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66 Cards in this Set
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Equine Infectious Anemia AKA
Incubation Period |
Swamp Fever AKA
1-3 weeks up to 3 months |
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Equine Infectious Anemia
Host & Mode of Transmission Incubation Period |
Horses
Arthropod Vector (stomoyxs = tabanid flies, horseflies & deerflies) Transplacental infection possible Iatrogenic transmission |
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Pathogenesis of Equine Infectious Anemia
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spreads to macrophages & lymphocytes to spleen, liver & LN where it repl. eventually cells burst releaseing virus into blood. lifelong
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What are the 3 forms of Equine Infectious Anemia?
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Acute
Subacute Chronic |
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Acute Equine Infectious Anemia
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Not test positive for at least 1 month
fever, depression, severe anemia, jaundice, bloody feces, death |
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SubAcute Equine Infectious Anemia
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Moderate fever followed by recovery
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Chronic Equine Infectious Anemia
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Most common. Recurring acute bout, weight loss, ventral edema stomach & limbs, anemia, usually die w/in 1 year
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Testing for Equine Infectious Anemia
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Asymptomatic = no clinical signs & Test positive for Coggins
Diagnosis - coggins, AGID (agar gel immunodiffusion) looks for AB Nursing foal may temporarily test positive. Recently infected horse may test negative |
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Equine infectious anemia Tx & Prevention?
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No Tx
+ EIAV euthanized or isolated & permanently marked Routine use of Coggins reduces disease |
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Host & Where find Equine influenza
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Donkey & mule
World wide except australia & newzealand |
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How is Equine Influenza Transmitted?
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Direct/Indirect
Aerosol Coughing can spread up to 3 m Wind up to 8km |
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What's the incubation time for Equine Influenza?
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1-3 day
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Describe pathogenesis for Equine Influenza
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Replicates in respiratory epithelium. Destroys tracheal & bronchial epithelium & cilia. Cough devel early & persists several weeks. Nasal discharge initially serous may become mucopurulent due to secondary bacterial infection
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How would you dx equine influenza?
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Virus isolation
nasopharyngeal swab or embryonated chicken egg Influenza A antigen detection kit HAI |
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Tx & Prevention for equine influenza?
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Supportive -rest/restricted activity
takes ~21 days to regenerate respiratory epithelium Control dust/ventilation Vaxx -inactive H7N7 & H3N8 |
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Equine Viral Arteritis Hosts
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Horses (esp. standardbreds &warmbloods) Ponies, Zebras
Stallions can become carrier |
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Equine Viral Arteritis Transmission
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Aerosol most common
Venereal, Congenital Indirect possible Shed in nasal secretions, blood, semen & placenta |
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Equine Viral Arteritis incubation
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~7 days
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Equine Viral Arteritis clinical signs
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leukopenia, limb edema (particularly hind limb), edema of prepuce & scrotum, conjunctivitis, lacrimation/periorbital/supraorbital edema. Urticaria (skin rxn on both sides of neck)
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Equine Viral Arteritis effect on repro
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no fertility problems with mare
stallions have period of temporary infertility. reduced sperm quality & quantity b/c scrotal hyperthermia |
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Equine Viral Arteritis pathogenesis
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replicates in bronchial & alveolar macrophages. Spreads to regional LN w/in 48 hr. Spread by leukocytes. Localizes in vascular endothelium of smaller BV. Carrier stallions, localizes in accessory sex glands (ampulla of vas deferens)
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Dx, Tx, Prevention of Equine Viral Arteritis
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Dx -clinical signs, isolation, neutralization, ELISA
Tx - usually recover on own. Symptomatic tx if needed Prevention -test for infected animals (carrier stallions = cause for persistence, shed in semen), modified live vaxx |
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Equine Viral Arteritis differentials
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equine influenza
EHV-1 & 4 African horse sickness Equine adenovirus |
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Hendra virus Hosts
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Horses, Humans, Fruit Bats (natural reservoir host) cats & guinea pigs experimentally infected
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Hendra virus Transmission
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Not very contagious, requires direct contact with lung exudates, urine or infected tissue
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Hendra virus Incubation
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horses 8 - 18 days
humans... unknown |
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Hendra virus pathogenesis
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tropism for vascular tissue --> edema & hemorrhage of vessel walls, fibrinoid degeneration w/pyknotic nuclei in endothelial & tunica media cells. Also see giant cells in endothelium. Alveolar walls destroyed. See alveolar & intravascular macrophages. Been found in vascular endothelium of cerebrum, kidneys, stomach, spleen, LN & heart.
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Hendra virus clinical signs
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frothy clear to serosanguinous nasal discharge, cyanotic or jaundiced mucous membranes. Edema or intermandibular space, cheeks, infraorbital fossa, limbs, or prepuce. Neurological signs (ataxia, muscle fasiculation, head pressing)
Death within 1-3 days (mortality ~70%) |
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Hendra virus Dx, Tx, Prevention
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history, clinical signs, isolation, PCR, cytopathic effect ~3 days, ELISA
Tx -none Prevention -none -outbreaks in australia, horses were slaughtered |
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What is this?
What family is it in? |
Rota Virus
Family Reoviridae |
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Rotavirus hosts & causes...
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Foals less than 2 months
90% of diarrhea cases in foals |
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Rotavirus transmission
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Direct, Indirect, Infected foals highly contagious
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Rotavirus incubation
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1-4 days
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Rotavirus pathogenesis
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replicates in & destroys enterocytes on villi of small intestines (malabsorptive diarrhea) --> lactase deficiency allowing lactose into large intestines --> osmotic diarrhea
Diarrhea lasts 4-7 days... or more |
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Rotavirus clinical signs
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Diarrhea, depression, dehydration, fever
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Rotavirus Dx, Tx, Prevention
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Dx -specific rotavirus test, visolation from fecal sample
Tx -supportive, isolate infected Prevention -vaxx mare before birth |
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REO = ?
