There is a paucity of data about use of HBOT in veterinary medicine, and no randomized, controlled clinical trials for any condition have been published. Thus, veterinarians must rely on the comparatively more robust human literature.9,10 Documented efficacy is strongest for carbon monoxide (CO) toxicity and decompression sickness.11-13 These are uncommonly encountered in veterinary medicine, but if a patient were presented with CO toxicity, HBOT might be effective in reducing CO half-life.14
Several laboratory studies in small animals exist, including one that incorporated an autogenous cancellous bone graft. This study in cats demonstrated that a median percentage of bone was marginally higher in the group that received HBOT as compared with those that did not receive treatment (58.23% vs 47.06%, respectively); on removal of a single outlier, these results were statistically significant.15 Another feline study that featured blinded observers compared skin flap viability in which the flap color appeared subjectively healthier in the treated groups.16
A study in canine cardiac arrest patients showed improved neurologic outcome in both neurologic deficit scoring and reduced neuronal death postarrest in dogs that received HBOT.17 Dogs have also been used as a model for the effects of HBOT on the CNS, with positive results reported in the HBOT-treated groups subjected to complete global cerebral ischemia,18 spinal cord compression,19 and ischemic spinal cord injury.20
Anecdotal veterinary treatment applications in various species have involved crotalid envenomations, refractory osteomyelitis, reperfusion injury, myocardial ischemia, pancreatitis, and anaerobic infections.8,21,22 Results from a retrospective study of HBOT suggest that the following conditions were frequently treated: compressive and vascular myelopathies, crotalid envenomation, surgical or traumatic wounds, and atypical infections.23 The reliance of HBOT practitioners on low-grade evidence has likely prompted some to withhold advocacy for the treatment until additional information is made available by proponents.