves. If this happens, your dog can either be injured by being caught and stopped suddenly, or the toes suffers tearing from the limb causing muscular damage. Keeping the extra claws trimmed can avoid this from happening.

Unless your dog is having problems caused by the dewclaw or the extra appendages, then there is no need to do anything about them. Often the dewclaw is attached by bone or sometimes it may only be attached via skin. Keeping the toenail trimmed regularly will keep it from causing any rubbing or sores to the rest of the leg and foot, and it will keep it from being caught on anything. These polydactyl toes can be removed surgically to keep them from causing any problems to your dog.

Some owners of dogs that are non-working dogs or who are not involved in dog shows have the dewclaw removed as it is a simple surgical process and your dog will recover quickly from it. But if you dog is a show dog, some official bodies require the dog to be registered with the requirement that the dewclaw(s) are present. A number of ancient shepherding dog breeds were polydactyls and, as stated above, it can be an advantage in snowy conditions. The Great Pyrenees is the most known polydactyl canine and can even have six hind toes. This is one condition that is not a great concern for your dog.

If your dog does have surgery to remove any extra toes/dewclaws, the down time is remarkably small. Once it has been removed, stitched if needed and dressed, your pet will require little recovery time. Just ensure the dressing remains clean and care for it once your dog is home. Keeping the dressing dry and cared for as advised by your veterinarian will avoid any infection from setting in.

If you opt to leave the toes, just ensure that the extra claws get trimmed as well as the others. These extra claws don’t always get worn down as the others do, especially if they are not in contact with the ground, so make sure you are aware of each of your dog’s polydactyl toes and know which way the nail is growing. Other than that, just enjoy your very special dog.