Corns

It was only a matter of time before I posted on this topic. Most greyhound owners are at least aware of, if not well acquainted with the tricky affliction that is corns. Eddie has been spared this malady, but Cassie has had a couple of mild corns previously.

The first signs of a corn is usually lameness on hard, but not soft, surfaces. Corns appear as round, sometimes whitish, domes or discs on the paw surface. Although it is said that corn are often misdiagnosed as skeletomuscular problems, I have found that vets often are aware of the problem in greyhounds. It is worth considering corns when faced with otherwise unexplained lamenss, and dealing with them as soon as possible, since they can lead to secondary problems, as the dog modifies its gait due to the pain.

Examples of corns on
greyhound footpads.

Commonly thought only to occur only in greyhounds, corns, or circumscribed hyperkeratotic lesions, are found in other breeds too. However, it does seem that they are most problematic in greyhounds and lurchers, due to the lack of cushioning fatty tissue in their toe pads making the condition more painful. In fact, it is also suggested that this lack of fat is one of the reasons greyhounds tend to get corns far more often than other breeds.

Viral infection and foreign bodies in the pad are also cited as possible reasons, but mechanical pressure is likely to be if not a causal then at least a significant contributory factor in the formation of corns. Corns usually develop in the centre of the two middle, weight bearing, toes of the paw, and more commonly on the front paws, which take the most weight in a greyhound. This seems to indicate that pressure on the pad from the toe bone is crucial to the formation of corns in greyhounds. 

In humans, corns usually develop on feet due to mechanical pressure, such as ill-fitting shoes or protruding bones. The difference between corns and the simple thickening of the skin known as a callus, is that in a corn a hard plug of keratin (skin tissue) is formed, pressing into the skin and underlying nerves, making it potentially very painful when under pressure. Corns are fairly easy to remove in humans, but tend to recur. 

I have been previously been able to deal with corns on Cassie's paws myself. I soaked Cassie’s foot in epsom salt solution (traditionally used to “draw out” corns, foreign bodies and infections in humans as well as horses and dogs), and then filed down the skin on the pad until I could see the corn kernel clearly. When possible I then hulled the corn using a large gauge surgical needle (which works as a little sharp spade). Sometimes would have to soak and file the foot a few times, with a couple of days break in between, before being able to get the corn out. One corn came out on its own, during a walk, after a few times soaking and filing.

Many vets will use a similar technique, working the corn out with a scalpel or a dental root elevator. Often this can be done without much discomfort to the dog, but vets can and do sedate some dogs to make the procedure easier.

The dental root elevator technique. Click to enlarge. 

This time, however, my usual technique didn’t work. There was hardly any sign of the corn on the pad. This looked more like a lesion from a bit of glass or something. I managed to extract some corn tissue from the site, which did seem to alleviate Cassie’s lameness somewhat each time. I kept on having to repeat the procedure though, without being able to extract the whole corn kernel.

The vet advised that surgical removal would probably be necessary, but I chose to wait a couple of weeks, as I was going away and did not want to leave post-op care to the people looking after my dogs. When I came home, Cassie was much worse, however. She was almost constantly lame on the leg, even in protective booties, and even on soft ground.

Cassie was also getting pretty sensitive about me touching the foot. Usually she is quite patient and allows me to bother her corns with minimal grumbling. Now she was screaming and snapping. She was obviously in quite some pain. It seemed clear that surgical removal under general anesthetic was the way to go.

The operation was fairly quick – she was under for less than half an hour. However, the corn removed was a whopper, and deep. It had grown inside the pad, and trapped nerves against her toe bone. No wonder she was in pain. Her pad had to be stitched together with non-dissolvable suture, which will stay in for two whole weeks. She is on-leash only for this time, too, making sure the pad gets to heal.

The excised corn. Note how far below the
hard skin of the pad the corn extends.

The stiched pad. 

I am not sure why this corn grew – or moved? – inwards, into the flesh of her toe, when many grow outwards, in the harder outer layer of the pad, making them easy to remove. I wonder whether my interference had anything to do with how the corn developed. Ilaria Borghese, president of Thera-Paw and guru on corns, in her widely consulted article, also suspects intervention may be detrimental to the development of corns, especially if using salicylic acid products marketed for human corn removal. 

