Veterinary Virology Overview

A complete set of vocabulary flashcards covering the characteristics, transmission, and clinical signs of major equine, bovine, swine, and avian viruses.

Eastern Equine Encephalitis (EEE)

A zoonotic Togaviridae virus (Genus: Alphavirus) transmitted by biting mosquito vectors, primarily Culiseta melanura, from wild bird reservoirs; characterized by CNS signs such as head pressing and high mortality rates ($50-90\%$).

Western Equine Encephalitis (WEE)

A zoonotic Togaviridae virus transmitted by mosquito vectors from wild bird and small mammal reservoirs; causes CNS signs similar to EEE but with a lower mortality rate ($0-40\%$).

Venezuelan Equine Encephalitis (VEE)

A Togaviridae virus involving an amplification cycle in horses and transmission via biting mosquitos from wild bird reservoirs; causes severe neurological disease with mortality up to $80\%$.

Vesicular Stomatitis (VS)

A zoonotic Rhabdoviridae virus transmitted by biting insects and direct contact; causes oral and coronary band vesicles and drooling in horses, cattle, and swine.

Equine Infectious Anemia (EIA)

A blood-borne Retroviridae (Genus: Lentivirus) infection causing recurrent fever, severe anemia, and mucosal petechial hemorrhages; diagnosed by the Coggins Test (AGID) as the Gold Standard.

Bovine Leukemia Virus (BLV)

A Retroviridae (Deltaretrovirus) that can lead to fatal lymphosarcoma tumors in the heart, abomasum, and kidneys in $1-5\%$ of infected cattle and water buffaloes.

Avian Leukosis (ALV)

A Retroviridae (Alpharetrovirus) transmitted vertically or horizontally in chickens; produces visceral B-cell lymphomas that typically originate in the Bursa of Fabricius.

African Horse Sickness (AHS)

A Reovirus (Genus: Orbivirus) transmitted by biting midges (Culicoides) causing respiratory and circulatory impairment with high mortality in horses, donkeys, and zebras.

Bluetongue (BTV)

A Reoviridae (Orbivirus) primarily affecting sheep and transmitted by biting midges; clinical signs include ocular and nasal discharge, though it is rare in cattle.

Fowl Pox (FP)

A Poxviridae virus presenting in Cutaneous (nodules/scabs) and Wet (diphtheritic plaques) forms; histopathology reveals pathognomonic large eosinophilic Bollinger bodies.

Swine Vesicular Disease (SVD)

A Picornaviridae (Enterovirus) that causes severe lameness and vesicles, mimicking FMD; it is highly resistant in the environment and transmitted via fecal-oral routes or contaminated meat.

Foot & Mouth Disease (FMD)

A highly contagious Picornaviridae (Aphthovirus) with 7 serotypes (O, A, C, SAT 1-3, Asia 1); causes vesicles on teats and hooves and pathognomonic 'Tiger Heart' (Myocarditis) in calves.

Encephalomyocarditis (EMCV)

A Picornaviridae virus transmitted by rodent reservoirs through feed contamination; causes sudden death from acute myocarditis in piglets and reproductive failure in sows.

Porcine Parvovirus (PPV)

A Parvoviridae virus causing SMEDI (Stillbirth, Mummies, Embryonic Death, Infertility) without fever or diarrhea; the Gold Standard for diagnosis is Immunofluorescence on frozen fetal lung.

Bovine Respiratory Syncytial Virus (BRSV)

A Paramyxoviridae virus affecting young calves; causes high fever, bronchial cough, and lung consolidation with syncytia formation.

Rinderpest (Cattle Plague)

A Paramyxoviridae (Morbillivirus) characterized by the 4 Ds (Depression, Diarrhea, Dehydration, Death) and pathognomonic 'Zebra stripes' in the colon; declared eradicated in 2011.

Hendra Virus (HeV)

A highly fatal zoonotic Paramyxoviridae (Genus: Henipavirus) featuring acute respiratory signs and foamy hemorrhagic discharge; spills over from fruit bat reservoirs (Flying Foxes).

Newcastle Disease (NDV)

A zoonotic Paramyxoviridae (Avulavirus) causing respiratory distress, torticollis (twisted neck), and greenish-dark watery diarrhea; causes mild conjunctivitis in humans.

Equine Papillomavirus (Sarcoid)

A virus linked to Bovine Papillomaviruses 1 and 2 that causes irregular masses of proliferating fibroblasts; it is the most common skin tumor in horses and frequently recurs after excision.

Bovine Papillomavirus (BPV)

A virus causing cutaneous fibropapillomas (warts); specifically, Type 4 can cause intestinal papillomas and Types 1 and 2 are linked to Equine Sarcoids.

Equine Influenza (H3N8)

An Orthomyxoviridae virus transmitted via inhalation of aerosols, causing high fever for $4-5$ days and a harsh, dry, paroxysmal cough.

