Rick Farr B.Sc (Hons), B.V.Sc, MRCVS of Farr & Pursey Equine Veterinary Services gives his expert advice on worming your horse

Q: “Worming — how often do you worm your horse? Do you do it twice or four times per year? And what fundamentals should I know and bear in mind when it comes to worming?”

A: Worming is one of those subjects that everyone is always unsure of, however still manage to almost ‘muddle through’.

In my opinion, there are just a few items to remember when it comes to worming your horse:

1. There is no one single treatment protocol that fits all horses.
2. It is important to monitor the levels of parasite burden and treat accordingly.
3. Environmental contamination / burden of parasites should not be underestimated and pasture management is paramount in worm control.
4. Roundworms and tapeworms are treated very differently.
5. The very young and very old should be wormed more regularly.

So in answer to your question, how often should you worm your horse? If you are like me you were probably taught years ago to worm every 6-12 weeks. This can still be true in some circumstances, however the vast majority of our equine population should not be wormed this frequently. It is more important to ascertain whether you horse needs worming in the first place. Regular worm egg counts are necessary during the grazing season, which can be between March and September (weather dependent). Horses with single high worm egg counts, regular elevated counts or susceptible horses (very young or old) do then need treating. It is also important to remember that worm egg counts will only show you if your horse has a burden of roundworms, not tapeworms.

So what is a high count? Within our practice we class counts above 250 eggs per gram of faeces as above normal and therefore requiring treatment. With numbers over 500 we then give additional advice with regards to treatment as it is likely that the use of a wormer may cause anything from diarrhoea to colic symptoms.

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So you have found out whether your horse needs worming – but when do you treat? Once again, monitoring the worm egg count will tell you how often during the grazing season but, if the counts remain high, rotating the wormer drug class every six weeks may be necessary to get parasite populations under control.

Tapeworms are slightly different. Again, there are accurate ways of finding out whether your horse has a burden and I would advocate having either a blood test or saliva test done to check the levels of parasite burden. However, we still recommend that tapeworm treatment is done twice a year, in spring (March/April) and autumn (September/October).

Also all horses should be treated for encysted redworm, which at the moment cannot be tested for, typically around December. Make sure you choose a wormer that is effective against encysted redworm as not all wormers are.

There are also a few fundamentals you need to consider when it comes to worming:

1. We do not have any new wormers on the market, therefore over use or unnecessary worming results in resistance to the drugs. We already have a significant amount of resistance to all of the drug classes. Drug use should be strategic and part of a controlled management program.
2. There is usually only a small proportion of a herd which has a parasite burden. This small number reinfects the rest of the herd. If you identify these individuals through worm egg counts it is much easier to control parasites; this way the whole herd benefits.
3. High parasite burdens can cause weight loss, colic, performance issues and even death, parasite monitoring and strategic control can save you money in the long run.

Your vet will be able to give you a tailored worming protocol for your yard; get in touch with your local practice and get the advice you need to keep your horse healthy and also save you money!

The body of an emaciated horse has been found “dumped like rubbish” by the side of the road.

The piebald colt was found dead next to Lower Stock Road in West Hanningfield on Saturday (7 January) in an “extremely poor” condition with rope tied around his neck.

A witness said they saw a white pick-up truck pull up and leave the body there around 5.30pm.

The RSPCA is now appealing for information.

“It is difficult to know for sure how this horse died, but he was in a terrible state and would definitely have suffered before he died,” said RSPCA inspector Kate Fletcher.

“The horse was very young, probably just a year old, was suffering from diarrhoea, and emaciated. He looked as if he had had redworm and not been treated for it.

“The rope was likely put round his neck to drag him so he could be dumped like rubbish by the side of this road.

“We urge anyone with any information about how the horse died and how the body came to be dumped in this way to call us.

“Sadly it is not uncommon for horses to suffer from redworm at this time of year. This is easily treated, but if they are not they go downhill very quickly. We would like to remind all horse owners to de-worm their animals at this time of year.”

Anyone with any information should call the RSPCA on 0300 1234 8018.

Related articles:

• How to reduce the serious risk of small redworms in horses
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Treating worms in horses

Worming horses is an important part of every horse owner’s basic horse care routine. Internal parasites which are cause for concern include small strongyles (small redworms), large strongyles (large redworm), tapeworms, roundworms, pinworm and encysted small redworm.

Encysted small redworm are particular worrying. The larval stage of the small redworm bury into the lining of the gut, where they lie dormant. They can then develop and emerge en masse from the gut wall in the early spring, causing diarrhoea and colic, with a mortality rate of up to 50%.

It is not currently possible to test for encysted small redworm, although a new saliva test is under developement, so it is recommended that all horses are treated to remove these in late autumn or early winter to remove the associated risk. All other worming should be undertaken only when tests show a horse is carrying a specific worm burden.

“Don’t be afraid to ask for help” was the take-home message from equine internal medicine specialist Dr Wendy Talbot at the British Horse Society’s (BHS) welfare conference this week (20-21 September).

Parasite resistance and ongoing research mean advice around worming has changed a lot in recent years.

“I think something that is quite misunderstood is how serious this problem can be and how tricky it can be to sort out the right worming control programme for your horse,” said Dr Talbot.

“You certainly should not be afraid to ask what the most up-to-date advice is.”

During her presentation, Dr Talbot showed what can happen to any horse who is left with severe untreated worm burdens — or when parasites are treated too late.

This includes colic, weight loss and in severe cases, a ruptured gut and ultimately death.

Larval cyathostominosis, the emergence of encysted small redworm en masse from the gut lining, is fatal in 50% of cases.

Faecal worm egg counts cannot give an indication of whether a horse is suffering from encysted small redworm, so horses need to be treated for this in late autumn or early winter regardless. The presence of tapeworm also cannot be detected in faecal egg counts, although vets do offer blood and saliva tests.

Dr Talbot stressed pasture management as the “most important” preventative measure in avoiding horses building up major worm burdens.

