MAYES & SCRINE

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Dawes Farm, Bognor Road, Warnham, Horsham,
Sussex RH12 3SH

Tel: 01306 628222
Fax: 01306 628379

office@equinevetpractice.co.uk info@equinevetpractice.co.uk

 

Laurence writes... on Cushing’s Disease

I’m sure we all know an elderly pony with a long curly coat who has been diagnosed with Cushing’s. In recent years Cushing’s Disease has certainly been seen with increasing frequency (probably because ponies and horses are now living longer due to better management) and we felt it was time to run through a few of the facts about the condition.

Cushing’s affects ponies much more frequently than horses, is almost exclusively seen in animals over the age of 15 and its prevalence increases with age. In fact it has been suggested that Cushing’s is a normal ageing change and that all horses would develop Cushing’s if they lived long enough.

The clinical signs of Cushing’s Disease result from an overproduction of the body’s natural steroid, cortisol, by a gland that sits next to the kidney called the adrenal. The production of cortisol is normally regulated by hormones released from a part of the brain called the pituitary gland. Release of hormones by this gland are in turn inhibited by a chemical called dopamine (stay with me now, this section allows you to understand the treatment we use). During Cushing’s Disease there is a decrease in the inhibition by dopamine, allowing the pituitary gland to enlarge and produce more hormones, which in turn leads to an increased production of cortisol by the adrenal.

The clinical signs are often vague and non-specific but can include:

1. Weight loss, most obviously through the saddle region and the quarters, usually accompanied by a pot-belly
2. Lethargy
3. A long, curly coat which is not shed is summer
4. Excessive sweating, compounded by the long hair coat
5. Increased drinking and urination
6. Recurrent infections, especially dental, respiratory and foot abscesses
7. Laminitis

It should be emphasised that not all horses with Cushing’s will have all of these signs at the same time. If we are concerned that your pony has Cushing’s disease but the signs alone are not conclusive we may need to perform further tests. The simplest tests involve taking a blood sample to look at specific hormones such as insulin, cortisol or ACTH (adrenocorticotrophic hormone – one of the hormones released by the pituitary).

The same blood sample can also be used to check the general health of your pony. These hormone tests often do not prove Cushing’s disease is present but can give some strong clues. The most accurate test we use is called the low dose dexamethasone suppression test and involves taking a blood sample, immediately giving a steroid injection and then taking a further blood sample the next day. Giving any horse a steroid injection carries a small risk of causing laminitis, but this is rarely seen. Unfortunately this test is not 100% accurate either, and a negative result does not completely rule out Cushing’s.

The particular test we employ depends on the precise situation, and there are a number of other choices we can consider but that would be a whole article in itself.

Having diagnosed Cushing’s disease we must then all decide on the best course of action. Often simple management changes can address the main symptoms, so lets go through the above list of signs and their treatment.

1. The diet can be altered to increase the protein and energy content to help with weight loss. This must be done carefully so that we do not risk inducing laminitis. Because of the ongoing nature of this condition it is unlikely that diet alone will ever replace all of the wasted muscle.
2. Lethargy may be improved by the other management changes
3. The coat should be clipped out which will make the pony more comfortable and…
4. Decrease the sweating
5. Increased drinking and urination is not a problem to your pony, unfortunately the extra mucking out may be to your back!
6. Regular dental care and vaccination can help minimise infections. Careful, frequent foot trimming will decrease the incidence of foot abscesses. We can also advise you on treatment programmes for worms and external parasites, which often contribute to the general malaise caused by Cushing’s.
7. Laminitis in ponies with Cushing’s is much more serious than a standard grassinduced episode of laminitis. Specific medical treatment of Cushing’s is required in this situation if we are to have a chance of beating this problem.

If management changes alone have not controlled the disease adequately we may need to use drugs to treat the condition. Treatment will be lifelong, is fairly expensive and will improve the clinical signs but not eliminate the disease. The most common drug that we use is called pergolide. This drug increases dopamine production, hence decreasing the production of cortisol - producing hormones from the pituitary. It takes about 3 weeks to start seeing an improvement in the hair coat and urine production and in each individual it can take time to find the optimum dose. There are other medications that we can use in certain circumstances (bromocriptine, trilostane, metapyrone and cyproheptadine) that all have slightly different mechanisms of action to pergolide.

