Over the past year, a number of research articles have been published that are specifically related to canine hydrotherapy, making a recap of the literature necessary. Dr Arielle Pechette Markley joined us for a lecture where she discussed each of these recently published articles in turn.
Key findings from the latest research include:
• Early post-op hydrotherapy in hemilaminectomy patients does not seem to increase the risk of complications in comparison to previous reports on post-op complications. (Caution should still be used in early post-op rehab.)
• Greater stifle extension can be achieved during UWTM than during swimming, and maximum flexion can be achieved with a water level at the stifle.
• Muscle activation patterns will vary with the depth of the water level.
• Water flow rate can be gradually increased during swimming to maximise limb excursions.
• Swimming protocols should start with floatation devices and progress to no floatation devices.
• Swimming increases the range of motion of the forelimbs more than that of the hindlimbs.
• The ‘doggy paddle’ swimming stroke is consistent across breeds, unlike overground gait patterns which vary greatly among breeds.
• The neck angle of the dog does not vary while swimming, with or without a floatation device.
• The increased ROM during swimming is mainly attributed to an increase in flexion.
• The power phase of the swim cycle is shorter than the recovery phase, particularly in the hindlimbs.
• Swimming increases elbow ROM in dogs with ED more than in healthy dogs.
Below are short summaries of the recent research articles on canine hydrotherapy. For a more complete discussion of each, including their limitations and clinical relevance, we highly recommend watching the webinar in the Onlinepethealth Hydro Members portal by Dr Arielle Pachette Markley.
The Latest Research (2018-2021)
Safety of early postoperative hydrotherapy in dogs undergoing thoracolumbar hemilaminectomy, by Mojarradi, A., De Decker, S., Backstrom, C. & Bergknut, N. (2021).
Many of us will have seen this article making the rounds on social media, and will already have had discussions about their methods and findings. The objective of this article was to report on the prevalence and types of post-operative complications in dogs receiving early hydrotherapy after a hemilaminectomy.
They included 83 dogs who started hydrotherapy within five days post-op, and did not control for any other rehabilitation protocols, therapeutic exercise, etc. Hydrotherapy usually started from day two post-op, and included either UWTM or swimming 2X per day. The surgical wound was not covered during hydrotherapy. They reported 10 minor and 16 major complications, as well as the euthanasia of 13 dogs owing to urinary incontinence, lack of improvement or progressive myelomalacia within two weeks post-op.
One of their major conclusions – that 100% of dogs with complications started hydrotherapy within five days post-op – was also one of their inclusion criteria. All dogs in this study started hydrotherapy within five days of being operated on. The complications rate and type were comparable to the findings of other studies evaluating complications in this condition, regardless of hydrotherapy treatment.
The impact of water depth and speed on muscle fibre activation of healthy dogs walking in a water treadmill, by Vitger, A.D., Bruhn-Rasmussen, T., Pedersen, E.O., Fuglsang-Damagaard, L. and Harrison, A.P. (2021).
This article assessed the effect of water depth and speed on muscle fibre activation of healthy dogs walking on a water treadmill. They assessed 25 healthy dogs at two water velocities and four different water depths, with the acoustic myography pads placed on the biceps femoris and vastus lateralis bilaterally.
They found that increasing the speed at any water depth required increased muscle fibre activation for both muscle groups. Highest workload was required in water at the level of the mid-femur, with workload increasing with increased speed. The biceps femoris experienced a higher demand compared to the vastus lateralis.
25 healthy dogs were included.
Effects of hydrotherapy and low level laser therapy in canine hip dysplasia, by De Oliveira Reusing, M.S., Do Amaral, C.H., Zanettin, K.A., Weber, S.H. and Villanova, J.A. (2021).
Laser therapy was administered at at 1J/cm2 per point at four lateral points and two medial points around the hip in the laser treatment groups. Hydrotherapy protocols included 15 min of UWTM with the water just below the level of the greater trochanter. A third treatment group combined laser and hydrotherapy, and a fourth group acted as control, with no intervention.
There was a decrease in the CBPI in all groups, and a decrease in pain interference in locomotion, improved QOL, and bilateral increase in thigh circumference in the combination treatment group.
32 dogs were included in this study.
Effects of a floatation vest and water flow rate on limb kinematics of Siberian huskies swimming against a current, by Fisher, C.J., Scot, K.C., Reiter, H.K., Reid, M.A., Roe, C.M., Colee, J.C. and Hill R.C. (2021).
Stroke frequency increased by 17% when dogs were not wearing a floatation device, and increased by 5% when the water flow rate was increased. The total excursion of the limb decreased by 38% when the floatation device was worn, and increased by 69% when the water flow rate was incrementally increased.
Carpal excursion was greater than tarsal excursion.
Seven huskies were included in this study.
The ‘dog paddle’: Stereotypic swimming gait pattern in different dog breeds, by Fish, F.E., DiNenno, N.K. and Trail, J.
There was no difference in gait pattern between dogs of different breeds. The swimming stroke could be divided into a power phase and a recovery phase. The power phase is shorter in both fore- and hindlimbs, and has a greater velocity than the recovery phase.
