Feeding, Vetting, Deworming & Dewclaws

Our philosophy on feeding, deworming and dewclaws.

Do the Dew(claws)?

 written by M. Christine Zink DVM, PhD, DACVSMR

 

I work exclusively with canine athletes, developing rehabilitation programs for injured dogs or dogs that required surgery as a result of performance-related injuries. I have seen many dogs now, especially field trial/hunt test and agility dogs, that have had chronic carpal arthritis, frequently so severe that they have to be retired or at least carefully managed for the rest of their careers. Of the over 30 dogs I have seen with carpal arthritis, only one has had dewclaws.

If you look at an anatomy book (Miller's Guide to the Anatomy of Dogs is an excellent one – see Figure 1 below) you will see that there are 5 tendons attached to the dewclaw. Of course, at the other end of a tendon is a muscle, and that means that if you cut off the dew claws, there are 5 muscle bundles that will become atrophied from disuse.

Those muscles indicate that the dewclaws have a function. That function is to prevent torque on the leg. Each time the foot lands on the ground, particularly when the dog is cantering or galloping, the dewclaw is in touch with the ground. If the dog then needs to turn, the dewclaw digs into the ground to support the lower leg and prevent torque. If the dog doesn't have a dewclaw, the leg twists. A lifetime of that and the result can be carpal arthritis, or perhaps injuries to other joints, such as the elbow, shoulder and toes. Remember: the dog is doing the activity regardless, and the pressures on the leg have to go somewhere.

Perhaps you are thinking, "None of my dogs have ever had carpal pain or arthritis." Well, we need to remember that dogs, by their very nature, do not tell us about mild to moderate pain. If a dog was to be asked by an emergency room nurse to give the level of his pain on a scale from 0 o 10, with 10 being the worst, their scale would be 0, 0, 0, 0, 0, 6, 7, 8, 9, 10. Most of our dogs, especially if they deal with pain that is of gradual onset, just deal with it and don't complain unless it is excruciating. But when I palpate the carpal joints of older dogs without dewclaws, I frequently can elicit pain with relatively minimal manipulation.

As to the possibility of injuries to dew claws. Most veterinarians will say that such injuries actually are not very common at all. And if they do occur, then they are dealt with like any other injury. In my opinion, it is far better to deal with an injury than to cut the dew claws off of all dogs "just in case."

Figure 1. Anatomical diagram viewing the medial side of a dog’s left front leg demonstrating the five tendons that attach to the dewclaw.

--from Miller’s Guide to the Dissection of the Dog

If you'd like to learn more about dewclaws and to see them in action, check out the videos below!

What is the dewclaw? 

All dogs are born with a toenail on the inside of their front legs called the dewclaw. When looking at a dog's foot the toes that make contact with the ground are essentially the pinky, ring, middle, and index fingers - the dewclaws are like the thumb. Feeling the nail you should be able to move the dewclaw a little (forwards and backwards) and you'll probably be able to feel the tendons that connect the nail to the leg. The presence of these tendons suggests that the front dewclaw has a function and that removal of the front dewclaw may have lifelong consequences for our dogs. 

There are some breeds (Great Pyrenees, Saint Bernard, and Briards) that are born with dewclaws on all four legs or even double dewclaws on the rear leg. Some believe that the presence of rear dewclaws on the Great Pyrenees was purposely bred to give greater stability when working on rough terrain and snow. However, in most breeds the presence of a rear dewclaw is rare and are often non-functional meaning that there is no tendon attaching. When feeling the rear dewclaws you'll be able to move the nail more freely as they're often only attached by skin.  

When standing, the front dewclaw may not appear to be functional because it doesn't come in contact with the ground but observing the dewclaw when the dog is in motion tells a different story. 

The function of front dewclaws

Five tendons attach to the dewclaw and play an important role when the dog is in motion. For example: 

  • When a dog’s lead leg is on the ground during the gallop or canter, the dewclaw is on the ground to stabilize the carpus 

  • When a dog turns, the dewclaw digs into the ground to support the structures of the limb and prevent torque

  • Some dogs also use their dewclaws to help them climb trees and out of water, or hold items as they chew 

If a dog does not have dewclaws, there is a higher potential for the carpal ligaments to stretch and tear which could result in laxity and arthritis over time (OUCH!). This can then result in more stress being generated through the dog's carpus, elbow, shoulder, and spine as it tries to compensate for the lack of digit. 

The Research Behind Digit Injuries

A 2018 study of digit injuries found that digit injuries were more likely to occur in the front limbs (P< 0.001) than hind and that digit 5 (the outside digit) was the most frequently injured while the dewclaw (digit 1) was the least frequently injured. 

Previous research has thought that our dog’s third and fourth digit were the most important due to their central location within the feet and due to their length in comparison to other toes but research has shown that substantial weight is also placed on the fifth pad and on the metacarpophalangeal and metatarsophalangeal pads. This observation was also found within the present study with digit 5 seeing the most amount of injury. The researchers suggested that forces applied when dogs are turning at high speeds on the agility course may act as repetitive stressors to digits 3, 4, and 5 and that these digits may be of more importance to athletic function than previously recognized. 

Of particular note is the research found that the first digit (the dewclaw) was at a low risk of injury. The results of the study suggested that the removal of the dewclaws in the forelimb may be a risk factor for injury to other digits. The front dewclaws may have a function in preventing torque on the limb, and as such, the removal of dewclaws may predispose the dog to injury. 

​Source: Cullen KL, Dickey JP, Bent LR, Thomason JJ, MoÃns NM. Survey-based analysis of risk factors for injury among dogs participating in agility training and competition events. J Am Vet Med Assoc. 2013;243:1019-24. ​

Why do some advocate front dewclaw removal?

There are a number of reasons why someone may choose to remove front dewclaws from their dog. Breeders may choose to remove dewclaws on 3-5 day old puppies or owners may choose to remove front dewclaws later in life. This choice can be very personal and can vary between owners, breeders, veterinarians and dog breeds. So what are some of the reason behind removal? 

  • Belief that front dewclaws are a non-functional digit. For many years, people believed that because the nail of the dewclaw doesn't touch the ground in standing that it must not have a real purpose and therefore removal of the nail wouldn't impact the dog in any way. Rear dewclaws, on the other hand, do not have any associated tendons and are considered non-functional (though they may be required for some breed standards to be present). 

  • Breeders fear pet owners won’t cut dewclaws or will miss them. Some breeders fear that pet owners will miss the dewclaw when trimming their dogs nails and risk the nail becoming embedded or ripping. 

  • Cleaner front look. In the conformation ring some breeders and owners feel that the dewclaw detracts from the dog's overall appearance. 

  • Risk of injury and fear of the dog ripping their dewclaw. Some feel that the dewclaw is an unnecessary risk and remove the nail to prevent potential injury.​

How to Avoid Injury to the Dewclaw

Keeping the nail short is key to avoiding injury with dewclaws! ​Like other toenails the nail of  dewclaw needs to be trimmed regularly but due to the location of the dewclaw the nail will not make contact with the ground and will not wear down naturally like other toenails.  Left untrimmed the nail can curve down and become ingrown, risking infection. Untrimmed, the nail will also develop a longer quick making it difficult to maintain proper length. Long dewclaws also have a greater risk of catching on things and risk injury. Speaking with vets, you may be surprised at how few dewclaw injuries they see in dogs with well managed nails.