Although Cushing’s is a progressive disease, with the above management changes many ponies continue to have an excellent quality of life for several years. Complications such as recurrent infections or laminitis may eventually occur and can necessitate euthanasia. If you have any queries or concerns relating to this article, please call or email the practice and ask to speak to one of the vets.

What’s in a Vetting…

The Pre-Purchase Examination, or “Vetting”, is a stalwart of veterinary practice. Assessing anything before buying can be quite taxing even it is new. Horses are second hand, well used goods and have no service history. Everyone complains about the vetting procedure (normally the seller), but the fact that “to vet” something is engrained in the english language must mean we’ve got something right.

A full Five Stage examination is always recommended. We currently charge £185 (exVAT) plus the visit (£20 to Warnham, £250 to Gloucestershire). It takes around one and a half hours. It includes a full visual, physical, oral and ophthalmic examination, examining the feet, trot up, flexion tests, seeing ridden, stethoscope examination before and after strenuous exercise, a rest period, repeat trot up, turn, back-up and lunge-on-the-hard.

A blood test is taken for storage and passports are checked. If the buyer is not going to be present the vet tries very hard to speak to them beforehand regarding the horse’s intended use and their experience, so suitability can be assessed. If the examination turns up something very concerning then the vet likes to be able to speak to the buyer straightaway. The vetting can then be stopped and less money charged.

Although we are not horse valuers, we each do around fifty vettings a year so we do get some idea of the market. The price usually reflects the stamp of the horse, if it doesn’t we feel we should let the buyer know. It is courteous for the vet to speak to the seller regarding any adverse findings. Contrary to popular belief, we can vet a horse when the seller and buyer are existing clients.

Obviously we are acting on behalf of the buyer and any conflict of interest only occurs if the seller gets upset. Therefore, we make it clear that failure is an option before we start. All findings of veterinary significance have to be listed on the vetting certificate, it is negligent of the vet not to do so. This often concern buyers as it can lead to insurance exclusions. Exclusions just mean that you have to take a risk on the excluded part of the horse. The insurance company will usually lift an exclusion after a suitable period (e.g. at renewal). Our advice is not to sit on an exclusion for year after year, and don’t miss buying the horse you want just because an insurance company won’t insure a small part of a big animal.

If the horse is expensive, e.g. over £10,000, then x-rays can be considered. Often insurance companies request x-rays over and above this value too (check with them before the vetting, they also often request certain views). X-rays may also be recommended if the vetting turns up something unusual, like a bony lump or swollen joint.

Two Stage examinations can be done. These are shorter and more limited than a Five Stage exam. Also, the Practice’s indemnity insurers insist that the buyer signs a consent form acknowledging the limitations of the procedure. Because of the increased indemnity risk we charge £125+VAT for a two stage vetting.

When booking a vetting, the office staff take all the details, and help you arrange a time for the vet, seller and buyer to attend. Often the buyer doesn’t know the name of the seller or the horse and has forgotten where the place is! If the buyer is not attending, the vet will ring them on the way to the vetting. When the buyer is not an existing client we will ask for credit or debit card details.

Although none of us can gaze into a crystal ball, a thorough, methodical and professional examination can assist you in avoiding the pitfalls of horse buying. Knowing the buyer as a client (their ability, personality and requirements) can add an extra dimension to the process. Judging by the number of vettings we do, most of you agree.

My horse has just gone lame

Horses go lame for a ridiculous number of reasons, which can be hard to pin down. I would advise you to always be observant e.g. when turning your horse out, or when walking to the mounting block. Often a lameness is noticed when out riding: unless very lame, horses can easily be ridden or hand walked back home.