“Get out there and pick up the droppings, ideally every day, but if not, twice weekly will still help,” she said.

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Top tips:

• Ask your vet or a suitably qualified person for help in preparing a worming plan for each horse — advice has changed in recent years
• Remove droppings from your fields
• Carry out egg counts every two to three months — this will help with targeted worming
• Keep a log of what wormers you have used over the past few years to avoid using the same drug time after time, where possible
• Don’t forget egg counts cannot give an indication of encysted small redworm. Horses need treating for this in late-autumn/early winter

Don’t miss next week’s issue of Horse & Hound — out Thursday, 28 September — for a full report from the BHS welfare conference

With the nights drawing in, there is no denying that autumn is here. Make sure you and your horse are ready for the colder weather with our seasonal horsecare guide.

1. Hardcore
Putting hardcore down in gateways before the winter will help these areas stay compact, and prevent them from becoming too muddy and slippery.

2. Winter rugs
If you didn’t get your winter rugs cleaned and repaired in the spring, now is the time to do it. Or if you need new rugs, it’s time to go shopping! Take a look at the latest rugs on the market.

3. Clippers
Get your clippers serviced and the blades sharpened by a specialist so you are ready to tackle those winter woolies. If you want to learn how to clip like the experts, check out our clipping masterclass video.

4. Worming
Autumn is the ideal time to test and treat horses for tapeworm, while vets recommend all horses should be wormed for encysted small redworm during November/December. So now is the time to get organised and order your worming supplies, checking that the active ingredients are the right ones for the the types of worms you are targetting.

5. Bedding
Choose bedding wisely if your horse is to be stabled in the coming colder months. If your horse suffers from respiratory problems consider using a dust-free bedding combined with rubber matting. You may find you can save yourself money by buying in bulk.

6. Dietary changes
If your horse is overweight the next few months is the ideal time to slim him down, or if he is inclined to lose weight now is the time to start thinking about his autumn/winter feeding regime before any weight loss occurs. Remember that good quality forage is important before turning to cereal feeds. Feeding oil will also help maintain condition.

7. Mud fever
Mud fever can start in autumn if conditions are wet and muddy. Avoid long periods of exposure to these conditions, as bacteria from the soil can enter the horse’s body through damaged skin or cuts.

8. Vaccinations
Check if your horse’s vaccinations are due. It’s easy to allow them to slip and costly if you have to restart the full course. Consult your vet if you are unsure what vaccinations your horse needs.

9. Teeth
Get your vet or equine dental technician to check your horse’s teeth before winter, to ensure they are able to make the most of their feed. This is particularly important for youngsters and older horses.

10. Grass
Laminitis is most commonly associated with spring grass, but cool nights lead to an increased accumulation of sugars in grass. If you own a laminitis-prone horse consider whether you need to restrict their grass intake.

11. Fly gear
Clean your fly sheets and masks and store them ready for use in the spring. Bring all your fly sprays, shampoos and other liquids indoors to prevent freezing and thawing, which may make them less effective.

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12. ‘Winterise’ your yard
After the ground has frozen you won’t be able to sink new fence posts, so make sure they are all secure now. Check gutters and downpipes are in good condition and clear of debris. Insulate your pipes and unhook hoses when not in use, especially during the night when it may drop below freezing.

13. Cooling
If your horse works up a sweat while being ridden, have a wool or fleece cooler to hand to throw over him while he’s cooling down to prevent him from becoming chilled.

14. Shooting
If you live in an area where deer stalking or shooting may occur, it is best to avoid riding out at peak times. Outfit yourself and your horse in bright colours or talk to your fellow riders to make sure you can be seen and heard.

A new video has been created to alert owners to the potential fatal effects of encysted small redworm.

The animation explains the life cycle of the small redworm, and the life-threatening damage it can do to horses.

The parasite is ingested during grazing, then larvae survive in autumn and winter by burrowing into the walls of the intestine. Here they form cysts and their development pauses as they “hibernate” over the winter.

Up to 90% of the small redworm in any horse could be these encysted parasites.

In spring, the larvae can erupt from their dormant state, to carry on their development, in large numbers. This causes damage to the walls of the intestine, which can lead to diarrhoea, weight loss and colic.

This condition, known as larval cyathostominosis, is fatal in up to 50% of cases. Any horse can be affected, with those under six particularly at risk.

Vet Wendy Talbot, of animal health company Zoetis which created the video, said: “Many horse owners may believe they know all they need to about worming but research shows a lack of understanding about the danger posed by encysted small redworm.

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“Unfortunately, once the horse shows symptoms of larval cyathostominosis it is a very difficult condition to treat effectively. The intention of our new video is to help owners get to grips with why encysted small redworm can cause serious harm to their horses and how important it is to take steps to prevent it by speaking to their vet or SQP [suitably qualified person] about worm control.”

Faecal worm egg counts will not detect encysted small redworm as the larvae do not produce eggs. Horses may be carrying several million of the encysted larvae and yet have a negative or low count.

For all the latest news analysis, competition reports, interviews, features and much more, don’t miss Horse & Hound magazine, on sale every Thursday.

Acquiring a horse who has clearly had a setback in care — with the aim of restoring him to full health — can be hazardous.

Often, it cannot easily be determined why the horse has fallen into his present state and whether those issues can be fully remedied. If a horse is found to be thin and debilitated at a veterinary pre-purchase examination (PPE), the largely external nature of this examination, taken with the often unreliable dietary and veterinary history supplied by the owner, can place the examining vet in a difficult position when advising the client as to whether or not he will recover.

Certainly, if you are thinking of buying such a horse, a PPE is highly desirable. This will include a detailed inspection of the horse’s teeth, and maybe also a blood test to investigate any debilitating illnesses that might be present.

If you do decide to take on a horse with an unknown history, or a youngster who arrives looking less than a picture of health, a good first question would be: “Is he wormy?”

