A very common call this time of year is for summer mastitis. Like last week on a Monday evening I got a call to a sick heifer. The farmer found her isolated from the rest of the herd and very stiff. On arrival on the farm in a low field beside woods on a warm humid evening, I was greeted with a flurry of flies on departing the jeep. As I approached the crush, slow always to make assumptions I glanced underneath to confirm my suspicions of summer mastitis.
She had a temperature of 104 degrees and severe swelling and inflammation around one teat and quarter. The teat was quiet enlarged with several flies congregating on the end of the teat. While the farmer lifted the tail I stripped out the smelly custard like discharge again typical of summer mastitis. So upon diagnosis we treated her with a parenteral antibiotic and pain killers and also completely stripped out the teat. It is very important when stripping these out great care is taken even in quiet animals due to the pain of the condition. Her aftercare was 4 days of antibiotics and because he had help and was willing, the farmer was going to keep stripping the quarter for the next 4 days also.
So I was asked about how she got mastitis? she was only 14 months and not in calf. Although less common in such animals I have even seen bulls and steers get this problem occasionally in the small teats either side of their penis. Most commonly it affects dry cows but at risk times and risk areas it should always be watched out for.
It is a bacterial mastitis caused by a bacteria called trupella pyogenes which causes an infection in the quarter. It is thought to be spread by the common head fly. This head fly likes the conditions that I drove into that evening, shade near woods and warm humid conditions. Most farmers now know whether certain fields are risk for flies.
The symptoms are like I described above, often starting with the teat enlargement and progressing into the udder swelling and pain. The affected animals often become quiet stiff and isolated due to the pain caused by the mastitis. Most commonly when I see them I will have to amputate the teat to allow drainage of the infection. While regular stripping can help it is usually not an option, especially in beef cattle it is simply too dangerous hence why we opt for lancing the teat or amputation. This is a job that must be done correctly to prevent haemorrhage.
So if the head fly contributes to spread the obvious thing is preventing head flies having access to that area of the cow/heifer. We do this using a range of fly control methods. There are products called synthetic pyrethroids which can be in pourons, sprays or in fly tags. I also still recommend the use of Stockholm tar painted on to the udders in flanks in at risk areas and topped up every 3-4 weeks in combination with pourons.
In real problem areas we have used dry cow therapy quiet effectively with the use of antibiotics and teat seals or also teat seals on their own. The teat seals work well by preventing or plugging the teat and not allow bacterial transfer from the fly. This procedure must be done carefully and extremely aseptically. There are numerous other products on the market so find the solution that works for you and be consistent with relevant applications as required.