1. Preventative Health Program for Horses
Vaccinations
CTVT pages
LACP

2. Overview General overview History Physical examination Why vaccinate?
How do I vaccinate?
What diseases should I vaccinate for?
When should I vaccinate

3. Physical Examination
New additions to a stable or established herd should be Coggins’ test-negative for EIA and quarantined for 1 month before introducing them into general population.
Physical Examination: TPR, weight, eyes, dental, musculoskeletal system and skin should be examined.
You must always obtain a history in conjunction with your exam on the horse.

4. Why Vaccinate?
Critical component of a horse health maintenance program
Primes the immune system for a quick response when exposed to infection
Prevent life-threatening diseases
Minimize or eliminate contagious diseases that affect performance or herd health

5. Why Vaccinate? Prevent some FATAL diseases Rabies Tetanus
Encephalomyelitis (EEE/WEE/VEE)
WNV

6. How vaccines work:
Passive Immunization

7. How vaccines work:
Active Immunization

8. How vaccines work: Passive Immunization Active Immunization
Brief period of protection
Antibody absorption one time only
Active Immunization
Prolonged period of protection
Boosting of protective response by additional exposure

9. Vaccination can NOT guarantee disease prevention in all cases
Vaccination should be used in conjunction with good nutrition, deworming, pasture management, and minimizing stress in your herd

11. How? Most vaccines are given IM (in muscle)
Some are available to give IN (intranasal)
􀂄 Influenza
􀂄 Strangles

12. Technician Note Horses that are immunologically naïve or have
An unknown immunization history should
Receive an initial immunization,
Followed in 4 weeks by a second
Immunization.

13. Vaccine Reactions Anaphylactoid reactions: allergic reactions Fever
Lameness
Swelling or abscess formation at the injection site

14. What should I vaccinate for?
ALL HORSES
Tetanus
Encephalomyelitis
West Nile Virus
Rabies
(Risk-based vaccines)
MOST/PERFORMANCE
Influenza
Equine Herpesvirus
SOME
Strangles
Potomac Horse Fever
Botulism
Rotavirus

15. Tetanus Vaccines Caused by Clostridium tetani
The toxoid version of this vaccine is given to immunize horses against a disease characterized by muscle rigidity and spasms that may result in respiratory arrest and convulsions.
Administration of antitoxin to unvaccinated horses induces immediate protection that lasts approximately 2 weeks.

16. Tetanus
Caused by bacteria found in soil and ingested by horses or enters a wound.
Called “lockjaw” because it especially effects the muscles of the neck and jaw.
Present in intestine, manure, and soil
Spores can exist for years in soil
Spores enter through wounds, lacerations, umbilicus

17. Clinical Signs of Tetanus
Muscle stiffness
Sawhorse stance
Third eyelid prolapse
Lockjaw
Flaring nostrils
Hypersensitive to touch

18. Stiff legged gait. The muscle of the legs become
Rigid and stiff that the horse may fall and not
Be able to get up again. Convulsions may
Occur and death is caused by paralysis
The breathing muscles.

19. Tetanus Not contagious Mortality rate is high
All horses should be vaccinated annually
Tetanus toxoid vaccine is safe and provides good protection
Tetanus antitoxin is for previously unvaccinated horses

20. When to vaccinate - Tetanus
Not typically seasonal, vaccinate any time of year
Most horses in spring, in combination with EEE/WEE
Boost if wound or surgery >6 months from last dose

21. Equine Encephalomyelitis Vaccine
EEE=Eastern Equine Encephalomyelitis
WEE=Western Equine Encephalomyelitis
VEE=Venezuelan
Often referred to as “sleeping sickness”
This vaccine protects against a viral neurologic disease transmitted by biting mosquitos.
In areas where winter freezes are uncommon, semiannual vaccination may be advisable.

22. EEE is a mosquito spread disease of birds that
Sometimes is transmitted via a mosquito bite
To horses and people.

23. Encephalomyelitis WEE seen throughout North America
EEE seen mostly in the East and Southeast, prevalent in Texas
VEE not in US for many years – reportable foreign disease

24. Clinical Signs of Encephalomyelitis
Result from inflammation of the brain and/or spinal cord
Fever
Depression
Staggering gait (ataxia)
Paralysis
Seizures

25. Abnormal Mentation

26. Abnormal Gait - Ataxia

27. Encephalomyelitis EEE/VEE – mortality rate 70-90% die
WEE – mortality rate about 50%
Vaccination is safe and generally very effective against these diseases

28. When to Vaccinate – EEE/WEE
ALL horses should be vaccinated annually in the spring, prior to mosquito season
In Texas, recommend boosting every 6 months for EEE/WEE
Foals should receive first dose at 3-4 months of age, and 2 additional doses one month apart

29. ENCEVAC™ Line of Equine Vaccines
For vaccination of healthy horses against Eastern and Western Equine Encephalomyelitis. (Sleeping Sickness). Encevac™ is a formaldehyde inactivated, adjuvanted bivalent equine vaccine consisting of Eastern and Western Equine Encephalomyelitis viruses.