Although parasites, principally redworms, are an important cause of debility in adult horses, determining whether they are responsible for failure to thrive in an individual case can be difficult. Contrary to a widely held belief, there is no correlation between the faecal worm egg count (often erroneously called a “worm count”) and the number of worms in the horse. Horses with high egg counts may be healthy, but are an important source of infection for other horses. Conversely, those with a large burden of encysted redworm larvae may have low counts or even be completely negative. Tapeworm will often also go undetected.

Horses who are persistently thin are often described as “worm damaged”. There is actually no evidence that even a severe parasitic colitis (an inflammation of the colon lining), if the horse survives it, causes any irreparable damage. With good aftercare and correct nutrition, an affected horse can make a full recovery.

If no information on the horse’s worming history is available, the likelihood of the presence of a heavy burden may have to be inferred from his background — perhaps he has come from heavily stocked premises, for example, with overgrazing and poor management.

Treatment, based on veterinary advice, may be needed. However, it must be administered with care in the winter if there is a chance that the horse is heavily infected with encysted redworm larvae. The sudden killing of these parasites might provoke an adverse reaction.

It may be prudent for the horse to receive anti-inflammatory medication at the same time as being treated with moxidectin, the wormer of choice in this situation. Although a five-day course of fenbendazole is marketed for the treatment of encysted redworms, resistance to this 40-year-old drug is now widespread — and the inflammatory response, if it does work, is greater than with moxidectin.

A possible redworm burden must be treated with care to avoid a potential adverse reaction

Back to basics

Lice are common in malnourished, debilitated horses during winter and spring, unless the horse has been clipped. Itching of the neck, chest and buttocks is a giveaway sign.

The eggs, called nits, look like hayseeds but are attached to the hair shafts. Adult lice may also be seen if the hair is carefully parted, especially if this is done immediately after a rug is removed. Topical treatment should be given on veterinary advice, as some of the lice treatments sold in tack shops and feed stores are ineffective.

Overgrown, neglected feet must be corrected by trimming. Severe overgrowth should be removed in two or more stages, each around two weeks apart. The aim is to correct any excess growth, rebalance the foot to centralise the load into the centre, reduce any misshapen areas known as flares and address hoof cracks. A poorly shod horse may require repeated sessions with a skilled farrier over an extended period before his feet regain satisfactory function.

The horse should be observed eating hay prior to purchase, as if he has any difficulty in doing so that is significant. A full dental examination is mandatory at the PPE and allows a prognosis to be given. Sharp enamel points alone do not generally cause weight loss, unless accompanied by quidding (dropping unchewed feed) or abnormal salivation. It is often thought that “a good rasping” will improve a horse’s body condition, but this is rarely the case.

Soft or cowpat-style droppings should be regarded with suspicion in a thin horse. If dietary causes can be excluded, essentially eating either rich grass or soft, wet, low-fibre haylage, there may be an underlying inflammatory bowel problem which might prove difficult to resolve.

consult with your vet about an appropriate worming programme

Building condition

Assuming that all other health issues have been dealt with, it should be possible to put weight on a malnourished horse in around four to six weeks. Plenty of good summer grass, or the best- quality hay (soft, green and leafy) or haylage, fed ad-lib, should be the cornerstone of the new diet.

Any substantial increase in hard feed levels must be implemented gradually and carefully to gain maximum nutritional benefit without causing additional problems.

In order to keep the meal size small, at least three, or preferably four, feeds should be given over a 24-hour period.

It is logical not to ride the horse during his recovery, as some of the extra calories and protein provided will be diverted to provide the “fuel” for movement rather than rebuilding his body condition.

There is sometimes a reluctance to feed a horse adequately as there is a concern that this will make him more difficult to ride — although evidence that diet truly affects a horse’s temperament under saddle consult with your vet about an appropriate worming programme is almost entirely anecdotal. If this is a consideration, increased calories and protein can be provided by feeding high-calorie, fibre-based feeds, such as oil- fortified alfalfa combined with a feed balancer.

The horse’s body condition score should gradually improve, but this can be subjective and sometimes disheartening. Monthly weighing with a weight tape will allow his progress to be monitored more objectively. If there is no significant improvement in six weeks, seek further advice from your vet. In the majority of cases, there is no reason why a thin horse cannot be restored to a healthy state provided common heath issues are addressed. However, inevitably, a few of these horses are found upon further investigation to have persistent or unmanageable illnesses — and turn out to be a bad buy.

Case study

When the gamble pays off: annie Warren’s Missy arrived from Ireland in poor condition, but appropriate care allowed the pair to enjoy a season’s hunting six months later

Annie Warren bought five- year-old mare Missy unseen from a dealer in Ireland last spring.

“I wanted a horse to produce and bring on,” says Annie. “Missy looked great in the photos and videos I saw, but when she came off the lorry I was a bit shocked. She had travelled badly and was noticeably thin and tucked up.

“I had little by way of health history to work with, so I organised a veterinary assessment,” she adds. “Her hooves were good but quite long, so I had those properly trimmed. A week later she developed a bad respiratory infection and extensive ringworm. I was quite worried about her.”

After considerable veterinary input and a whole summer on good grass, Missy was finally restored to full health.

“I wasn’t really happy with her condition until the autumn,” says Annie, who hunted her successfully all winter. “By then she had put on weight and looked much better. I was so relieved that there were no long-term problems. Missy proved to me that with the right advice and feeding, you can make a huge difference to a horse who has had a bad start.”

Ref: Horse & Hound; 8 March 2018

A vet has urged owners to be aware of worming horses correctly after a mare with a huge ascarid (large roundworm) worm burden had to be put down.

Doug Thal DVM DABVP of Thal Equine in Santa Fe, US, and creator of the Horse Side Vet Guide told H&H the four-year-old a mare was referred to his clinic with signs of colic.

