Sponsor Content with Commentary
If one reads three or more of the articles* recently published about infectious bovine keratoconjunctivitis or, pinkeye in cattle, they may be confused about a) what conditions predispose calves to infection(s), b) what vector(s) are responsible for disease transfer and c) what bacteria cause pinkeye infections or may be present as cofactors or co-pathogens in an infected animal?
AHD Sponsor Addison Biological Laboratory is a pioneer in pinkeye diagnostics, as well as autogenous and commercial vaccine production. They have provided guidance to simplify and understand pinkeye in cattle. Founder Bruce Addison has been working with pinkeye disease for almost 50 years and has processed countless thousands of bacteria samples. His work guides these clarifications.
A. Calves with eye injuries are most susceptible to infection. Common eye injuries result from tall grass or weeds, face flies, UV light, swiping tails, plant seeds, pollen, dust, wind and other potential co-infections or cofactors.
B. Once irritated, the calf’s eye discharges tears, attracting face flies (Musca autumnalis). As these flies buzz from cow to cow, they land on the mucus membrane and tear duct of the eye, which allows for direct transmission of bacteria. Calves bunching together can also directly transfer bacteria to each other.
C. To be clear, a calf with pinkeye is actively infected with Moraxella bovis, the primary infectious agent definitively shown to cause IBK. Moraxella bovis generally does not cause IBK unless there is damage to the cornea. Moraxella bovoculi is also a pinkeye pathogen. It attaches to Moraxella bovis as well as the damaged cornea and produces a toxin.
To summarize:
- Infectious bovine keratoconjunctivitis (pinkeye) is primarily caused by Moraxella bovis
- Moraxella bovoculi does cause pinkeye and is most infectious as a co-pathogen attached to Moraxella bovis. Calves with both pathogens often move to a Stage 3 infection rapidly.
- Mycoplasma bovoculi, while likely present, has not been shown to be an infectious co-pathogen but may contribute to immune suppression as a cofactor to disease severity. Vaccination for Mycoplasma bovoculi has not shown to be effective.
- While identified in some laboratory results, Mycoplasma bovis does not cause pinkeye.
- Autogenous vaccines remain an option for DVMs and producers in specific circumstances. It is important to vaccinate for both Moraxella bovis and Moraxella bovoculi whether using commercial bacterins or an autogenous program. Find information on the autogenous program here <Link>.
Consider: Our propensity to abbreviate M. bovis and M. bovoculi creates confusion and may lead to assumptions that even properly administered vaccines have failed. The genus Moraxella sp. versus Mycoplasma sp. are easy to mix up when discussing lab results and diagnoses.
Sources: Search results for: cattle pinkeye, AHD Archives. Link.
Vaccinating for both Moraxella bovis and Moraxella bovoculi combined with solid management practices to reduce environmental stressors and good nutrition will reduce the risks of pinkeye in calves and the cow herd.” – Austin Springer
