Management of Pig Health

1. Management of Pig Health John J. McGlone, Ph.D. Pork Industry Institute Texas Tech University

2. Approaches to Ensure Pig Health • Biosecurity – keep diseases out • In-coming breeding stock • Wildlife (rodents, birds) • Feeds and biologicals • Disease Prevention • All-in-all-out & pig flow (breaks cycle) • Sanitation -- kill pathogens • Vaccination • Sub-therapeutic antimicrobials • Therapy

3. Biosecurity • Rule #1 put as much distance as possible between your pigs and other pigs • Rule #2 isolate, test and acclimate in-coming breeding stock – do not allow entry if infected • Rule #3 Control flow of people, pigs, feed and equipment

4. Sanitation • The pathogen cycle • Clean, new facility • Pigs shed bacteria • Room cleaned 99% • Pathogens build-up over time • Effective sanitation (see book Table 20-1) • Remove all organic matter • Sanitize at a minimum (killing 99% of bacteria)

5. Heard Health Program • Veterinary-approved • Disease surveillance • Necropsy ill pigs • Blood collection • Fecal, urine, skin scrapings collections • Slaughter check • Liver • Lungs • Snout • Intestine • Skin • Kidney

6. Heard Health Program • Euthanaisa • Blunt trauma for piglets • CO2 for piglets, too • Penetrating captive bolt for larger pigs • Vaccinations • Antimicrobials

7. Giving injections

8. Injections

9. Pig Disease Categories • Diseases we do not want to get (that we know about) • Diseases that are regulated by the US government with an eye towards eradication • Other diseases to manage 2

10. Pig diseases we do not want (by exotic disease entry or by bioterrorism) • Hog Cholera • Hoof and Mouth • African Swine Fever 3

11. Hog Cholera • Classic Swine Fever • Viral; single stand of RNA • Family: Togaviridae, Genus: Pestivirus • Same family as BVD • USA eradication was from 1962-1976 • Has not been eradicated from Europe (note The Netherlands). 4

12. Hog Cholera • Infected pigs shed virus for 10-20 days • Can be transmitted in utero • Feeding garbage exacerbates the spread; leading to the outlaw of this practice in many states. • 6-day incubation period; Respiratory; enteric; anorexia; hunched; ataxia; leukopenia 5

13. Foot (Hoof) and Mouth 6

14. Foot (Hoof) and Mouth • A picornavirus • Family: Picornaviridae; Genus: Apthovirus(Aptha, in Greek means vessicles in the mouth) • RNA virus; 7 serotypes • Can infect pigs, cattle, sheep & goats • Aerosol is highly contagious 6

15. Foot and Mouth • Can be transmitted in semen; not the fetus • North and Central America is free; South America, Africa & Asia are infected • 3-5 day incubation period • Vessicles in mouth and between toes; • Sharp fever, abortion; skin lesions leading to sluffing of tissue 7

16. African Swine Fever 8

17. African Swine Fever • DNA-containing virus; Family: Iridovirdae • Only pigs (including wart hogs and the like) are susceptible; ticks may be carriers • High fever & mortality; respiratory distress;Hemorragic disease • May resemble Hog Cholera • Little antibody formation -- no vaccine 8

18. Vaccines? • Foot and Mouth -- yes • Hog Cholera -- yes • African Swine Fever -- no • What else is out there??? 9

19. Diseases that are regulated by the US government • Pseudorabies • Brucellosis • You can be validated as free from these by state agencies • Feral pigs are major carriers of these and other diseases 10

20. PseudorabiesAujeszky’s Disease 11

21. PseudorabiesAujeszky’s Disease • Viral; Herpesviridae of the subfamily alphavuirus; DNA • While pigs are the only “natural” host, it infects all farm animals and vermin • All pigs can be infected; suckling pigs are least affected • Transmitted by aerosol, fluids, incl. semen 11

22. PRV • 2-4 day incubation period • Nervous symptoms among younger pigs (ataxia) and respiratory and reproductive symptoms among older pigs (G-F & sows) • Mortality can be 100% among piglets • Farrowing rate is reduced due to abortions and many stillbirths are observed

23. PRV • Few gross lesions; respiratory & GI tracts are affected • Genetically-engineered vaccine allows vaccination titers to be distinguished from natural infections • States & USA quarantine the herd as a part of the eradication program

