Sweet Itch in Horses

Flies and midges can be both a nuisance and a health issue for horses and certainly an annoyance to the rider. Midges cause sweet itch, mosquitoes and other flying insects can carry diseases and flies can irritate the eyes and skin whilst at the same time causing stress for horses.

Sweet itch is a ‘disease’ caused by midges as their saliva is their weapon of choice to soften the horse’s skin to enable them to chew their way through the outer layers of skin thereby causing inflammation, discomfort and pain. The horse then has an allergic reaction or suffers hypersensitivity. The midge saliva contains enzymes and proteins to soften the skin as well as agents that encourage blood flow and prevent clotting.

It is the female midge that lands on the horse and her aim is get her feed of blood for her eggs to develop fully. This tiny pool of blood is just under the surface of the skin and is sucked up by the female midges. The reaction of the horse is to release a defence mechanism from the white blood cells which is mainly histamine which in turn leads to more itching and discomfort. Lesions occur around the head, ears, mane and tail, the horse then can start rubbing and even biting the affected areas which can cause bacterial infections.

Our UK midge is called Culicoides and is tiny, most no more than 1.5mm across the wingspan, the females can spend over 15 minutes on their egg laying and bloodsucking process but on a summers evening a single horse can be bitten up to a thousand times and each time Culicoides is injecting foreign proteins from their saliva.

Midges inhabit marshy areas and areas with standing water but even rivers and streams will pose extra risk to horses.  They are also partial to rotten horse manure and dirty stable bedding so like so many other issues regarding horse health cleanliness and bio-security are the first lines of defence. Topical products which also help in the sweet itch battle are Killitch and Z-itch Research has indicated horses fed with omega-3 fatty acids such as Chia Seeds as omega 3 oils may help control inflammation and feeding herbs such as Super Skin may have beneficial effects. Dusk and dawn are the periods midges favour for their annoying endeavours so those times could be when you could physically protect your horse. Midges are poor fliers so the use of fans is also an option

31st October, 2016.

Almost a third of owners are using the wrong wormer, or one to which there is widespread resistance, when they treat their horses for encysted small redworm.

The new findings from the 2016 National Equine Health Survey (NEHS) confirm that misunderstanding about worming remains commonplace, say experts at animal health company Zoetis.

Severe infestations of encysted small redworm larvae can lead to fatal disease.
Treatment should be regardless of the results of faecal worm egg counts as these tests do not show the presence of encysted small redworm.2

More than 77% of respondents to this year’s NEHS intended to treat their horse for encysted small redworm. But of the 89% of respondents who could remember what they used, only 68% of these actually used an effective product.

The remaining 32% used a product not indicated to treat for the encysted larval stages of these parasites or used a product for which there is widespread evidence of resistance.

The survey also showed that 68.4% of those who specified how they treated for encysted small redworm had correctly used moxidectin either as solo therapy or in combination with praziquantel.

Just over 5% had used a five-day course of Fenbendazole, a product which is licensed but for which resistance has been widely documented.2

However, of the remainder, 19% had used ivermectin and 7.5% had used other products, none of which are licensed or effective against encysted small redworm.

Encysted small redworm kills horses every year, particularly young animals or those with an incorrect worming regime,” said Wendy Talbot, vet at Zoetis.

She recommended owners needing more information should speak to their vet or SQP (suitably qualified person).

References: 1NEHS The National Equine Health Survey, conducted by the Blue Cross and supported by Zoetis, was completed by 5635 horse owners and keepers in May 2016, with records returned for 16,751 horses. The survey contained questions on general horse health, care and management and was validated by Professor Josh Slater of the Royal Veterinary College. 2Matthews (2008) Equine Veterinary Education, p 552-560.

My thanks to the authors for the above article and useful advice

SH Wetherald E-SQP

Anthelmintic resistance in horses

Anthelmintic resistance in horses has been reported since the 1970’s, mainly to the benzimidazole group of drugs. This has led to less use of that drug group which naturally has meant more use of ivermectin based products and more recently Moxedectin based products. The other main group (Pyrantel) is traditionally used for both routine worming but more so for tapeworm treatment and then at twice the double dose. The resistance we have seen in recent years is when treating for Roundworms (nematodes).  It is thought that genes for pyrantel/ivermectin resistance are naturally rare in nematodes of equines and therefore resistance should be slow to develop. However, the advent of drugs that do kill the encysted stages (such as moxidectin) is decreasing the worms in “refugia” and thus potentially increasing the likelihood of resistance and how soon that resistance may arrive in the UK horse population  As there are no current plans for introducing new classes of anthelmintic (worming) products we have  to be vigilant in the correct use of the existing products on the market and to adopt animal health plans that take all circumstances into account including the use of faecal egg counts and strategic worming.

