Farm
Fly Control on the Farm
added 30th May 2011
Well, its the end of May, and the weather’s really warming up now...and that means FLIES!
On the cattle, there’ll also be lice starting to cause some itching and worry, and the nuisance flies will have them gadding before long.
On sheep though, flies are far more dangerous. Even if they’re dagged well, flystrike is a real risk at this time of year. The flies are attracted by the smell of dung*, and lay their eggs in it. All’s well and good so far, because flies and their eggs are the main reason we aren’t waist deep in the stuff - they’re vital to its decomposing.
However, when they’re on a sheep’s backside, the maggots that hatch from the eggs don’t just eat the dung - they start to eat the sheep, too. Then more flies come and lay more eggs, and if you’re not careful, soon enough you end up with the sheep’s back end being a heaving mass of maggots as they eat her alive. That’s flystrike. (By the way, its not just sheep - rabbits suffer really badly from it too!).
So, what can be done to prevent it?
Well, firstly, good management. On lowland flocks, tails should be docked when possible, as without the tail to trap everything, their backsides dry out quickly and are much less attractive to those pregnant flies.
Also, sheep should be dagged regularly (for those of you new to sheep, that means trimming up all the dirty wool and droppings around the backside).
At this time of year, you should also be thinking of shearing, especially longwool breeds - less wool means less to dag, but it’ll also make the sheep more comfortable and give the maggots less to hide in. One June, several years ago, I saw a longwool ewe who looked a bit tender on her rump, but otherwise looked fine. I pulled back the wool to see a carpet of maggots with a bit of hipbone sticking through... Not a lot that you can do with that, sadly, and she was on the cull waggon that afternoon. The trouble was, the long wool had completely hidden the severity of the problem.
But all too often, these simple things aren’t enough, and you need a bit of help.
This month, we’re starting a special offer on Clik and Coopers Spot-On - two preparations designed to deter and kill flies, their eggs, and the maggots. Spot-On is even licensed to treat established flystrike, not just prevent it!
Having seen all too many case that could have been prevented, I really advise anyone with sheep to seriously consider using these or another similar product - it’s just not worth it not to, on economic or welfare grounds.
David Harris BVSc MRCVS
MyVetMeds
* by the way, I’m obliged to say “dung” here rather than anything more descriptive, because this blog is also open to children...!
Easter Indulgence on the Farm
added 2nd April 2011
Although a lot of flocks have finished lambing now, here in the West Country we’re still going strong, with the last ewes of the “early-lambers” finishing as the moorland flocks begin. On my holding, we’re still waiting for one old ewe to lamb down, while many of the surrounding smallholders are just starting.
A good friend of mine runs a large dairy farm, and has just diversified into sheep. She actually had a ewe that produced quins - yes, 5 viable, healthy lambs! - this spring. They were all reasonably sized (like a normal big triplet or small twin), and 2 weeks on, they’re all still going strong, with little or no supplementary feeding. 4 of them were ewe lambs, and I think that’s a line they’re going to want to breed from as they grow the flock!
We can’t all have such prolific ewes (sadly!), but we can do a lot to support the lambs we get. The key thing, of course, is colostrum. This “first milk” is thick and creamy - sometimes almost yellow - and is ultra high-energy, giving the newborn lambs all they need to get them started. More importantly, lambs are born with little or no immune system, and the colostrum gives them antibodies and immune cells. Cleverly, a ewes colostrum will give immunity to the diseases the lamb is likely to face on that particular farm.
The lambs have to get colostrum as soon as possible, because after 24 hours, the gut “closes”, so the lamb can’t absorb the immune cells and proteins. If a lamb hasn’t has colostrum by a day of age, it almost certainly won’t survive.
This is a major problem for lambs of ewes with poor quality or very little colostrum (perhaps they’ve had mastitis, or twin lamb disease); and for orphan lambs. For these groups, artificial colostrum is the only answer. It is possible to use cow colostrum, but it needs modifying to be fit for lambs to drink - and, of course, it relies on a cow calving down at the same time as the ewe! More convenient is the powdered colostrum, like Col-Late. This comes in single-dose sachets, and just has to be mixed with warm water, then given by bottle or stomach tube. One of my ewes produced a rather sickly little lamb, so we gave him a bottle of Col-Late colostrum: he picked right up, and is now a healthy bouncing thug of 5 weeks!