“She came in and we had to put her on the surgery table, she had a twist of the entire small intestine and I untwisted it. When I opened the intestine to empty it, I found these parasites,” Dr Thal said, adding that he took out 15 roundworms 25 to 45cm in length during surgery, then another 20 came out of a stomach tube over the next few days. The mare underwent surgery again on day three, when it was found a piece of the intestine had died and she had to be put down.

“These are typically a parasite seen only in young horses, but the mare was four,” he said. “By two years old, the immune system typically eliminates ascarids, so seeing these numbers in an adult horse is very rare. I’ve seen horses die from not being wormed, or not being wormed properly. This was the first time I had ever seen such a clear resistance situation.”

In this case Dr Thal said the mare, who is thought to have had a rare immune tolerance to the parasites, had been “aggressively de-wormed”.

“If anything, she had been over-wormed. She was apparently being wormed every five weeks on a rotation with ivermectin and other wormers, and yet the worms were still in her small intestine,” said Dr Thal. “I cannot prove that the parasites were the reason she had the intestinal twist, and were related to the reason she had to be euthanised, but I can’t help think that this contributed.”

Dr Thal said some owners are worming incorrectly due to misinformation.

“People are taking these powerful chemicals and using them randomly, over and over. There are ultimately going to be consequences to that [as the worms build up resistance to the chemicals],” he said. “People think they’re doing good by deworming, but often it’s based on misinformation. Simply throwing wormers at horses is not the right way to think about worming. My advice to people is to understand management to reduce worm burdens, and this requires understanding the basics of a typical worm cycle.

“Adult worms live in the intestines of the horse, eggs are laid. They pass out into the environment in the manure. Eggs mature on the pasture to an “infective” stage, and are re-ingested and the cycle repeats. By understanding this basic cycle, people can make better, more logical worming decisions.

“People should whenever possible pick up manure from paddocks and therefore prevent horses from re-ingesting worms through the manure. Or if horses are on pasture, use appropriate pasture rotation.”

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Although not relevant in this case, Dr Thal warned owners to seek professional advice before considering alternative worming methods.

“The horse industry is fraught with people who use faulty logic and are not afraid to confidently share their misinformation on social media. Their approach is ‘I did this for my one horse, my horse seems ok to me so this treatment must be effective – now I am going to spread the word to everyone I know that this works’. In the social media age in which we live, this effect is amplified by 1,000, and it can lead to widespread bad decision-making, and horses can suffer as a result.

“My main message is that people need to be careful, be sceptical and ask the right questions. When considering products, ask for scientific evidence. Work with your vet.”

For all the latest news analysis, competition reports, interviews, features and much more, don’t miss Horse & Hound magazine, on sale every Thursday.

Horse owners and yard managers have been advised to take their horses’ passports with them when buying wormers and other medicines.

The Veterinary Medicines Directorate (VMD) has issued a guidance update stating that prescribers should ask to see passports before they supply the products.

But although owners have been advised they may be asked to show the document, not having it does not mean they cannot be sold the medicine.

Stephen Dawson of the Animal Medicines Training Regulatory Authority (AMTRA) said: “It’s important to note that while we are encouraging owners to bring their passports along, not bringing them doesn’t prevent the horse being wormed or benefiting from other medicines.

“It just means that if the vet, pharmacist or AMTRA SQP [suitably qualified person] prescribing and supplying medicines has not recently seen the horse’s passport and been able to confirm personally that it has been signed out of the food chain, they have to act accordingly.

“As the horse is a food-producing species under EU law, then without the passport it must be assumed the horse may enter the food chain, and the wormer or other medicine chosen accordingly.”

Mr Dawson added that some medicines cannot be supplied without sight of a passport as they are only suitable for horses who have been signed out of the food chain.

“But most horse medicines are okay to prescribe in either case, so it’s just a question of the range to choose from being a bit smaller,” he added.

An AMTRA spokesman added that AMTRA SQPs have a legal requirement to ascertain the status of any animal before they prescribe or supply medicines.

“The update is simply reinforcing this existing requirement,” he said. “The current status of the horse is determined by checking the declaration in the passport. While the owner will be able to advise the medicines prescriber of the horse’s status, the updated guidance clarifies that AMTRA SQPs should only rely on the passport’s declaration when they have seen it personally.

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“Where livery yards buy in bulk on behalf of owners, presenting multiple passports is not likely to be practical, so prescribers will again choose from medicines which can be safely and legally given to horses that might enter the food chain.”

For all the latest news analysis, competition reports, interviews, features and much more, don’t miss Horse & Hound magazine, on sale every Thursday.

Owners have been urged to treat horses for encysted small redworm before spring – or risk possibly fatal consequences.

A number of recent cases of serious disease caused by severe encysted small redworm infections have been reported, prompting Wendy Talbot, vet for animal health company Zoetis, to speak out.

The parasite is ingested during grazing, then larvae survive in autumn and winter by burrowing into the walls of the intestine. Here they form cysts and their development pauses as they “hibernate” over the winter.

In spring, the larvae can erupt from their dormant state, to carry on their development, in large numbers. This causes damage to the walls of the intestine, which can lead to diarrhoea, weight loss and colic. The condition, larval cyathostominosis, can be fatal.

“Over the past few weeks I have heard of a number of cases of larval cyathostominosis,” Ms Talbot said. “Unfortunately people think their horses are safe from this parasite if they have had a recent, negative faecal worm egg count but this absolutely is not the case.

“Because encysted small redworm are hibernating, they won’t show in faecal worm egg counts. A horse could actually have a burden of several million encysted small redworm larvae yet show a negative or low count.”  

There is no test for encysted small redworm, and all horses aged six months and over should be dosed for it, in late autumn or winter, and “certainly before spring”.

The two active ingredients licensed to treat encysted small redworm are a single dose of moxidectin or a five-day course of fenbendazole.

But there is widespread evidence of small redworm resistance to fenbendazole, so a resistance test is recommended before using it. Moxidectin is highly effective against adult small redworm including encysted larvae.

