ANSC 625 - Viral Diseases

herpesvirus

What pathogen causes Marek's disease?

ubiquitos

Marek's disease is ____ in commercial flocks

virus multiplies in feather follicles and then is inhaled as infected dust or dander by other chickens

How does Marek's disease spread?

invades and transforms lymphocytes to form tumor-like lesions

How does Marek's disease develop?

death with no prior signs or neurologic (nervous tissue invaded by lymphocytes, paralysis)

What are the two presentations that Marek's can take?

lymphoid tumors - accumulations of abnormal lymphocytes in organs and/or feather follicles

What lesions develop with Marek's?

non-specific - decreased weight gain and egg production

What are the signs of Marek's disease?

yes

Is there a carrier state with Marek's?

presence of tumors and presence of disease in younger birds, viral PCR on tissue post-mortem

How is Marek's diagnosed?

strain and dose, age at exposure, active immunity, host gender/genetics, strain and dose of vaccine, environment

What does the incidence of disease depend on?

good biosecurity and vaccination

How is Marek's disease prevented?

Marek's disease

This chicken has lowered egg production and presents like this. What disease does it likely have?

retrovirus

What pathogen causes equine infectious anemia?

equids (horses and ponies most severe, donkeys and mules show no signs)

What species are susceptible to EIA?

increases production of pro-inflammatory cytokines, incuding fever, RBCs and destroying platelets

What does EIA do?

biting insects and instruments/needles contaminated with blood, all bodily fluids and tissues considered infectious, transplacental

How is EIA transmitted?

1. acute fever, depression, low platelets

2. reccurrent episodes of fever, depression, low platelets, anemia, tachycardia, tachypnea, jaundice, petechia, epsitaxis, weakness

3. become carrier

What are the three phases of EIA development?

Coggin's test

How is EIA diagnosed?

There are 6 wells, 3 with confirmed antibody and 3 samples from equids. In the center antigen is placed, and moves towards the antibody. If the line between two antibody with sample between is bendy, the test is negative, as the antigen never met antibody. If the line between two antibody and sample between is straight, the test is positive, meaning there was antibody present in the sample.

How does the Coggin's test work?

USDA APHIS approved lab submitted by USDA accredited vet

Who can do Coggin's tests?

reportable, interstate

EIA is ____ in NH, and testing is required for _____ transport

no

Is there a vaccine or treatment for EIA?

euthanasia or permanent isolation of positive horse, sterile tools, cleaning equipment between horses, cover open wounds, proof of EIA testing, insect control

How is EIA prevented?

EIA

This horse has had episodes of tachypnea and jaundice, alongside this weight loss. What disease does it likely have?

calicivirus (RHVD 1 and 2)

What pathogen causes rabbit hemorrhagic disease?

wild and domestic European rabbits

Who does RHVD 1 affect?

European rabbits and hares, wild American cottontails

Who does RHVD 2 affect?

direct and indirect contact (inhalation, ingestion, fomite) with bodily fluids

How is RHVD transmitted?

high

RHVD has both ____ mortality and morbidity

rapid death with no signs, fever, anorexia, lethargy, seizures, dyspnea, jaundice, petechia, bleeding from body cavities

What are the signs of RHVD?

liver necrosis and hemorrhages in organs

What are the lesions of RHVD?

PCR or serology

how is RHVD diagnosed?

no

Can RHVD be treated?

good biosecurity and vaccination

How is RHVD prevented?

yes

Is RHVD reportable?