Lecture 22-23 4/23/24 Flashcards
What are the characteristics of equine papillomavirus/equine sarcoids?
-skin warts of horses
-not as common as those in cattle
-typically seen on nose and around lips of young horses
-small, elevated, papillary masses
-most common equine skin tumor
-often self-limiting
What are the characteristics of equine influenza virus?
-type A influenza
-highly contagious
-accounts for majority of upper resp. infections in horses
-able to undergo antigenic drift and shift
-spread via aerosol
-infects and replicates in both upper and lower resp. tracts
What are the clinical signs of equine influenza?
-inflammation and serous discharge
-febrile for 4-5 days
-cough
-depression and/or inappetence
Why is it important that equine influenza severely damages resp. epithelium and destroys the mucociliary apparatus?
predisposes horses to secondary bacterial infection, esp. with gram-neg aerobic bact.
How is equine influenza virus diagnosed?
RT-PCR on nasal swab
-serological testing
Which options are available for equine influenza prevention?
-inactivated vaccines
-modified live intranasal vaccines
What are the characteristics of EHV-1?
-herpesvirus
-causes equine rhinopneumonitis
-once present in a population, it will stay
What are the common clinical signs of EHV-1?
-cough
-mucopurulent nasal discharge
-fever
-depression
-abnormal lung sounds
How does EHV-1 cause fetal death/abortion?
-after infection the upper resp. tract, EHV-1 infects the WBCs
-WBC infection causes viremia and dissemination of virus to repro. tract
What are the consequences of EHV-1 spreading to the CNS?
-thrombosis
-ischemic neural damage
-myeloencephalopathy (EHM)
-hindlimb paralysis
-cranial nerve abnormalities
-tail and anus paralysis
What are the risk factors for EHV?
-positive and susceptible horses in herd
-fall, winter, or spring season
-EHM in horses older than 3 years
-resp. disease in horses younger than 2 years
-abortion in mares at any age/gestation length
How is EHV-1 diagnosed?
-qPCR
–nasopharyngeal swabs if showing resp. signs
–whole blood if animal is viremic
What are the characteristics of using serum testing for EHV-1?
-does not indicate whether virus is actively present
-need paired titers to potentially identify infection
-can only be used to rule out infection in adult horses
What are the characteristics of doing CSF analysis when suspecting EHV-1?
-EHV-1 causes a yellow discoloration of CSF due to breakdown of RBCs
-not specific to EHV-1, but can rule it in or out
What are the treatment options for EHV-1?
-supportive care
-steroids to decrease CNS inflammation
-acyclovir and valacyclovir
What are the characteristics of EHV-1 prevention/control?
-inactivated and modified live vx available
-vx do not claim to protect against EHM and are contraindicated in neurologic animals
-viral shedding can occur 2 weeks after infection
-aborted materials are major source of virus
What are the characteristics of rabies in equine?
-invariably lethal and of public health significance
-five licensed rabies vx in the US
-“dumb” form leads to lots of drooling; can look like other diseases
What are the characteristics of eastern and western equine encephalitis?
-caused by alphaviruses
-maintained in environment by birds and mosquitos
-most common in mid-summer and fall
-present with fever, depression, blindness, ataxia, convulsions
-EEE is nearly always fatal; WEE has 30-40% mortality