“It’s imperative to use the right worming product,” Ms Talbot said. “Treating with a wormer that does not specifically target the encysted stages (ivermectin, pyrantel or single dose fenbendazole) during late autumn and winter can actually increase the risk of a horse with a high encysted small redworm burden developing larval cyathostominosis.”

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Owners are advised to discuss worming programmes and products with a vet or SQP (suitably qualified person) animal medicines advisor.

Cyathostominosis can occur in horses of any age, but there is a higher risk in horses under six. Cases usually involve “a history of poor pasture management”, as not poo-picking regularly can expose grazing horses to high levels of small redworms.

“It’s important to note that cyathostominosis can happen despite previous wormer administration, especially if the wormer is not effective against larval stages,” Ms Talbot said.

“Early clinical signs of cyathostominosis include poor weight gain and general ill-thrift at any time of year but particularly over the winter. If your horse has any clinical signs it is important that you contact your vet as soon as possible for advice.

“More advanced signs of disease include the onset of colic and diarrhoea, by which time the condition is already quite advanced.  It is imperative any horse showing these signs is assessed by a vet as soon as possible and the appropriate treatment is given.”  

For all the latest news analysis, competition reports, interviews, features and much more, don’t miss Horse & Hound magazine, on sale every Thursday.

Owners have been asked for their help in final evaluation of a new blood test for encysted small redworm.

Austin Davis Biologics, who provide EquiSal Tapeworm testing, is in the final stages of statistical analysis of a test that can detect the presence of the parasite (encysted cyathostomin).

The company hopes to have the test ready to launch later this year.

Dr Corrine Austin told H&H the test, which has been developed with funding from the Horse Trust, will be a positive step forward in worm control and targeted drug use.

“If we end up with large scale resistance to moxidectin, we are in trouble,” she said.

“We hope this test will mean we can protect the efficiency of moxidectin treatment and that we are only using that drug when it is really required.”

She added this is especially important as wormer resistance is an issue, so a test that can pinpoint which horses do — and which don’t — need treating is “very exciting”.

Austin Davis Biologics is searching for owners whose horses are having blood tests for other health reasons between now and the end of July who would be happy for an extra sample to be taken at the time.

They also need to be provided with faecal egg count results for that horse and for the whole yard. A history of faecal egg count data would also be helpful.

Article continues below…

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“We have been developing this with the Moredun Research Institute and this really is the final stage of evaluation,” added Dr Austin.

“We are wanting to look at the correlation between the faecal egg count data and the encysted blood test results in a final screen to fully understand the use of it in the field.”

Dr Austin added owners will need to speak to their vets beforehand and the company can also provide pre-paid postage, collection tubes as well as consent forms.

For more information, contact enquiries@equisal.com

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A new blood test which can diagnose encysted small redworm burdens will launch in September.

The test, which will be available to horse owners via their vets, can diagnose all stages of the small redworm life cycle – including the encysted larval stage, which has previously been undetectable.

A spokesman for Austin Davis Biologics (ADB), who have launched the test and also produce the Equisal tapeworm saliva test, said: “Until now it has not been possible to test for encysted small redworm as faecal egg counts only detect the presence of egg-laying adult worms. This has meant that a routine winter treatment to target this life cycle phase has become the recommended practice.

“Small redworms are the most common gastrointestinal parasites to infect horses. When horses harbour a large burden of encysted larvae that emerge on mass from the intestinal wall clinical signs develop such as diarrhoea and colic, which can be fatal (larval cyathostominosis).”

Due to resistance in worms to the active ingredient fenbendazole, which has historically been used as a five-day course to target encysted small redworm, moxidectin is now the preferred choice of active ingredient to eliminate the encysted stage.

“To protect the effectiveness of moxidectin, targeted treatment programmes are required to ensure that the drug is only administered when it is really needed,” continued the spokesman. “The commercial availability of a diagnostic test to detect all intra-host stages of small redworm will be of great value to veterinarians enabling them to make a differential diagnosis as well as informed treatment decisions,” he said.

The test has been developed by Professor Jacqui Matthews’ group at the Moredun Research Institute, with the main funding being provided by the Horse Trust.

Article continued below…

New encysted small redworm test: owners asked for help with final step

It is hoped the new test will prove a significant step forward in targeted treatment and preventing resistance to wormers

Owners urged to take action over potentially fatal parasite

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Professor Mathews said: “It is great to see the commercialisation of this much-needed test to support sustainable worm control in horses. The test fills an important gap in our diagnostic toolbox and will enable horse owners to work with their veterinarians in targeting treatments against cyathostomin infections and hence help protect these important medicines for the future”

Dr Corrine Austin of ADB said research into a saliva-based test for small redworm is “ongoing” and is expected to be commercialised several years from now.

Vet practices can contact ADB at info@austindavis.co.uk to register interest in the diagnostic blood test service.

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Horses can carry a number of different types of worms in their guts. Monitoring a horse’s worm burden and treating cases which have above recommended levels of intestinal parasites is key to maintaining a horse’s good health. A major worm burden can be life-threatening, with potential damage to the gut leading to colic, diarrhoea and other significant on-going problems for the horse, even after the worms have been treated. Young horses tend to be more susceptible to worm-related problems, although horses of all ages can be affected.

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Horse owners may be facing an “Armageddon” of wormer resistance if we do not take urgent evasive action.

This is the message from Dave Rendle, equine internal medicine specialist, speaking as part of a session on human behaviour change, at the 2020 National Equine Forum yesterday (5 March).

While fellow speakers had covered owners’ attitudes to colic and strangles, and how these may be changed, Mr Rendle covered what he believes is “one of the most alarming issues facing the industry”.

“I hope I can convince you of the importance of this,” he said, explaining that resistant parasites are those on which drugs are no longer effective.

