Equine Infectious Disease Flashcards
Viral disease of horses and other equidae. This disease can be caused by several strains but most commonly Type 1 and Type 4
Equine Herpesvirus Infection (Equine viral rhinopneumonitis, Equine abortion virus)
EHV Type 1 causes
Respiratory disease, abortions, and/or neurologic disease
EHV Type 4 causes
Respiratory disease especially in weanlings but can rarely cause abortions also
Etiology of Equine Herpesvirus Infection
Type 1: EHV-1
Type 2: EHV-4
Neurologic form of EHV type 1 is called
Equine Herpesvirus Myeloencephalopathy
Respiratory form of EHV type 1 and type 4 is called
Rhinopneumonitis
Both EHV-1 and EHV-4 spread via
Aerosolized secretions from infected coughing horses
EHV-1 also transmitted by
Contact with aborted fetuses, fetal fluids, and placentae associated with abortions
Which type of EHV is reportable?
EHV-1
Symptoms of EHV
-Fever, serous nasal discharge, malaise, pharyngitis, cough, inappetence, secondary bacterial infections
Treatment for EHV
None, supportive care
Vaccination of EHV may:
Reduce the severity and duration of disease but will not totally prevent the disease
How should mares be vaccinated for prevention of abortion
During 5th, 6th, and 9th months of gestation using inactive EHV-1 vaccine
A highly contagious viral disease that spreads rapidly among naive horses
Equine Influenza
Etiology of Equine influenza
Viral: H3N8 orthomyxovirus, equine influenza A type 2
Clinical signs of Equine Influenza
High fever, serous nasal discharge, submandibular lymphadenopathy, dry/harsh cough, depression, anorexia, weakness
Sample needed for virus isolation and antigen detection of Equine influenza
Nasopharyngeal swabs
All horses should be vaccinated against equine influenza unless
They live in a closed and isolated facility
Etiology of Equine Viral Arteritis (EVA)
Viral: enveloped single-stranded RNA virus
Is EVA zoonotic and reportable?
Zoonotic-No
Reportable- YES
Transmission of EAV
Respiratory, venereal, and congenital routes or by indirect means
Reservoir for EVA
Carrier stallions
Clinical signs for EVA
Fever,swelling of; legs, scrotum, sheath, mammary glands, above/around eyes. Anorexia, depression, conjunctivitis, nasal discharge, abortion in pregnant mares, pneumonia and death in young foals
The only definite means of diagnosing EVA is by
laboratory testing
Equine strangles etiology
Streptococcus equi (gram-positive, Bhemolytic cocci)
An infectious, contagious disease of Equidae characterized by abscessation of the lymphoid tissue of the upper respiratory tract
Equine Strangles
Is equine strangles zoonotic and reportable?
Zoonotic- No
Reportable- YES
Transmission of Equine strangles
Fomites and direct contact with infectious exudates. Vectors: flies
Within 24-48 hrs of initial fever spike, horse will exhibit signs of typical strangles including
Mucoid to mucopurulent nasal discharge, depression, submandibular lymphadenopathy
Diagnosis of Equine strangles is confirmed by
Bacterial culture of exudate from abscesses or nasal swab samples
Which vaccine provides the most protection from Equine Strangles
intranasal vaccine containing live attenuated strain of S. equi
Equine strangles vaccine should be given every _ months after initial 2 dose series
6
How does Tetanus enter the body
Through wounds, particularly puncture wounds if the wound is dirty
Tetanus is caused by the bacterium:
Clostridium tetani
Classical signs of Tetanus
progressively worsening muscular stiffness and spasms
Tetanus toxoid vaccine
purified, inactivated toxin
Tetanus antitoxin vaccine
produced by hyper immunization of donor horses with tetanus toxoid
How is vaccination recommended for Tetanus in all horses and ponies
On an annual basis
A horse disease caused by retrovirus and transmitted by bloodsucking insects
Equine infectious anemia (EIA)
Although most infected horses show no symptoms, of EIA
There is no cure and they remain contagious for life
Transmission of EIA
Blood transmission by horseflies, deer flies, or mosquitos, or by in-utero passage from mare to foal
Diagnosis of EIA
Coggins (AGID) and C-ELISA tests
Only protection of EIA is
Prevention! There is no tx, vaccine, or cure
EIA positive horses must be
lifelong quarantined
Potomac Horse Fever etiology
Neorickettsia risticii
Potomac horse fever is
seasonal, vaccination should be timed to precede anticipated peak during summer or fall
Leptospirosis clinical signs
Recurrent uveitis, late term abortion, acute renal failure
Rotaviral Diarrhea is a major infectious cause of
Foal diarrhea
Western, Eastern, Venezuelan Encephalitis (WEE,EEE,VEE) is characterized by signs of
CNS dysfunction and moderate to high mortality
Etiology of (WEE,EEE,VEE)
Arbovirus; Genus: Flavivirus (enveloped RNA virus)
The principal means of transmission and amplification of EEE is
Mosquito-avian-mosquito cycle
West Nile virus (WNV) etiology
Arboviruses
Transmission of WNV
Enzootic transmission cycle between wild birds and mosquitos
Prevention of WNV
Mosquito control
Is Equine Viral Encephalomyelitis zoonotic and reportable?
YES and YES
Equine Protozoal Myeloencephalitis (EPM) etiology
protozoan, Sarcocystis neurona
Definitive host for S neurona in the US is the
opossum
Transmission of EPM
horses ingest S neurona sporocysts in contaminated feed or water