Sometimes, you get a sickly or weak little lamb, that you just want to give a helping hand to - personally, I like the Col-Late Kick Start (yes, I gave my weak one a good dose of this as well!). It’s a general purpose boost and tonic for lambs up to 3 weeks of age.
The other important thing about sickly lambs is to keep them warm - a draught-free pen or stall (or a box lined with straw and a blanket on top) is great. Sometimes supplementary heat from an infra-red heat lamp is useful, it can work wonders - remember the old shepherds, who used to put weakly lambs into the oven for a few minutes!
David Harris BVSc MRCVS
Spring Campaign- On-farm worming
added 28th February 2011
As stock get turned out to pasture in the spring, they become exposed to the larvae from last season’s worms, which have lain dormant over the winter. Many roundworms overwinter on the pasture, ready to infect stock in the spring - even the snow and ice we’ve seen this season won’t have killed them all, and as the weather warms there will be L3 larvae crawling round the pasture, just waiting to be eaten and infect young stock (especially calves). In untreated herds, as many as 75% can develop symptoms, including scours and weight loss. Some species, like Nematodirus battus, can survive on pasture for years, infecting lambs in the spring following a mass hatching on the pasture in early-mid spring. These worms are particularly nasty, as the ewes are unaffected, while their lambs succumb around them.
Other roundworms, (like Ostertagia and Cooperia) survive over winter inside the gut, going into hibernation (“hypobiosis”) until the spring. Then, many hundreds of worms can emerge together, causing severe damage to the gut wall, and set stock back by months, or even result in significant losses. This “Type II” disease is more common after a hard winter, and although it usually only affects a proportion of the herd, symptoms are usually more severe and more likely to result in fatalities.
Ewes (and goats) often start releasing worm eggs at around the lambing. This “periparturient” or “Spring Rise” puts the new season’s lambs at risk, and can even cause a loss of production in the ewes. As a result, it is often wise to worm ewes before lambing, to reduce the contamination of the environment, and the infection of their lambs.
Worms are a common cause of lost productivity, in growing, finishing and breeding stock; but they can be deadly for young animals turned out to graze in the spring. If you have a particular problem on your farm, you can always talk to your vet to arrange a tailored parasite control plan; or decide on a program of routine worming. To make life easier, this spring, we’ve discounted a range of wormers for your farm, helping you to nail the worms before they affect your bottom line.
Sudden Death in Farm Animals
added 9th February 2011
Sudden Death In Farm Animals
Last week I seemed to spend all week around dead animals. I hasten to add that I did not aid the beasts on their way but they were all ‘found dead’. The first was a 3 year old bull in the prime of his life out in the field supposedly enjoying the sudden addition to his life of multiple female members of the species. One day he was fine, the next the farmer found him dead under the hedge. It is the farmer’s duty to report a sudden death so that his vet can check the carcase for anthrax before it is moved. Anthrax is a notifiable disease as the spores are highly infectious and can cause serious illness and even death in both animals and humans. To test a carcase for anthrax requires taking some blood and then making some blood smears on microscope slides. These slides are then taken back to the practice for staining and microscopic examination. Making blood smears is a fairly simple procedure except when you are in the middle of a field and it is raining as it was on this occasion!
Fortunately the test showed that anthrax was not present and therefore not the cause of death. Once a vet has confirmed this to the owner then they can arrange for the carcase to be removed by their fallen stock collector. In this case the owner had only recently purchased the bull and was keen to know the cause of death. Thus once the bull had been collected I duly went to the collection centre to carry out a post mortem examination (PME). The PME indicated that the bull had contracted a Clostridial infection which resulted in the rapid multiplication of bacteria and release of toxins into its body and subsequent death. The most frustrating aspect of this case is that Clostridial bacteria are present everywhere and thus any bovine in the UK can contract the disease but it is easily preventable by the use of cheap but effective vaccines. From now on this farmer will be routinely using Clostridial vaccines in all of his stock. The animals need a primary course of 2 doses of vaccine 4-6 weeks apart and then an annual booster.