“Resistance develops because parasites are subject to natural selection, like all living things, and as we impose selection pressure on them by killing susceptible ones, it’s the ones that aren’t susceptible to the drug that reproduce. The more we worm, the more resistance we get.”

Mr Rendle said wormers were developed in the 1960s and by 1985, it had been highlighted that routine worming needed to stop. Over the next decades, evidence emerged of resistance to every class of wormer we have available.

“We’ve still got that resistance as it doesn’t go away, but for the first time, we don’t have any more classes of drug to turn to,” he said.

“We’re on a slippery slope, and what’s at the bottom is not an appealing picture.”

Mr Rendle said if all horse owners turned to targeted worming – using the drugs only when needed, which can be determined through diagnostic testing including faecal worm egg counts – this could decrease the drugs’ use by 80%. But he said concerned vets often fail to engage with owners of large numbers of horses, such as producers and breeders, who “don’t think resistance will have an impact on their animals”.

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He said in Sweden and Denmark, where wormers have become prescription-only drugs, their use has dropped dramatically, and urged the UK industry to work together to decrease our own use.

“I see an Armageddon on the horizon that I’m anxious to avert but I fear we’re facing a point of diminishing returns,” he said.

“There are difficult questions ahead but we need to think smart, embrace diagnostics and start educating people, or we’ll find ourselves back in the 1950s with reduced stock capacity – and more and more horses dying of colic.”

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With the nights drawing in, there is no denying that autumn is here. Make sure you and your horse are ready for the colder weather with our seasonal horsecare guide.

1. Hardcore
Putting hardcore down in gateways before the winter will help these areas stay compact, and prevent them from becoming too muddy and slippery.

2. Winter rugs
If you didn’t get your winter rugs cleaned and repaired in the spring, now is the time to do it. Or if you need new rugs, it’s time to go shopping!

3. Clippers
Get your clippers serviced and the blades sharpened by a specialist so you are ready to tackle those winter woolies. If you want to learn how to clip like the experts, check out our clipping masterclass video.

4. Worming
Autumn is the ideal time to test and treat horses for tapeworm, while vets recommend all horses should be wormed for encysted small redworm during November/December. So now is the time to get organised and order your worming supplies, checking that the active ingredients are the right ones for the the types of worms you are targetting.

5. Bedding
Choose bedding wisely if your horse is to be stabled in the coming colder months. If your horse suffers from respiratory problems consider using a dust-free bedding combined with rubber matting. You may find you can save yourself money by buying in bulk.

6. Dietary changes
If your horse is overweight the next few months is the ideal time to slim him down, or if he is inclined to lose weight now is the time to start thinking about his autumn/winter feeding regime before any weight loss occurs. Remember that good quality forage is important before turning to cereal feeds. Feeding oil will also help maintain condition.

7. Mud fever
Mud fever can start in autumn if conditions are wet and muddy. Avoid long periods of exposure to these conditions, as bacteria from the soil can enter the horse’s body through damaged skin or cuts.

8. Vaccinations
Check if your horse’s vaccinations are due. It’s easy to allow them to slip and costly if you have to restart the full course. Consult your vet if you are unsure what vaccinations your horse needs.

9. Teeth
Get your vet or equine dental technician to check your horse’s teeth before winter, to ensure they are able to make the most of their feed. This is particularly important for youngsters and older horses.

10. Grass
Laminitis is most commonly associated with spring grass, but cool nights lead to an increased accumulation of sugars in grass. If you own a laminitis-prone horse consider whether you need to restrict their grass intake.

11. Fly gear
Clean your fly sheets and masks and store them ready for use in the spring. Bring all your fly sprays, shampoos and other liquids indoors to prevent freezing and thawing, which may make them less effective.

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12. ‘Winterise’ your yard
After the ground has frozen you won’t be able to sink new fence posts, so make sure they are all secure now. Check gutters and downpipes are in good condition and clear of debris. Insulate your pipes and unhook hoses when not in use, especially during the night when it may drop below freezing.

13. Cooling
If your horse works up a sweat while being ridden, have a wool or fleece cooler to hand to throw over him while he’s cooling down to prevent him from becoming chilled.

14. Shooting
If you live in an area where deer stalking or shooting may occur, it is best to avoid riding out at peak times. Outfit yourself and your horse in bright colours or talk to your fellow riders to make sure you can be seen and heard.

Horse & Hound magazine, out every Thursday, is packed with all the latest news and reports, as well as interviews, specials, nostalgia, vet and training advice. Find how you can enjoy the magazine delivered to your door every week, plus options to upgrade to access our H&H Plus online service which brings you breaking news as it happens as well as other benefits.

The owner of a months-old foal who was given a 2% chance of survival owing to extensive worm damage wants to share his story to give others hope.

Coloured colt Beau was thought to be about two months old when Jodie King bought him in September. He was sold at that age as his dam had rejected him, not allowing him to feed and continually chasing him away.

Jodie followed her vets’ advice on his care but by mid-November, he was unwell, and losing weight.

“I’d noticed he didn’t really interact with the others but thought, as did the vet, that he just didn’t know how to be a horse, as he’d only ever been chased off and shoved,” she told H&H.

“He had loose stools and a cough, and seemed lethargic, so I got the vet.

“It was heartbreaking because the vet said ‘he’s at breaking point now. The odds have always been against him but he’ll either survive or he won’t; he’ll get better or he’ll die’. It was absolutely gut-wrenching.”

The vet put Beau on a probiotic and told Jodie to monitor him for a month but two days later, he took a turn for the worse.

“He was freezing cold, lying down and with no appetite,” Jodie said. “I wrapped rugs round him and called the emergency vet. I couldn’t wait as I didn’t think he’d make it.”

Tests showed that Beau, who had likely never nursed and so not benefited from any of his dam’s immunity, had a large roundworm burden, which was causing major issues. Roundworms are a notorious problem in foals, not least owing to issues of resitance to many common wormers. Parasites can persist despite treatment, causing issues, as happened in this case.

