Why you should wait until your dog fully grown before Canicrossing

Posted by Ginetta George, 29th January 2022

One of the most common questions we get asked by our customers, is ‘how old should my dog be before they can Canicross?’ We always advocate waiting until your dog is fully grown before they do anything too rigorous as their growth plates are still forming but we thought we’d get an expert in to explain in more detail why this is so important. Grace Bird, who is our guest today, is a radiographer and DogFit Trainer, so she not only has the knowledge but she can relate it to this sport we all love so much. 

Grace also has experience working with reactive and anxious dogs, so we thought we’d take the opportunity to ask her why she feels Canicross is such a great outlet for them.

Welcome, Grace. You’ve got a really rewarding job working with animals. Could you tell us a bit about your journey, your background and how you got to be where you are today?

Currently, I’m a radiographer at a small animal hospital. Before that, I worked as a radiographer in the NHS. A radiographer is someone who takes x-rays, CT scans, MRIs and ultra-sounds. Anything that involves medical or diagnostic imaging. I enjoyed working with children in the NHS, but an opportunity came up for me to move to the animal world, so I grabbed it with both hands. I love animals – and really, really love dogs. I thought that being able to see dogs as my patients each day would be fantastic. To merge two of my loves together. So, that’s how I got into the job that I’m currently doing.

Another of my passions is DogFit training. I’ve only just got into it, so it’s all very exciting right now. I’m at the beginning of my journey and I’m loving it already. I got into running at university. I did my first race in my first year there. I signed up for it, got the running bug and never looked back! I have also always wanted a dog ever since I was tiny. So, as soon as I got my first house I got myself a dog and couldn’t wait for the two to merge together.

So, you went from being a human radiographer to being a pet one. I guess it’s a completely different subject!

Yes, I deal with slightly different body parts, but much cuter patients – if I’m allowed to say that!

When you do the x-rays, do the animals put to sleep or do some remain conscious?

Some are conscious – they’re the really fun ones to work on. One of the studies we do is the swallow study, which assesses how dogs swallow and if they have any regurgitation issues. They have to be awake for that. So, we all get covered in this special dyed dog food, which goes everywhere as we try to get the dogs to eat it and then take a picture of them while they’re doing it.

Sometimes the animals are encouraged to go to sleep using sedation as it’s a bit fairer for them if they don’t have to be awake. My favourite time, though, is when cats are not sedated and we play them videos of birds instead. They are absolutely fixated watching the birds and sit very still for their scan. I love that!

DogHavingXrayDogs aren’t quite so easy to manipulate, then?

No, they just want to chase things!

It’s rewarding to work in a vets and also in the NHS. We get to see patients on almost every pathway. It’s not just one area of illness that we deal with. We also get to see resolved cases too. So, when we take a picture of a broken bone, or fracture, we see the very first bit, but we also get to do the recheck when it’s been plated and then when they take the cast off we finally see it healed. That’s just one example of how we get to observe the entire healing process. Then, the patients get discharged and can go on their way. That’s the case with both animals and humans, and it’s lovely to see.

You mentioned being a DogFit trainer, which is quite critical to what you do and one of your ways of bringing your passions together of dogs and fitness. How did you first discover Canicross and what made you come on board as a certified DogFit trainer?

My husband and I have always been runners, ever since we met. Our dog Stanley is a border collie and very well suited to this kind of thing. He was such an active puppy and wanted to come with us when we ran, but we had to say no until he was one year old.

When was little and first saw Pongo in One Hundred and One Dalmatians on the bike I wanted to exercise with dogs! I thought it looked really fun, but I didn’t realise there was a proper way to do it with all the kit; that there was an actual sport. We were on a walk with Stanley in Cannock Chase one day, a little way away from our home, when we saw a group of people running with their dogs in special kit. It said DogFit on the back of their t-shirts, so I went home and hunted them down. They invited me along to a taster session and that was that.

The reason why I wanted to go on to become a trainer was , as I said, that we first saw a group in Cannock Chase, which was a good hour away from our home at the time. I looked into it and found that there were no groups set up closer to our home. I thought it was a shame to have to travel so far to do it and decided to set one up a bit nearer to us.

