Equine Matters - Summer 2016

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Here, our experts will answer any veterinary or health related questions you may have.

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Question 3:

My mare seems to be constantly in

season now that the weather is warmer and she’s

becoming very difficult to ride, especially around

geldings. Is there anything I can do

Hormonal behaviour in mares can start around

the beginning of the natural breeding season,

approximately March time, and often will finish

when the days get shorter in the autumn. The

behaviour usually correlates with the mare’s 21

day oestrus cycle. There are various options for

controlling oestrus behaviour, anecdotally

certain homeopathic supplements may help,

although this is not proven. There is a licensed

oral medication for postponing oestrus in

horses. It is a liquid containing the hormone

progesterone and acts to suppress natural

hormones and prevent cycling.

Other treatments available include long-acting

GnRH analogue vaccinations. This is only

available overseas as a licensed product. In

the UK it is possible to use a similar porcine

product, off licence. This is administered

intramuscularly, repeated at four weeks, then

at six monthly intervals. The vaccination can be

very effective, but should not be used where

breeding is intended in the future, as it is not

known how effectively mares may return to

normal oestrus activity.

Finally, a rather novel way of stopping oestrus

activity involves introducing plant oil or

sterilised peanut oil into the mare’s uterus at

day ten post ovulation which has also been

effective at suppressing unwanted oestrus

behaviour.

Rebecca Goodwin BVetMed CertAVP(EM) MRCVS,

Cliffe Equine Clinic, East Sussex

Figure 1.

Intradermal skin testing

Question 2:

I have just had my event

horse’s back checked and I’ve been told

that he might have kissing spines because

he’s very tense. What is the best way to

find out whether this is true, and is there a

treatment

Usually we would start by palpating your

horse's back and watching him move on the

lunge and ridden. The first test we would

perform would be radiographs (x-rays) of the

back and this can be very useful. If these are

normal your horse does not have kissing

spines. If they are moderately or very

abnormal, then kissing spines is likely, but

not certain. Therefore further tests including

nuclear scintigraphy, (bone scanning) or

numbing the horse's back with local

anaesthetic

(figure 2)

and then asking you

to ride again are often necessary.

There are two main treatment routes, medical

and surgical. Medical treatment includes

steroid injections into the affected area of the

back, painkiller sachets, physiotherapy and

sometimes medicines to reduce bone damage.

This can be very effective but does not give

a permanent cure - perhaps lasting six

months. Also as the underlying problem

worsens (kissing spines is a progressive

disease), they may become less effective.

Surgical treatment involves making the space

between the bones that are rubbing together

wider so that they no longer rub. This may

be achieved by removing part of the bones

or by transecting the ligament between the

bones. The exact method will depend on

the individual case. Surgery is usually

done standing under sedation and local

anaesthetic. It is a considerable undertaking,

but does give the prospect of a true cure.

David Rutherford BVM&S

CertES(Orth) Dip ECVS MRCVS,

Fellowes Farm Equine Clinic Ltd

Figure 2.

Injecting local anaesthetic

between the vertebrae

Question 1:

My horse, a 25 year old

gelding, has suffered from urticaria every

October/November for three years. Allergy

testing has shown he reacts to flies that are

around in the summer only! It always starts

with lumps and some of them ooze serum,

which can be difficult to remove due to his

long winter coat, and within two days he

develops severe urticaria. After three weeks

the urticaria vanishes overnight and he is left

with lumps all over his body.

I have tried a course of three antihistamine

injections, but after 2-3 days the urticaria

returned.

A few weeks ago he was diagnosed with

Cushing’s disease. He has no problems in

changing his coat and the urticaria always

starts after he has moulted fully

Do you have any advice

Urticaria is basically an allergic reaction to

something, not necessarily something in the

environment - it could be something the horse

eats. If the allergy test was testing antibodies

in the blood, that is not reliable in the horse,

so I wouldn't take anything from the results.

Intradermal skin testing is more useful

(figure

, although still not without its problems, with

a significant amount of false negative and

positive results. If this test has not already

been performed, I would recommend referral

for this skin testing.

An elimination diet could be tried, consisting

of basic hay (single grass type) and chaff,

and alter the stable management ideally to

rubber matting or paper. After at least two

months on this regimen, if clinical signs have

abated, you could start reintroducing one

thing at a time. These are frustrating cases.

Although short lived, there was a response to

antihistamines, so these could be fed daily to

reduce clinical signs if the horse is very

irritated. Cushing’s will also mean the horse

will have a predisposition to bacterial skin

infections so, unless the ACTH concentration

is only just above the normal range, I would

treat with pergolide and possibly a long

course of antibiotics if a bacterial component

is proven.

Dr Kirstie Pickles BVMS MSc PhD

PGCert (Couns Skills) CertEM (IntMed)

DipECEIM MRCVS,

Scarsdale Veterinary Group

EQUINE MATTERS