“The vet treated him but said she couldn’t give him more than a 2% chance of survival,” Jodie said. “She gave him the treatment and said ‘it’s up to him now’.”

Jodie appealed on social media for cheap rugs for Beau but the first “seller” took her money and did not send the rugs.

“I was overwhelmed,” she said. “So many people offered to send rugs. A lot of time there’s tit for tat in the equestrian community but when something like this happens, people come together.”

Jodie, who said when Beau no longer needs the rugs, she will either return them or pass them on to someone in a similar situation, said the colt is improving; eating and no longer coughing.

“A few days ago, he cantered for the first time; it made me cry,” she said. “I couldn’t give up on him because he was willing to fight, so I had to fight for him. We were each other’s reason to keep going.”

Jodie’s vets warned that Beau may have issues in future owing to the worm damage.

“I haven’t got thousands to pay for a foal who might not get better,” she said. “But you can’t put a price on his life; I’ll do whatever it takes.

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Jodie hopes her story will give hope to anyone else in a similar situation.

“He is proof that if you know your horse isn’t ready to give up the fight, then keep fighting that fight for them,” she said. “He is a horse of a lifetime and I really hope he will live a long and healthy life full of love, enjoyment and a bond like no other.

“Slowly he will learn what it means to really be a horse but I will be there with him every step of the way, and show him I will never give up on him. He will only know love for the rest of his life, and even if I can never ride him, he won’t go anywhere.

“I couldn’t have got through this without my family, friends and the overwhelming support from social media. People who were once strangers are like little guardian angels for my boy and I will for ever be grateful so thank you all.”

Worming programmes should always be discussed with a vet as wormer resistance is a major issue.

Horse & Hound magazine, out every Thursday, is packed with all the latest news and reports, as well as interviews, specials, nostalgia, vet and training advice. Find how you can enjoy the magazine delivered to your door every week, plus options to upgrade to access our H&H Plus online service which brings you breaking news as it happens as well as other benefits.

In our 29th weekly episode of the first series of The Horse & Hound Podcast, H&H’s showing editor Alex Robinson chats to showing producer Katy Marriott-Payne about her three Olympia M&M champions. Moving on to the week’s top news stories, our news team join our podcast host Pippa Roome to discuss an exciting change at Badminton, temperatures when transporting horses, and attempts to stamp out the cruel practise of soring in the USA. We also catch up with vet Ricky Farr to talk about worming during the winter months.

Episode 29 of The Horse & Hound Podcast, our popular audio service available exclusively every Thursday morning for our H&H Plus subscribers, is now live.

Each episode is available for all H&H fans to listen to 24hrs after its early release to our H&H Plus members. Search for “The Horse & Hound Podcast” in your preferred podcast app and click subscribe to be notified about each new episode. This will allow more listeners to make The Horse & Hound Podcast an essential part of their week on Friday morning.

• View all episodes of The Horse & Hound Podcast

In episode 29, native pony specialist and three-time Olympia M&M champion Katy Marriott-Payne talks to H&H showing editor Alex Robinson about her Olympia highlights and her thoughts on the changes that the competition has undergone in recent years.

“It takes three goes at Olympia before you know what’s going on and how to prepare for it as it’s a show like no other” – Katy Marriott-Payne

H&H podcast host Pippa Roome is joined by H&H news editor Eleanor Jones, senior news writer Lucy Elder and news writer Becky Murray to discuss some of the week’s key stories, including an exciting change at Badminton, why the European eventing championships won’t be going ahead next year, the rules around temperatures when transporting horses and attempts to stamp out the cruel practise of soring in the USA.

“Soring is intentionally injuring horses’ legs and hooves to produce the high stepping ‘big lick’ that is commonly seen at shows for Tenneesee walking horses – attempts are being made to stamp it out” – Eleanor Jones

In this week’s advice section we catch up with equine vet Ricky Farr of Farr & Pursey Equine about what worming challenges owners need to think about during the winter.

“There are lots of worms that can affect your horse – there are almost 50 species that could be in there…” – Ricky Farr MRCVS

We hope you will enjoy our latest episode and would love to hear your feedback, so please do send your thoughts to pippa.roome@futurenet.com

H&H Plus podcast: episode 29

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The Horse & Hound Podcast: episode 20 – Jayne Ross’s HOYS memories | Autumn horsecare | News round-up

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The Horse & Hound Podcast: episode 13 – Simon Reynolds | Care at hot horse shows | News round-up

The Horse & Hound Podcast: episode 27 – Michael Whitaker | Caring for hunters | News round-up

Research into parasitic diseases produces more questions than answers, finds Peter Green MRCVS

Liver fluke is a large parasite that lives in the liver of grazing animals. Animals catch the infection on damp or marshy pasture where the intermediate host, a small snail, thrives. Cattle, sheep, goats and deer can be severely affected, and farmers regularly have to dose their stock to treat liver fluke.

In one survey in Ireland, 9.5% of horses at an abattoir were infected with liver fluke; in Spain, 60% of horses were found to be positive on a blood test. We know how cattle and sheep get the infection: they ingest the early stage of the parasite as they graze. It seems obvious that horses are infected this way, too.

More evidence has emerged to indicate that reducing worming frequency does not typically have a negative effect on horses’ health, and may help prevent an “equine welfare crisis”.

Leading equine parasitologist Martin Nielsen’s research supports the move away from the traditional approach, of frequent worming without diagnostic testing.

Dr Nielsen’s study involved 99 mares and 93 foals at stud farms in New Zealand. Researchers evaluated the worm egg counts, weight and health of groups of horses under different parasite control programmes.

They found no significant difference in egg counts between the mares wormed routinely at different set intervals, and those only wormed when counts exceeded a certain level. The foals who were wormed at two and five months old had significantly more ascarid (roundworm) and strongyle (redworm) eggs than those wormed monthly with alternate products, but all the horses were healthy.