I have indeed considered but decided not to try these products, because I am worried I’d do more harm than good. There are also reports of a successful technique using duct tape, but I have not tried this. In my opinion, considering the that mechanical pressure seems to be the best contender for the cause of corns in greyhounds, perhaps prevention is better.

If the theory that the lack of fat in the greyhound foot pads causes corns is right, then we could say greyhounds have ill-fitting paw pads. Like in humans, corns will recur if the pressure that caused them in the first place is not dealt with. Unfortunately, unlike shoes, paws cannot be changed for a softer, more comfortable pair. The problem of corns, if a dog is afflicted by them, is therefore usually chronic or recurring. Whatever way you treat the corn, if the underlying mechanical cause is not addressed, they will most likely come back. The long term success of surgical removal is not very good - over half of excised corns return one to three years after surgery according to a study - so I am half expecting Cassie's corn to reappear at some point, although I will try to prevent it. 

The easiest way to prevent recurring corns is to use padded shoes on dogs with a history of the affliction. The best ones I have found are the Thera-Paw boots (for UK distributor click here). A more drastic measure is to partially or completely amputate the affected toe. Some studies have found this to be more successful than any surgical removal of corns, while others report that corns return on remaining toes (which presumably now take the pressure when the dog moves). An experimental treatment involving the implanting silicone gel cushions in the pad has been tried but doesn’t seem to have moved on to any clinical use in canines.

Thera-Paw cushioned boot.

I expect the gait of individual greyhounds, which affects how weight is distributed on their pads, is relevant to whether any particular hound develops corns or not. I wonder, therefore if correcting other possible skeletomuscular issues, using pain relief, physiotherapy and other relevant therapies, may aid dogs with recurring corns. 

As Cassie has a history of corns, and the recently removed one is likely to recur, I am thinking of having her wear her Thera-Paws any time we walk for any length of time on hard surfaces, taking it off only when she has a run-about on grass (they don't tend to stay on when she reaches 5th gear!).

I know many greyhound are affected by corns, and would love to hear from you if you have any experience with corns. Any miracle cures? A novel way of preventing corns? Please leave a comment!

Sources and Links:

I F. Borghese, Corns and Warts, http://www.therapaw.com/Docs/cornandwartarticle.pdf

Carol L. Machery, William E. Feeman III, (2006) Using a dental root elevator to remove footpad corns in dogs: Two practitioners' experience, Veterinary Medicine, December 1, 2006. Access online: http://veterinarymedicine.dvm360.com/vetmed/Medicine/ArticleStandard/Article/detail/392957

M. J. Guilliard, I. Segboer, D. H. Shearer, (2010) Corns in dogs; signalment, possible aetiology and response to surgical treatment, Journal of Small Animal Practice 51, 162–168

S. F. Swaim, T. Amalsadvala, D. B. Marghitu, E. A. Sartin, J. A. Hudson, E. D. Stoenescu, Pressure Reduction Effects of Subdermal Silicone Block Gel Particle Implantation: A Preliminary Study, Wounds 16:10, 299-312.

Corns in humans: http://www.bupa.co.uk/individuals/health-information/directory/c/corns

What the Deaf Puppy Taught Me

My parents got a little boston terrier girl, Bettina, a couple of months back. She came to them at seven weeks old. Soon they realized something wasn’t quite right, and a few weeks later she was diagnosed as probably completely deaf from birth. There was no question of returning her, but understandably my parents were a little upset, and concerned about the implications of her deafness.

Just kept on sleeping right through the bangs.

My intuition was that deafness in a dog is much less problematic than it may appear to us humans. Yes, the dog will probably never be able to be let off leash with as much freedom as a hearing dog: not only is recall difficult, but they can’t hear either the sounds of danger or our warning cries.

