Infectious Diseases and Vaccinations

Question 1

What are the core Vaccines?

Answer 1

• Rabies
• Tetanus
• West Nile Virus
• Eastern Equine Encephalitis

Question 2

What are the optional Vaccines?

Answer 2

• Equine Influenza
• Equine Herpesvirus
• Strangles
• Potomac Horse Fever
• Botulism
• Equine Viral Arteritis

Question 3

What does disease spread require?

Answer 3

a susceptible host, an infective agent and a supportive environment

Question 4

What are risk factors that effect desicions about vaccinations for a horse?

Answer 4

• geographic location
• pregnancy
• age
• exposure to other horses
• in and out traffic
• stress

Question 5

What vaccinations would you give to a horse living in a rural setting and why?

Answer 5

with little or no contact with other horses they have minimal risk of exposure to agents so core vaccinations are recomended

Question 6

Why do rural horses show severe signs when exposed to an agent?

Answer 6

cause no previous exposure so reduced immunity

Question 7

What vaccinations would you give to a pregnant horse and why?

Answer 7

they are at high risk cause agent can kill fetus in utero, damage placenta, hypothermia –> abortion

• Keep separate from horse traffic
• core vaccinations plus some additional ones (influenza, Equine herpesvirus, strangles)

Question 8

What vaccinations would you give to a foal and why?

Answer 8

have passive immunity from mother for first 9-12 weeks and produce immunoglobins at birth but not enough until 2 months old.
- Vaccinate mare 4-6 weeks before foaling and foal at about 6 months after birth (sooner if not vaccinated mother)

Question 9

What vaccinations would you give to a traveling horse and why?

Answer 9

higher risk of exposure due to higher traffic and higher stress levels which can lead to reduced immune function
- core vaccinations plus influenza, equine herpesvirus and strangles

Question 10

What is rabies?

Answer 10

• rapidly progressive fatal disease that is shed in the saliva (large amounts) and transmitted by bites or mucosal exposure
• infects nerves and the salivary gland
• preventable by vaccination

Question 11

What are the 3 types of rabies?

Answer 11

• furious
• dumb
• paralytic

Question 12

What are the CFIA rules regarding Rabies?

Answer 12

• vaccinated livestock exposed to virus should be re-vaccinated immediately and watched for 45 days
• unvaccinated livestock should be slaughtered or kept under observation and isolation for 6 months

Question 13

What is tetanus?

Answer 13

often fatal disease caused by clostridium tetani

• spore present in soil can contaminate wounds, open lacerations, surgical incisions and umbilici of foals
• produces neurotoxin which causes muscle spasms
• vaccination neutralizes toxin

Question 14

What is the west nile virus?

Answer 14

spread by mosquitoes and causes encephalitis

• zoonotic, immediately notifiable
• low mortality and sickness in horses (fatal in 30% of those showing neurological signs

Question 15

What is the treatment for west nile virus?

Answer 15

• supportive care, slings, fluids, anti-inflammatories

- vaccinations prior to mosquito season

Question 16

What is eastern encephalitis?

Answer 16

virus spread by bird-feeding mosquito that is not zoonotic

• immediately notifiable disease in canada
• 80-90% of infected horses show acute and lethal neurological disease

Question 17

What is the progression of Eastern equine encephalitis?

Answer 17

1. initially fever and depression
2. progresses to encephalitis (mania, propulsive walking, hyperesthesia, aggression)
3. recumbancy and death

• NO TREATMENT

Question 18

What are optional vaccinations? (characteristics)

Answer 18

• have variable impact on health of horses
• low risk of causing life-threatening disease
• vaccine is less than perfect in ability to prevent disease
• occur primarily in specific regional or geographical area
• a managing factor significantly increases the risk of developing the disease