Transcript Pink eye
Pink Eye James Reecy Annette O’Connor Abebe Hassen Gary Snowder Pink Eye Reported in the USA since 1889 45% of Missouri herds have endemic IBK Average prevalence = 8% More common in the young – 10-60% Immunity develops with age No gender affinity How Effective Are We At Controlling Pink Eye? Kansas ranchers reported it as the 2nd most common infectious disease in 1993 NAHMS : diseases with economic impact Internal/ external parasites (way in front) Open cows Pink eye Foot rot Between 17 and 65 lbs decrease in weaning weight $150 million yearly General Information What causes “pink eye” Moraxella bovis, ……, is considered to be the cause of IBK” Gellatt 1131 “ food animal ophthalmology” page What Causes “Pink Eye” Moraxella bovis Brannamella ovis? High UV light Dust IBR infection IBR vaccination Mycoplasma infection Mycoplasma bovoculi Trauma Face flies- Musca autumnalis (since 1946) What Causes “Pink Eye”? M. Bovis Long Grass UV Light Stress What Causes “Pink Eye”? M. Bovis Face Flies UV Light Why Do Only Some Calves Get Pink Eye? Individual differences Genetics Dam colostral immunity Options For Control/ Prevention Remove reservoirs for M.bovis Cattle ( sub-clinical carriers) Face Flies, Stable Flies, Horn Flies ( for 3-4 days) Wildlife ? Options For Control/ Prevention Are the technologies up to the job? Options For Control/ Prevention Not up to the job Vaccines Fly control Dust control Pasture clipping Options For Control/ Prevention Vaccines: Pilated forms of M bovis are virulent – allows attachment At last count there were 7-8 pili groups, they do not provide much cross protection Each pilis type is associated with specific ab production Failure in vaccines is due to low cross protection and emergence of new pili. Also naturally animals produce lacrimal IgA to M bovis, vaccines stimulate serum IgG, IgM, and secretory IgA Why Does Control/ Prevention Fail? Fly control Adulticides, traps, larvicide's rarely achieve > 50% control Due to small amount of time spent on animal At any one time , < 5% of the entire female population ( only females) on cattle Overlapping generations means that traps don’t work Local migration is easy – they moved from Nova Scotia to in 1950’s to North Dakota in 1960: renewing populations constantly What The Future Options Genetic selection Improved vaccines Better treatment Assumptions Genetic variation in resistance/ susceptibility to the pinkeye exists Low heritability (<.15) Disease incidence is low ~10% Requirements of the project Serve as a model for disease resistance/susceptibility research Internal parasites Respiratory Use field records Need - nematodes to develop data collection scheme Need ~8,000 records Data Collection Two seasons When cases are actively observed Weaning Scoring system Data sheets Score 1 – An active lesion involving less than onethird of the cornea. Score 2 – An active lesion involving one-third to twothirds of the cornea. Score 3 – An active lesion involving more than twothirds of the cornea. Score 4 – An active lesion with perforation of the cornea Herd Code: ______________ Instructions: 1. During the summer months when pinkeye is active and observed in the herd, make a record of each calf that exhibits tearing in one or both eyes, or has a visible eye lesion (see scoring card). Multiple records on an individual calf are permissible, just be sure to record the observation date for each record. 2. At weaning time when you take your weaning weights, reevaluate the all calves. Record all calves with a current “pinkeye” infection or “healed’ calves with cornea scarring (see scoring card). IBR Vaccination Program Mature Cows First Calf Heifer – Pre Calving Calves Pinkeye Vaccination Program Mature Cows First Calf Heifer – Pre Calving Calves Vaccinated (y=yes,n=no) Date Vaccinated Dosage 1 Date Vaccinated Dosage 2 Product Vaccinated (y=yes,n=no) Date Vaccinated Dosage 1 Date Vaccinated Dosage 2 Product Stress Calf Tattoo Observation Date mm/dd/yy 0. 1. 2. 3. 4. Conditions None Dusty Tall Grass Flies Other (specify) Treatment Active Infection Tearing or Eye Lesion Present in left or right eye Left Right 0. 1. 2. 3. 4. None Antibiotic Patch Sutured Other Healed Eye(s) Cornea Scar Severity Left Right Current data collection Iowa State – Rhodes Research Farm American Angus Association Contacted a few breeders to start collecting data Iowa, Missouri, Indiana, Wisconsin Universities Ohio State Kentucky Percent of Infected vs. non Infected in August 44.6 55.4 %Non Infected %Infected Percent of infection per eye %Infection in left eye 18 44 38 %Infection in right eye %Infection in both eyes August Severity Call Change in Severity Over Time 0 1 2 3 4 0 205 29 3 3 1 25 32 5 4 14 2 2 3 1 4 1 2 1 3 2 2 1 August Severity Call Right No Abrasion Abrasion Left No Abrasion Abrasion No Abrasion 205 Abrasion 29 35 66 No Abrasion 220 Abrasion 21 18 76 Data Analysis No sex or eye effect Heritability MTDFREML Model Y = + CG +animal +PE + error CG = Sex-weaning group (4) PE = permanent environmental h2 = 0.18 MARC Pinkeye data Gary Snowder 19 years of data Calves listed as being treated in the herd book Number of records 907 to 10,947 head per breed 1.3 to 22.4% incidence Breed Angus Hereford Red Poll Charolais Simmental Limousin Gelbvieh Pinzgauer Braunvieh MARC I MARC III N 6,347 4,579 998 2,878 1,775 961 2,391 908 907 4,336 10,947 Incidence 3.7 22.4 3.1 6.5 7.6 3.4 2.1 1.3 1.8 3.9 5.9 h2 0.25 0.28 0.09 0.00 0.10 0.11 0.05 0.02 0.12 0.03 0.26 PREVALENCE BIK HEREFORD AND ALL OTHERS 70 60 50 40 30 20 10 0 1983 1986 1989 1992 1995 1998 2001 Future Direction Moraxella bovis infection rate vs. Corneal abrasion Field data collection Mechanism?