However, although their hearing is very acute, dogs don’t really use sound to communicate very much. Their hearing is mainly utilised to orient themselves and detect prey and dangers. Barks, growls and whines, although vocal, are always accompanied by expressions of the face and body. The vast bulk of canine communication takes place through the mediums of smell, touch and body language. Although it is impossible for us to understand their world of smells, we would benefit from paying a lot more attention to their use of the latter two.

I visited my parents for a week recently, and met Bettina for the fist time, aged four months. Indeed, my feeling about deaf dogs was confirmed. Not only was Bettina so easy to communicate with, and so fast to learn, but she also emphasized some important lessons for me about communicating with all dogs, deaf or hearing.

My mother still holds out some hope that Bettina can hear high-pitched sounds, and uses whistles when calling her together with the hand signals. Bettina is so attentive that it almost seems that she can hear us at times. I don’t think she can, and felt that accepting this was a relief and lesson in dog communication. I don’t think that one should stop talking to deaf dogs, mainly because of the reasons that I set out in my post about talking to dogs – as humans we need verbalizing to communicate, so talking shapes our body language. However, walking and playing with Bettina felt extraordinarily relaxing and calm, and our communication so intense, precisely because I accepted she couldn’t hear. Instead I completely focused on my non-verbal signals. It was somewhat of a revelation.

At four months Bettina knew signs for attention (tap on shoulder), good girl (clap hands), no (wagging finger), sit (fist with thumb up), fetch (motion of pointing hand towards the object), gentle come here (beckoning hand), decisive come here (hand slapping thigh), and recall on a lead (two gentle tugs). I also taught her lie down (fist pointing to floor). There is certainly nothing wrong with the little pup’s brain. Having worked with older rescue dogs for so long it was a joy to spend time with such a quick and keen learner.

Even the seemingly impossible recall when she was off leash was mitigated by her obviously compensating for her lack of sound location by frequently turning to look at us. There was only one moment when Bettina’s deafness frustrated me. When she was doing something naughty at a distance and I could not shout “ah-ah!” the way I do to my dogs. You had to be very quick to get to her, push her away from and wag your finger at her. However, as she was quick to respond to being corrected in this way, it made me think about how often verbal reprimands are so very ineffectual.

Deaf but destructive! 

I hear so many owners shouting at their dogs, to come here, to do this, to stop that. Almost always the shouts are repeated – because, of course, the dog isn’t likely to do something just because you shout louder, if they weren’t going to in the first place. Yes, a sharp “No!” or “Ah-ah!” can have the effect of getting their attention, but if it doesn’t almost immediately, it is unlikely the dog will comply.

With a deaf dog there is no point in shouting. Rather you have to show them what you want them to do or not do, using your body. You need to prod and point, and gently or firmly bump and push. You need to make your body speak, through posture and signs.

As I said, touch and body posture is a massive part of doggy communication. Observe dogs interacting, and you will notice how much they use it – they are always posturing, and shoving and prodding each other. Even when they are looking away, or sniffing nearby, they are talking to one another!

If you use your body it is remarkable how quickly and well dogs respond. Often I need to show my clients that their commands of “come” need to be accompanied by gestures and posture that makes the dog interested and willing to come back, and their commands of “wait” or “stop”, with a posture that makes it clear where the line is drawn.

Only days before going to visit my parents my friend was playing with her dog Frank and my Eddie. She was giving them treats for simple obedience commands. She told Frank to sit and he quickly complied. She told Eddie to lay down, but he just stared at her uncomprehendingly. She tried again – nothing. Eddie is usually very good at lying down for a treat, so I tried to figure out why he wasn’t this time. I quickly realized that her hand signal for “lie down” was subtly different from mine. She holds her arm out, palm facing the floor. I point at the floor. As soon as I told her to change the signal, Eddie promptly lied down. It was so obvious that he responds much more to the hand signal than the words he hears!

When training dogs it is therefore imperative to remember to use consistent gestures as well as commands. Playing and working with Bettina was a lesson in speaking without words, a way of speaking that is closer to the dogs’ own way. It was so clear that words are really not necessary to communicate effectively with dogs, and although they can help us humans get to grips with what we mean, if we rely on them we forget the most important tool for talking to dogs: our bodies. 

Play needs no words.