Horse Vaccinations

There are a number of diseases that horses can be vaccinated against which include:

  1. Tetanus
  2. Strangles
  3. Hendra virus
  4. Equine Herpes Virus
  5. Salmonella

Tetanus

What is it?  

Tetanus is a disease caused by the bacteria Clostridium tetani. Bacterial spores live for a long period in the environment and cause disease when they enter wounds, proliferate and release a potent neurotoxin. Once the clinical signs of tetanus have set in, the disease has a very high fatality rate. The most common times to be affected are teething, castration and from wounds.

Clinical Signs Muscle spasms, stiff gate, 'sawhorse stance', respiratory distress, 3rd eyelid protrusion, increased sensitivity to noise/light/touch, leading to death
Who needs it? Recommended for all horses from 6 months of age onwards. Ideally all horses to be castrated will have their 1st dose at least 4 weeks prior so that tetanus antitoxin is not required at the time (2nd vaccination will be given instead)
Initial Doses 2 doses 4 weeks apart
Boosters 1 booster 12 months after initial course then every 5 years
Tetanus Antitoxin Tetanus Antitoxin (TAT) is often given to horses suffering from wounds that are not up to date with vaccination. Antitoxin is designed to eradicate circulating toxin from an established infection and only has up to 10 days of action. It is also much more expensive than the vaccination.

 

Strangles

What is it?  

Strangles is a highly contagious bacterial infection caused by Streptococcus equi equi. The bacteria is highly contagious between horses and can survive in the environment for extended periods. It proliferates in the lymph nodes in the throat latch area causing large abscesses which in some cases can compromise the horses airways. Controlling the spread of the disease involves expensive and time consuming quarantine measures.

Clinical Signs Initially lethargy and inappetance due to fever followed by a watery nasal discharge which generally becomes thickened and yellow coloured. Large abscesses form under the throat and can burst out through the skin or internally into the back of the throat. In a small percentage of cases the swelling can restrict or cut off breathing (hence the same Strangles).
Who needs it? Recommended for all horses which travel for competitions, breeding or any other reason that may come into contact with large numbers of other horses. The disease is contagious before any clinical signs develop, therefore can spread rapidly before its even known to be a problem
Initial Doses 3 doses 2 weeks apart (1st and 3rd dose can be combined with Tetanus in a 2 in 1 shot)
Boosters Label claim is a booster every 12 months, however new recommendations suggest immunity wanes in that time and as such a booster every 6 months would be ideal for horses going to competitions. A compromise could be ensuring that the annual booster is given at the start of the competition season.


Hendra Virus

What is it?  

Hendra virus is a fatal disease passed to horses from fruit bats in their urine/saliva/etc. Infected horses can then spread the virus in rare cases to humans. For more specific information on Hendra virus please see the article under the Information Sheets menu.

Clinical Signs Neurological, respiratory and gastrointestinal signs can all be attributed to Hendra. One of the major concerns is the lack of consistent clinical signs to distinguish the disease in the field.
Who needs it?

Recommended for all horses travelling to high risk Hendra areas (coastal/NE NSW/SE Qld).

Some competitions and some workplaces (e.g. feedlots) require horses to be vaccinated

Initial Doses 2 doses 3-6 weeks apart
Boosters 1 booster in 6 months and then annually thereafter

 

Equine Herpes Virus

What is it?  

Equine Herpes Virus (EHV) has a number of strains that affect horses in different ways. The major concerns in Australia are EHV-1 & 4 which can cause abortions in pregnant mares as well as respiratory and neurological infections in other horses. Like other herpes viruses, once contracted, the animal may become permanently infected.

Clinical Signs

Mid and late term abortions, still births or birth of weak/underdeveloped foals.

Respiratory and neurological signs of varying severity

Who needs it? For mares with a history of difficult pregnancies or a diagnosis of EHV caused abortion.
Initial Doses 2 doses 4 weeks apart prior to pregnancy
Boosters Booster doses in the 5th, 7th and 9th months of gestation - note that mares which were previously exposed and have become permanently infected may still abort.

 

Salmonella

What is it?  

Salmonella is a common pathogen in almost all species. In horses the largest concern is in young foals who can become infected and develop severe colitis and septicaemia. Adult horses can also develop potentially fatal colitis from salmonella infection

Clinical Signs Watery diarrhoea, lethargy, inappetance, listlessness, recumbency, dehydration, death
Who needs it? To reduce the chance of newborn foals developing salmonella, mares can be vaccinated to pass on come immunity through their colostrum
Initial Doses 2 doses 4 weeks apart - the second dose mus be at least 6 weeks prior to foaling
Boosters 1 booster every pregnancy (4 weeks prior to foal being due)