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Respiratory
Enteric Orphan |
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African Horse Sickness Hosts
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Horses & mules = most seriously
Zebra & donkey rarely get clinical signs Camels & dogs can get it too |
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African Horse Sickness Transmission
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Arthropod vector (biting midges -culicoides imicola & culicoides bolitinos)
Dogs can get it from eating infected equine meat |
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African Horse Sickness incubation
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3-5 days for respiratory form
1-2 weeks for cardiac form |
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African Horse Sickness Pathogenesis
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replicates in pulmonary &/or cardiac endothelial cells
Vessels become leaky --> heart failure & pulmomary edema |
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African Horse Sickness peracute clinical signs
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Pulmonary form
dyspnea, coughing, abducted forelegs, dilated nostrils, frothy serofibrinous nasal discharge, profuse sweating, death less than a week most common form in dogs |
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African Horse Sickness Acute clinical signs
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Mixed form
See cardiac & pulmonary forms Usually ends up in death |
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African Horse Sickness fever clinical signs
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mildest form
fever dissipates in morning, but worsens during day. mild anorexia & depression. Supraorbital edema. congested mucous membranes. tachycardia |
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African Horse Sickness Dx, Tx, & prevention
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Dx - virus isolation & ELISA
Tx -cull affected, Prevention -Vaxx. quarantine new imports 2 months & test |
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Equine Herpesviruses Hosts
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Horses -more so in younger horses
recovered can become carrier at least 60% carry latent virus in CD8 cells |
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Equine Herpesviruses Transmission
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Direct or indirect contact with nasal secretions, aborted fetuses, placentas or placental fluids. Can be shed up to 10 days at a time. Shed when stressed or using corticosteroids
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Equine Herpesviruses incubation
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2-10 days
EHV -3 clinical signs develop 4-8 days after sexual contact |
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Equine Herpesviruses pathogenesis
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EHV-1 -replicate in many tissues, including brain
EHV-4 -limited to respiratory tract epithelium & LN Virulence of any is associated with Thymidine kinase (tk) gene. Accelerates new DNA synthesis by salvaging thymidine from degraded DNA Abortion due to transfer virus from infected leukocytes to placental endothelial cells --> thrombosis & ischemia & eventual entry of virus to fetus. Maternal lesion can be extensive so as to initiate abortion before virus has chance to replicate in fetus (virus negative fetus) More often, virus replicates in liver, lung, adrenal gland & spleen of fetus |
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EHV-1 clinical signs
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most common cause of abortions in mares = 2-12 weeks after infection and 7-11 months of gestation. Aborted fetus = "fresh."
May see respiratory dz, myeloenchephalopathy |
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Equine Herpesviruses Dx, Tx & Prevention
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Dx -clinical signs & virus isolation
Tx - supportive, Prevention -Vaxx available for 1 &4 "herpes is stronger than love" |
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West Nile Encephalitis Hosts
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Horses, Humans, Birds primary reservoir
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West Nile Encephalitis Transmission
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Mosquito (culex spp.)
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West Nile Encephalitis incubation
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3-14 days
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West Nile Encephalitis pathogenesis
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in horses, virus attacks CNS
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West Nile Encephalitis clinical signs
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Neurological (head pressing, twitches, partial paralysis etc) Colic, lameness, anorexia & fever
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West Nile Encephalitis Dx, Tx, & prevention
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Dx -Clinical signs, Isolation IgM capture ELISA
Tx - supportive, many horses recover Prevention -vaxx available, mosquito control |
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West Nile Encephalitis clinical signs in people
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80% asymptomatic
20% mild signs -fever, headache, body ache, nausea, rash on chest, stomach & back. Last days to weeks. |
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Eastern Equine Encephalomyelitis Hosts
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Horses, Humans, some birds
(mammals = dead end host) |
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Western Equine Encephalomyelitis Hosts
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Horses, Humans, some birds
Horses & people = dead end hosts Secondary amplifier = prairie dogs & black tail jackrabbit |
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Venezuelan Equine Encephalomyelitis Hosts
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Epizootic = horses
humans (dead end host) Enzootic = rodents = vertebrate host, primary vector = Culex Melanoconionhumans (dead end host) |
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Equine Encephalomyelitis transmission
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arthropod vector (also considered bridge vector b/c brides gap of bird & mammal)
EEE (coquilletidia perturbans, Aedes canadensis, Aedes sollicitans, Aedes vexans & Culex nigripalpus) WEE (Culex tarsalis, Aedes melanimon, Aedes dorsalis & Aedes campestris) |
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Equine Encephalomyelitis incubation period
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EEE & WEE 4-15 days
VEE 1-6 days Horses 1-8 days |
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Equine Encephalomyelitis pathogenesis
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virus travels thru lymphatics to LN & replicates in macrophages
EEE mortality up to 90% |
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Equine Encephalomyelitis clinical signs
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altered mentation -head pressing, aimless wandering, impaired vision, ataxia. usually die 2-3 days after clinical signs start
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Equine Encephalomyelitis Dx, Tx & prevention
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Dx -clinical signs, geographic location & time of year. AB capture ELISA for IgM (EEE specific) HAI, Complement fixation, Virus neutralization
Tx - supportive Prevention -Vaxx Found in US, but still EEE & WEE are reportable |