The swimming cycle alternates the use of all four limbs. The forepaws spend 60% in the power phase, 40% in recovery. The hindpaws spend 26% in the power phase and 73% in recovery.
Stroke frequency increased with decreasing body size, which is the only significant difference between breeds.
Eight dogs of six different breeds were included in the study.
A comparison of stride parameters and carpal and tarsal joint angles during terrestrial and swimming locomotion in domestic dogs, by O’Rourke, S. and Wills, A.P.
The study aimed to establish a baseline for swimming kinematics in healthy dogs, and to compare the gait to overground locomotion.
Stride length and frequency was reduced in swimming vs trotting, maximum carpal flexion was higher during swimming than trotting, and tarsal maximum flexion was higher during a swim than a trot. Tarsal maximum extension angle was larger during a trot. The overall ROM increased as a result of the increased flexion in the limb.
Eight healthy dolichocephalic dogs of a variety of breeds were included in the study.
A comparison of apparent neck and back angles before, during and after canine hydrotherapy, by Birch E and Simms, R.
During trotting, there were no differences in neck and back angles before and after swimming. There was a change in the topline of the dogs between swimming and trotting, with a ‘flatter’ topline apparent during swimming. The use of a life jacket, harness or no aid did not change the neck or back angles.
31 dogs of different breeds were included, predominantly Labradors and border collies.
A single hydrotherapy session increases range of motion and stride length in Labrador retrievers diagnosed with elbow dysplasia, by Preston T. and Wills, A.P.
This study compared healthy dogs to dogs with ED, assessing their elbow range of motion and stride paramenters while walking on a treadmill, before and after a single hydrotherapy session.
Both groups of Labradors had a greater range of motion in their elbows after swimming, but the ED group showed a greater improvement. All dogs had an increased stride length after swimming.
12 Labradors, six healthy dogs and six dogs with bilateral ED were included in the study.
Dr Arielle Pachette Markley goes in to a lot more detail on each of the above research articles, including a discussion of their limitations, clinical relevance and methodology. You can watch this webinar now in the Onlinepethealth Hydro Members portal.
Earlier research articles
Effects of partial immersion in water on vertical ground reaction forces and weight distribution in dogs by Levine, D., PhD, Marcellin-Little, D.J., DEDV, Millis, D.L., DVM MS, Tragauer, V., Mag Med Vet and Osborne, J.A., PhD. (2010).
This well-known paper demonstrates changes in weight bearing and weight distribution in relation to the height of the water; weight bearing is reduced by 15% when the water is at the height of the stifle, and by 62% when the water is at the level of the hip joint.
Interestingly, the weight distribution between fore- and hindlimbs was that 64% of the weight was carried on the forelimbs, both when water levels were at the height of the tarsus and the height of the stifle. Significantly, weight bearing on the forelimbs increased to 71% when the water level was at the height of the hip.
This study used a sample size of ten dogs.
The effect of water depth on limb kinematics of the domestic dog during underwater treadmill exercise by Barnicoat F. and Wills, A.P. (2016)
Barnicoat et al. performed a kinematic analysis in the underwater treadmill at various water depths to assess the effect of water level on the stride of healthy dogs. They found a significant reduction in duty cycle with increasing water depth. The swing phase and stride length increased as water depth increased, while the stride frequency decreased as the water depth increased.
This study used a sample of eight clinically sound dogs, over two sessions.
Kinematic analysis of the hind limb during swimming and walking in healthy dogs and dogs with surgically corrected cranial cruciate ligament rupture by Marsolais, G.S., DVM MS, McLean, S., PhD; Derrick, T., PhD, Conzemius, M.G., DVM, PhD, DACVS (2003).
Marsolais et al. determined that for healthy dogs, swimming results in a greater range of motion in the hip joint than walking, but for CCLR dogs, swimming caused no increase in ROM of the hip joint in relation to walking. In both groups of dogs, swimming produced greater flexion and therefore ROM of the stifle and the tarsal joints. The ROM of the stifle in the surgical dogs was much less than in healthy dogs, in both walking and swimming.
This study included thirteen healthy dogs and seven dogs with CCL ruptures.
Aquatic treadmill water level influence on pelvic limb kinematics in cranial cruciate ligament-deficient dogs with surgically stabilised stifles by Bertocci, C., Smalley, N., Brown, K., Bialczak and D. Carroll (2020).
Bertocci et al. determined that the water level in an underwater treadmill influenced pelvic limb kinematics and temporal gait outcomes. As the water level increased, stifle flexion increased, with the greatest amount of stifle flexion shown when the water was at the level of the stifle and the hip. Hip flexion increased when the water level was at hip height. The stance phase of the stride also decreased when the water level was at the height of the hip.
Ten dogs were included in this study.
Effect of water depth on muscle activity of dogs when walking on a water treadmill by Parkinson, S., Wills, A.P., Tabor, G. and Williams, J.M. (2018).
