Infectious disease and vaccinations Flashcards
core vaccine diseases
- rabies
- tetanus
- west nile virus
- eastern equine encephalitis
optional vaccinated diseases
-equine influenza, equine herpesvirus, stragnles, potomac horse fever, botulism, equine viral arteritis
epidemiologic triad
-spreading disease requires 1. susceptible hosts 2. infective agent 3. supportive environment
risk factors of vaccination
- geography
- pregnancy
- age
- exposure to other horses
- in and out traffic
- stress
geography, horses, and vaccines
-horses in rural areas with little contact with other horses have little risk of exposure to agents
-if exposed, however, can show severe signs because of no previous contact and thus reduced immunity
RECOMMENDATION: CORE VACCINES
broodmares, pregnancy, and vaccines
- HIGH RISK: agents can kill fetus, damage placenta, cause hyperthermia, and result in abortions
- ie. herpes can become active and cause abortion STORMS amongst herds
- vaccines AND mares must be separated
- recommend core and optional vaccines like influenza, equine herpesvirus and strangles
age, foals
- passive immunity from mare’s colostrum provides most of foal’s antibodies for first 9-12 weeks
- foals produce own antibodies, but not enough for first 2 months
- recommend vaccinate mare 4-6 weeks BEFORE foaling, and foal at 6 months; if mare not vaccinated, foal at 3 months
in and out traffic
- barns with many horses lead to high exposure rates
- horses attending competitions and travelling have high risk of exposure and stress that can reduce immunity
- recommend core + vaccines for influenza, equine herpesvirus, and strangles
rabies virus
causes fatal disease in mammals
- virus shed in saliva and transmitted inbites
- approx 1 case each year past 3 years
rabies hosts in NA
skunks, fox, raccoon, coyote,
bat most common case, only reservoir of rabies in BC
rabies symptoms
rapidly progressive but preventable with vaccines
- symptoms develop in 10 days
- furious, dumb, paralytic, consider all neurological cases potentially rabies
- rabies vaccines are licensed and must be used by veterinarian
livestock exposed to rabies must be revaccinated in…
45 days; unvaccinated are to be slaughtered immediately or kept under watch for 6 months
tetanus
aka lockjaw, often fatal and caused by clostridium tetani
- spores present in soil and contaminate wounds and umbillici of foals
- C. tetani produces neurotoxin causing muscle spasms
- vaccine neutrilizes toxin
west nile virus
- spread by moquitoes and cause encephalitis (inflammation of brain)
- zoonotic
- low mortality and sickness in horses
- fatal in 30% of horses showing neuro signs
- 40% of survivors have residual neuro deficits for months or even permanent disability
- severe cases may have ataxia, weakness of hind limbs, recumbency, muscle fasciculations, fever
west nile treatment
supportive care, slings, fluids, anti-inflammatories
-vaccination prior to mosquito season
eastern equine encephalitis
-virus spread by mosquitoes that feed on birds
-immediately notify in canada
-occurs in eastern canada
-NOT zoonotic
80-90% of horses get lethal neurological disease
rapid progression in 24 hours-10 days: fever, mania propulsive walking hyperesthesia aggression, recumbency and death
NO TREATMENT only prevention
-vaccine covers both EEE and WEE
optional vaccines
diseases that have
- variable impact on health of horses
- low risk of life-threatening
- vaccine is not great at prevention
- occur in a specific region
- vaccines increase risk, ie. botulism
equine influenza
acute, contagious, resp disease
- unique ability to mutate rapidly and spread between species
- high infection rate but low mortality in horses
- incubation of 2-3 days
- sudden onset and rapid spread
influenza vaccine
-does not always prevent influenza
-most susceptible between aages 1-5
-vaccinate pregant mares 4-6 weeks prior to foaling
-must revaccinate at 6 weeks, 6 month intervals
clinical signs: fever, dry cough, nasal discharge
