SHARING OPTIONS: Cattle grazing rough grazing areas are more prone to red water infection due to the higher prevalence of ticks in these areas. Above is a picture of photosensitisation which is a dermatitis (infection of the skin) which is related to the impaired liver function. There is a build up of metabolites in the skin, which interact with UV radiation from sunlight. Summer mastitis is a common disease in dry cows but is very preventable with correct management. Previous Next Fly activity and mastitis Fly activity has increased a lot over the past two weeks and with that so have the number of cases of mastitis in dry cows and heifers.