Close visual and manual examination of the suspected (or all) limbs may reveal swelling or heat. An affected foot may be warm. If the horse was shod in the last week, or has lost a shoe it may be just as advisable to call the farrier as the vet. If there is swelling, I would advise you to call us, especially if it is sore or still there the next day. If the lameness is mild some people prefer to wait a few days and see what happens, usually keeping the horse in on box rest. I would advise against administering bute without veterinary instruction. Subtle lameness with no heat or swelling may settle even if the horse continues to go out in the paddock, although turn out is not recommended if the lameness worsens.

When asked to attend, we try to come as soon as we can, although this may be after a few days if the lameness is not severe, has been going on for sometime, or a particular vet is requested. In the first instance, we thoroughly examine the horse including in hand at walk and trot, visually and manually (often using hoof testers), and perhaps on the lunge. If time and the horse allow, we may perform a simple nerve block (such as numbing out the foot) to help point us towards the lower or upper limb or even the back. On this first visit we are often able to pinpoint the cause of the lameness, initiate treatment and advise on management to get the horse better as quickly as possible.

Unfortunately this is not always the case: there may be no obvious reason for the lameness, even to us, and we may advise a period of rest before re-examination, admission to the clinic for Lameness Investigation or even referral to a specialist hospital. Which way to proceed is not always straightforward and the ultimate decision is always made by the owner/carer after detailed discussion with us.

If a lameness persists and when the cause is unknown or requires verification, we often ask you to bring the horse to the clinic for a Lameness Investigation. This may only require imaging of the known affected area of the lame leg (e.g. x-ray/ultrasound scan). However, there is often no obvious “affected area” and nerve blocks or joint blocks may have to be performed to try and localise the lameness. This involves clipping, sterilising and injecting an area of the leg with local anaesthetic and, after a short period, checking to see if the lameness has been affected by trotting up or lunging the horse. Usually more than one block is required and sometimes more specific blocks, e.g. joint blocks, may have to be performed the next day when the original block has worn off. This process and the subsequent imaging and treatment often takes several hours over one or two days. For this reason, we often ask you to leave your horse at the clinic overnight, so the investigation and treatment can be completed.

Treatment for the lameness can obviously vary depending on diagnosis. It may involve joint injections, courses of drugs or shockwave therapy. Management, such as box rest, controlled walking or paddock rest, is likely to be important. Corrective farriery, either by your own farrier or (with his approval) by a specialist farrier, may be necessary. Physiotherapy, e.g. by a human qualified Chartered Physiotherapist who has then specialised in animals (ACPAT members) is often recommended. Other alternative treatments may be discussed. Diet Supplementation may also be advised.

If the lameness continues to be perplexing or is cause for concern for the attending vet, the patient may be referred to a specialist equine hospital, such as Liphook, Bell Equine, RVC or Newmarket. This is also the case when more complex imaging may be required, such as Scintigraphy ( a bone scan) or MRI scanning. Referral is also necessary if specialist orthopaedic surgery is required.

Follow up examinations to check the case is going well are very important. All in all, lameness can be a difficult problem to solve: good communication, cooperation and often a bit of time and patience are paramount to success.

Those Pesky Flies...

A horse vet’s job gets just a little more dangerous when horse flies are around.

The midge season usually starts mid-April. Being allergic to midge bites is the cause of Sweet Itch which usually affects the mane and tail head, but can be all over. Nearly all horses and ponies are affected by midges to some extent. The disease is always most prevalent where the midges are worse e.g. on the clay soils and near standing water.

A complete barrier is the most effective way to keep the midges off – such as a barrier rug. I find the Boett Rug is best (www.sweetitch.co.uk) although certainly not the cheapest. Beware the little darling rubbing it off! Otherwise, the use of an effective midge repellent, such as Switch, a pour-on that only needs to be applied weekly AND a daily/twice daily application of a chemical barrier can be very effective. Chemical barriers include “Kill Itch” (commercially available), a home made mix of Benzyl Benzoate in Liquid Paraffin or Avon Skin So Soft Bath Oil. The Avon Bath Oil can be watered down and, in our opinion, is very effective. It’s available from your local Avon lady or from us at the practice.

