Summer Mastitis

This is the peak time of the year for cases of summer mastitis mainly in dairy cows and occasionally beef animals. Summer mastitis is a disaster because the bacteria that cause it destroy the cells in the udder that produce the milk so at best production from the quarter will be severely compromised more often it will be lost all together. For the infection to get established it needs to overcome the defences of the cow or heifer. It does this with the help of flies that are attracted to moisture and introduce bacteria into the teat canal. Individuals with teat damage or warts at the end of their teats are particularly vulnerable to developing summer mastitis.

Swift Action

This infection develops so quickly it is not always possible to notice the early stages of the disease some affected animals will stand away from the rest of the group they may be the ones that are particularly troubled by the flies. The bacteria start to form an abscess in the udder, as it develops one of the quarters will become hot and swollen. It can be difficult sometimes to strip out the quarter as the inflammation and build up of milk will make the animal uncomfortable. Antibiotic tubes will not be sufficient on their own to treat summer mastitis, if possible strip the quarter and insert a tube twice each day and inject an antibiotic and a non steroidal drug to control the inflammation and reduce the pain. Cows will need at least three days of antibiotics, but you should continue to strip the quarter for at least a week.

Preventative Measures

Spot on fly repellents do help to stop summer mastitis getting established but you must remember to renew them before they run out of steam. Teat sealants are helpful as they create a physical barrier to stop the bacteria moving up the teat canal. Dry cow tubes were never really designed to protect cows and heifers against summer mastitis they will be effective when they are first put in but you shouldn’t rely on them for the full time that the cow will not be producing milk. The national animal disease information service indicates that there has been an eighty percent reduction in reported cases of summer mastitis in the past twelve years and the hope is that preventative measures and early treatments will reduce this further.

Dairy Cow Worms

Sample taken from dairy cows at abattoirs show that they consistently carry thousands of worms, mainly ostertagia, in their gastro intestinal tract. It has long been known that cattle develop an immunity to gut worms during the first eighteen months that they are grazing, but this is never complete so worm numbers can mount up to significant levels from time to time. Worm larvae taken in with the grass mature in the gut and steadily reinfect the pasture. During the summer the uptake of larvae is diminished as the larvae are stranded in the dry cow pats, they need moisture to survive and are only on the grass when it is wet so your cows get a bit of a break from the parasites. This will change as we go further into the autumn and the ground is wet again.

Is it Beneficial?

When easy to use pour on wormers were developed with no milk with hold it was thought that it was better to worm all of the dairy cows at least once a year to reduce this worm burden and improve the health of the herd. Often this would be apparent with an immediate production increase, but now after several years of worming dairy herds the increased milk production after worming is not always seen. It would seem to be logical to plan the worming for late in the autumn before winter housing. This is a time when the worm challenge is at its peak and where you can expect maximum benefit as the cows will not ingest many worms during the winter and will stay worm free for longer.

Badger Control

You will have been pleased to hear that the long awaited pilot badger cull has now started and so far the protesters have not managed to interrupt the process to any significant extent. Nobody is happy to have to cull badgers but at last we are starting to put right mistakes that have been made in the past. No doubt in the coming months there will be many more arguments aired in the media. Because things have got out of control it is going to take a long time before we start to see a fall in the number of reactors detected on farms. In Ireland where they don’t seem to have as much trouble implementing control measures when they have a new herd breakdown the accepted routine is to snare and shoot as many badgers as possible on the farm involved to stop the spread of infection. They report that forty per cent of the badgers dispatched are visibly affected by tuberculosis. At best it will be a long time before we get to this level of control for our badgers. It should be noted that in spite of all of this work the numbers of new reactors on farms in Ireland was reduced by just fifty five last year although in some areas there have been spectacular reductions in the numbers of cattle testing positive.

Cattle Vaccine

For as long as I can remember when asked about a cattle vaccine against Tuberculosis MAFF and now DEFRA have always said that they were working hard to develop a vaccine that would be effective in cattle and not interfere with the skin test and that it would be ten years before it became available. I have never been able to find out why it is always ten years away. I am sure somebody said the same words on the radio last week when the badger cull was in the news. Now I have found in a Journal that DEFRA are asking for tenders from companies that can do field trials on the Bacillus Calmette-Guérin vaccine in cattle and an accompanying diagnostic test that would distinguish infected from vaccinated animals.

Field Trials

The trials are to start next year in England and Wales and are expected to last for two to five years. The remit is to determine the sensitivity and specificity of the new test. To work out the effectiveness of the vaccine under UK field conditions and to provide information on the safety of the vaccine and the practicalities of using it on commercial farms.

Possible New Test

This could be a radical change as it would seem that instead of trying to find a new vaccine they will rely on a version of the human vaccine developed all of those years ago and change the testing method so that it will not confuse vaccinated and infected animals. We are out on a limb with this disease as all of the other countries in Europe apart from Ireland, have this disease under control and will be reluctant to allow vaccinated cattle to leave the UK.

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