The effect of a buoyancy jacket on the heart rate of dogs during swimming

Canine hydrotherapy is becoming increasingly popular for rehabilitation, management of degenerative conditions and as a fitness training aid. During swimming, the use of buoyancy jackets is recommended to provide support and ensure a neutral spinal position, with these aids being particularly utilised for weak and vulnerable patients. Despite being commonly used, there is minimal research investigating the effect of buoyancy aids on physiological parameters in swimming dogs. In this study, seven healthy acclimatised dogs completed six laps of a hydrotherapy pool with and without a buoyancy jacket under the guidance of a qualified canine hydrotherapist. When not wearing a buoyancy aid, all dogs were fitted with a standard safety harness. Dogs were fitted with a Polar heart rate monitor (sampling once every five seconds) which was worn under the buoyancy jacket or harness and kinematic markers were placed on both the dorsal and medial aspect of the jacket or harness. Vertical displacement of the dogs was calculated in motion analysis software and corrected for the thickness of the buoyancy jacket. Data were analysed via a paired t-test to test for differences in displacement and heart rate between the two conditions. Minimum heart rate was significantly lower (p<0.05) in the buoyancy jacket compared to the harness. However, there was no significant difference in maximum (p = 0.864) or mean (p = 0.089) heart rate between the jacket and harness. Minimum and maximum displacement (p< 0.001) were significantly higher for dogs swimming in the buoyancy jacket compared to the harness. Only small differences were observed in heart rate between dogs wearing a buoyancy jacket and harness indicating that further research is warranted to assess how beneficial buoyancy aids are for dogs that may have cardiovascular conditions. When wearing the buoyancy jacket, dogs swam higher in the water than when wearing a harness. This may have energetic implications for swimming and should be considered in the design of future hydrotherapy protocols.