Controlling management, such as turning out at night, may help. However, midges are often worst at dusk and bringing the horse/pony in may just give them a place to scratch. Don’t forget to tape off their rubbing tree.

Feeding anti-itch supplements may help e.g. Equine America Itchnomore or Hilton Herbs Sweet Itch Mix. In severe cases, we have to resort to the use of injectable or oral corticosteroids to control the itching.

General fly control can be harder to achieve. The use of fly rugs, masks and head guards do help – but check these regularly as they can cause injury. I have to say that I think that many of the more commonly used repellents I see on yards are not terribly effective. But what is? The weekly pour-on Switch and the fortnightly spray-on Deosan Deosect can be.

Gloves and protective clothing should be worn when applying these. They contain permethrins, well known chemical insect repellents. Permethrins are also in Coopers’ Fly Repellent Plus, but more dilute. Several of our livery yards now use Deosan Deosect, mixed up correctly in a garden sprayer and applied carefully once a fortnight.

All these products are available from us, and should be available from merchants with suitably qualified staff. D.E.E.T. is another effective chemical insect repellent. It is available on the sweet itch website or in shops for humans as Jungle Formula or own brands (Boots) – these can be used on horses. Making up your own fly repellent can be a good idea. Lavender oil, ginger, garlic, citronella oil (available from Holland and Barrett) in a liquid paraffin base are all good ingredients. Remember to patch test all fly sprays first, to detect reactive horses.

Judy finds that Kerosene – that is pink paraffin or aviation fuel – can be a very effective fly repellent. This can be hard to source these days. Please consult the practice on how much to dilute it – do not use it neat and patch test it first. Whatever you use, I truly hope it is effective and keeps those pesky flies at bay...

I want to breed my mare

This time of year, we have many enquiries regarding breeding. “Hobby” breeding should only be undertaken after serious consideration.

Mares should not be bred for sentimental reasons or if they have a problem that could be passed on to the next generation (e.g. arthritis, navicular disease, poor conformation). One also has to be prepared to pay a stud to supervise the foaling or accept the stress and risks of foaling at home. Mammalian birth is a life threatening procedure and in equines it is possible (albeit rare) to lose the mare and the foal if things go wrong. After the birth, the nursing and the weaning, there’s then three years of looking after a wild youngster, and homebreds are often the wildest, before having a useful animal.

Although it is possible to breed a mare, even a maiden mare, at any age, their fertility rates start to drop over 15 years old. The conformation of their genital tract is also a major fertility factor. Choosing a stallion for your mare can be a difficult matter. They are advertised in horse magazines, posted on the internet and listed with Breed Societies. Recommendation by someone you trust is usually the best.

The most likely breeding methods available are natural and artificial insemination (AI). Natural covering in the presence of trained staff, although a potentially violent process, often gets good results. Professional studs with proven stallions and veterinary control can achieve pregnancy rates of 80%. If you select a stud and stallion for natural covering they are likely to request certain swabs and blood tests before the mare goes to stud. These can vary, so ask them specifically what is required (e.g. external and/or internal CEM and/or EVA blood test) before booking them in. Laboratory Certificates can take up to 10 days after the samples were taken and usually need to accompany the mare to stud.

If you select AI you have higher vet fees. This is in addition to the stud/semen fee. Your mare is often more likely to conceive if sent to the stud as fresh semen is the most fertile. Also, professional studs often have a stud vet on site everyday and can offer favourable veterinary packages, e.g. around £250 + VAT per insemination. Many offer grass livery. Many owners send their mares to stud for chilled AI, e.g. from Europe, for convenience and logistics.

At our practice, we offer chilled and frozen AI. Traditionally, chilled was thought to be more fertile than frozen, but variations in chilling techniques, hot weather and couriers mean that this is not necessarily the case. Knowing the viability of the stallion’s semen and the reliability of the stud (from a source other than the stud) is extremely helpful. We charge £250+VAT to £300+VAT per insemination, including all the scans and washouts. Courier fees (for semen transport) are extra. For the first time this year, we offer grass livery at £10/day (including bringing them in and preparing them for stocks/ insemination/scans etc). If the mare is admitted to the clinic when she comes into season she is likely to be here for around 5 days. If a client insists on insemination at home then normal visit fees are charged in addition to the insemination fee.

