Equine Infectious Disease Prevention Programs Flashcards
Vaccine efficacy depends on what?
the type of vaccine and route of administration
When should you being vaccines for foals and how many do they typically require?
6 mo of age; 3 vaxs
What are the core vaccines for equines?
- Tetanus
- Encephalitis
- EEE, WEE, West Nile Virus
- Rabies
What is tetanus? What are the clinical signs of this disease? How is it treated and how can it be prevented?
- Neuro dz caused by Clostridium tetani, present in intestines, manure, soil, spores enter thru wounds, umbilicus
- C/S: stiff gait, facial mm spasm, third eyelid prolapse, sawhorse stance, excessive response to external stimuli, recumbency
- Tx: sedatives, mm relaxants, tetanus antitoxin, penicillin or metronidazole
- Prev: all horses should be vaccinated - tetanus toxoid vax, booster if open wound/sx procedure >6 mo since vax, begin @ 6 mo of age if foal recived colostrum from vaxed mare
What are the 4 arboviruses and what is their lifecycle?
- Alphavirus: EEE, WEE, VEE
- Flavivirus: WNV
- Lifecycle: mosquitos and birds (crows) = reservoir, dead-end hosts = horses and humans
What are the clinical signs of West Nile Virus?
- fever
- mm fasciculations
- weakness/ataxia
- flaccid paralysis
- changes in mentation
- CN deficits
What are clinical signs of Eastern Equine Enchephalomyelitis?
- neuro signs 5d after exposure
- death 2-3d later
- low grade fever first
- viremia for 2d
- fever (up to 106)
- during viral proliferation
- behavior change: irritable, somnolent, self-mutilation, hyperesthesia, hyperexcitable, decr food/water consumption
- dementia: head-pressing, leaning against wall, compulsive walking, blindness –> seizures
What time of year do most EEE outbreaks occur vs. WNV outbreaks?
- EEE: April-Sept
- WNV: June-Dec
What is the differene between the viral targets and mortality rates of EEE and WNV?
- EEE:
- Mortality: 75-95%
- Targets cerebral cortex
- WNV:
- Mortality: 30-33%
- Targets mid-hind brain/spinal cord
What are the vaccination protocols for EEE and WNV?
- EEE: in FL, booster EEE/WEE every 4-6 mo, booster 1 mo prior to peak mosquito season
- WNV: vax dependent
- Fort Dodge/BI: 2x per year
- Merial - 1x per year
- Intervet Prevenil - 1x per year
- Vax broodmares 30-60d prior to foaling
- Foals: begin vax series @ 3-4 mo (3 vaxs!)
What is the most common reservoir of rabies? What are the clinical signs of this disease? What is the vaccine protocol for rabies?
- Raccoons
- C/S: can look like anything - incubation = 2-9 wks, dumb form, ascending paralysis, furious form
- Vax protocol: annual Killed vax IM
- Foals: begin at 6 mo
What are the risk-based vaccines for equines?
- Influenza
- Equine Herpesvirus (Rhinopneumonitis)
- Strangles
Describe the pathogenesis of equine influenza. What are the clinical signs for this disease, and what is the vaccination protocol for this?
- susceptible population <3 yrs, incubation period 1-3d, stressful conditions/travel
- C/S: high fever (1-5d), cough (sev wks), nasal d/c, lethargy, depression, reduced appetite, mm soreness
- rest is ESSENTIAL following infxn
- Vax protocol: vax q 6-12 mo–> decr viral shedding (inactivated IM, MLV IN, canarypox vector IM)
- Broodmares - give IM vax in last 30d of pregnancy
- Foals @ 6 mo
Describe EHV 1 and 4
- EHV 1: abortion (7-9 mo of gestation), neonatal death, neuro dz, resp dz
- fever and nasal d/c prior to neuro dz
- EHV 4: resp dz
- also known as rhinopneumonitis, C/S nearly identical to influenza
- incubation time 2-10d, shed virus for 2-3 wks, most common in weanling and yearling
- transmitted via resp route, contaminated equipment and stress can cause recrudescence
How is EHV prevented?
- vaccination decr shedding of virus and severity of C/S
- foals and weanlings - start b/t 4-6 mo
- yearlings - q 6 mo
- broodmares - booster at 5, 7, 9 mo of pregnancy to prevent abortion (usually occurs @ 7-9 mo)
- vax 30 d prior to foaling w/ EHV 1+4 for colostral immunity