Surface electromyography was used to evaluate the activation of the gluteus medius and longissimus dorsi in sound dogs at four different water heights on the water treadmill.
There was a significant decrease in the workload of the gluteus and longissimus at the higher water levels, while the workload of the gluteus increased at the tarsal level. Some dogs showed a lateral side bending during walking on the WT, as well as variable head heights and postures which could have impacted the workload of the muscles.
This study included seven dogs.
Physiological effects of water temperatures in swimming toy breed dogs, by Nganvongpanit, K., Boonchai, T., Taothong, O. and Sathanawongs, A.
This study looked at the effect of water temperature on the heart and respiratory rate during swimming, and changes in rectal temperature, blood glucose and blood lactate before and after swimming in 21 small-breed dogs in water temperatures of 25°, 33° and 37°C. The heart rate and respiratory rate were monitored every five minutes during a 20-min swim, while the other parameters were measured before and after swimming. They found the highest respiratory rate in dogs swimming in 25°C water, and the highest heart rate in dogs swimming in 37°C water. Their recommendation to avoid tachycardia, hyperventilation and hyperthermia is to swim dogs in water that is 33°C.
This study included 21 small-breed dogs.
The increase in published articles in this industry is extremely inspiring and encouraging!
In each of these papers, we learn something that has clinical relevance to us as hydrotherapists. However, all of these studies also have significant limitations. And so, while we can take something from each paper, we are still in need of more research in the field of canine hydrotherapy in order to develop beneficial protocols for rehabilitation, and most importantly to provide an evidence-based approach to the use of this modality.
We need to establish the biomechanical effects of walking and swimming in larger populations of healthy dogs, and across different breeds. We need to establish the effect of hydrotherapy on spinal motion and the muscle activation and recruitment of different muscle groups. And we need to repeat all of this in patient populations with specific conditions and pathologies!
Let’s do this, guys. If you have a treadmill or pool and an enquiring mind, let’s generate the research that will develop our field.
- Watch What’s new in hydrotherapy research, with Dr Arielle Pachette Markley now.
- Download our FREE research citation booklet to keep track of the research relevant to you.
- Watch Adapting your hydro protocol, with Ellen Martens, for free.
- Read The tendencies and challenges of different breeds during hydrotherapy
- Read Achieving goals of hydrotherapy with tools
- Read Understanding swimmers syndrome
1. Barnicoat, F. & Wills, A.P. (2016). The effect of water depth on limb kinematics of the domestic dog during underwater treadmill exercise.
2. Bertocci, G., Smalley, C., Brown, N., Bialczak , K. & Carroll, D. (2020). Aquatic treadmill water level influence on pelvic limb kinematics in cranial cruciate ligament-deficient dogs with surgically stabilised stifles.
3. Birch, E. & Simms, R. (2021). A comparison of apparent neck and back angles before, during and after canine hydrotherapy.
4. De Oliveira Reusing, M.S., Do Amaral, C.H., Zanettin, K.A., Weber, S.H. & Villanova, J.A. (2021). Effects of hydrotherapy and low level laser therapy in canine hip dysplasia.
5. Edge-Hughes, L. (2007). Underwater treadmill therapy in dogs: Finding the evidence to create a protocol for its use. A small scale sample literature review.
6. Fish, F.E., DiNenno, N.K. & Trail, J. The ‘Dog Paddle’: Stereotypic swimming gait pattern in different dog breeds.
7. Fisher, C.J., Scot, K.C., Reiter, H.K., Reid, M.A., Roe, C.M., Colee, J.C. & Hill R.C. (2021). Effects of a floatation vest and water flow rate on limb kinematics of Siberian huskies swimming against a current.
8. Levine, D., Marcellin-Little, D.J., Millis, D.L., Tragauer, V. & Osborne, J.A. (2010). Effects of partial immersion in water on vertical ground reaction forces and weight distribution in dogs.
9. Marsolais, G.S., McLean, S., Derrick, T. & Conzemius, M.G. (2003). Kinematic analysis of the hind limb during swimming and walking in healthy dogs and dogs with surgically corrected cranial cruciate ligament rupture.
10. Mojarradi, A., De Decker, S., Backstrom, C. & Bergknut, N. (2021). Safety of early postoperative hydrotherapy in dogs undergoing thoracolumbar hemilaminectomy, J Small Anim Pract.
11. O’Rourke, S. & Wills, A.P. A comparison of stride paramenters and carpa and tarsal joint angles during terrestrial and swimming locomotion in domestic dogs.
12. Parkinson, S., Wills, A.P., Tabor, G. & Williams, J.M. (2018). Effect of water depth on muscle activity of dogs when walking on a water treadmill.
13. PrestonT. & Wills, A.P. A Single hydrotherapy session increases range of motion and stride length in labrador retrievers diagnosed with elbow dysplasia.
14. Vitger, A.D., Bruhn-Rasmussen, T., Pedersen, E.O., Fuglsang-Damagaard, L. & Harrison, A.P. (2021). the impact of water depth and speed on muscle fibre Activation of healthy dogs walking in a water treadmill.