Oxygen Toxicity and Common Uses of HBOT in Small Animal Patients: A Retrospective Analysis of 2,756 Treatment Sessions

Hyperbaric oxygen therapy (HBOT) is commonly utilized for various human conditions with a low incidence of major adverse effects (0.002-0.035%). Despite growing use in veterinary patients, there remains a paucity of literature describing its use and associated complications. The purpose of this study was to report clinical use of HBOT in small animals, identify the rate of major adverse events, and assess clinical improvement in a large subset of patients with intervertebral disc disease (IVDD) receiving HBOT following decompressive surgery. Electronic medical records from an academic teaching hospital were searched for small animals receiving HBOT between November 2012 and February 2020. Data extracted from the medical records included signalment, treatment indication, and adverse events. For cases with IVDD undergoing decompressive surgery, the duration of clinical signs and outcomes were also collected. Treatment sessions totaled 2,756 in 542 dogs and 24 cats. Common indications included neurologic injuries (50.4%), tissue healing (31.4%), control of oomycete infection (5.5%), neoplasia or post-radiation injury (5.4%), and various miscellaneous conditions (7.4%). Oxygen toxicity, manifesting as tremors or generalized seizures, occurred in 0.7% of treatment sessions, with increasing age (p=0.009) and female sex (p=0.008) identified as risk factors. Patients with IVDD (n=156) were younger (p=0.004) and underwent fewer treatment sessions than other indications (p=0.049). In conclusion, HBOT appeared safe across various indications, although oxygen toxicity affecting the central nervous system was higher than reports in humans. Future prospective, randomized, controlled trials should evaluate specific clinical indications and outcomes. <br>