Randomised Control Trial Comparing Cypermethrin-Based Preparations in the Prevention of Infectious Bovine Keratoconjunctivitis in Cattle.

Jennifer Allan,Steven Van Winden

doi:10.3390/ani10020184

Abstract

Simple SummaryInfectious bovine keratoconjunctivitis (IBK) caused by the bacteria Moraxella bovis is commonly seen in the summer months spread by face flies causing a painful eye disease. This trial investigated the difference in number of cases of IBK between two groups of animals that were treated with two different fly control products, one a pour-on and one an impregnated ear tag. The growth rate per day was also investigated between animals with cases and those without and between the treatment groups. The trial enrolled 197 animals. Cases of IBK and growth rate were recorded over the grazing season (April–November 2018). Fifty-four cases of IBK were recorded. There was no difference in number of cases between the two treatment groups and there was no difference in growth rate between animals that had a case and animals that had not. Animals that had white faces, which in this trial were Hereford cattle and also the animals under 12 months old were found to be more likely to get a case. Overall, there was no significant difference between the two fly control preparations in preventing IBK, younger animals and white-faced breeds are significantly more likely to suffer from IBK. Infectious bovine keratoconjunctivitis (IBK) caused by Moraxella bovis is commonly seen in the summer months spread by face flies. This trial investigated the difference in incidence of IBK cases from natural exposure between two groups of animals, one treated with Cypermethrin pour-on preparation (PON, n = 98) and one with Cypermethrin impregnated ear tags (TAG, n = 99). Daily Live Weight Gain (DLWG) difference was investigated between animals with cases and those without and between treatment groups. A randomised positive control study, enrolled 197 animals split into two treatment groups. Cases of IBK and DLWG were recorded over the grazing season (April–November 2018). Fifty-four cases of IBK were recorded. There was no association between the two treatment groups (p = 0.362) and case status. Breed and under 12 months old were significant factors for having a case; (OR 2.3, p = 0.014 and OR 3.5, p < 0.001 respectively). There was no difference in DLWG between animals that had a case and animals that had not (p = 0.739) or between the two treatment groups (p = 0.215). Based on our results, there is no significant difference between PON or TAG preparations in the prevention of IBK. Younger animals and white-faced breeds are significantly more likely to suffer with IBK.

Highlights

Infectious bovine keratoconjunctivitis (IBK) is one of the most common ocular infectious diseases to affect cattle in the UK
Unpigmented conjunctiva is more damaged by U.V. light and animals in their first grazing season are likely to not have encountered M. bovis previously [2]
A randomised prospective positive control study was used to compare the number of cases of IBK and growth rates of calves split into two groups; Ear tag (TAG) and Pour-on (PON) group

Summary

Introduction

Infectious bovine keratoconjunctivitis (IBK) is one of the most common ocular infectious diseases to affect cattle in the UK. The bacterium involved, Moraxella bovis (M. bovis), is a Gram-negative opportunistic pathogen and can be found on the conjunctiva and in nasal and ocular secretions. In the lead to the clinical presentation of IBK, multiple factors are involved including environmental factors;. U.V. light, dust, fly population, other pathogens present and host factors; age, breed and immunity [1]. Young animals and breeds with unpigmented conjunctiva, for example Herefords, are at an increased risk of infection. Transmission can be from ocular secretions in infected cattle to other cattle through fomites or mechanical vectors, most commonly face flies [3,4,5]. Outbreaks occur more commonly in the summer months due to an increase in fly population and U.V. light exposure. U.V. light causes degeneration of epithelial cells in the cornea and female flies disrupt the conjunctiva when feeding; both allow the

Objectives

Methods

Discussion

Conclusion