24. Brucellosis • Bacteria -- Brucella suis • Infects pigs and humans (a different organism infects cattle -- Brucella abortus -- with only a little cross over) • Nearly eradicated in the USA (TX still infected) • Venereal disease of swine; Reproductive failures, especially abortions 12

25. Major Classes of Production Diseases (ones some chose to live with) • Respiratory • Enteric • Reproductive • Parasitic • Metabolic

26. Respiratory • PRRS • Atrophic Rhinitis • Mycoplasmal pneumonia • Swine influenza • Actinobacillus pleuropneumoniae

27. PRRS

28. PRRS • Lelystad virus • In 1997, 68.5% of USA farms were seropositive • Farrowing rate declines by 50% • Stillbirths & preweaning mortality & growing pig mortality increases by 300%(1-3 pigs/litter born dead; 2 to 6 % mortality in each of nursery & G-F)

29. PRRS • Modified live vaccine offers poor protection • No effective treatment • Widespread problem; not solved by SEW or any measure other than “all-in-all-out and wait” or depopulate

30. Atrophic Rhinitis

31. Atrophic Rhinitis • Caused by 2 organisms: • Bordetella bronchiseptica causes a non-progressive form of AR • Progressive (severe) AR is caused by toxigenic Pasteurella Multocida • When both organisms are present, the AR is especially symptomatic

32. Atrophic Rhinitis

33. Atrophic Rhinitis • Severe turbinate atrophy, bloody & crooked noses, followed by increased incidence of respiratory tract lesions and infections • Genetic predisposition is possible • Caustic air environments exacerbate the symptoms • SEW may help eliminate the bugs

34. Atrophic Rhinitis • Production set-backs are the most costly • Vaccines are available for BB & PM • Sulfamethazine is effective, but banned in some countries; a host of partially effective antibiotics are available • Suggest: Depopulation

35. Mycoplasmal pneumonia

36. Mycoplasmal pneumonia • Also called enzootic pneumonia • Bacteria: Mycoplasma hyopneumoniae • Nose-to-nose contact spreads the organism • Highly prevalent in the the USA, Europe, Australia and most modern pig countries • Lungs have lesions; secondary infections; performance set-backs

37. Mycoplasmal pneumonia • Several antibiotics are available; all are only partially effective • SEW may help prevent its spread • Suggest: Depopulate

38. Actinobacillus pleuropneumoniae

39. Actinobacillus pleuropneumoniae • Also called Haemophilus pleuropneumoniae • Bacteria of the name: Actinobacillus pleuropneumoniae • Widespread distribution • Economic cost is associated with rapid, high mortality, rather than only production set-backs

40. Actinobacillus pleuropneumoniae • Brought on by stress; can be acute or chronic • Rapid fever, foamy, bloody respiratory tract discharge; death within 36 hours; tract is inflamed and bloody; • Rapid, high levels of certain antibiotics can be effective • Suggest: Clean up or depopulate

41. Swine influenza • Also called swine flu, caused by a virus; Influenza A virus (Orthomyxoviridae family); Different serotypes; • Birds and other mammals may carry or become infected by the virus -- including humans • Mild stress brings out symptoms

42. Swine influenza

43. Swine influenza • Significant respiratory symptoms, including dog-barking type of coughing • Fever is mild; 1-3 day incubation period • No specific treatment is available; make sure water is available

44. Pneumonic Pasteurellosis • From Pasteurella multocida (gram negative coccobacillus) • See Atrophic Rhinitis for more details • Often isolated and labeled the cause of death following acute respiratory distress • Many antibiotics are available

45. Enteric Diseases • TGE • E. coli • Swine dysentery • Ileitis (proliferative enteropathies) • Clostridium • Coccidia • Rotavirus

46. TGE

47. TGE • Transmissible Gastro Enteritis • Viral: Coronavirus; RNA • Severe enteric symptoms; there is a Porcine Respiratory Coronavirus (PRCV) that cross reacts with TGE

48. TGE • 18 h to 3 day incubation period; then severe scours; 50-100% of piglets will die; fewer older pigs; sows vomit; watery to yellow scours with a foul odor • Destruction of intestinal epithelium; pigs unthrifty for life • Feed-back of dead pigs is best • Strikes more in winter

49. E. coli • E. coli is a common intestinal bacteria; pathogenic E. coli is the enteric organism; • Enteric Colibacillosis; many serotypes • Gram negative, flagellated rods; bacteria produces endotoxin • Symptoms like TGE; lower death loss and it should respond to antibiotics if treated early

50. Swine dysentery