In the world of Hydrotherapy, the use of a flotation device is a controversial topic, one that should form the subject of far more high-quality research, and open discussion.
The lack of really good research on which to base clinical decisions in canine hydrotherapy is a source of some frustration to me. The studies we have are mostly small, old, and not of very high quality. At most, they guide broad clinical protocols and reasoning, but they don’t answer questions like, ‘If I use a flotation device, do I delay the therapeutic goals of hydrotherapy?’ This might be too broad a question for a single research paper, but the questions we ask all come down to this. We really need to see far more comprehensive, recent research on so many aspects of canine hydrotherapy.
I could find only two research articles that refer to the use of flotation devices – both based on small studies and both leaving many questions unanswered.
What are our goals?
When performing hydrotherapy, our goals for treatment may vary enormously, depending on the patient and the outcomes we need at different phases of the rehabilitation journey. We may, for example, have a Great Dane suffering from an FCE in the acute phase. Our overarching goal is to regain functional mobility but to do so we will have smaller steps and goals along the way.
On day 1, for instance, our first objective may be to introduce the dog to the water in a fear-free, safe environment, protecting the airways and reducing panic in the patient. Once that is achieved, we want to stimulate movement in the water, encouraging the establishment of correct neurological pathways. From there we want to normalise neurological function and build strength and endurance.
In a different scenario, perhaps a Labrador suffering from severe elbow dysplasia, our interim goals will look very different. We may want to slowly increase flexion of the elbows, then increase muscle strength and over time reduce body weight.
The tools we use to aid us in achieving these goals may differ quite a bit. In Podcast Episode 42 Harnesses or Flotation Devices, Angela Griffiths shares a few more scenarios where the clinical reasoning and patient needs may lean towards or away from the use of a flotation device. Jenny Williams states, “the therapist needs to be aware that goals will change not only from one session to the next, but within a single session as well”.
A buoyancy aid or a harness. Many of us use both, while others use only one or the other. Some hydrotherapy centres use buoyancy aids on every single dog because they form part of their safety protocols; other centres never use buoyancy aids because they believe they delay the achievement of therapeutic goals and recovery.
We have a great tool in our ability to observe objective, visible things, such as the restriction caused in the shoulder by a specific kind of harness, or the swimming biomechanics of different body types in the water. Add our skills of observation to our clinical reasoning, and we are well on our way to making sound clinical decisions to meet our patient goals.
Two research papers
In our Hydro training video this month we discussed Swimming Kinematic and Flotation Analysis of Conscious and Sedated Dogs Using Three Canine Flotation Devices, (Corum et al., 2014). This paper was not aimed at our profession, but rather at pet owners and the commercial industry of life jacket production, so I can only extrapolate their findings to make (hopefully) clinically relevant observations.
The authors tested three different flotation devices, and found differences among the three when it came to the range of motion available in the elbow joint. This is not surprising to us – we know that there are designs of life jackets that restrict the mobility of the shoulder, and for this reason many of us choose a jacket that leaves the shoulder open and free. But increased mobility goes hand in hand with a decrease in stability. And so I must ask myself, ‘Are there scenarios where I may want to use a jacket that slightly restricts the amount of flexion available in the elbow?’
The question also arises, ‘Is the reduced range of motion with some flotation device due to a physical restriction, or is it due to the increased buoyancy of the dog , which causes them to exert less effort in swimming?’ This may very well be the case, in which case one naturally asks, ‘Does reducing their swimming effort help me achieve my goals for this patient? Or will it slow progress down?’
The second paper, or rather research poster, The effect of a buoyancy jacket on the heart rate of dogs during swimming (Metcalf & Wills, 2017) compared the heart rates of dogs swimming with and without flotation devices. The authors found that the maximum heart rate was reduced in dogs that wore flotation devices. This adds some weight to the idea that swimming in a flotation device reduces swimming effort, but it certainly does not allow us to conclude that the dog is using a smaller range of motion in the forelimb because he is reducing his swimming effort. The causes of certain responses, and the specific effects of certain flotation devices are just a puzzle at the moment, one that still requires many missing pieces.
Sedated dogs as a ‘stand-in’ for compromised dogs
In the first study, when the dogs were partially sedated, they no longer had full control of their bodies and the life jacket became a life-saving device. The experimenters measured the dogs’ fear response together with their stability in the water. Will we ever swim a sedated dog? No. But we may be swimming a highly compromised dog that does not have control over its body, and in which case we may see a similar behavioural response to a sedated dog. Possibly.
When life jackets were tested that are similar to the ones we use clinically ((the Ruffwear and Astral Buoyancy), the sedated dogs responded with fear and panic. Additionally, the life jackets did not help the dogs maintain stability in the water; their roll increased and they struggled to keep their airways clear. So one is left with the question, ‘How would using a life jacket on a severely compromised patient help them feel safer?’ Certainly it seems a normal life jacket on its own would not. The dogs were not placed in the water sedated without a flotation aid, so for our purposes we can’t compare the two with each other and see where the lesser fear response was, and what the better clinical practice would be. However, we would also never have a severely compromised dog in the water without at least one set of hands and a body for support, to create feelings of safety and stability in the patient.
The third device they tested was an inflatable life jacket. This device not only stabilised the dogs in the water, preventing rolling motion, but helped the sedated dogs remain relaxed, sleepy and calm. Perhaps a device such as this may be useful in situations where dogs are fearful, severely compromised, and require many hands in the pool to assist.
“As therapists we would never ordinarily consider using a device like this, but the research doesn’t lie,” comments Jenny Williams when I asked her about this. Please watch the research refresh Swimming kinematic and flotation analysis of conscious and sedated dogs using three canine flotation devices for more commentary on the study. Here is a YouTube video of what this flotation device looks like.
Podcast Episode 42 Harnesses or Flotation Devices discusses the biomechanical changes we commonly see in dogs that are swimming with and without flotation devices. For more in-depth information on how the normal biomechanics of the canine is impacted, you can watch the webinar recording ‘Anatomy and Biomechanics of the Axial Skeleton’ by Jenny Williams in the Hydro members portal.
What does it all boil down to?
Until we have real evidence that conclusively tells us what the best protocols and procedures are in any given hydrotherapy situation, with any given breed or body type, or for the treatment of specific conditions (a pipe dream, I think, at this point), we are going to have to rely on our skills of observation, clinical reasoning and objective outcome measurement.
My advice is, with every patient, in every scenario, set your treatment goals, find an objective way to measure them, and use the tools that will bring you closest to those goals. At the end of the day, a tool is only as useful as the hands and mind that wield it. Make sure that your therapeutic and reasoning skills remain sharp and up to date, and always be questioning why!!
I would love to hear your thoughts and opinions on this, as well as your preferences. Please share them in the comments below, or join the conversation we are having on this subject in the Hydro Vetrehabbers Facebook group right now!