Principal Investigator: John Angelos

Infectious bovine keratoconjunctivitis (IBK; ‘pinkeye’) is the most common eye disease of US cattle. Characterized by a painful corneal ulcer, IBK can cause permanent visual impairment and even blindness due to eyeball rupture in severe cases. While a causal association between IBK and Moraxella bovis was established many years ago.

1. our discovery of Moraxella bovoculi suggested that the disease may be multi-factorial. 

2. While recent studies implicate M. bovoculi in the majority of IBK cases,

3.4. One challenge study that tested a lab-adapted strain of M. bovoculi could not demonstrate a causal association.

5. Nevertheless, a commercially-available M. bovoculi bacterin to prevent IBK (Addison Biological Laboratory, Inc) was just released during spring 2017.

This suggests that an effective challenge model has been established by industry and that M. bovoculi plays an important role in IBK pathogenesis. Cattle industries throughout California and the USA are negatively impacted by IBK through reduced weight gain and high treatment costs.

California’s natural and organic beef industries continue to grow and a focus on disease prevention is increasingly important because marketability of antibiotic-treated animals for these segments of the beef industry is reduced. In addition, the individual animal pain and suffering caused by IBK makes control of this disease important for cattle health and welfare.

Currently commercially available IBK vaccines are ineffective against diverse strains of M. bovis and the California Cattleman's Association has continued to urge UC Davis to develop a more functional vaccine against IBK. If the vaccine that we propose to test is effective it has potential to benefit cattle industries throughout California and the USA.

The Sierra Foothill Research and Extension Center (SFREC) is an ideal location at which to conduct this study because it possesses all of the needed facilities for safe cattle handling and weekly animal observations. In addition, the SFREC site exposes cattle to all of the natural risk factors known to be associated with IBK including exposure to ultraviolet radiation, flies, dust, and plant awns. The SFREC therefore will provide a rigorous and realistic test of the ability of the experimental vaccine to prevent naturally occurring IBK.