Safety and blood changes after eye drops in healthy dogs

Abstract

OBJECTIVE: To evaluate ocular and general safety of topical anti-human VEGF bevacizumab and the effect on serum vascular endothelial growth factor (VEGF) values in healthy dogs. PROCEDURES: Nine university-owned beagles received 0.05 mL of 0.25% bevacizumab eyedrops (Avastin, Roche) in one eye and 0.05 mL of 0.9% saline solution in the other eye as a control, administered at 12 hours intervals over a period of 28 days. Continuous monitoring for vital parameters and ocular examinations were conducted. Complete blood counts including hematology and coagulation parameters were performed before trial start as well as 24 hours, 7 days, and 28 days after trial start. Measurements of serum VEGF values were obtained using an ELISA-based approach at days 0, 7, and 28. The experiment was designed as a masked placebo-controlled study. RESULTS: No clinical signs of ocular toxicity or systemic incompatibility were noted in any dog at any time point of the study. No signs of pain were present in any dog at any time point. All blood count values remained in normal clinical ranges without relevant variation. There was no significant change in mean serum VEGF values between day 0 and day 7 and between day 0 and day 28. CONCLUSIONS: The results indicate that topical bevacizumab treatment is safe in healthy dogs. However, further studies are needed to assess safety and efficacy in diseased dogs with naturally occurring corneal neovascularization.