Equine Vaccinations

Vaccination is a vital part of equine health management and protects your horses against many infectious diseases. There are three main vaccinations that we reccommend.

Tetanus

Tetanus is an often fatal disease caused by the anaerobic bacteria (grows in low oxygen conditions), Clostridium tetani. The spores of Cl. tetani are commonly present in the soil and can contaminate puncture wounds, crushing wounds, open lacerations, surgical incisions and the umbilici of foals. Upon gaining entrance to the body, they produce a powerful neurotoxin that blocks neurotransmission, resulting in unopposed muscle contraction and spasm (tetany). Horses often adopt a "saw horse" posture. Other symptons can include protusion of the third eyelid, stiffness of gait, holding the tail high and rigid, rigid back muscles, and recumbancy.

The incubation period is approximately 8 days, however can be up to 21 days.  Horses of all ages can be affected. Horses are the most susceptible of all of the animal species. 

Tetanus is preventable by vaccinating against horses with the following schedule:

1st Vacc         3mths +         

2nd Vacc        4 weeks after first

Yearly thereafter

**It is advisable that broodmares are vaccinated annually 4-6 weeks before foaling to boost the concentration of anti-tetanus antibodies in their colostrum.

 

Strangles

Strangles is a highly contagious and serious infection of horses and other equids caused by the bacterium, Streptococcus equi. The disease is characterized by severe inflammation of the mucosa of the head and throat, with extensive swelling and often rupture of the lymph nodes, which produces large amounts of thick, creamy pus.

Horses of all ages are susceptible, though strangles is most common in animals less than 5 years of age and especially in groups of weanling foals or yearlings. Foals under 4 months of age are usually protected by colostrum-derived passive immunity. S. equi is main-tained in the horse population by carrier horses but does not survive for more than 6–8 weeks in the environment. Although the organism is not very robust, the infection is highly contagious. Transmission is either by direct or indirect contact of susceptible animals with a diseased horse. Direct contact includes contact with a horse that is incubating strangles or has just recovered from the infection, or with an apparently clinically unaffected long-term carrier. Indirect contact occurs when an animal comes in contact with a contaminated stable (buckets, feed, walls, doors) or pasture environment (grass, fences, but almost always the water troughs), or through flies.

Susceptible horses develop strangles within 3–14 days of exposure. Animals show typical signs of a generalized infectious process (depression, inappetence, and fever of 39°C–39.5°C). More typically of strangles, horses develop a nasal discharge (initially mucoid, rapidly thickening and purulent), a soft cough and slight but painful swelling under the jaw, with swelling of the submandibular lymph node. Horses are often seen positioning their heads low and extended, so as to relieve the throat and lymph node pain.

Strangles is preventable where horses are vaccinated. We reccommend vaccinating to the following schedule:

1st Vacc         3mths +         

2nd Vacc        2 weeks after first

3rd Vacc         2 weeks after second

Yearly thereafter (also sold as combined vaccine with tetanus)

 

Hendra Virus

Hendra virus infection is a serious condition which can be fatal. The virus was first discovered after an outbreak of illness in horses at a stable in Hendra, Brisbane in 1994. Since then, seven people have been confirmed to have Hendra virus infection, four of whom died. All the events occurred in New South Wales and Queensland.

Horses may contract the virus by consuming water or food contaminated with saliva or droppings of infected flying foxes (bats). Spread between horses occurs in situations of close contact. Spread to humans occurs through direct contact with body fluids of sick horses, such as nasal secretions or blood products. Usually a high level of exposure is required to acquire the virus, such as may occur among stable workers and veterinarians. There is no evidence of human to human spread.

Symptoms are highly variable but usually have a very rapid, acute onset and range from mild to severe. The incubation period for Hendra virus in horses ranges from 5 to 16 days. Signs consistent with colic have been the initial sign described in many cases. Dead horses may appear to have met with misadventure. Many horses are found dead with few, if any, prior signs.

Clinical signs of Hendra virus include:

  • A high case fatality rate
  • Pyrexia (fever)
  • Discomfort (weight shifting between legs)
  • Neurological changes
    • Aataxia - “wobbly gait”
    • Head-pressing
    • Muscle twitching
    • Depression
    • Altered consciousness - “dazed”
    • Aimless walking
    • Aead tilting
    • Circling
    • Apparent blindness
    • Urinary incontinence
  • Respiratory distress
    • Dyspnoea
    • Tachypnoea
    • White or blood-tinged frothy discharge from the mouth and nares, particularly in the terminal stages
  • Weakness
  • Collapse with inability to rise and/or sudden death.

The best and most secure way to reduce risk of exposure is by vaccinating your horses. The vaccine is registered and recorded with your horses microchip. Therefore, if your horse is not microchipped, it will also need one inserted at the time of the first vaccination.

The vaccine schedule for Hendra is:

1st Vacc         3mths +         

2nd Vacc        3-6 weeks after first

3rd Vacc         6 months after the second

Yearly thereafter