DNA Viruses

Question 1

Characteristics of Herpes viruses

Answer 1

Enveloped
Icosahedral capsid
Nuclear inclusions
Host specific
Typically self-limiting but can be serious disease in immunocompromised or novel hosts
Latency
Recrudesce under stress = lifelong shedding
Disease caused by alpha, beta, and gamma herpesviruses

Question 2

Alpha Herpesviruses that cause disease in domestic animals

Answer 2

Human herpesvirus 1 (herpes simplex 1, oral herpes)
Human herpesvirus 2 (herpes simplex 2, genital herpes)
Human herpesvirus 3 (chickenpox, shingles)

Question 3

Diseases caused by Bovine Herpes 1

Answer 3

Infectious Bovine Rhinotracheitis (IBR)
Infectious Pustular Vulvovaginitis (IPV)
Infectious Pustular Balanoposthitis (IPB)

Abortion

Question 4

Virus that is often part of Shipping Fever complex

Answer 4

IBR

Question 5

Necropsy findings of EHV 1 and 4

Answer 5

Rhinopneumonitis 
Abortion (fetus not autolyzed, have focal necrosis of liver)
Neurological disease (small hemorrhages, vasculitis)

Question 6

Virus isolation of EHV 1 and 4

Answer 6

From respiratory tract, blood, fetal, placental samples

Cell culture

Question 7

Techniques used to diagnose EHV 1 and 4

Answer 7

Necropsy
Virus Isolation
Serology
Histopathology
PCR (can differentiate between EHV 1 & 4)
Immunofluorescence Assay

Question 8

What is EHV 3?

Answer 8

Equine Coital Exanthema (Equine Herpesvirus 3)
Worldwide distribution
Clinical signs: vesicles on the skin of vulva or penis that progress to erosions, scabs
Heal in about 2 weeks
Secondary bacterial infection common

Question 9

Beta herpesviruses that cause disease in domestic animals

Answer 9

Human herpesvirus 5 (Cytomegalovirus (mononucleosis-like syndrome))
Human herpesvirus 6 (Roseolovirus (Sixth Disease))
Human herpesvirus 7 (Pityriasis Rosea)

Question 10

Gamma herpesviruses that cause disease in domestic animals

Answer 10

Human herpesvirus 4 (Epstein-Barr virus (infectious mononucleosis, Burkitt’s lymphoma))

Human herpesvirus 8 (Kaposi’s sarcoma-associated herpesvirus)

Question 11

How do wildebeest and sheep present with Bovine Catarrhal Fever?

Answer 11

They don’t!

They are ASYMPTOMATIC!

But these species shed the virus to susceptible species (cattle) where it has 100% mortality and low morbidity

Question 12

Unique characteristics of Pox viruses

Answer 12

Have intracytoplasmic inclusions (bollinger bodies) (DNA viruses typically intranuclear inclusions)

Very large! Can be seen with electron microscopy

Question 13

Pseudopox virus

Answer 13

Virus that causes ring/horseshoe lesions on teats of cows and may cause “milker’s nodule” infection on human hands

Question 14

Considered the “most important of all poxviruses of domestic animals” due to high mortality causing economic loss

Answer 14

Capripoxviruses

Sheep pox, goat pox, Lumpy Skin Disease of cattle

Notifiable foreign animals diseases! (USDA/APHIS)

Question 15

Clinical findings of goat/sheep pox

Answer 15

Benign and malignant forms

Benign: skin lesions only, usually under tail

Malignant: depression, high fever, ocular/nasal discharge, skin lesions on unwoolled skin, 50% mortality

Question 16

What is Lumpy Skin Disease?

Answer 16

Disease of cattle, very similar to sheep/goat pox
Similar respiratory, and skin lesions with generalized lymphadenopathy
Spread from SE Africa
High morbidity (100%) but LOW MORTALITY (1-2%)

Must distinguish from pseudo-lumpy skin disease (BVH2)

Question 17

Virus that causes lesions on the comb, wattles, and face of poultry

Answer 17

Fowlpox

Has intracytoplasmic inclusions!

Question 18

Unique characteristics of parvoviruses

Answer 18

Environmentally resistant! (Not enveloped)
Rapidly dividing!
Have eosinophilic intranuclear inclusions

Question 19

Parvovirus in pigs causes what syndrome?

Answer 19

SMEDI
S = stillbirth
M = mummification
ED = embryonic death
I = infertility 

No clinical signs in non-pregnant sows/gilts

Question 20

Canine Parvovirus 2

Answer 20

Asymptomatic, subclinical disease is very common
Sever disease is most common in puppies
Enteritis syndrome
Septic shock
Death is common if aggressive supportive care is not instituted
Myocarditis of puppies that are infected in utero during 1st week of life (rare)

Question 21

Characteristics of circoviruses

Answer 21

Smallest known DNA virus of vertebrates
Naked(no envelope), icosahedral shape
Circular, ssDNA genomes
Pathogens of birds and swine
Replication takes place in cell nucleus in rapidly dividing host cells
Large basophilic intracytoplasmic and occasional intranuclear inclusions
Persistent infection is common

Question 22

Psittacine Beak and Feather Disease

Answer 22

Cockatoos, parrots, budgies
Circovirus targets feather follicles, beak, claws -> necrosis, malformation
Most infections are subclinical
Natural infection of young birds during feather formation

Question 23

Transmission and clinical signs of Canine Adenovirus 1/Infectious Canine Hepatitis

Answer 23

Transmission: ingestion/inhalation of infectious bodily secretions

Clinical signs:
Depression, lethargy, anorexia, abdominal pain/distention, pale MM, recovery occurs within 4-7 days, may have permanent corneal opacity from immune response

Question 24

Equine Sarcoids

Answer 24

Very common- 20% of all horse tumors
Large, firm lesions anywhere on body, range in appearance
Caused by Bovine papilloma virus 1, BPV2
Classifications: verrucous, fibroblastic, mixed