Useful Products: Bravoxin
Clare Finn BVSc MRCVS
The trouble with eyes! Part 1: Conjunctivitis
added 31st January 2011
Horses are very prone to various conditions affecting their eyes. Some are more serious than others, but all have the potential to be painful and difficult to manage.
Conjunctivitis is a very common condition, often seen in the summer months when flies are abundant. It can be contagious, but in general seems to affect individual horses rather than an entire yard. Bacteria are generally to blame, but sometimes fungi and viruses have been implicated. Some cases of conjunctivitis are caused by allergic reactions. It is thought that flies carry the germs onto the eyes whilst feeding on the normal secretions found around the eyes.
Conjunctivitis is the inflammation of the soft pink tissue around the eyeball- the conjunctiva. It doesn’t affect the surface of the eye- the cornea. A horse with conjunctivitis may have swollen eyelids and want to rub the eye. It can be difficult to see what is going on underneath all that swelling. In milder cases the eye produces more discharge and this is often white or yellow rather than watery like tears. Conjunctivitis can affect one or both eyes- the latter is often seem in a case of conjunctivitis caused by an allergy.
Any condition affecting the eye requires veterinary advice at the very least. This is because there are a lot of “nasties” out there that can look like simple conjunctivitis in the first instance, only to go on to be a major problem- such as an ulcer or scratch to the cornea or uveitis- a very painful condition that can lead to blindness if left untreated.
Conjunctivitis normally responds very well to antibacterial eye drops or ointment. The frequency of application depends on the condition and your vet will instruct you on this, but often it can be up to 3 times a day.
Steroid eye drops are occasionally prescribed if the inflammation is severe, but care must be taken to ensure the surface of the eye is not damaged, as steroids delay healing of any surface damage and can make matters worse. Your vet will put an orange stain in the eye to check for ulcers or scratches. If the cornea is damaged the stain shows up green on the damaged areas.
Conjunctivitis can also cause the tear ducts to become blocked. So tears run down the face instead of via the tear duct down the nose. Again, the special stain mentioned previously can be used to check to see if the tear ducts are open. If intact, the dye will appear in the nostrils after a few minutes- indicating that the tear ducts are working! It is important to control inflammation and preserve the tear ducts, as permanent blockage leads to tears continuously running down the face.. This can scald the skin and also increases the risk of future episodes of conjunctivitis as flies are attracted to all the extra secretions around the eyes.
If the eyes are very swollen, vets will often describe an anti-inflammatory pain killer such as phenylbutazone (bute). This brings the swelling down very quickly- making it much easier to get the medication into the eye.
There are several things you can do to try and prevent conjunctivitis. Regularly clean the eyes with clean cotton wool and boiled, cooled water or a weak tea solution (no milk!) Weak black tea has antiseptic properties and wont hurt the eye. Wipe the eyes clean starting at the outer corner nearest the ear and wiping across to the front. In summer use a good fly repellant and fly hood to protect the eyes from flies. Make sure the hood doesn’t sit too close to the eyes as it can be irritating so go for one that appears to have protruding “bug eyes!” Regularly wash the hood to avoid any accidental introduction of infection via the hood itself. If your horse has conjunctivitis in one eye, make sure you wash your hands after treating the eye and preferably clean the good eye first. Wash your hands between dealing with each horse to prevent possible spread of germs.
Finally- don’t put anything in a horses eye that you wouldn’t happily put in your own eye! A lot of lotions and potions can be irritating to the eye and actually make matters worse.
Always speak to your vet about a sticky eye. I can’t stress this enough! There have been many occasions when I have seen a nasty case of corneal ulceration that the owner thought was “just a conjunctivitis” so left for a few days before calling us. From a vet’s point of view, serious eye conditions such as ulceration do so much better if treated early on in the process. We are fighting an uphill battle if we only see the eye after a few days when all manner of complications may have set in!
