What is VTEC 0157?

This is the gut organism that can cause severe disease in children, some elderly people and patients that are on drugs that interfere with their immune system. It can affect anybody often the symptoms are mild but for unknown reasons some people are very sensitive to the infection and may suffer kidney damage that can be permanent. The organism is carried in the gastro intestinal tract of cattle and sheep. It does not affect livestock adversely in any way but it is the cause of over a thousand food poisoning incidents each year and it is hoped that studies will reveal the true extent of the infection on farms so that steps can be taken to control the infection.

Personal Hygiene

The chances are that if you have the organism on your farm you will have immunity to it by now. To limit its spread you should always wash your hands before eating and take care not to wear any outer clothes that have been in contact with your livestock in the house or kitchen. Take extra care when there are young visitors about, this is one of the reasons why schools are now reluctant to visit farms. There is no reason why young children should not have close contact with animals as long as you make sure they wash their hands afterwards.

Farm Monitoring

The Veterinary Laboratories Agency are to undertake a study to evaluate simple control measures that you can undertake on the farm to limit the spread of VTEC 0157

They want to identify affected farms by taking faecal samples from buildings and fields. Then the idea is to sample every six to eight weeks for the period of a year. In this way they will be able to see if simple control measures such as isolation different groups of animals, changing bedding frequently and keeping water troughs clean will eliminate the infection from the farm. More work is needed to determine any management practices that might make it more likely that some farms are affected by this problem. This is a difficult situation to deal with. Organisms like Salmonella are relatively easy to identify as it affect both stock and people you know where to look for it if your calves are ill. This will involve many more samples and long term monitoring to find the full picture. It is not clear how the survey will be run or if the results of the study will be published. It might well be that the intention is to develop new codes of practice on how to manage farms and limit the spread of disease. It is difficult to see how we could ever get to a point where there are no health risks to people who visit or work on farms no matter how much monitoring is done.

Lead Poisoning

It is not very often that animals are poisoned by lead, but it remains the most common poison that farm stock have problems with. We see so few cases now that I did not realise that there is a seasonal incidence of lead poisoning. Cases are seen mainly in May, June and July. Calves are more likely to be affected than adult cows, as they like to lick at things and readily absorb the mineral into their blood stream. Calves seem to like the taste of this mineral and will actively try and find it. The course of the disease can be rapid often leading to sudden death with no apparent illness. Sometimes affected animals will appear to be blind, pressing their heads into corners and walking in a strange way as they lift their feet high above the ground. There is an antidote that reduces the amount of lead in the blood stream, but this will only work if they have absorbed only modest levels.

Investigations

One recent case that I had investigated revealed that the source of the mineral was some mine waste disturbed when new drainage pipes were put in. Many sites were investigated as other areas of the farm had been disturbed as stone had recently been used under concrete in a yard. It was also of interest that paint samples taken from a tractor and digger parked on a field the calves had access to were high in lead. It was not thought that the calves had been licking this paint, but it is still a potential hazard. Another way that calves can be poisoned by lead is if they lick at old car batteries or ash where painted wood has been burnt. It has been known for cattle to ingest used engine oil or grease, both of which can have potentially toxic levels of lead.

Plastic Bottles

Norbrook have announced that they are to put all of their calcium and magnesium mixtures into plastic bottles. It has surprised me that they have not done this before. They say that the old flutter valves will fit their new plastic bottles, but recommend that you use a Quick Fit Flutter Valve and tube that fits through the top of the bottles. They will supply one of these in each box of twelve bottles so hopefully you will not have to buy one separately. This sounds like a good idea, as the old style flutter valves are difficult to sterilise and have a habit of not working very well when you most need them. Also plastic bottles are easier to dispose of and should stay intact if you drop one.

Coughing Cows

Husk is about again. The summer rain that keeps the grass growing also helps the lungworm larvae. In dry summers the parasite is trapped in the ground, when the grass is wet the larvae are found on the leaves and more of them are consumed when the animals graze. There is a constant battle going on between the immune system of the cow and the parasite trying to get established in the body of it's host. At times of stress such as pregnancy or expected high milk production the pendulum will swing in favour of the parasite. Cattle should not cough during the summer months, if they do it is because they are coughing up lungworm larvae that have reproduced and finished their life cycle so that more eggs are spread onto the fields. Modern wormers are very good and are the only thing that you can use when you hear your cattle coughing in the summer and autumn. You might be able to keep the parasite under control by this means alone although the dosing needs to be repeated each year. Some farms find the lungworm vaccine more effective. I never hear cows cough on farms that vaccinate all of their calves before they first go out in the spring.

Flock Management

Did your lambing go on and on last year? There can be several reasons for this if the rams have been over worked or not working properly. Sometimes Toxoplasma infections can play a part with sub fertile ewes, but most of the animals affected during the summer would not breed any way. It is possible if you have enough rams to compress the lambing period by using intra vaginal sponges. They are easy to insert. They should stay in place for fourteen days and depending on how early you want the lamb work better if the ewes have a hormone injection when the sponges are removed. If you can it is better to have a ram to ewe ratio of 1:10 and to make sure that they are on a small field so that all of the ewes can be found. Not all of the ewes will lamb in the first week, but you will get a break of three weeks before the rest of them produce so it is easier to organise the lambing sheds.