Lesson
6
Important
Contagious Disease
Influenza (Flu)
Cause
- Virus
– This is a very contagious disease. When it shows up in a barn area, it is
very difficult to prevent exposure to all horses in the area.
Transmission
- The disease is
spread through horse to horse contact, ---aerosol, shared water, feed, where
horses congregate. The virus can be carried in the air from a cough or sneeze
for up to 30 feet.
Symptoms- Fever 106, off feed, dull or
depressed, cough, runny nose.
Treatment
– Rest,
alleviate stress, bad weather, overcrowding, hauling. Prevent secondary
bacterial infections.
Prevention - Vaccinate at least
annually. In high risk cases, vaccinate
well prior to event or every 3 months.
Intranasal vaccine may prove to offer longer immunity (possibly up to 9
months.)
Rhinopneumonitis
(Rhino)
Cause- Virus EHV-1 EHV-4
Respiratory. EHV-1b abortion (Pneumabort)
Transmission - Same as Influenza.
Symptoms - Usually milder than flu, but
very similar. Less commonly seen are neurological symptoms which may
include: incoordination or
paralysis. Rhino can be fatal.
PREGNANT MARES - Uncomplicated abortion or stillbirth (last trimester).
The mare can carry the virus in system.
Treatment-- Rest. Keep from stress.
Neurological symptoms require vet care.
Aborting mares usually no after effects.
Prevention - Vaccinate Respiratory -
Modified live virus vaccine at least annually. Poor immunity- best every 3
months.
Pregnant mares - killed virus
vaccine. Vaccination a must at third, fifth, seventh and ninth months.
Calvenza vaccine is available that is an
intranasal or injectable vaccine that protects against the respiratory form of
Influenza and rhinopneumonitis.
Viral
Arteritis
This
disease is similar to Rhinopneumonitis, but much less prevalent, can also cause
abortions.
Vaccine
is available, may be used in special circumstances. (If you expect exposure or
are traveling internationally.)
Encephalomyelitis
(Sleeping
Sickness)
(EEE,
WEE, VEE (up from Mexico), West Nile Virus)
Cause - Virus
Transmission - Mosquito born disease. Bird - mosquito- horse or man. No horse to man transmission except for VEE.
Symptoms - Fever, depression,
incoordination, staggering, paralysis.
May result in death.
Treatment - Intense veterinary care.
Prevention: At least annual vaccination.
Preferably spring and fall.
Strangles—Distemper
Cause: Bacteria - Strep equi
Transmission- Very contagious. Horse to horse. Spores can live in soil for years. Aerosol, inanimate objects. There is a two to three-week incubation
period.
Symptoms - Lymph glands under jaw or
throat area enlarge, painful, hot, abscess.
The hrose goes off his feed, thick nasal
discharge, cough. The horse will have
difficulty swallowing or breathing ( strangles). Lymph glands abscess and burst.
Bastard strangles - abscess
formation in other areas of body.
Treatment-- Penicillin. Let abscess rupture before Penicillin
administered, if possible. Good sanitary
practices.
Prevention – Vaccine may cause
complications - abscess formations at injection site, produce clinical disease.
The question is always is the vaccine worst than disease? There is a new intranasal (Pinnacle IN)
treatment which is effective, with fewer side effects.
Possible
lifetime immunity once infected. Quarantine the horse; avoid contact, good
preventative measures.
Tetanus
(Lockjaw)
Cause
-- Bacteria
“toxin”, or wound infection (navel).
Bacterial spores found in soil and manure.
Symptoms-- About 7-10 days after wound
infection, the horse will show stiffness of limbs and neck. There will be stumbling, erect ears. The
third eyelid will be evident especially when the horse is excited. The horse may have a stiff “sawhorse”
appearance. Death is possible.
Treatment -- Antitoxin, Penicillin, dark
quiet surroundings, good nursing care.
Put cotton in ears to reduce sensitivity to sound.
Prevention
- Tetnus toxoid annually. Good immunity. Tetnus antitoxin
where immunity is questioned.
Equine Infectious Anemia (EIA)
Cause - Virus
Transmission
- Biting
flies. Seen in about 1% of population, mostly in wet areas of country, which is why it
is also known as swamp fever.
Contaminated needles and syringes.
Symptoms - ACUTE --fever, depressed,
weak, decreased appetite, could die within 2 or 3 days.
