Worm Problems

This month there have been reports of mainly sheep, but some goats and alpacas as well that have died as a result of intestinal parasites. Sounds like some people have been caught out when their normal practices have not been adequate or they have tried to manage without their tried and tested worm control. It is not always young animals that die from parasitic gastro enteritis adults are susceptible as well.

Anaemic Sheep

Haemonchus contortus was once thought of as a sheep parasite in the south east of England. It has now become a problem where sheep are kept intensively throughout the UK. This parasite sucks blood if lambs take in sufficient numbers they become anaemic, look at the colour of the membranes around their eyes. There will be swelling under the jaw and if you get them to move you will notice that they soon start to pant. This parasite does not cause scouring, you might think you have a respiratory disease or fluke as it does not look like gastro enteritis. Older animals with Haemonchus will loose weight which if not treated will lead to emaciation as they have no energy to search for fodder.

Lambs with Parasites

Trichostrongylosis and Teladosiosis are the parasites that affect 8 to 10 month old lambs in the early winter. These animals have a profuse dark coloured foul smelling diarrhoea which you will not confuse with anything else. There are other less pathogenic strains of strongyl  worms which may confuse the diagnosis. Strongyl egg counts above 500 eggs per gram should start to ring alarm bells even if you have a mixed infection numbers can build up so quickly that the damage will have been done . As well as the anthelminctic treatments it is important to move the lambs on to a different pasture to give them a chance to recover form the parasites.

Regional TB Policy in Wales

The Welsh Assembly has announced a new regional approach to the eradication of bovine TB. It is still not clear what the intension is to control the disease in wildlife now they have had to abandon their flag ship policy of badger vaccination. There isn’t any vaccine so somehow they will need to come up with a different approach to badger control.

Missing Wildlife Controls

The plan is to establish areas of low, intermediate and high TB incidence across the country with control measures tailored to each region. There will be a focus on risk based assessment with the targeting of chronically infected herds with individual action plans developed for each farm in partnership with farmers, vets and the Animal and Plant Health Agency. The Welsh Assembly is not making it easy here. Until they come up with some legal way to reduce the badger numbers on farms we will just keep on going around in circles.

Lame Dairy Cows

It has long been known that on average 20% of dairy cows show some degree of lameness and this has an impact on their welfare as well as on their milk production. It would seem to me that we have made little progress about understanding lameness and the way to prevent it. There have been improvements in the way that cows are housed and buildings are designed to help the flow of animals for milking, feeding and drinking. It is still not easy to get a surface that is resistant to wear which cattle can walk on comfortably without damaging their feet.

Foot Trimming

The recommendations are that high yielding dairy cows do not have their feet trimmed at all in the first eighty days of lactation as during that time the horn is wearing away as quickly as it is replaced so it will take too long to re grow. The most efficient time for foot inspection and possible trimming is four weeks before drying off. Your thoughts should go to the surfaces the cows tread on and not the lame cow that you have in front of you. The aim should be to keep the feet as dry as possible, repair any areas where the concrete is damaged promptly and groove places where it is worn and they cannot get a good grip.

Daily Treatments

Some authorities advise that all of the cows should pass through a foot bath with 5% formalin once every day. There is some advantageous to use a foot bath with just water in first to pre wash the feet and keep the treatment footbath cleaner, but this did not give any noticeable benefits. It would be better if the feet are not normally contaminated with slurry as you will never get them right. It has been found that the formalin could be diluted down to 3% after a while if you are clear of problems, below 2% it will have little effect so you will need to calculate the amounts carefully.

Mixing Treatments

On some farms they recommend copper sulphate or even a mixture of copper sulphate and formalin. It is strange to think that that essentially we are still using the same strategies that were used fifty years ago as dairy cows have changed considerably in that time. Formalin has long been under threat of disappearing as there are health and safety issues that have to be taken into consideration. It is not the most pleasant of chemicals to work with or dispose. I cannot help thinking that there must be some chemical or additive that would do a better job than formalin or copper sulphate.

New Ideas

There has talk about developing a vaccine against digital dermatitis as it tends to be young cows and brought in individuals that have the most problems with this infection. Older animals seem to be able to resist the infection. There does not seem to be any progress with this, but it has been noted that some family lines are resistant to developing the disease and there is hope that in the future bulls will be selected that can pass this trait on to their off spring.

The Last Worm Dose

At this time of the year there is limited feeding value from pasture and stock may sink in weight and condition if they have a worm burden to contend with as well. There is a tendency to delay the last worm dose until the stock come in. The ivomec type wormers, in whatever form you administer them, do have a persistent action so they will go on killing worms for twenty eight days or more after each application. There is always the option of getting the stock in to worm them and keeping an eye on the calendar to see that they are housed before the end of the activity period is reached.

Easy Worming

 Modern wormers are efficient and effective. It is better to use the pour on products when their backs are dry as, no matter what it says on the box. There will be more that runs off saturated skin and it is an expensive dose if some of it ends up on the floor. It is always difficult when you fatten bullocks and heifers at grass as you might not always know exactly when they are going to be selected for slaughter and you might have to gamble with the gap between worming doses so that you do not put the meat withhold times in jeopardy.

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