Local people now have the opportunity to train with you, which is great. You also do parkruns with Stanley, plus I think you have another dog called Tessa?

We’ve got Stanley and Tessa. Stanley is three years old. Tessa is a rescue dog and she is six, but we’ve only had her for seven months. Parkrun was Stanley’s first running event and he absolutely loved it. It’s a great way in because lots of other people run with dogs there and some of them will have heard of Canicross. It’s a good way to link the two.

So, Tessa is six years old – how are you building up the training with her, because despite being a slightly older dog, it was all new to her when she first came to you.

Tessa comes from Romania and came across to us just before she turned six. She’s something of a mixed breed with some shepherd in her, so she is bigger and slightly less agile than Stanley. She was also starved before she moved to the UK, so we had to build her back up slowly. She didn’t have the stamina and muscle that came so quickly to Stanley who had benefitted from the right food and environment as a puppy. We took Tessa for a walk up quite a large hill early on and didn’t think too much of it. She had to have a nap at the top of it! She was just so tired because she had never done that level of exercise before. It highlighted to us that you couldn’t just go straight in with her. So, we did a bit of a ‘Couch to Five K’ programme with her. Taking the time to do this really helped her progress to longer distances and build up muscle. Now, she really enjoys running with us.

We are often asked how old your dog should be before starting Canicross. As a radiographer, what medical reasons would you give why people should wait until their dogs are fully grown? We always advocate waiting until they are fully grown because their growth plates are still forming, but is there anything you can add as a professional?

Growth plates are a really good place to start. For anyone who doesn’t know what a growth plate is, the proper name is an epiphysial plate. We have them, as do dogs, cats etc. A growth plate is a small piece of bone that has not ossified yet or become solid. It stays as cartilage until it reaches the right size and is where all the growing in the bone takes place. They are normally located at the ends of longer bones. You appear on x-rays as a small, black line; a little like you would imagine a break or fracture to look. You will see a gap, or capsule right next to the joint that allows it to move and then the little black line is right next to that at the head of the bone. On an x-ray, bones show up as white, growth plates are black and anything else that isn’t bone is a slightly darker shade of grey.

So, you have this area that is not hard bone, but it is pivotal to the growth of your bone. If something happens to the growth plate, it’s going to change how the bone forms. For example, if you fracture a bone while out running and the break passes through the growth plate as well, it will heal in a slightly different way that will alter how the bone grows. It will become different to all the others. You could end up with one leg that is shorter than the others, or that goes off at a different angle. All due to the break in the growth plate and how it heals.

I’m not saying the running itself will lead to all of the growth plates in your dog breaking, but everyone knows that puppies run around like mad all the time. You won’t categorically injure your dog by running with them when they are less than a year old, but the chances will increase when compared to an older dog. Just like us, too, dogs are more likely to have a traumatic injury while running, rather than walking. The younger puppies are, the less sense of direction and knowledge about their own bodies they will have, which also makes them more likely to trip, slip and fall over.


When a dog is in a harness and you are deciding which way the pair of you are going to go, there is also the issue of an abrupt movement to consider. Puppies don’t always have the same ability to support themselves if they suddenly go off balance. That’s why you often find that if puppies are just running around the garden, they don’t injure themselves quite as much because they have more control over how they move and fall. We are the same – if we are holding onto someone else, we are much more likely to fall because we don’t have the same amount of control over how our body moves.

The other thing to consider is something called ossification centres. That means instead of there being a growth plate, the mature bone that hasn’t formed yet. Not all of your bones are formed in your body when you are born. It’s the same with dogs and other animals. A really obvious example of this is the kneecap, or patella. Babies don’t have kneecaps – they start out as cartilage and turn into bone by the time the child turns two. There are all sorts of bones like this all over the body. The last one only forms fully in an adult human when the person reaches 25 years old. Technically, your skeleton isn’t fully mature until then.

The same process happens in dogs, but at a much faster pace. So, they get their fully formed kneecaps at nine weeks. Dogs also have all sorts of bones that fully form at different times in their life. So, by waiting until they are fully grown before starting running with them, you can make sure their body is working as it is meant to. For a dog, most of the bones and almost all the growth plates involved in running will be ossified at 12 to 15 months.

