I am a member of an excellent Facebook group, Canine Conditioning and Body Awareness Exercises. The posts that appear in this group are varied, but I have learned a lot whilst being a member and I have to say it is one of the most effectively moderated groups I'm a member of - the admin manage to keep the group on topic, and are quick to remove posts or comments that give poor information.
Over the course of the past week, I had read a couple of posts that had talked about using swimming to build up hind leg strength. I commented on the relevant posts to explain that swimming isn't actually all that good for this purpose, as dog's generally use their front legs to power through the water. Not surprisingly, this is something that not many people know, so I decided that I would get some video footage to illustrate my explanation.
I've decided to share the video and some more information here, so that it's more widely available. First, there are a few points that I need to cover:
✔ I was in the process of cleaning the pool, so I'm afraid there is some detritus floating about - the camera is located just below the skimmer. Sorry about that.
✔ The dog in this video is my own dog, Ripley. He is not wearing a harness, as I wanted to replicate a dog free swimming. I NEVER take any other dog in to the pool without a harness, and always remain in contact with them throughout their time in the pool. Ripley is a competent swimmer, and is used to being handled by me in any way needed. He is practised at entering and exiting the pool (and I do support him at those points), and he responds to my verbal cues as needed.
✔ I do not usually allow dogs to retrieve from the water line - again, this has been done to replicate free swimming. I am also comfortable that Ripley's head carriage is such that any intake of water is minimal.
In the video, you can see how the hind legs are held in flexion a lot of the time (meaning they are bent up towards the body). That's not a natural position that we would see replicated on land. The general movement of the hind legs in the water is very jerky. Those back legs also kick out at awkward angles at times.
The power is really coming from the front legs, with the hind legs supporting steering along with the tail. My experience of being in the pool with dogs is that they can make forward progress in the water without using their back legs at all - there are definitely some that need encouragement to use them.
This was really done to demonstrate how a dog moves in water when they are free swimming. I wanted to highlight why this form of exercise isn't the best or most appropriate for building hind limb strength. There were of course some questions raised in the thread, as there are dogs that have been through rehabilitation for hind limb issues that has involved swimming in some form. What I would like to raise awareness of is that there is a difference between swimming and hydrotherapy in a pool. There is an awful lot more than swimming happening during a hydrotherapy session in a pool (or at least there should be for maximum effect). So I'm really not saying that swimming shouldn't or couldn't be used for hind limb rehab - I am saying it isn't always the most effective option. The majority of the time I will start those cases out in the underwater treadmill.
On a slightly more technical note... There is a concept in sport science known as the SAID principle. This stands for Specific Adaptation to Imposed Demands, and states that in order to have a positive impact exercise has to mimic the demands needed in life/sport. Amongst other factors, the buoyancy of the water has an impact on how the dog moves, and swimming doesn't reflect the movements that they make on land. It is non weight-bearing, and so the muscles needed to provide support and stabilisation on land may not be triggered or in action whilst swimming.
Swimming is great fun for many dogs, and is good cardio exercise for them, but it should not be considered a cure all. There are also cases where dogs should NOT swim (primarily if there is a spinal issue). Also bear in mind that the water in a hydrotherapy pool should be heated to at least 28°C - the water temperature is part of the therapy, and open water in the UK is unlikely to reliably reach that temperature!
Just a few things to consider when thinking about the difference between swimming and hydrotherapy in a pool.