Poisoned Cattle

This is the time of the year when botulism cases reach their peak. I know that we have talked about this condition before. The reason I have brought it to your attention again is that some people are not seeing this newsletter and have seen spectacular losses as the result of a gate having been left open or animals managing to get through an electric fence. In our area in the past month there have been reports of twenty four eighteen month old dairy heifers dying and four others being recumbrant for twenty days or more. On another farm thirteen bulling dairy heifers either died or were euthanased over a period of seven days even though they only had access to the poultry manure for two hours or so. Two cows were affected on a dairy farm, these animals did not have any contact with manure, on a nearby poultry farm carcasses were left outside and it was thought foxes had brought the dead hens onto pastures that cows were using.

Poultry Manure

The disease is caused by bacteria that grow in the acidic conditions in the manure and produce a toxin that has the effect of paralysing animals that eat it. There is no antiserum and no effective treatment, animals that survive are the ones that have only had a small amount of the toxin and are able to regain their strength, most affected animals will not survive. Broiler waste is the most dangerous particularly if there are any parts of carcasses mixed in the manure. No poultry waste is completely safe. It should be kept well away from cows and young stock. I realise that it has to be stored somewhere before it is spread on the fields , so make sure cattle can gain no access to the tips and are not walked across fields where. the manure has recently been spread. Once the muck has been incorporated in the soil there is no risk. In these dry conditions at the moment it will stay on the surface for some time and you will need to be extra vigilant.

Worming Dairy Cows

There has been some literature circulating to the surgery about worming cows, I think some of it may have been sent out to you as well. Most herds will see a significant increase in their milk yields if they worm adult cows and heifers once during the year. The reason they target the summer is this is when the challenge from lungworms usually starts and it is a good time to put a halt to the worm cycle. In times of drought cattle get a holiday from the worms as the larvae are unable to survive in the dry conditions and instead of their usual trick of migrating up the grass stems when the dew is on the grass they are trapped firmly down with the roots as they need some moisture to survive. Also dung pats dry up quickly in the sort of temperatures that we have had recently and any worm larvae will be trapped inside undisturbed by grazing animals until it next rains. I have not come across any problems with lungworm in dairy herds so far this year.

Wait for the Infection

When it does rain there will be a significant worm challenge and the most logical time to use the wormer is three weeks or so after the weather breaks as that will be  when the cows have to cope with all of the summers worms. It does not matter too much when you worm the herd in the autumn as long as you do it sometime. The drug is supposed to be weather proof, but there will inevitably be some run off if the cattle are wet. It is expensive stuff to pour on the ground so it would be better to use it on a dry day if you can.

Abortion Vaccines

Toxovax does seem to be about and available this year, it is the live vaccine for sheep to protect them against infertility and abortion caused by the toxoplasma parasite. The vaccine always has a short shelf life and is delivered to us direct from the manufactures so should be kept refrigerated and used as soon as possible once it arrives. This vaccine should not be used within three weeks of mating the ewes. It works well if given at the same tine as the enzootic abortion vaccine as long as you give them both on different sides of the body. By the time sheep get to the lambing pens you would have invested a great deal of time and effort to them. Often protection from abortion is the last piece of the jigsaw to maximise the lamb crop.

Downer Cows

The recent rain has been welcome to revive the grass. Before it started and even now we were having problems with downer cows. I think this has been because their feet have become so dry they slide on any hard surface. Sometimes in dry summers vertical cracks will start in the wall because of the dry conditions, these are difficult to manage if they work their way up to the coronary band. If the dry weather returns there may be some advantage in walking the cows through a foot bath with just water when they come out of the parlour to get some moisture into their feet.

Infected Eyes

Recently I have seen several calves with severe eye infections. It is difficult to determine the exact cause. Some may start as trauma, the eye may have been knocked, hair or dust could have irritated the eye. In the summer this simple situation develops because flies are attracted to the moisture around the eye and can transmit a bacterial infection Moroxella bovis that will cause ulceration to the front of the eye. Sometimes the whole of the eye suddenly becomes inflamed and infected and the front part of the eye begins to point because it has become so inflamed. These eyes are often infected with an infection from the soil called listeria. Sometimes both eyes are infected and the calf will have real difficulty working out where the boundaries of the field are and where the rest of the group are.

Don’t Give up Hope

Inflamed and infected eyes are sensitive to light and it is difficult to catch and treat them on a field so it is far better to get them into a building away from the sunlight. If the eyes are severely infected they often respond better if we can inject an antibiotic under the upper lid. Any ointments we use will drain out of the eye with the tears so they should be repeated at least daily. Eyes do have a remarkable ability to recover from infection and even the most hopeless cases will come right if you are patient with them.

Micotil

The European Commission has finally published a safety warning for Micotil following the deaths of two farmers in North America and severe adverse reactions associated with accidental self injections in Europe. Although there have not been any problems in the UK new regulations dictate that any Micotil dispensed after 30^th July 2006 must be administered only by a Veterinary Surgeon.I have no doubts that you can safely give this injection but for on farm use we will find you a safer alternative for pneumonia cases.

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