الملخص

Epidural anesthesia is a technique widely practiced in veterinary medicine despite reservations about its probable local neurotoxic side effects. This study was undertaken to assess the clinical, radiological, gross, and histological changes following administration of epidural lidocaine in dogs. Twelve healthy male dogs were used for this study and were randomly assigned to two equal groups of six each. Group A (Control group) received distilled water while Group B received 2% lidocaine hydrochloride at a dose of 4.5 mg/kg. The body weight for each dog. Clinical observations were made during the period of anesthesia and after that period. Radiological examination was done before the injection and after 24 hours. Gross and histological examinations of the spinal cord were carried out 72 hours post-injection. Both groups showed transient ataxia. However, the treated group (lidocaine group) demonstrated additional transient motor dysfunction and vocalization, all of which resolved within one hour. Gross examination demonstrated focal redness with small hematomas at injection sites. The lidocaine group demonstrated significant histological alterations at 72 hours, including axonal degeneration, neuronal atrophy, Schwann cell swelling and vacuolation, pronounced perineuronal vacuolation, and early transient degenerative micro-lesion despite the transient nature of the clinical signs. Despite these tissue alterations, all clinical motor effects were fully reversible. The statistical analysis showed significant changes between groups at the level (p < 0.05). Epidural administration of lidocaine at 4.5 mg/kg induces transient and fully reversible clinical motor effects in dogs. However, the observed histological alterations at 72 hours suggest potential localized neurotoxicity. Therefore, while lidocaine remains a viable option for veterinary anesthesia, careful dosing, vigilant perioperative monitoring, and the consideration of neuroprotective strategies are recommended to mitigate potential tissue risks.