For her entire life, Tinchy has had a huge interest in playing with and chewing stones. As a pup, she started with gravel, picking it up in her mouth and running around with it. She has continued to do this, and as time has passed, she has progressed to enjoy picking up – and chewing- large stones.
This behaviour is her favourite pastime: if Frank is in the garden, doing odd jobs, or sitting in a garden chair reading a newspaper, Tinchy often sits near by, picking up pieces of gravel and chewing on them, in the same way as many dogs might gnaw on a bone. And she also likes Frank to throw stones for her: she will drop a large stone at his feet, then bark at him, getting agitated until he agrees to throw it for her. She then picks it up, brings it back, and gets him to throw it again. Eventually, when she gets tired, she lies down and idly chews on the stone.
Whatever it is about stones, they seem to intrigue Tinchy, and she has an ongoing fascination for them. There have been two significant consequences of this passion for stones.
The first problem happened four years ago. Tinchy is normally a good eater, but out of the blue, she started to turn her nose up at all food. At the same time, she started to vomit, so Frank took her down to the vet to be checked. An x-ray showed that she had managed to swallow a stone that had been small enough to swallow, but too big to pass through her intestines. This stone had become lodged half way down her digestive tract, causing a complete obstruction. She needed a major operation to have the stone removed. She made a good recovery, and since then, Frank has been meticulous about keeping her away from medium sized stones. Small stones, like gravel, don’t seem to cause her any harm: she often passes them in her faeces. And large stones are too big to swallow, so Frank has always felt that they can’t do her any harm. She just loves chewing them so much that it would seem a shame to take them away from her. When Tinchy came in to see me recently for her annual check, I discovered one significant consequence from her stone-chewing habit: her teeth have been worn down. Her large canine teeth – the pointed ones at the front of the mouth – have flattened surfaces rather than sharp tips, and the large molar teeth at the back have been flattened almost to the level of the gums. These changes don’t bother Tinchy but there may be some negative consequences.
First, when the canine teeth are worn down, the pulp cavity inside the tooth may be exposed. This can cause pain, and can allow infection in to the roots of the teeth. This is why humans need root canals to be filled if a tooth is broken. Luckily for Tinchy, dogs’ teeth are better than human teeth at coping if they are worn down gradually. A hard substance – known as secondary dentine – naturally forms, acting as a sealant to close off the root canal. Arguably it could be described as a type of natural root canal filling. This means that dogs who gradually wear down their teeth – like Tinchy – often suffer no severe consquences from exposure of the pulp cavity. It would be different if a tooth broke suddenly, so that the pulp cavity was immediately opened and exposed: this would indeed cause pain and allow infection in, and a root canal filling might need to be considered. A dog like Tinchy is at risk of a tooth fracture like this: if a stone was thrown and she tried to catch it mid-air, she could easily break a tooth. However this has not happened to date, and hopefully it never will happen.
The second possible negative consequence is that Tinchy’s back teeth could become so flattened and worn down that she could no longer chew her food properly. Having said that, modern dog food is easy to chew: I know plenty of dogs who have had all of their back teeth extracted after developing serious dental disease, and they do not seem to suffer any adverse consequences. They are still able to pick up, grind down and swallow their kibble. The gums and the underlying bone structure of the jaws are often tough enough to allow pieces of biscuit to be broken and ground down enough to be swallowed.
In the worst case, a dog like Tinchy might have to be fed soaked food to help her eat her dinner, so that the kibbles are softened. In reality, this is rarely needed.
The main risk to her is the ongoing possibility of stones becoming lodged inside her in some way. When she was recently x-rayed to check her hips for arthritis, I noticed that there were dozens of small pieces of gravel visible in her abdomen. They could be seen as small white dots on the x-rays.
Tinchy is obviously still swallowing small stones, and she is then passing them in her faeces. This does not cause her any harm, but there is a risk that at some stage, the small stones could cluster together, forming a solid mass like concrete. If this happened, she would again go off her food, and start to vomit, and she’d need a major operation to remove them. There’s no sign of this happening, and Frank is aware of the risk.
Tinchy continues to love playing with stones, and Frank simply has to keep a close eye on her. With luck, she’ll live to a ripe old age without any complications.