Antimicrobial photodynamic therapy can be an effective adjuvant for surgical wound healing in cattle.

Background: Rumenostomy is a useful procedure commonly performed in cattle for medical treatment of domestic ruminants with forestomach diseases. Methylene blue (MB)-mediated antimicrobial photodynamic therapy (APDT) has been broadly investigated to treat infected wounds.
Aim: The aim of the study was to evaluate the effectiveness of MB-mediated APDT (MB-APDT) combined with chlorhexidine and zinc oxide ointment on wound healing process after rumenostomy.
Methods: Fourteen Nelore bulls were subjected to rumenostomy procedure. Animals were randomly divided into MB-APDT (MB associated with a red diode laser performed immediately after surgery and repeated on days 3, 5, 7 and 10) and control groups. Daily care included topical cleaning with chlorhexidine 2% followed by topical zinc oxide ointment. Animals were followed-up until the 28th day.
Results: Wounds presented a better post-surgical profile in MB-APDT group when it was compared with the control group. In MB-APDT group, it was also possible to observe less pain on palpation of wounds borders, less edema and inflammatory exudate. Additionally, animals from MB-APDT group were faster discharged from the cattle care facility.
Conclusion: Our results support the use of MB-APDT for the post-surgical management of rumenostomy. This pilot study ratifies the use of APDT in cattle and also suggests that it could be performed for other surgical procedures as a complementary approach or an alternative for topical administration of antibiotics.
(Copyright © 2020. Published by Elsevier B.V.)