Flashcards in Reproductive diseases Deck (39)
What are two causes of reproductive diseases in pigs?
2. porcine parvovirus
What people are affected by leptospirosis? What are the clinical signs?
Women of child bearing years
bacteremia, abortion, flu-like, cyclical fever
What are the signs of leptospirosis in pigs?
largely subclinical and endemic
Why does the importance of leptospira vary with geographic region?
local maintenance host
Leptospira has an affinity for what organ?
Swine are susceptible to which serovars of leptospira interrogans?
What are the maintenance hosts for lepto serovar pomona?
What are the maintenance hosts for lepto serovar bratislava?
What are the characteristics for infection in a maintenance host (lepto)
1. efficient tranmission
2. high insidence
3. chronic disease
4. persistence in kidney
5. low Ab response
6. few organisms
What are characteristics of infection in an incidental host?
1. low susceptibility
2. high pathogenicity
3. acute disease
4. sporatic transmission
5. short renal infection
6. MARKED AB response
7. many organisms
What are the methods of transmission of lepto?
vertical (venereal, transplacental)
Environmental survival of lepto is enhanced by what?
1. moisture and warmth
2. wildlife acess
3. stagnant water
4. susceptible to dessication
What isthe pathogenesis of leptospira?
1. penetrate mucus membranes
2. brief bacteremia
3. prompt agglutinating Ab
4. clearance from most systemic organs
5. Persistence in kidneys and genital tracts (immunologically privileged)
6. transplacental infection if preg
What are the clinical signs of lept infection in incidental infections?
2. transient anorexia, pyrexia, listlessness
What are the clinical signs of infection in sows/gilts with pomona?
abortion, stillborns, live weak piglets
What are the clinical signs of infection with bratislava in pigs/gilts
infertility (sometimes later term abortion)
What is the pathology of incidental lept infection
mild renal damage, liver necrosis
What is the pathology of maintenance/chronic lepto?
kidneys: diffuse focal interstitial nephritis
1. edema in body cavities,
2. petechial hemorrhage,
3.focal liver necrosis (uncommon but suggests lepto)
How is leptospira diagnosed?
2. demonstration of leptospires or antigen/DNA (special stains, PCR)
What are issues with using serology for leptospira diagnosis?
cross reactions common
issue with vaccination pig (interpretation)
low titres in maintenance host
4x increase useful but may not occur in maintenance host
high titres rare
low titres in fetal serum could be significant
How is leptospira treated and controlled?
1. vaccination--polyvalent bacterin pre-breeding/before infection
2. antimicrobials: streptomycin, oxytetracycline
3. biosecurity (wildlife, rodent control, stagnant water)
Where is porcine parvovirus found?
What des porcine parvovirus cause?
embryonic and fetal death
no clinical dz in post natal animals
What is the transmission of parvovirus?
What are the features of parvoviridae?
resistant to many disinfectants
remain infectious for 4 months in environent
Cannot get rid of from farm!
What are the features of immunity for parvo?
high levels of passive immunity that decrease over 3-6 months
passive antibody interferes with development of active immunity
When should gilts be vaccinated against parvo?
prior to conception
Are sows generally immune or susceptible to parvo?
immune (active immunity by natural infection persists for life)
What is the pathogenesis of parvovirus?
1. virus only replicates for cells undergoing mitosis
2. predilection for fetus
3. predilection for endothelium
4. vascular necrosis