ANSC 251 EXAM 4 Questions with Complete Solutions (Latest 2025)
Porcine respiratory syndrome virus (PRRSV):
type of virus, impacts, first observed, common names, types of strain, symptoms/signs observed - Correct Answers ✅Arteriviridae RNA virus
Impacts: Abortions, dead pigs, slow growth
First clinical syndrome: NC in 1987
Also called: Blue-ear pig disease, "mystery swine disease"
and "mystery reproductive syndrome" term-6
Two types: Type 1 (European) and type 2 (North-American)
Clinical signs: Reproduction
late gestation:
-weak, stillborn, mummified piglets -anorexia and agalactia in sows
Early gestation:
- abortions
Respiratory 1 / 3
ANSC 251 EXAM 4 Questions with Complete Solutions (Latest 2025) -Dyspnea and tachypnea, poor growth, interstitial pneumonia Cutaneous signs possible -Hyperemia or cyanosis of extremities
PPRSV: Targets, immune response - Correct Answers
✅Virus targets: macrophages
-Alveolar and tissue
-Acute disease: Lung, Lymphoid tissue, possibly kidney,
spleen, heart, thymus, skills, reproductive tract, and nervous system
-Chronic phase: virus found in peripheral lymph nodes; tonsils
Effects on macrophages: decreased production of TNF-alpha
and phagocytosis, induction of apoptosis
immune response: decreased IFN-alpha and TNF-alpha,
increased IL-10 (suppresses TH1 response)
PPRS: who's at risk, sources of infection, prevention, tests to
detect disease, if zoonosis, economic impact - Correct Answers ✅Exists as quasispecies (frequently and quickly mutates) Who's at risk: larger farms more susceptible to spread 2 / 3
ANSC 251 EXAM 4 Questions with Complete Solutions (Latest 2025)
Source of Infection: New introductions, infected semen,
uncleaned transport
Transmission: Feces, semen, urine, mammary secretions, and
nasal secretions
Live best: frozen conditions (years)
Prevention:
Minimize exposure (biosecurity, flow management, antimicrobials) and maximize immunity (vaccination, acclimation, lactation management, proper nutrition) Not zoonotic
Porcine endemic diarrhea virus (PEDV): - Correct Answers
✅Coronavirus; 2 viral strains First identified in U.S. in April May 2013 (rapid in Hog states)
Impacts: Severe diarrhea (dehydration + lack of nutrient
uptake = piglet deaths)
- / 3