Lecture 9 10/17/24 Flashcards
What age of pig is found in a farrowing barn?
piglets from birth to weaning at about 21 days
What age of pig is found in a nursery barn?
feeder pigs 3 to 9 weeks of age
What age of pig is found in a finishing barn?
finishing/market hogs 9 to 20 weeks of age
How are sows organized within their barn?
based on farrowing date
Why is it important to maintain a temperature of around 95 degrees in the farrowing barn?
to prevent cold stress that would predispose the piglets to illness/infection
Why is it important to regularly clean the finishing barn?
ammonia smell can come up through the slatted floor and cause poor air quality
What stressors can impact a pig at weaning?
-nutritional stress
-cold stress
-respiratory stress
-social stress
What are the antemortem diagnostics that are commonly done in pigs?
-physical exam
-nasal/nasopharyngeal culture
-tonsillar scraping
-sacrfice and necropsy
What are the therapeutic options used in pigs?
-parenteral or in-feed antibiotics
-NSAIDs
-depopulation/repopulation
What are the characteristics of atrophic rhinitis?
-two bacteria work together to cause synergistic disease
-involves Bordetella bronchiseptica and Pasteurella multocida
-type D toxin produced by P. multocida
What is the pathophysiology of atrophic rhinitis?
-piglets acquire B. bronchiseptica from sow
-B. bronchiseptica causes mucosal damage
-P. multocida co-colonizes nasal cavity
-toxin produced by P. multocida induces osteoclastic activity
How does age of the pig impact the severity of atrophic rhinitis?
pigs that get infected at a younger age will have more severe turbinate atrophy
What are the consequences of atrophic rhinitis?
-leads to secondary bact. infection
-poorer performance compared to uninfected pigs
What are the clinical signs of atrophic rhinitis in farrowing/nursery pigs?
-sneezing
-nasal discharge
What are the clinical signs of atrophic rhinitis in finishing pigs?
-distortion of snout and face
-excess lacrimation
-epistaxis
-failure to thrive
What percent of market hogs have some sort of atrophic rhinitis lesion?
50-70%
What are the characteristics of atrophic rhinitis treatment?
-mass medication by adding antibiotics to feed
-animal must be well enough to eat
-sickest animals likely to remain infected
How is atrophic rhinitis prevented?
-vaccine given to sows
-improved management
-ventilation
-continuous slaughter checks
Which bacteria causes necrotic rhinitis?
Fusobacterium necrophorum
What is the pathophysiology of necrotic rhinitis?
F. necrophorum colonizes damaged mucosa that results from trauma (such as trimming milk teeth)
What are the clinical signs of necrotic rhinitis in neonates/weaners?
-severe swelling of the nose
-abscessation
-foul breath
-facial deformities
-bull nose
What are the treatment options for necrotic rhinitis?
-euthanasia
-wound debridement
What are the characteristics of inclusion body rhinitis?
-caused by porcine cytomegalovirus
-gamma herpesvirus
-latency in leukocytes
What is the pathophysiology of inclusion body rhinitis?
-latently infected sow acts as reservoir
-stressful event causes sow to shed virus and expose piglets
-virus replicates in nasal and ocular tissue
What are characteristics of the influenza virus?
-orthomyxovirus
-RNA virus
-segmented genome
What are the two influenza envelope proteins and their purpose?
-hemagglutinin: used to enter cells
-neuraminidase: used to leave cells
Which influenza strains are the main strains found in pigs?
-H1N1
-H3N2
-H1N2
What is antigenic drift?
mutations in the genetic structure of the virus
What is antigenic shift?
reassortment of the genome segments of the virus
Why is it important that pigs can be infected with both avian and human influenza strains?
pigs serve as a hub for viral reassortment
What are the characteristics of influenza transmission?
-virus likely circulates at low levels in the herd and waits for increased susceptibility
-transmission occurs through resp. secretions
-replication occurs in nasal, tracheal, and bronchial epithelium
What are the characteristics of influenza infection?
-mild to severe necrosis of the resp. epithelium leads to lung cell death and consolidation
-viral shedding can occur within 48 hours of infection
-clinical signs begin around 4 days after infection
-post-infection virus can be shed for up to 3 days
What are the clinical signs of influenza in pigs?
-diarrhea
-coughing
-sore throat
-lethargy
-lack of appetite
-sneezing
-nasal and ocular mucous
-fever
-weight loss
-poor growth
How is influenza virus diagnosed?
-PCR
-viral isolation
-serology
-indirect fluorescent antibody
What are the characteristics of influenza prevention?
-vxs are not reformulated fast enough to provide good immunity
-vxs can reduce disease severity
-better to follow all in/all out
-reduce stress and temp. changes
-depopulate in the face of severe epidemics
