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PRRS ControlPractitioner’s View
John Hayden BVSc MRCVSIntegra Veterinary Services
PRRS diagnoses – trend and seasonality(data for Q3 and 2015 incomplete)
Main PRDC pathogens in GB Viruses
PRRS and swine flu predominant PCV2 associated disease lower level
Mycoplasma hyopneumoniae (Mycoplasma hyorhinis)
Bacteria Haemophilus parasuis predominant Pasteurella multocida mainly secondary APP declining Bordetella bronchiseptica, Trueperella pyogenes Streptococcus suis common concurrent disease
Parasitic pneumonia
Disease detection:Diagnoses concurrent with PRRS in 2014:
Syndrome Diagnosis NumberPRRS (total) 49
Systemic(13)
Streptococcus suis 13
PCVAD 0
Respiratory(27)
Past. multocida 17
Haemophilus parasuis 5
Swine influenza 0
Mycoplasma 3
APP 2
Enteric(10)
Salmonellosis 7
Gastric ulceration 1
E.coli 2
Other(9)
Trueper. pyogenes 5
Unusual other 4
Cost of PRRS
•£70 per sow per year•£3.50 per finisher pigXavier de Paz PRRS cost for the European swine industry. https://www.pig333.com/what_the_experts_say/prrs‐cost‐for‐the‐european‐swine‐industry_10069/
Where were we?
•Pre‐2001 – Sows herds experienced regular waves of infertility, abortions, low viable pigs.
•2001 – Porcilis PRRS – off licence use in breeding herds started to stabilise immunity across the herd
•Used once per cycle – 7‐10 days after farrowing to start with
•Then mid‐pregnancy – 6‐10 weeks in‐pig.
Stability and Control
• Use of Porcilis PRRS in most herds once per cycle• Porcilis PRRS in boars 6‐monthly• Negative repops to ‘insure’ against breakdown• Introduction of only negative stock and then vaccinate on entry• Closed herds – testing of gilts at 15 weeks, before vaccinating to monitor• Production of virus negative pigs• Rearing and finishing negative• Ability in some instances to eradicate PRRS altogether• Good times
Then what?
•2006 – first East Anglian reports of novel strains – later found to be different on the dendrogramfrom the original Lelystad and Porcilis PRRS viruses
Then what?
•2006 – first East Anglian reports of novel strains – later found to be different on the dendrogramfrom the original Lelystad and Porcilis PRRS viruses
•PRRS symptoms despite vaccination.•Breakdowns in ‘negative’ but vaccinated sow herds detected in off‐site finishing
Diversity in Britain over time (ORF5-based):
1990s
Diversity in Britain (over time):
2004-2005
Diversity in Britain (over time):
2006-2007
Diversity in Britain (over time):
2008-2009
Diversity in Britain (over time):
2010-2011
Diversity in Britain (over time):
2012-2013
Diversity in Britain (over time):
2014-2015
Where are we now?
•Despite heavy use of vaccine – sometimes up to 4 x before a maiden gilt farrows and twice a cycle for sows we have some herds testing strongly PRRS positive on PCR.
•Some herds have stopped using vaccine altogether and the problem has ‘burnt out’ (VLA meeting, Feb 2015)
•Other vaccines – dead and alive are ‐ available but I have not tried them
Is it all about vaccines?
Monitoring•Bloods – 12 unvaccinated pigs, every 3 months•Rope tests – PCR / antibodies
New tools
•ReproCyc PRRS EU – 2ml for sows
•PRRS Flex EU – 1ml for piglets / growers
•Unistrain PRRS
Whole herd PRRS elimination
Experiences since August 2015
• ReproCyc PRRS EU – used as a blitz to stabilise the herd by vaccinating ALL boars, sows, gilts and weaner gilts over 30kg
• Day 0, Day 21 and then every 15 weeks• All stages of pregnancy / lactation• Virus has nowhere to hide• Reduced transplacental transfer – so aim is no viraemic pigs are born
Herds ‐ done
•Gilts at all stages of pregnancy•Sows at all stages of pregnancy•Some returns after first dose, but within 2 days of the injection – so in theory too soon to be due to the vaccine
•Second dose – no observed problems•2 full herds done in November
Planned•3rd dose after 15 weeks•Full herd 2nd doses in December
Spreadsheet to calculate vaccination dates etc
PRRS Programme ‐ to produce PRRS‐free weaners15‐Oct‐15
Vaccinate all weaned pigs at weaning with PRRS Flex EU : 15‐Oct‐15 26‐Nov‐15 10‐Mar‐16 21‐Apr‐16Vaccinate all sows, boars, gilts on site with ReproCyc PRRS EU : 26‐Nov‐15 17‐Dec‐15 31‐Mar‐16 14‐Jul‐1630 weaned pig blood tests # 28‐Jan‐16 10‐Mar‐16 21‐Apr‐16 02‐Jun‐16 14‐Jul‐16If weaned pig bloods are negative stop vaccination of weaners 04‐Aug‐16 15‐Sep‐16Weaners monitored ##
ALL INCOMING GILTS & BOARS ReproCyc PRRS EU on entry# Ear swabs to SAC for PCR PRRS before PRRS vaccination## 6 bloods for PCR and ELISA from each batch on site
New monitoring ideas
•PCRs done at SAC Edinburgh from:•Drop of blood on a swab / cotton bud from ear‐prick
•Possibly tail stump blood drops on a cotton bud•Possibly tails removed at docking
Aim 1
•Production of PRRS negative weaned pigs
Aim 2
•PRRS negative rearing and finishing pigs
Aim 3
•Think about regional eliminations
Acknowledgements
• Susanna Williamson (APHA Bury St Edmunds)• Jean‐Pierre Frossard (APHA Weybridge)• PH Rathkjen (Boehringer Ingelheim Animal Health)
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