At the agricultural level work is being done to limit the resistance issue in sheep and cattle and it is from these species that we can learn how resistance develops and how to avoid the situation becoming so significant in the equine population.  A new approach is required to ensure that with regard to treatment of our horse’s products remain efficacious to thereby avoiding compromising equine welfare.

So what can we do to avoid resistance developing?

Appropriately timed treatments:  Use the advised dosage intervals and note that these intervals differ between active ingredients

Pasture Management: Minimize pasture contamination by picking up droppings, graze with other species such as sheep or cattle, treat new horses on arrival and quarantine them. Harrow pastures when conditions allow such as during spells of hot dry weather.

Correct Dosing: It is vital to dose at the correct rate for the weight of your horse the best method is on a weigh bridge but failing that use of industry leading weigh tape or weight estimation formulas are of value. Under dosing is one of the main reasons for the development of resistance and remember we all lie about our weight so if you do estimate the weight think about adding an extra 10% on top of your estimation. If you administer a sub therapeutic level of the drug and thereby expose the worms to the drug, but perhaps not at a sufficient dosage to kill them. Worms that survive treatment may pass on their “immunity” to subsequent generations and those generations will become more adept at surviving chemical treatments with the potential for resistance to develop to that drug.

Use faecal worm egg counts: Monitor the parasite burden through the warmer months by testing and when you get the results consult an expert on how to read the results and how to decide on a strategy. Most of the worms live within a few susceptible animals so try to identify those animals by a risk assessment of the burden in each horse. This approach can then lead to targeted worming and treating only those animals that actually have a parasite burden. Also consider testing for tapeworm with a saliva antibody test.

Consider testing for tapeworm by using saliva samples: This test identifies horses with a low burden, a borderline result or a moderate/high burden, and treatment is recommended for any borderline or moderate/high results. In scientific terms the Tapeworm Test has both high sensitivity and specificity, which is important for correctly identifying horses with tapeworm burdens.

Rotate the active ingredients: The jury is out on this one but there is a consensus that rotation has a role to play on basis of rotating the selected products in the grazing season only or perhaps a 1 or 2 year scheme but changing active ingredient each time you worm could well have the opposite effect and increase resistance as each different generation of parasite get exposed to different drug classes

Selecting ingredients that actually work: When you do decide to use a wormer use one that is known to be effective against the particular parasite you are targeting.  If you are using products where resistance is suspected check on the efficacy by using a Faecal egg count reduction (FECR)

Select the right ingredient for the target parasite: Although many different ingredients treat a broad spectrum of worms and parasites some treat for more specific burdens, some only treat for a single issue such as tapeworm and some treat parasites at different times in the life cycle. Try to understand the main threats and choose a product accordingly.

Understand the life cycle of the parasite: Different worms have different life cycles which is why we have different approaches with regard to when we actually treat for them rather than a blanket plan of treating at certain times of year. A seasonal approach is fine if these life cycles and previous treatments are factored into the equation. The worms are not in the host for very long as for most of the cycle they are as free living infective larvae on the pasture which is the reason for pasture management as part of the animal health plan.

Understand Refugia: Refugia could be described as those worms which are not exposed to a drug when treatment is carried out - either because they are on the pasture or because they are in horses that have not been treated The refugia provides a resource of drug susceptible parasites which in a way will dilute those parasites that have built up resistance to certain chemicals. These provide a dilution effect slowing the development of resistance in the worm population. By maintaining a group of parasites that are not exposed or have reduced exposure to an anthelmintic (worming chemical) horse pasture management will be improved.

Develop an Animal Health Plan: By recording all wormer treatments and egg counts as well as basic individual horse details such as age, weight etc. develop a plan to suit each individual horse.

When in doubt ask: Worming horses does not have to be complicated but the more we understand the better equipped we are to treat correctly. If your horse has any health problems then the first point of call is your Vet. Also in the UK we are lucky to have over 5000 SQPs who are specially trained and qualified to advise and prescribe anthelmintics (wormers). Many of those are specialists in the equine world and as such undergo continuous professional development in the field of parasitology. They are on hand instore and online to help with advice and hopefully explain why we need a new approach in the field (literately) 

SH Wetherald E-SQP

www.wormers-direct.co.uk

A reminder about Encysted small redworm in horses

March 2016

(originally posted Feb 2105)

Now with extensive use of targeted and strategic worming we need to be even more aware of the danger of mass eruption which often happens in early spring. This mass emergence can lead to a disease syndrome known as “Larval cyathostominosis” causing diarrhoea and colic with up to a 50% mortality rate¹.