30. West Nile Vaccine Another mosquito transmitted virus
Humans and horses are dead-end hosts.
Spread by mosquitoes-Culicoides spp. and some birds.
Prevalent throughout the U.S.
Causes inflammation of the brain an spinal cord
Not contagious from horse to horse

31. Clinical Signs of West Nile Virus
Can vary
Fever
Muscle tremors
Incoordination/ ataxia
Hypersensitive
Facial nerve or other paralysis

32. West Nile Virus Mortality rate about 33%
Associated with inability to stand, prolonged recumbency

33. When to Vaccinate - WNV Several vaccines available
-Fort Dodge West Nile Innovator – killed
-Merial’s RecombiTek – recombinant vaccine
-Intervet’s PreveNile – modified live chimera vaccine
Annual vaccination recommended
In Texas and states with larger mosquito populations, may boost every 4-6 months

34. Equine Rhinopneumonitis Vaccine (herpes #1)
Pregnant mares should be vaccinated with this vaccine in the 5th, 7th, and 9th months of gestation to prevent a viral disease whose strains can cause upper respiratory disease, abortions, stillbirths, and weak neonatal foals that fail to survive.

35. Equine Influenza Vaccine
The duration of protective immunity from this vaccine is short-lived, requiring vaccination every 2 to 3 months during periods of exposure.
Disease outbreaks usually occur in horses 1 to 3 yrs. of age after mixing with infected horses at the racetrack or showgrounds.

36. Equine Influenza Incubation period 1-3 days High fever (1-5 days)
Young horses are at risk!
Spread by aerosolized droplets, infected fomites – highly contagious

37. Equine Influenza – Clinical Signs
Cough (several weeks) and fever
Lethargy, depression, reduced appetite, muscle soreness
Nasal discharge
Most horses recover in days with supportive care

38. When to Vaccinate - Influenza
Intranasal vaccine every 6 months
Intramuscular vaccine every 4 months
Start foals at 9 months of age
FLU AVERT® Intra-nasal spray vaccine for Equine Influenza

39. Strangles Vaccine
Respiratory disease caused by infection with Streptococcus equi.
Spread by mucous or contaminated fomites. What are fomites?
Intranasal and IM vaccines
Vaccination not 100% effective but can lessen the severity of incidence.
2 Types: Atypically (transient-cold like) and Bastard (spread of infection to the organs)

40. Strangles: Streptococcus equi spp. equi
Transmission: Ingestion or inhalation of infected discharge
Horse-horse contact or fomites
Highly contagious
High morbidity, low mortality
Incubation period 3-5 days

41. Strangles – Clinical Signs
Cough, fever, lymph node enlargement
Respiratory distress due to retropharyngeal lymph node enlargement
Complications
-Purpura
-Metastatic (“Bastard”) strangles

42. Vaccination for Strangles
Previously affected farms
May lessen disease severity
Vaccine reactions
-Purpura
-Abscesses if IM vaccines become contaminated
Annual booster
Intranasal vaccine

43. Equine Viral Arteritis
Vaccine induces partial to complete protection against the clinical signs of disease, but if virus challenged the virus can replicate in the animals body.
Clinical signs: fever, depression, nasal discharge, lacrimation, coughing, and limb swelling.

44. Potomac Horse Fever Vaccine
It is believed that aquatic insects are the vectors: snails
Efficacy of the vaccine is unknown.
Prevalent in the eastern states near large waterways.
Use of this vaccine is usually in areas where it is a problem.

45. Botulism Vaccine
Usually given to mares 30 days prior to foaling for the prevention of shaker foal syndrome.
Given in areas of high incidence geographically.

46. Botulism Clostridium botulinum
Causes flaccid paralysis
Endemic in KY
2 Forms
􀂄 Shaker foal syndrome
􀂄 Forage poisoning
Vaccinate for type B usually in broodmares

47. Anthrax Vaccine
Anthrax vaccines are available for use but are not widely used except where a genuine risk is identified.

48. Rabies Vaccine 100% FATAL in all cases
Virus affecting the nervous system
Vaccinate horses where wildlife (skunks, foxes, raccoons, bats) rabies is endemic in the Houston area.
Spinalcord or brainstem signs.
Very, very commonly vaccinated for here in Texas!

49. Clinical Signs of Rabies
Can look like anything!
Behavioral changes, blindness
Ataxia and incoordination
Fever
Hypersalivation
Paralysis
Colic

50. Rabies
The rabies virus is killed by most disinfectants. Only lives in dried saliva or carcass for 24 hours. But it can live for days in refrigerated carcasses.

51. When to vaccinate - Rabies
Incubation period 2-9 weeks
Death in 3-5 days once signs develop
Vaccinate once a year
Vaccine is safe and effective
EquiRab, a rabies vaccine designed specifically for horses

52. Rotavirus Most common cause of infectious diarrhea in foals
Clinical Signs- profuse watery diarrhea, fever, lethargy
Highly contagious

53. Rotavirus Vaccination
Prevention- vaccination of pregnant mares 30 days before foaling in endemic herds may confer modest protection

54. Vaccine X +/- EEE/WEE* West Nile Virus* Rabies* Tetanus*
Pleasure or
Show
Pregnant Mare
Pasture Horse
Boarding Facility
Weanling (> 6 mo)
Frequency
EEE/WEE* X
Annual
West Nile Virus*
May/Sept
Rabies*
Tetanus*
Herpes (Rhino)
+/-
Q 6 months
Influenza
Strangles
PHF
April/June
EPM
Botulism
Atlantic states
Comments
High rate of exposure
Maternal Antibodies in last 30 days of pregnancy
Protect from non-equine vectors

55. Management Practices Quarantine and monitoring of new horses
Isolation facility and protocol
Requirements prior to introduction of new horse
Separation of groups of horses according to use, susceptibility to infection

56. Management Practices Vector control Management of sick horses
Keep good records!

57. THE END FOLKS….