Pig health and disease Flashcards
Pig biology & behavior
- reach maturity at ~6 months, live up to 6-10 years
- kept in backyards = up to 16 yrs b/c less stressful, healthier
- litters 9-13 piglets in commercial breeds
- similar biologically to humans: monogastric digestive system, immune system
- intelligent: easily trained, excellent hearing & sense of smell
- social animals: house in groups, have social hierarchy
- behaviors: rooting, love mud baths (helps thermoregulate b/c no sweat glands), running, swimming
- very sensitive to heat & humidity
- dry skin => likes scratching
More biology
- gestation in sows/gilts: 4 months
- farrowing: nursing piglets, 3 weeks
- nursery: weaning, 6-8 weeks
- growing/finishing: 16 weeks (280 lbs)
Pork production in US
- most consumed meat in the world
- US: 3rd largest producer/consumer of pig products, largest exporter of pig products
- production mainly in MW & North Carolina
- mostly indoor confinement = highly controlled, reduced disease risk, but high density (so disease outbreaks is a concern)
Major types of pig operations
- farrow to finish (all in one)
- breeding and farrowing sows
- feed offspring to market weight (280 lbs)
- 10 month cycle
- expensive, labor intensive but greatest economic potential
- farrow to feeder
- gestation to nursery phase
- sold for finishing
- reduced operations
- less costly, not full market weight
- feeder to finish
- finishing operation
- reduced operations (don’t manage breeding stock)
- more disease risks so purchase from single farm
Coccidiosis - is pig specific (Triad)
impacted
- commercial production & backyard pigs
- young piglets (farrowing, >10 days)
- intestinal disease: damages GI
- sub-clinical on most farms, sows bring into farrowing facility
Environment
- biosecurity protocol: cleaning/disinfecting, quarantine
- warm, comfortable farrowing environment
Pathogen
- protozoa, genus Eimeria (many species)
- transmission: vehicles (fecal material), fomites
Coccidiosis
clinical signs
- diarrhea at 10 days, lethargic, not gaining weight, dehydration (make sure have access to milk)
diagnostic test
- usually by visual inspection of piglet’s clinical signs
- necropsy: visual inspection of intestines if there’s mortality in litter
Treatmet
- anti-coccidial agents for piglets: poor efficacy but may help if provided before GI tract damage
- antibacterial agents: not practical b/c of meat withdrawal period of many months
- anti-coccidial disinfectants: clean b/twn litters
Streptococcus suis Infection (triad) - zoonotic!
impacted
- commercial & backyard pigs
- nursing & newly weaned pigs
- worldwide, confined indoor housing
- huge problem in Asia
- identified in 1987, zoonotic
Environment
- biosecurity: disinfectants kill bacteria
- housing density
- reduce stressors: aggressions, ventilation, humidity & temp
Pathogen
- bacterial pathogen: Streptococcus suis
- transmission: horizontal direct, vertical direct, vehicle, fomites, mechanical
Streptococcus suis
clinical signs
- loss of appetite, fever, inflammation, lethargic, arthritis, pneumonia, shaking/convulsing
- if shaking/convulsing = not going to survive
diagnostic test
- swab nasla cavities/tonsils: present w/o clinical infection therefore challenging to diagnose
- clinical signs & analyze records (# impacted, age impacted, # morbidity/mortality, temp, humidity)
- necropsy: tissue sample, bacterial culture, PCR testing
- lots of deaths!
Treatment
- antibiotics: but resistance, no highly effective treatment options
- prevention is key: eliminate stressors in young pigs, biosecurity, control of other diseases
- have become resistant, no effective treatment atm
Porcine reproductive and respiratory syndrome (PRRS)
impacted
- commercial production
- all age groups
- worldwide, prevalent in US
environment
- biosecurity b/twn different ages of pigs
- quarantine new animals, test
- PRRS vaccines (not really effective)
- early weaning & isolating litters of piglets
Pathogen
- PRRS virus (genus Arterivirus)
- PRRSV-1 (European origin)
- PRRSV-2 (N American origin)
- 2 clinical presentations
- breeding animals: respiratory impairment
- pigs of any age: respiratory disease
- transmission: vertical direct, horizontal direct, fomites, vehicle
PRRS
clinical signs
- fever, lethary, poor growth, dyspnea, sneezing, vomiting in older animals, reproductive problems (premature, stillborn, mummified fetus, weak piglets), infected w/ other pathogens
Diagnostic test
- blood sample: PCR or ELISA test
- necropsy: tissue sample (usually lung), PCR or ELISA
treatment
- no effective treatment
- establish control program & monitoring disease; need more research