The increased use of FWEC (Faecal Worm Egg Counts) and how to interpret the results is adding to the need to understand the importance of treating for encysted small redworm. These inhibited encysted are the larval stages of the small redworm. 

Encysted small redworm (small strongles/cyathostomes) are the most common worms found in horses today and may account up to 90% of the redworm burden in the horse ². They are also the most pathogenically significant equine parasites ^3, in fact many horses can be infected all of their lives ⁴.

Studies have shown that many horse owners are failing to worm with an effective product for the control of encysted small redworm, often assuming that the products they were using did treat for encysted small redworm when in fact they do not. Some owners simply do not treat at all. The most common reason for not treating for encysted small redworm was that the horse had had a clear faecal egg count.

Encysted small redworm don’t show up in a standard faecal worm egg count because the larval stages are dormant and buried within the gut wall, even if the horse has shown a negative or low count it could still be harbouring several million encysted small redworms ⁵, a potential fatal health risk to the horse.

Encysted small redworm can remain dormant inside a horse for up to 2 years, but usually develop and emerge from the gut wall all at the same time in the early spring. It is most important to use a wormer containing moxidectin or a 5 day fenbendazole course licensed to treat encysted small redworm. It is important to remember that there is now widespread resistance to fenbendazole in parasite populations⁴, whereas moxidectin has been shown to be effective against benzimidazole resistant worms. Treating with products that do not specifically treat for encysted small redworm can increase the risk of larval cyathostominosis^6.

So when you next need expert advice on an animal health plan that includes worming and testing your horse or make sure you enlist the help and advice of an SQP (Suitably Qualified Person)

 

SH Wetherald E-SQP
(with thanks to Zoetis for their input and guidance)

(originally posted Feb 2105) 

¹        Dowdall S. et al (2002) Veterinary Parasitology 106, 225-242 

²          Bairden K. et al (2001) Veterinary Record 148, 138-141
³          Love S. et al (1999) Veterinary Parasitology 85, 113-122
⁴          Matthews JB (2008) An update on cyathostomins: Anthelmintic resistance and worm control. Equine Vet. Education 20 552-560
⁵         Dowdall S. et al (2002) Veterinary Parasitology 106, 225-242
⁶        Craig R. Reinemeyer and Martin K. Nielsen. Handbook of Equine Parasite Control

FEI’s prohibited substances

DO YOU COMPETE YOUR HORSE?
DON’T GET CAUGHT OUT!

As the competition season is fast approaching you need to know what changes have been made to the list of the FEI’s prohibited substances. 

If you are competing under FEI rules, the active compound in Devils Claw, Harpagoside, has now been moved on to the FEI controlled medication list for 2016. Riders and owners are being urged to check all their supplements properly so they don’t find themselves potentially using prohibited substances without even being aware. 

Vetrofen Healthy and Vetrofen Intense offer a safe (clear to use under FEI rules) and effective alternative to any Devils Claw products, as well as being amazing value.

VETROFEN INTENSE
Vetrofen Intense contains a completely natural antioxidant blend that targets both comfort and recovery in all horses. It has been scientifically formulated to help horses and ponies when they require support in dealing with intense activity, the natural ageing process and recovery after exercise. Vetrofen Intense supports the body’s inflammatory response to aid recovery to short term problems such as bruising, strains or injury as well as supporting function and flexibility in joints, muscles, ligaments and tendons, all of which can all detract from performance.

VETROFEN HEALTHY
Vetrofen Healthy is a new everyday value supplement which is designed to give everyday support and improved comfort and mobility in active or ageing horses. The supplement helps to provide additional antioxidant nutrients to support the body’s own inflammatory response mechanisms, as well as provide comfort and greater flexibility in joints, muscles, ligaments and tendons.  The concentrated and varied antioxidant profile of Vetrofen Healthy works to promote overall wellbeing and quality of life for your horse, representing a unique and proven approach to managing comfort and recovery.

Both the products have been scientifically formulated to help, support and enhance your horse’s performance, whether at competitions or simply enjoyment at home.

