Viral Diseases Flashcards
What type of virus is Bluetongue? To what viral family does it belong?
Orbivirus, Reoviridae
How is Bluetongue spread? What clinical signs does it present with?
Arthropod-borne disease
Somatitis, depression, coronary band lesions. Fever, hyperemia, and congestion of tissues of mouth, lips, and ears. Cyanotic membranes.
Sheep more likely to show clinical signs
Reportable, due to similarities to FMDV.
What type of virus causes Epizootic Hemorrhagic Disease? Describe the condition.
Reoviridae, related to Bluetongue.
Acute and fatal infections in farmed and wild ruminants, primarily WTD. Transmitted by Culicoides biting midge. Usually occurs when deer congregate in wet areas during dry period of late summer/early fall and disappears with the frost.
What is the most common bovine neoplastic disease in the US? What causes it?
Bovine leukemia, caused by BLV deltaretrovirus
What type of lymphoma is associated with BLV? What clinical signs are expected?
Only adult or enzootic forms of bovine lymphoma are associated with BLV.
30% have lymphocytosis, <5% develop B cell lymphoma.
Loss of condition, diarrhea, anorexia, ataxia, melena, paresis (downer) with tumors in abomasum, spinal canal, heart, and uterus
Describe distribution and management of BLV. What human agent is it closely related to?
50% of US cattle are positive, 1% develop lymphoma
BLV eradication efforts are underway in some US states and other countries
Closely related to human T-lymphotropic Virus 1
What causes Bovine Herpes Mammillitis? What lesions are present? Why do we care?
Bovine herpesvirus 2
Ulcerative teat, udder, oral, and skin lesions. Requires deep penetration of skin
Differential for FMDV
What type of virus and viral family is bovine viral diarrhea? What species are susceptible?
Pestivirus of the Flaviviridae family
Sheep and goats susceptible
Describe BVD. What strains are there? Clinical signs? Important dates for in utero infection?
Cytopathic and noncytopathic strains
Causes abortions, congenital abnormalities, reduced fertility, immunosuppression, and acute and fatal disease
Gestation day 50-100: Abortion/stillbirth
Gestation 90-170: Thymic atrophy, cerebellar dysfunction
Or normal, persistently infected calves
Vaccination available
What is the most important viral disease of goats? What Family and Genus does it belong to?
Caprine Arthritis Encephalitis Virus
Family Retroviridae, Genus Lentivirus
What are the clinical signs of caprine arthritis encephalitis virus?
Signs only occur in 20% of affected animals
Most common: Progressive arthritis in goats over 6 months of age. Swollen, painful carpal joints, pneumonia in older animals, hard udder syndrome
Neuro signs in kids 2-6 months old with unilateral weakness progressing to hemi- or tetraplegia (lower muscle disease), head tilt, blindness
What is the pathogenesis of caprine arthritis encephalitis virus? What lesions does it cause? How is it controlled?
Transmitted through colostrum and contact. Infects cells of the mononuclear system and becomes sequestered as provirus in host cells.
Causes severe synovial hyperplasia with inflammatory cell infiltration, demyelination and inflammation in brain and spinal cord, gray, noncollapsing lungs
Prevent via feeding heat-treated colostrum only
>65% seroprevalence in industrialized countries
What is the primary pathogen in Bovine Respiratory Disease Complex? What are the clinical signs, forms of disease, and recovery length?
Infectious bovine rhinotracheitis virus - Bovine herpesvirus 1
Causes conjunctivitis, rhinotracheitis, pustular vulvovaginitis, abortion, encephalomyelitis, and mastitis
Respiratory Form: IBR or Red Nose
4-5 day recovery after onset
Vaccination, usually in combination with PI-3
What type of virus is bovine parainfluenza 3 (PI-3)? Describe the condition.
RNA paramyxoviridae
Causes a mild resp. disease as a sole pathogen with cough, fever, nasal discharge, and potentially abortions. Rarely alone, more severe when combined with other agents.
By itself, self-limiting. Vaccine available for cattle, none for sheep and goats - use cattle vx
What type of virus causes bovine respiratory syncytial virus? Describe the condition.
Pneumovirus, paramyxoviridae
Causes subclinical or severe disease (initial exposure)
High fever, cough, nasal discharge, and conjunctivitis. Interstitial pneumonia, open-mouthed breathing, and emphysema.
Vaccinate
What virus causes border disease or hairy shaker disease?
Pestivirus of Togaviridae family. Antigenically unique from BVDV, bovine vaccines don’t work
What animals are primarily affected by border disease? What clinical signs are seen?
Primarily sheep, but goats are susceptible.
Early embryonic death, abortion of macerated or mummified fetuses, or birth of lambs with developmental abnormalities (tremor and hirsutism)
What family and genus does the virus causing contagious ecthyma (orf) belong to?
Poxviridae, Parapoxvirus
What are the clinical signs of orf?
Papules, vesicles, and pustules of the face, genitals, and coronary band. Most commonly at commissures of the mouth in animals under 1 year.
How is orf spread? What lesions can be appreciated? How is it controlled?
Shed in scabs. Infects through superficial lesions. Virus is very stable in environment.
Ballooning degeneration of epidermal and dermal layers, edema, and cellular hyperplasia. Painful.
Control with vaccination
What type of virus is foot and mouth disease?
Picornavirus
What species does FMD affect?
Most highly infectious agent described to date. Affects a variety of species. Very contagious with aerosol spread.
Subclinical in goats, swine represent important hosts/propagators.
How does FMD present?
Acute disease with vesicles around the mouth, hooves, and teats, fever, anorexia, and salivation
What type of virus causes malignant catarrhal fever?
Gammaherpesviruses.
Several species-specific gammaherpesviruses - OvHV-2 is the sheep associated form