This age varies between breeds and between individual dogs. The only way of really telling is by giving your dog an x-ray. I wouldn’t recommend having one just to see this, though. As we’ve said, quite often animals have to have sedation first. It can also be quite an expensive vet trip just to find out if your dog happens to have earlier fusing growth plates. That is why I would agree that one year is a good estimated age to start training with your dog.

Does the skeleton form earlier in smaller breeds?

It’s not that much earlier. The range is different, depending on which bone you’re talking about and which individual dog. Some bones have a difference of a couple of weeks between breeds and others might have four to five months. It’s not a hard and fast rule that larger dogs take longer to fully mature. It’s all down to the breed and genetics involved.

Many people tell us that they have a puppy around nine or ten months that is super active and they are desperate to get started with Canicrossing. We tell them that they really do need to hold off for the whole recommended time. The most important thing to remember is that, if you’re not sure if your dog is fully grown or not, ask your vet for advice.

Absolutely. If you’re not sure about any aspect of your dog’s health and suitability for Canicrossing, your vet will be able to help. There are all sorts of things to think about other than bones that might mean certain dogs might not do so well in Canicrossing. If you have any concerns, ask your vet and they will be happy to help.

In your role and following your experience as a vet and working in an animal hospital, is there anything else that people should consider when thinking about Canicrossing?

Yes, it’s not just the case that once a dog gets to one year old, they’re good to go! It’s the same as if you were thinking about it from a human perspective. Several things stand out, such as the impact and intensity of the exercise you’re doing, the weight of the dog, its diet, outside temperatures and the dog’s breathing airway system too. Regarding temperature, it’s quite cold outside during the winter months. Dogs tend to do quite well in the cold with their furry coats, but you still need to be careful. Think about icy conditions and protecting their paw pads from any ice or snow on the ground. Think about how you can often find it harder to breathe in the cold, so perhaps set off a bit slower and get the dog into the run more steadily, rather than hitting it at a million miles an hour. They’re just like us, in that the cold will still have an effect on how they are feeling.

On the flip side, humidity and heat is really important too. It’s easy to check the weather forecast online to know when it might be too hot to run with a dog. There are some fantastic charts you can find that tell you the difference between temperatures and humidity. It’s really important not just to go on what the temperature is outside, but to also check the humidity levels. If it’s too humid outside, your dog won’t be able to breathe as well. Dogs don’t sweat out of their paws like we do; they’re covered in fur and ‘sweat’ by panting, so will dehydrate a lot quicker than we do.

You can check the ground temperature by putting your hand on it. Consider whether it’s better to run on tarmac or grass in the summer – that’s a good one. It’s easy to check weather, temperature and humidity on our phones nowadays to help us decide whether to go out for the run as planned or perhaps leave it until the weather is more suitable. That said, it is fantastic to get your dog out for exercise as much as you can. It keeps your dog fit and healthy, plus it reduces the risk of them getting arthritis – again, just like us. If you start them off exercising from a young age (not below one year!) and keep it going through their life, it will offer huge, long-term health benefits.

Active dogs will also have a much greater chance of keeping their weight under control. Weight is one of the biggest problems for canine bones. As much as I have discussed growth plates and starting to run a dog too early, if they become overweight, this can really increase the chances of damaging their bones. So, keeping their weight in check and exercising them often is really good way to help with that.

Also, a dog’s diet can really impact how well they can run. It is important to ensure that your dog has the right nutritional value for the exercise you are giving it. That is something that is entirely dependent on your type of dog and personal preferences. I’m not going to go into detail about which food is best – it’s a personal choice that your vet can help you with if you are concerned.

When you start exercising your dog in a slightly more extreme way than just walking, you really do have to start thinking more about these things – the food you’re giving them, the temperature… we have spoken to other guests about this too, as it is such an important subject. Thank you for your advice – it’s brilliant.

Something else that you mentioned is that you are passionate about working with rescue dogs – reactive and anxious dogs. Tell us a bit more about that.

We are still getting to know Tessa, my rescue dog, and you never quite know what dogs like her have been through or what you are actually getting when you adopt them. It’s part of the joy of rescue dogs! It can have a real impact on where you take her and what you do. You need to be aware of what might trigger your dog and work out ways to avoid it happening.