SH Wetherald

E-SQP

Animalife’s Vetro Collection comes to

www.wormers-direct.co.uk

“Feel the Difference”

Vetrofen, Vetroflex and Vetrocalm

Available in the unique Lifestage formulations

Vetrofen is designed to support comfort and recovery

Vetroflex supports joint health and performance

Vetrocalm provides support for horses that suffer from stress, tension and behavioural issues

Call 0800 331 7758 and speak to one of the trained professionals in store about which product is best for your horse, or order online 

Free gift with every Animalife purchase*

(*While stocks last, item subject to change and T&Cs)

MUD FEVER EFFECTING HORSES

 Mud Fever Effecting Horses

Mud Fever is the enemy of horse owners in winter with wet cold conditions and the constant of wetting and drying of the horse’s skin, it’s not long with the infection takes control

What is Mud Fever?

Properly called pastern dermatitis, is not a single disease but can be seen in differing forms and refers to a whole range of skin reactions to a number of different irritants. Frequently called cracked heels or greasy heels, and is caused by an infectious agent called dermatophilus congolensis, which thrives in muddy wet conditions and can range from a mild skin irritation to very painful infected sores, and can in some cases cause significant swelling with severe lameness

Infection can stay dormant in the skin, by becoming active when the skin is compromised, usually by prolonged wetting.

Symptoms or signs to look for in mud fever

The condition affects the lower limb, most commonly the back of the pastern. It starts off as matted hair with dry scabby crusts, caused by the infection of inflamed skin

If the skin is injured in anyway or damaged by a cut, wound, bite, harness sore or through prolonged wetting — the balance between host and organism is disturbed. The organism enters the horse’s body through the broken skin, and multiplies in the damp, warm epidermal layers, starting an active infection causing the mud fever

Causes of mud fever

There are various factors as to what causes mud fever such as:
Prolonged damp, wet and then mild conditions
Standing deep in mud, water, soiled conditions
Some opinions are that actually constantly washing the mud off limbs/legs before and/or after work or after turn out to remove dirt without fully drying them afterwards
Even Skin trauma, from rubbing overreach boots or not properly fitted bandages can cause chaffing, such as sand from schools and irritate the skin
Generally unhealthy skin
Poor immune system, if the horse is unwell and the body cannot fight infection
Horses with white limbs (socks) are said to be more prone with the pink skin being more prone

Heat, redness, swelling of pain to limbs

Prevention or Cure?

Drying of the limbs thoroughly is vital to prevention and cure using clean towels, kitchen roll or dry material can be used to blot moisture

Avoid over washing of the limbs as this can irritate the moisture balance of the skin

Be vigilant as the sooner you spot the first signs of mud fever, the quicker you can take action and so prevent a lengthy, and costly, recovery

If you can limit or stop access to the muddy areas to prevent the horses stood in muddy, wet conditions such as fencing off those areas

You can apply barrier on the limbs to prevent water or moisture getting to the skin but when choosing barriers,  Consider topical barrier creams (usually produced in an oily base) such as tea tree oil, sulphur, MSM, aloe vera, honey with vitamin E, calendula )

Good products to look out for are Lincoln Muddy Buddy, Keratex Mud Shield Powder, Protoccon there are many external tropical barriers

You can buy supplements such as Naf Mud Guard or Global Herbs Mud X to help prevent mud fever
 

Cure?

Once your horse has mud fever it can be a nightmare trying to control it and completely get rid of the mud fever but there are options to consider.

You can buy supplements to put in your horses fed such as Global Herbs Mud X that will help fight the infection internally

Echinacea is a good natural herb to help strengthen the immune system.

Marigold (Calendula) is also a good natural herb with its blood cleansing properties

Bandaging the affected limbs can be a good way of keeping it clean and dry, but only if the skin has been properly prepared beforehand, and the correct bandaging technique is used. Bandaging that’s too tight or has moisture trapped underneath can encourage an infection to flare up again, so do only bandage if you feel can be done correctly

Washing the legs off with anti-bacterial washes such as hi bi scrub to remove the scabs/crusts of the mud fever and thoroughly drying before apply antiseptic creams, The scabs may form again quickly so initially the legs must be washed and treated daily, as once a horse has suffered with mud fever it is not unusual for them to have repeated attacks so prevention is better than the cure

Once the infection has been eradicated it is imperative to keep on protecting the area until the new skin and hair has formed so that re infection does not start again

In extreme cases of mud fever if the bacteria does penetrate deep into the skin, the leg may become swollen and a course of antibiotics may possibly be required from the vet

If any doubt at all about your horses health then consult your Vet

Below is a list of the products that are available to help with Mud Fever on our website

External

Vetericyn Liquid Spray

Derma Gel

Cotton Wool

Gold Label Leg Guard

Internal Supplements

Marigold Flowers Calendula

Echinacea

Global Herbs Mud X

Kelly Rothery E-SQP