Swine Influenza Virus (SIV)

A zoonotic Orthomyxoviridae virus with explosive onset, causing a deep barking cough and high fever (>42^\circ C) in swine.

Marek's Disease (MDV)

A Herpesviridae (Mardivirus) causing asymmetric paralysis (wing dropping), graying of the iris, and T-cell lymphomas; distinguished from ALV because it commonly affects the nerves.

Infectious Laryngotracheitis (ILT)

A Herpesviridae (Iltovirus) in chickens characterized by severe dyspnea and coughing up bloody mucus; pathognomonic Cowdry Type A intranuclear inclusion bodies are found in tracheal mucosa.

Equid Herpesvirus 5 (EHV-5)

A Gammaherpesvirus route associated with Equine Multinodular Pulmonary Fibrosis, leading to weight loss, cough, and patchy radiopaque areas on lungs.

Malignant Catarrhal Fever (MCF)

A fatal Herpesviridae (Gamma) infection in cattle/bison characterized by 'Blue Eye' (corneal opacity), 'Snotsiekte', and lymphadenopathy; carried by sheep and wildebeest.

Equid Herpesvirus 1 (EHV-1)

An Alphaherpesvirus that is the primary viral cause of equine abortion (late gestation) and can cause the neurological form known as Equine Herpes Myeloencephalopathy (EHM).

Bovine Herpesvirus 1 (BHV-1)

An Alphaherpesvirus with two subtypes: Infectious Bovine Rhinotracheitis (IBR or 'Red Nose') and Infectious Pustular Vulvovaginitis (IPV).

Bovine Herpesvirus 2 (BHV-2)

An Alphaherpesvirus subtypes including Bovine Mammillitis (teat/udder lesions) and Pseudo-Lumpy Skin Disease (nodules with depressed centers).

Equid Herpesvirus 3 (EHV-3)

The causative agent of Equine Coital Exanthema, a venereal disease resulting in pustular/ulcerative lesions on genitalia and subsequent depigmented spots.

Equid Herpesvirus 4 (EHV-4)

The primary cause of Equine Viral Rhinopneumonitis, causing profuse serous to mucopurulent nasal discharge, mostly in foals.

Pseudorabies (Aujeszky's Disease)

A Herpesviridae virus causing CNS signs and $~100\%$ mortality in piglets, and 'Mad Itch' in dead-end hosts like cattle and dogs.

Classical Swine Fever (CSF)

A Flaviviridae (Pestivirus) known as Hog Cholera; presents as high fever, purple skin discoloration, and pathognomonic 'Turkey Egg' kidneys with petechiae.

Bovine Viral Diarrhea (BVDV)

A Flaviviridae virus characterized by profound immunosuppression and the birth of Persistently Infected (PI) calves if the dam is infected during the first $100$ days of gestation.

West Nile Virus (WNV)

A zoonotic Flaviviridae virus causing muscle fasciculations, head tremors, and ataxia in horses; IgM Capture ELISA is the Gold Standard for diagnosis.

Saint Louis Encephalitis (SLE)

A zoonotic Flaviviridae virus where horses act as a reservoir but typically show no clinical signs; most common in equids under $4$ years old.

Avian Infectious Bronchitis (IBV)

A Coronaviridae virus in chickens causing 'The 3 Rs': Respiratory (rales), Renal (swollen kidneys/urates), and Reproductive (wrinkled/defective eggs).

TGE / PED (Swine Coronaviruses)

Highly contagious Coronaviridae infections causing explosive watery diarrhea and vomiting, with $~100\%$ mortality in piglets less than one week old.

Bovine Coronavirus (BCoV)

A virus causing malabsorptive diarrhea in calves and 'Winter Dysentery' (explosive bloody diarrhea) in adult cattle.

Porcine Circovirus (PCV2)

A Circoviridae virus diagnosed by the triad of clinical lesions, histological botryoid inclusions, and viral detection via IHC or qPCR.

Vesicular Exanthema (VES)

A Caliciviridae virus eradicated in the US since 1956; historically linked to raw garbage feeding and clinically restricted to swine and marine hosts.

Infectious Bursal Disease (IBD)

A Birnaviridae virus (Gumboro Disease) that causes severe immunosuppression and a swollen, hemorrhagic Bursa of Fabricius in young chickens aged $3-6$ weeks.

African Swine Fever (ASF)

An Asfarviridae virus transmitted by soft ticks (Ornithodoros) and oral routes; causes massive hemorrhage in lymph nodes and an enlarged friable spleen.

Equine Viral Arteritis (EVA)

An Arteriviridae virus where carrier stallions act as the natural reservoir; causes 'abortion storms' and widespread edema in the eyelids, abdomen, and scrotum.

PRRSV (Porcine Reproductive & Respiratory Syndrome)

An Arteriviridae virus causing late-term abortions (>90 days), mummified fetuses, interstitial pneumonia, and 'Blue Ear' in piglets.