Equine Infectious Diseases

Question 1

Anthrax

Answer 1

Also called Splenic Fever (enlarged, dark spleen)
* reportable disease
* affects all warm-blooded animals
* bleeding from orifices
* swelling SQ tissues

Question 2

Anthrax
Etiology

Answer 2

Caused by Bacillus Anthracis
* gram positive
* spore forming
* found in soil
* infects through contaminated feed
* spread via insects during outbreaks

Question 3

Botulism

Answer 3

Also called Shaker Foal Syndrome
* toxins produced from ingested spores on vegetation in intestinal tract
* severity depends on amount ingested

Question 4

Botulism
Etiology

Answer 4

Caused by Clostridium botulinum
* gram positive rod
* spore forming (anaerobic)
* found in conaminated soil, water, and feed

Question 5

Botulism
Clinical Signs

Answer 5

Creeping paralysis
* rapid, progressive neuro disease
* respiratory (high mortality)
* pharyngeal - foals unable to swallow after nursing

Question 6

Lyme Disease
Etiology

Answer 6

Caused by Borrelia burgdorferi
* gram negative spirochete
* transmitted via tick bite (deer / ixodid)
* needs to be attached for 24-48 hours

Question 7

Potomac Horse Fever
Etiology

Answer 7

Caused by Neorickettsia risticii
* transmitted by freshwater insects (caddis / mayflies)
* accidental ingestion of insect by horse
* gram negative cocci
* affects WBCs (monocytes)
* replicates in GI tract

Question 8

Salmonella
Etiology

Answer 8

Caused by various Salmonella species
* gram negative rod
* species S. typhimurium most pathogenic
* get from ingesting contaminated feed / water / feces of infected animals or contact with contaminated hands / environmental surfaces / shedding livestock
* causes watery, foul smelling diarrhea

Question 9

Strangles

Answer 9

Also known as horse distemper
* bastard / metastatic occurs when bacteria spreads to other LN; increases fatality

Question 10

Strangles
Etiology

Answer 10

Caused by Streptococcus equi
* gram positive coccoid
* shed by nasal and draining abscess discharge from infected

Question 11

Tetanus
Etiology

Answer 11

Caused by Clostridium tetani
* gram positive bacillus
* found in soil
* infects via exposure to wounds, incisions, or injection sites

Question 12

Tetanus
Clinical Signs

Answer 12

• Sawhorse appearance (rigid muscles)
• Recumbent (poor prognosis)
• Dyspnea

Question 13

Thrush
Etiology

Answer 13

Caused by Fusobacterium necrophorum
* gram negative bacillus

Question 14

Thrush
Clinical Signs

Answer 14

Degenerative condition of the frog
* odor
* black discharge
* lameness

Question 15

EPM

Answer 15

Equine Protozoal Myeloencephalitis
* reportable disease
* asymmetrical muscle atrophy
* cranial nerve abnormalities

Question 16

EPM
Etiology

Answer 16

Caused by Sarcocystis neurona OR Neospora hughesi (parasites)
* transmitted by eating opossum feces

Question 17

Piroplasmosis

Answer 17

• Reportable disease
• Weight loss
• Anemia
• Urine red-yellow in color

Question 18

Piroplasmosis
Etiology

Answer 18

Caused by Babesia equi OR Babesia caballi (parasites)
* transmitted via Am. dog tick (Dermacentor)

Question 19

EIA

Answer 19

Equine Infectious Anemia
* reportable disease
* also called swamp fever
* diagnose with Coggins test
* euthanize or quarantine for life

Question 20

EIA
Etiology

Answer 20

Caused by lentivirus (Retroviridae family)
* transmitted by blood-sucking insects

Question 21

Vesicular Stomatitis

Answer 21

• Reportable disease
• Excessive salivation
• White areas (vesicles) in mouth, coronary band, abdomen, muzzle, prepuce

Question 22

Vesicular Stomatitis
Etiology

Answer 22

Caused by Rhabdoviridae family
* transmitted by insects
* black / sand / house flies and mosquitoes

Question 23

Equine Viral Arteritis

Answer 23

• Reportable disease
• Flulike symptoms, pneumonia, and abortion

Question 24

Equine Viral Arteritis
Etiology

Answer 24

Caused by Equine arteritis virus
* transmitted by aerosol drops or infected semen

Question 25

Rhinopneumonitis

Answer 25

* Reportable disease (only if neurologic) * Upper respiratory tract affected * Abortion * Low sperm count * Neurologic signs

Question 26

Rhinopneumonitis Etiology

Answer 26

Caused by equine herpesvirus type 1 (EHV-1) and equine herpesvirus type 4 (EHV-4)

Question 27

Rabies

Answer 27

* Reportable disease (contact state officials) * Self mutalation most common sign * GI symptoms / loss of bladder control * Lameness

Question 28

Rabies Etiology

Answer 28

Caused by Rhabdovirus (enveloped RNA) * transmitted by saliva / bite mounds from bats, skunks, raccoons, and foxes

Question 29

EEE / WEE / VEE

Answer 29

Eastern / Western / Venezualan Equine Encephalomyelitis * reportable disease * rapid, progressive, and highly fatal neurological disease * fever * anorexia * ataxia / paralysis

Question 30

EEE / WEE / VEE Etiology

Answer 30

Caused by alphavirus * EEE more fatal * transmitted by mosquitoes

Question 31

West Nile Virus

Answer 31

* Reportable disease (if neurological) * Low-grade fever * Low appetite / Depression * Paralysis / Weakness * Droopy lip

Question 32

West Nile Virus Etiology

Answer 32

Caused by Flaviviridae family * transmitted by mosquitoes

Question 33

Biosecurity Goals (5)

Answer 33

* Prevent spread of active or potential diseases * Work with what you have * Know how disease is transmitted * Know risk factors of disease * Know who is susceptible

Question 34

Chondroids

Answer 34

* Seen with Strangles * Forms in the gutteral pouch (mouth) * Horse remains infectious as long as these are present