Rescue dogs tend to have the reputation for being more reactive and anxious after potentially going through negative experiences. On the other hand, our other dog Stanley, who has happily lived with us since a puppy, is also pretty reactive! We have tried to remove anything that could be a problem for him, but he is still a very anxious dog – that’s just his personality. Some breeds are simply more reactive than others. Border collies tend to be quite anxious and it’s part of what makes them such good working dogs and good learners too. They pick up commands fast because of the way their brains work.

However, because their brains are so fast, they can also react too quickly before thinking things through, which is where the impulsive reactions can come – acting before fully assessing the situation. Sadly, Stanley was involved in a car accident that resulted in the amputation of his tail. That took a year for him to fully get over. He had to have emergency surgery and would not let anyone put anything over his head for a long time afterwards, due to the cone he had to wear at the vets. So, getting him back out on the road and back into Canicross was a long journey. We’ve got there, though! He really loves it again. So, if you think that your dog is too reactive to wear a harness, it can happen with the right conditions. It’s nothing to be ashamed of, it’s just different dogs needing to work through things in different ways.

Canicross can be an amazing outlet for an anxious dog. When I go for a run feeling stressed or angry, it helps me calm down and I can tell that it is a really good release for Stanley too. He can get everything out of his system and then properly relax in the evening, back at home.

We’ve seen so many benefits for anxious dogs with Canicross. It can help them socialise safely with other dogs and get proper exercise, which makes an amazing difference.

Yes, the community offers such a safe space with all the dogs in their Canicross harnesses, running in the same direction and staying close to their owners. Running in a group like this can help nervous dogs socialise with other dogs while you get to know the instructors and other Canicrossers as well.

We always encourage people who have reactive or anxious dogs to come along to our DogFit classes as well because it is as safe environment and our trainers are experienced in looking after them.

Forces Wives Training

On another topic, I believe you are currently preparing for a very special expedition that you’ve got coming up. Do you want to tell us a bit about that?

I am very excited about it. I currently live in Scotland with my husband, who is in the military. We tend to move around a lot due to his job, but in March it will be me who is going away. There is a fantastic group that brings forces wives together to achieve different things and I am joining ten ladies going to Norway to re-enact an expedition that the Heroes of Telemark did across the Hardangervidda Plateau. We will be skiing for over 100km about 3,500 feet above sea level while dragging 300kg of kit behind us in below-freezing temperatures.

It’s going to be scary and fantastic at the same time! All going well, the expedition should take around five days. We will be training in Norway for a few days beforehand as well.

Forces Wives Team

It sounds like it will be an amazing trip. Has Canicrossing featured in your training schedule?

Definitely! Stanley and Tessa are both very much part of the team. They have come out with me on my training runs and the various cardio sessions that I’ve been doing. They are very interested when I do press ups and want to join in, making it much more difficult than it needs to be! The group that I’m going with, between the ten of us, has around 15 dogs and a lot of them have been involved in our training. We have several photos of us doing tyre pulling sessions with the dogs running along behind us!

It’s a great motivation to involve dogs in training for events like this, isn’t it? It can help get you out of the door and focused, plus it’s a great distraction. Training with your dog and having a goal to work towards makes a big difference.

It’s good for both of you. I tend to go for a solo run first and the go back and do a second run with the dog because I feel guilty. It really helps me rack up the distance – he makes me go back out!

One final question that we ask all of our guests is whether you have any advice for anyone listening who likes the idea of Canicross but doesn’t know where to start.

Training with Dogs

Just have a go. Get out and do it. One of the top questions people want to know when I do my DogFit training is whether their dog will pull them over. No, they really won’t! It’s a lot of fun and when you and your dog get out and run together. It can feel amazing and is great for mental and physical health. The benefits are clear for both for you and your dog, and the bond that builds between you when you see them responding to you telling them which way to go is very special. You’ll get to know some really great people too, whom you may not have met otherwise. Go and find a local group and you won’t ever look back!

If you would like to listen to our podcast with Grace, you can find it here:Talk Canicross

To find out more about The Forces Wives challenge that Grace mentioned you can find it here: Forces Wives Challenge

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