Sterile tail abscess in Naja annulifera - self-envenomation case

This is a 7'4" (224 cm), 2.27 kg Egyptian banded cobra, Naja annulifera. During handling at Biotoxins Laboratories, this animal accidentally bit itself about six inches anterior and dorsal to the cloaca. Here you can see the resulting swelling inside the coil in the foreground.

Here you can see where we opened and expressed the abcess after infiltrating the area with Lidocaine. A short incision around the borders of three scales in total produced some caseous material but revealed mostly swollen and irritated whole tissue consistent with envenomation. Heterophils, eosinophils and dead/dying red blood cells were seen on cytology, but no bacteria.

This is a closeup of the abcess after surgical incision, debriedment and flushing with dilute chlorhexadine. This animal is a five year old captive bred specimen in excellent body condition, alert and healthy appearing. No systemic symptoms from the envenomation were apparent. Final Rx was enrofloxacin 10 mg/kg PO q24h, chlorhexadine flushing and the application of 1% silver sulfadiazine cream q24h and a well cleaned cage with newspaper substrate and bleached cork bark as prophylactic against the risk of infection.

Unfortunately the abscess grew larger over the next few weeks, so a second surgery was indicated. This time debriedment was extremely aggressive.

View photos of the second surgery