“De-worming every six to eight weeks and rotating between products is still very common around the world but this sort of carpet-bombing is completely unnecessary and drug rotation does not prevent drug resistance,” Dr Nielsen said, adding that the persistent and growing resistance to the anti-parasitic drugs available to horse owners is “challenging us to find more sustainable and yet effective parasite control programmes”.

“Many people are not comfortable with de-worming less frequently, thinking it will compromise horse health, but our study shows that this is not the case; no adverse health effects were seen that could be ascribed to scaling down de-worming intensity.”

Dr Nielsen told H&H the aim of any worming programme should not be to eradicate worms, but to reduce the risk of parasitic disease, and that it is natural for horses to have worms.

“The worms are supposed to be there, just like horses also harbour lots of bacteria in their intestinal tracts – yet we don’t go around treating them with antibiotics all the time,” he said. “This study demonstrated that all horses (foals as well as mares) were healthy, and no differences were observed between the groups during the study. And that is what matters.

“Just treating at fixed and frequent intervals with no testing is the equivalent of fumbling in the dark. You will have no idea of what you are doing.”

Dr Nielsen has created videos on the subject, one for vets and one for owners, above, which the British Equine Veterinary Association (BEVA) is sharing to help spread the word.

BEVA health and medicines committee chairman David Rendle said: “This study provides further evidence to show that there is no justification for the traditional approach of calendar-based routine treatment and gives further reassurance that the frequency of treatment can be reduced without detriment to equine health or development of youngstock.

Continues below…

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“Spreading this information will hopefully encourage any horse owners who have not done so already to change from their old-fashioned habits of frequent de-worming to a diagnostic test-led, or at least a more strategic approach with routine drug-resistance testing.

“In so doing we can help avert the potential equine welfare crisis that all are agreed will inevitably ensue if the equine industry continues with the indiscriminate use of anthelmintics [de-wormers]. I would urge anyone who has not discussed worming with their vets recently to do so before the spring.”

Horse & Hound magazine, out every Thursday, is packed with all the latest news and reports, as well as interviews, specials, nostalgia, vet and training advice. Find how you can enjoy the magazine delivered to your door every week, plus options to upgrade to access our H&H Plus online service which brings you breaking news as it happens as well as other benefits.

A veterinary practice in Wales is offering free visits, vaccinations and wormers to riding schools hit hard by lockdown restrictions.

Abbey Equine Clinic in Abergavenny, south Wales, is offering a package to its clients, with the support of pharmaceutical companies.

County council-registered riding schools that are clients of the practice will each be given a voucher for a free visit, three equine flu and tetanus vaccinations and three wormers, to be used this month or next.

A spokesman for the practice said it wanted to do something to help its riding school clients during a very tough time.

“Most of us have happy memories of learning to ride on riding school ponies as children,” added clinic director Emma Jones MRCVS.

“Running the practice throughout lockdown has been hard, but nothing compared to the financial strain these riding establishments have been under, with all the overheads and none of the income. Organising this support has been something practical we can do to help.”

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H&H has reported on how badly riding schools have been affected by the coronavirus lockdown restrictions during the past year, especially the current one as they have all their usual winter costs but no income, and Abbey hopes measures like this scheme may help them survive.

The spokesman said: “This was only possible with the generous support of Boehringer Ingelheim Animal Health, Chanelle and Vet Plus, thank you.”

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Owners have been urged to treat horses for encysted small redworm before spring – or risk possibly fatal consequences.

A number of recent cases of serious disease caused by severe encysted small redworm infections have been reported, prompting Wendy Talbot, vet for animal health company Zoetis, to speak out.

The parasitic horse worm is ingested during grazing, then larvae survive in autumn and winter by burrowing into the walls of the intestine. Here they form cysts and their development pauses as they “hibernate” over the winter.

In spring, the larvae can erupt from their dormant state, to carry on their development, in large numbers. This causes damage to the walls of the intestine, which can lead to diarrhoea, weight loss and colic. The condition, larval cyathostominosis, can be fatal.

“Over the past few weeks I have heard of a number of cases of larval cyathostominosis,” Ms Talbot said. “Unfortunately people think their horses are safe from this parasite if they have had a recent, negative faecal worm egg count but this absolutely is not the case.

“Because encysted small redworm are hibernating, they won’t show in faecal worm egg counts. A horse could actually have a burden of several million encysted small redworm larvae yet show a negative or low count.”

There is no test for encysted small redworm, and all horses aged six months and over should be dosed for it, in late autumn or winter, and “certainly before spring”.

The two active ingredients licensed to treat encysted small redworm are a single dose of moxidectin or a five-day course of fenbendazole.

But there is widespread evidence of small redworm resistance to fenbendazole, so a resistance test is recommended before using it. Moxidectin is highly effective against adult small redworm including encysted larvae.

“It’s imperative to use the right worming product,” Ms Talbot said. “Treating with a wormer that does not specifically target the encysted stages (ivermectin, pyrantel or single dose fenbendazole) during late autumn and winter can actually increase the risk of a horse with a high encysted small redworm burden developing larval cyathostominosis.”

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Owners are advised to discuss worming programmes and products with a vet or SQP (suitably qualified person) animal medicines advisor.

Cyathostominosis can occur in horses of any age, but there is a higher risk in horses under six. Cases usually involve “a history of poor pasture management”, as not poo-picking regularly can expose grazing horses to high levels of small redworms.

“It’s important to note that cyathostominosis can happen despite previous wormer administration, especially if the wormer is not effective against larval stages,” Ms Talbot said.

“Early clinical signs of cyathostominosis include poor weight gain and general ill-thrift at any time of year but particularly over the winter. If your horse has any clinical signs it is important that you contact your vet as soon as possible for advice.

“More advanced signs of disease include the onset of colic and diarrhoea, by which time the condition is already quite advanced.  It is imperative any horse showing these signs is assessed by a vet as soon as possible and the appropriate treatment is given.”

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