Equine Newsletter Nov 2003

Worming

Those of you on The Equine Loyalty Plan at the practice will be aware of the need for comprehensive worming at this time of year. Your wormers will have been put up for collection as usual. For those of you bemused and puzzled by worms at this time of year this is what you need to do and why:

  1. October — Double dose with Strongid P to eliminate Tapeworms.
  2. November — 5 days of Panacur Equine Guard to kill encysted Round worms.
  3. December — Equest to kill Bots.

Herpes Virus

We regularly see suspected cases of this disease and know that it was recently discussed in The Horse and Hound, It is most usually seen as a runny nose and the horse or pony may be off colour.

Here are the facts:

Incubation is 3 — 7 days and the horse may be ill for up to three weeks. A secondary bacterial infection may occur which is why antibiotics may be given by the vet. As you will know from your doctor — antibiotics do not kill viruses, only bacteria.

Where there are horses there will be Herpes Virus. A new horse on a yard is just as likely to catch it from horses already on the yard as it is to bring the infection onto the place — remember three out of four horses carry it anyway!

There is a vaccine and all horses on The Loyalty Plan receive it. The vaccine can be given from 5 months of age followed by a second dose after 4 — 6 weeks. Immunity (whether vaccinal or natural) is short lived so a booster is given every six months. The virus is five times more common than Flu which is why we have always strongly recommended vaccination. If you have a pregnant mare the vaccine should be given in the 5th, 7th and 9th month of pregnancy to prevent abortion.

Influenza (‘flu’)

This is highly infectious, spreading by aerosol for distances of over 30 metres!

It spreads rapidly. Biannual peaks occur in the summer and the winter corresponding with racing seasons. It is five times LESS common than Herpes probably because vaccination is so widespread.

There are only 0.8 cases per 100 horses per month in this country. Severity of the signs depends on the dose of virus received by your horse but runny noses and a cough are the most common symptoms. As with Herpes virus a secondary bacterial infection may occur and antibiotics may be given.

The Jockey Club mandatory Flu vaccination policy has really worked in the UK — there have been no race meetings cancelled because of Flu since its introduction. The vaccine is safe in 3 — 4 month old foals. A primary course of two injections six weeks apart is given. The Jockey Club guidelines require a booster essentially six weeks later and another six months later. Annual boosters should be given. A period of rest after the vaccine is NO LONGER RECOMMENDED.

As with Herpes virus — where there are horses there will be flu.

Streptococcus equi

This also causes a respiratory tract infection.

Unlike Herpes and Flu this is a bacterial infection and so, in the main IS TREATABLE (unlike Flu and Herpes).

It is fairly common and may be increasing in prevalence in the UK.

It is sometimes given the ridiculous name ‘Strangles’.

WHERE THERE ARE HORSES THERE WILL BE THE STRANGLES BACTERIA.

It is highly contagious and is spread by direct contact between horses and ponies. It can also be spread via grooming kits, clothing, buckets, vermin and tack. It survives well on wood – 48 to 63 days.

Recovered animals may shed it for THREE years infecting other horses unknowingly.

76% of affected horses are immune to strangles for at least four years.

The disease manifests as a nasal discharge, with a temperature and occasionally the horse may be depressed. The signs are very similar to Herpes and Flu.

Incubation is 4 – 10 days and recovery may take up to 4 weeks.

Antibiotics are usually given though a minority of vets believe that they should not be.

Complications are rare but occasionally the lymph nodes around the throat become very enlarged and burst expressing some pus. This sounds more alarming than it actually is!

In extremely rare cases abscesses form throughout the body. This was more common in the days before antibiotics and was given the ludicrous name ‘Bastard Strangles’.

The disease is not a notifiable disease (such as Foot and Mouth) so there are no laws stating you should stop all movements on and off a yard that has a confirmed case. (See below for management of a case/outbreak).

A new horse entering a yard is just as likely to pick up the infection from a carrier animal on the yard as it is to bring it onto the yard. Horses may pick up the infection at shows and events and bring it back onto a yard.

There is no test to see whether a horse is a carrier.

Management/Prevention of outbreaks of respiratory disease

Ring us or chat to us at routine vaccinations/health checks about how to control these diseases.

Vaccinate as many horses as possible with Flu and Herpes vaccines. The bigger the population of vaccinated animals the less chance these diseases have to get a hold. Vaccination programmes have shown to be extremely successful.

If you can control the viruses with vaccination you are less likely to get a secondary bacterial infection in your horse, such as Streptococcus equi.

Isolate all horses which have shown signs for at least four weeks after the signs have resolved.

Prevent movement of personnel, equipment and tack etc between cases and between infected and potentially un-infected horses.

Place buckets of disinfectant at strategic locations and provide protective clothing and wellies for personnel dealing with cases. The clothing can either be washed off or placed in the washing machine immediately after handling a suspected case. Phenolics are the most effective disinfectants for equipment and areas contaminated with organic matter. Hibiscrub can be used for hand washing and for washing off protective clothing.

Burn infected bedding and control vermin, dogs and chickens etc.

Discourage horses from entering and leaving the premises.

Inform people entering and leaving the premises of the risks and ask them to don protective clothing on arrival and disinfect before leaving.

Prevention of outbreaks of respiratory disease.

Isolate all horses entering a yard for at least two weeks. Look for runny noses and listen for coughs.

Isolate all respiratory cases as soon as they become apparent.

We realise some of these recommendations may be difficult to implement practically but for the health and welfare of horses you must try to do your best.

Some take home messages about respiratory infections.

Your horse is just as likely to be a carrier animal as another person’s horse or pony.

Strangles is a stupid name for a fairly common bacterial disease.

If you see a horse with a runny nose apply huge dollops of common sense. Many people get runny noses! Know the facts, be understanding, sensible and logical and ring us for a chat.