Abstract

Successful management of large skin wounds that cannot heal through primary intention can be particularly challenging in zoo and wild animal practice. When the large size of a skin defect precludes surgical closure, therapeutic intervention often includes repetitive wound cleaning, debridement, and bandaging. Zoo and wild animal patients must often be repetitively anesthetized for wound treatments throughout the slow process of second intention healing.

The use of an extracellular matrix derived from pig urinary bladder and marketed as “ACell Vet™” (ACell, Inc., Jessup, MD, USA) has shown promise for wound repair in horses, other domestic animals, and people. This acellular matrix promotes new blood vessel formation and constructive remodeling of tissue by serving as a biologic scaffold across which new cells populate and differentiate. When applied to a wound, host tissues grow into the matrix, degrade it, and replace it with site appropriate tissue.

The use of “ACell Vet™” for treatment of wounds sustained by a Dall sheep (Ovis dalli) and a lion (Panthera leo) resulted in complete, uncomplicated healing of large skin defects. The sheep had sustained a severe horn injury for which complete cosmetic dehorning was necessary. Dehorning created an 8×7 cm open wound over the cornual sinus that could not be surgically closed. The lion had sustained a 7×7 cm bite wound over the dorsal and lateral aspects of its tail that was not amenable to surgical closure.

In each case, the “ACell Vet™” matrix was applied over the wound, moistened with saline, sutured to the wound edges, and lightly bandaged. Once this extracellular matrix material was applied, no further intervention was necessary, except for a single bandage removal in the sheep. (The lion removed the bandage on its own, leaving the “ACell Vet™” in place.)

Complete wound closure was achieved in both animals via natural host mechanisms and the matrix was absorbed without complication. Time until full wound closure with hair regrowth was approximately 4 months in each case.

Acknowledgments

Special thanks to Lion Country Safari lion keepers, hospital, and petting zoo staff.