CHRONIC- -very poor condition,
anemic, jaundice, limb edema (stocking up)
INAPPEARENT
CARRIER - unthrifty or normal in appearance.
Carries the virus in
the blood.
Prevention -- No Vaccine available at this
time in
Equine
Protozoal Myloencephalitis (EPM)
(Neurological
disease caused by protozoa which is carried by the opossum and is shed in
opossum droppings.)
Transmission--The horse eats contaminated feed
and gets infected with the protozoa, which travels to the brain and spinal
cord.
Symptoms-- In-coordination, and hindquarter
muscle atrophy.
Treatment –Marquis or Trimethoprim-sulfa
combined with pyrimethamine.
Prevention – A vaccine is available for
endemic areas. Control of opposum, skunks and other possible transmitters.
Potomac Horse Fever
Cause--Erlichiosis (richettsia)-found
along rivers of the east coast (Potomac River).
Spread by ticks.
Symptoms
– The horse goes
off feed, depressed, mild fever, mild colic (will go from no gut sounds to
severe diarrhea in 48 hours. Many horses
founder and many die.
Prevention
- Control ticks,
vaccinate in endemic area.
Other
Rabies-
a virus
transmitted by a dog, skunk, raccoon or coyote bite. Can vaccinate yearly against rabies.
Valley
Fever - Fungal
pneumonia. Dust, found in
Ringworm
- Fungal skin
disease. Very contagious and can be
transmitted by combs, saddle pads, brushes, bridles, etc. Treat with tamed Iodine, Clorox 10%, Nolvasan. There is
no vaccine.
Warts
– virus; usually
seen in young horses. Usually self limiting. Clears up in 2 to 3 months. Most
often seen on muzzle and lips. Spread by contact.
Lyme
Disease - Tick
born bacterial disease. Mountainous areas.
Polyarthritis, fever, lethargy, depression, Possible death or forever
lame. Vaccine is available, used regionally.
Rodococcus Equi - Dust pneumonia in foals. Bacterial. Generally there are lung
abscesses. Serum is available for preventions, but are new and
expensive. Treat with Erythromycin &
Rifampin. This is a stubborn disease.
EQUINE
VACCINES
Vaccines are available for the
following Equine diseases:
1.
Eastern equine encephalitis.
2.
Western equine encephalitis
3.
Venezuelan equine encephalitis
4.
West Nile encephalitis (new encephalitic disease) (vaccine recently available)
5.
Equine influenza injectible and new Intranasal
–(AVERT)
6.
Equine Rhinopneumonitis Upper-respiratory and abortion) Calvenza
–intranasal or injectable protects against the respiratory diseases of
Influenza and Rhinopneumonitis
7.
Equine viral arteritis (upper-respiratory and genital types)
8.
Tetanus (toxin and antitoxin)
9.
Botulism
10.
Strangles Injectible bacterin and new Intranasal (PINNACLE)
11.
Potomac horse fever
12.
Lyme disease
13.
Rabies
Recommended
Vaccination Schedule
For Mares in Foal:
The
third, fifth, seventh and ninth month of pregnancy. Killed Virus
Rhinopneumonitis vaccine (EHV-1b)
Six
weeks before foaling - VEWTF or EWTF.
Within
48 hours of birth. Tetanus antitoxin (if the mare was not vaccinated at 6 weeks
prior.)
Foals Six Months:
VEWTFR
& strangles vaccine (all followed by a booster 2 to 4 weeks later) followed
by one year VEWTFR & Strangles IN
Thereafter: All Adult Horses:
VEWTFR
in Fall OR Spring.
Flu
and Resp. Rhino every three months if exposure potential is high. Vaccinate at
least 1 week prior to hauling or big event.
Strep
Equi - Once a year. IN less side effects. Initial dose requires a booster 10
days to two weeks after first.
Younger horses weanlings to 4
years, more susceptible to Flu, Rhino, and Strangles.
Other Vaccines –
Rabies yearly if in endemic area.
Viral Arteritis- required by some countries, some states.
AVERT – New intranasal influenza
vaccine. May confer longer immunity than injectable.
CALVENZA – intranasal or
injectable – Protects against the respiratory forms or influenza and
rhinopneumonitis.
PINNACLE – Strangles vaccine– New
intranasal vaccine. Appears to be safer and more effective than injectable
form.