We recommend a pre-breeding examination, including swabs and a scan (even biopsy in problem mares) prior to AI. This costs £80+VAT if they are brought in (including lab fees, not biopsy). We also recommend pregnancy scans at 14, 24, 32 days. These are £44.50 +VAT each.

The average mare should be pregnant in one or two inseminations (seasons). If not they can be considered potentially infertile or “problem” mares: this doesn’t mean that they won’t get pregnant, just that much more veterinary intervention may be required and the cost can escalate. To a person who has not bred before, all of this can be a little overwhelming. We are more than happy, by appointment, to meet you at the practice to discuss it all and show you our facilities.

Low Intensity Worming

For sometime now, the Practice has been recommending a Strategic Worming Programme based on manufacturer’s guidelines.

An example of this would be Equest (moxidectin) quarterly and Equitape (praziquantel) biannually. This is a “blitz” approach to worming and is very effective at eliminating worm related problems, e.g. colic, weight loss and diarrhoea. We still strongly recommend a Strategic Worming Programme in an intensive management environment, such as a livery or competition yard. The horses should all be wormed at the same time and new horses should be wormed and tapewormed on arrival. New horses with an unknown recent worming history should be treaded with a low intensity wormer, e.g. pyrantel (Strongid-P, Pyratape). We recommend use of modern wormers: it has been shown that many types of equine worms are resistant to the older wormers, such as the benzimidazoles (Panacur and Telmin). It is recommended that horses are kept in for 48 hours after worming, for environmental reasons.

In a static horse population, i.e. where the same horses live together on the same land with little change, then a less intensive programme can be considered, especially if the dung is regularly removed from the paddocks. Modern wormers are very toxic.

For example, avermectins in field run-off is very dangerous to fish. Also, dogs can die if they eat Equest wormer and Equitape should be washed off after contact with human skin. In a closed equine community we are happy to recommend:

• Regularly picking up dung, e.g. twice weekly. This is good for the grass too.
• Twice yearly worming with a modern wormer.
• Annual treatment for tapeworm.
• Faecal Worm Egg Counts and annual Tapeworm blood tests. For example, worm egg counts three months after a worming.

This less interventionist programme would not compromise the health of most horses, although worming frequency may have to be increased if the tests show up worms or tapeworms. Fresh dung in a plastic bag at the practice by noon (we must know that you are coming by 10am) can be examined for worm eggs at a cost of £10 + VAT. Horses can be blood tested for tapeworm at a cost of Visit + £35 + VAT. Although slightly controversial, one could test a sample of the horses, e.g. two of four.

If you require more information about a Health Plan for your yard (including vaccination, health checks and/or teeth), please speak to one of the vets at the practice.

Strangles Info

Several yards in Surrey and West Sussex have had the misfortune of Strangles outbreaks. A new strain of Strangles arrived last year and our population seems to be susceptible. Here are a few facts and tips:

• Strep. equi is rarely fatal (1%). It is a contagious upper respiratory tract infection causing inappetance, fever, snots, cough and occasionally abscesses in the throat. Rare complications such as Purpura or “bastard strangles” cause the fatalities.
• It is contagious by shared air space (next door stable), being coughed over, shared water or by handlers “carrying” the snot from one horse to another. It is not blown across fields by the wind.
• If there is a yard outbreak it should be voluntarily quarantined. Infected horses should ideally be isolated from apparently unaffected ones, although the latter should not leave the premises. This means no shows, going out etc for weeks or even months.
• Veterinary advice for all involved should be sought, e.g. a yard meeting. See www.hblb.org.uk for the equine industry Codes of Practice. No laws, except welfare laws and export, apply to Strangles.
• The first signs are a temperature and a “sore throat”, both causing inappetance. The disease can take up to 14 days to spread from one horse to another.
• Up to 10% of affected horses can become carriers, and can shed the bug for months after apparently getting better. This is how it spreads between yards.
• After an outbreak, ideally all “in-contact” equines should have three clean swabs taken over at least a fortnight to weed out carriers, which can then be treated.
• A Strangles vaccine is available. At least 70% of the horses in the yard must be vaccinated for effective control and it must be done at least every 6 months. If this is done, an outbreak is unlikely and any quarantine should only be for a short time. Reactions can occur when a horse is vaccinated, especially when the primary course is given.
• New horses to a yard should be monitored closely for signs of respiratory disease for the first 2 weeks and should be isolated if there is concern.

