Bovine ocular microbiome: the next frontier in managing Pinkeye in cattle

Infectious bovine keratoconjunctivitis (IBK), or pinkeye, represents a significant economic challenge to dairy and beef cattle industries resulting in decreased productivity and increased treatment costs. The current IBK prevention and control strategies in cattle face challenges owing to the multifactorial nature of the disease, the rise of antibiotic resistance in IBK pathogens, and inconsistent efficacy of IBK vaccines. Recent efforts in metagenomic characterization of the eye microbiome in humans and animals, including cattle, have revealed that the ocular surface is colonized by relatively diverse and dynamic microbial community that is essential for maintaining ocular health and can be leveraged to enhance resistance against infectious ocular diseases. In this narrative review, we provide comprehensive insights into the ocular microbiota by summarizing the amplicon and metagenomic sequencing- and culture-based studies conducted in cattle, and by reviewing relevant findings from humans and other animal species. We also explore the potential of the ocular microbiome as a new frontier in managing IBK. Finally, we examine the gut-eye-microbiome axis and discuss its potential contribution in improving the resistance of cattle against IBK.