Although it is unlikely that your yard, whether private or livery, will experience an outbreak, I consider it important that such a scenario should be considered by the yard manager and the horse owners made aware of the yard policy. Should an outbreak occur, this may save considerable extra aggravation.

Fly Control

The fly population exponentially increases as the summer progresses and each generation hatches out.

The horse fly emergence in early July has now relented. Fly strike, in unattended wounds, thrushy feet and aged geldings’ sheaths, is now quite common, the latter often being confused with colic.

Fly repellents are just that, they can ease the number of flies on your horse or pony but do not eliminate them. The use of fly masks and fly rugs massively reduce the fly burden and we strongly recommend their use. Obviously they should be carefully fitted and regularly checked, and do not go well with barbed-wire fencing. Keeping horses in during the day keeps the flies off too, but beware stables that get too hot in the afternoon!

Commercially available fly repellents vary massively in their effectiveness. If you have one that works for you, then stick with it.

Some of the “natural” ingredients can be of dubious effect. Citronella, a traditional natural repellent is (allegedly) being withdrawn in the EU! Neme, lavender, ginger, garlic and tea are other commonly used natural agents.

Kerosene (paraffin/aviation fuel), diluted one teaspoonful/ 2 gallons water and “frothed”, is also an effective repellent. As with ALL products, patch test on a small area of the horse first to check that he/she does not react. Permethrins are effective chemical fly repellents. They are available commercially as Deosan Deosect, which is diluted and sprayed on fortnightly; Switch, a weekly pouron, and Cooper’s Fly Repellant Plus, which is a daily applicant (and much more dilute). All of these are available from us. Other products containing permethrins are available from horsey outlets. Some people use the permethrin-containing cattle ear tags in the mane, although we do not recommend this.

D.E.E.T. is also an effective chemical repellent. It can be bought from chemists, e.g. Boots’ Repel is 50% DEET and the roll on applicator is useful. 90% DEET is available from the sweet itch website.

Flies cause conjunctivitis, bite reactions, sheath infections and can carry disease. Did you know that sarcoids are caused by a fly-borne virus? - although the horse has to be genetically susceptible to getting sarcoids as well. Fly control will become more and more important as our summers get longer and warmer.

Mud Fever

The Mud Fever and Thrush season is well and truly upon us, despite (as I write) the relatively low rainfall. Sadly, Dermobion is no longer being manufactured as one of the active ingredients, nitrofurazone, is banned in the EU.

I still recommend washing twice weekly with Betadine or a medicated shampoo e.g. Horse Health's “Clear Up”. Give the scabs a good soaking, pick off any that want to come and then dry with PAPER TOWELS. Clipping the legs to expose the scabs is often essential.

Dispose of towels/scabs/hair away from other horses. Over washing can remove the skin’s naturally protective oils. Apply effective creams or gels to the sore areas. FUCIDERM is a powerful dog and cat gel that is very effective (prescription/vet only). Fungatrol (Equine America) can be tried.

The bad cases may require veterinary attendance and more aggressive treatment such as cling film “sweats” and antibiotics. Remember that in cobs and heavy horses mange mites may be present on the legs causing itching and stamping. This can be treated with a Dectomax injection. Mud fever can lead to Lymphangitis, a severe disease.

Thrush of the frog is another bacterial infection or “foot rot” that can cause lameness. I recommend a minimum of twice weekly control with peroxide or antibiotic spray (veterinary only). Scrubs with Betadine may help, and the application of sugar/Betadine (“sugardine”) can be very effective.