An Overview of Poultry Pathology Part I

1. An Overview of Poultry Pathology Part I H. L. Shivaprasad California Animal Health and Food Safety Laboratory System, Tulare Branch University of California, Davis

2. California Animal Health & Food Safety Laboratory System School of Veterinary MedicineUniversity of California, Davis To provide the citizens of California with the highest quality diagnostic laboratory support for: Mission

3. Disease Control Public health CAHFS Mission Health Management Food Safety Dissemination of New Knowledge Equine Health

4. Layers Broilers Turkeys CAHFS Laboratories Davis Turlock - Avian Tulare San Bernardino

5. Avian Taxonomy Phylum: Chordata Class: Aves Orders: 27 Families: 160 Genera: 1800 Species: 8600 Subspecies: >22,000

6. Major Categories of Birds • Domestic poultry (Egg laying and broiler chickens, turkeys and ducks) • Commercial and hobby/backyard flocks • Game birds (Pheasant, Quail, Chukar) • Pet and exotic birds • Ratites (ostrich, emu, rhea) • Birds of Prey • Birds in captivity (Zoos) • Free flying birds (California Fish & Game and National Wildlife Lab)

7. Segments of Poultry Industry (Broiler, turkey, egg layers) • Breeding – genetics • breeder replacements • Hatchery/custom hatching • Feed/feed mills • Housing – brooding/grow out (meat type) • Egg production • Processing (meat/eggs) • Transportation

8. Poultry Industry US/California • Eggs (Pullets/layers) – White Leghorn • Broilers/Fryers & Roasters (meat-type ) • White Plymouth Rock, White Cornish • Turkeys (Large White - Toms/Hens) • Ducks (Pekin/Muscovy/Mullard) • Pheasants (Ring necks: 18 - 20 weeks) • Squabs (500 g - 4 weeks) • Quail (meat/eggs), others?

9. Causes of Disease M: Malformation, Metabolic I : Infectious, Immunologic N: Neoplasia, Nutritional T: Toxic, Trauma Note: in commercial poultry infectious, nutritional and toxic causes are most important

10. Infectious • Bacteria • Viruses • Fungi • Parasites • Rickettsia

11. Tests Essential for Disease Diagnosis • History • Clinical signs • Necropsy (autopsy) • Serology (ELISA, HA/HI, AGID, etc.) • Immunology (FA, IHC, etc.) • Bacteriology/Mycology • Biotechnology

12. Tests Essential for Disease Diagnosis • Histopathology • Parasitology • Toxicology • Virology (egg embryos, cell culture) • Electron microscopy (DEM, TEM) • Hematology, chemistry, cytology • Pathogenicity tests

13. Diagnostic Protocol • Turn around time: • Report significant findings – same day • Serology, FA, IHC, bacteriology, biotechnology, Direct EM, histopathology – 12 to 48 to 72 hours • Toxicology - 3 to 5 days • Mycoplasma - 2 weeks • Virology - 3 to 6 weeks • IBV sequencing, TEM - variable

14. Disease Diagnoses - Philosophy • Quality: Accuracy of results • Rapid turn around time • Thorough diagnostic work up • Communication with the clients • Use of friendly, common and understandable language

15. Disease Diagnoses – Philosophy • Quality of service depends on the ‘quality and quantity of effort’ by the diagnostician/pathologist • sometimes it is difficult to find a cause • Client Confidentiality maintained

20. Avian Inflammation • reaction is rapid in birds, 36 hours • leakage of fibrin and fibrinogen common in early exudate • intense granulomatous reaction (12 hours) • coagulum of eosinophilic debris, degranulating heterophils, macrophages and giant cells

21. Avian Inflammation • macrophages, heterophils and thrombocytes are active phagocytes • pus is caseous but liquefaction can occur • birds respond with granulomatous inflammation to many insults

22. Avian Inflammation • acute inflammatory reaction in birds involves edema, congestion and vascular changes mediated by basophils and mast cells • 1-3 hrs: basophils, heterophils and monocytes • 2-6 hrs: basophils degranulate and die • 6-12 hours: lymphocytes, monocytes, macrophages

23. Avian Inflammation • 12-36 hours: lymphocytes, macrophages, giant cells • acute reaction peak by 12 hours (when giant cells appear) • 36-72 hours: regeneration and repair • fibroblasts, secondary lymphoid follicles, plasma cells • chronic reaction with caseation, macrophages, giant cells, granuloma formation

24. Avian Inflammation • Cells involved in inflammation: • Heterophils, mast cells, basophils, eosinophils • Thrombocytes • Monocytes/macrophages • Giant cells • Lymphocytes/plasma cells

25. Avian Inflammation • cells involved in inflammation: • heterophils: have lance-shaped granules, lack myeloperoxidase and alkaline phosphatase, have β-glucoronidase and acid phosphatase • very phagocytic • granules tend to round up in tissues, difficult to identify

26. Avian Inflammation • cells involved in inflammation (Cont.) • eosinophils: have spherical granules • function is not known, delayed type IV hypersensitivity ? • associated with eosinophilic enteritis in turkeys due to ascarids • basophils: contain histamine, involved in acute inflammation • thrombocytes: small round to oval cells with clear cytoplasm and small round nucleus (looks like small lymphocytes), phagocytic

27. Avian Inflammation • cells involved in inflammation (cont.) • monocytes: precursors to cells of MPS, phagocytic, can fuse to form multinucleated giant cells • Cytokines; IL-1, IL-2, IL-6, IL-8, IL-15, IL-18, etc., TNF, G-CSF, gamma interferon • lymphocytes: various morphologies involved in subacute inflammation including plasma cells

28. Fibrinosuppurative (heterophilic) inflammation – pericarditis, perihepatitis and airsacculitis

29. Fibrinosuppurative (heterophilic) cellulitis Fibrinosuppurative pneumonia Pus – liquefaction rare

30. Fibrinosuppurative (heterophilic) inflammation

31. Heterophils -(Lance-shaped granules) Heterophils and a eosinophil (arrow)

32. Eosinophilic enteritis, Ascarid larvae - Turkey Eosinophils – Turkey intestine

33. Granulomatous (Pyo?) inflammation

34. Granulomatous hepatitis (Yersinia pseudotuberculosis) Granulomatous inflammation

35. Granulomatous inflammation. Asper in giant cells. PAS

36. Fibrinous inflammation with bacteria. Gran. inflammation with Staphylococcus sp.

37. Avian Bacteria • E. coli • Salmonella sp. • Chlamydophila psittaci • Clostridia sp. • Mycobacteria sp. • Mycoplasma sp. • Bordetella avium • Pasteurella multocida • Gallibacterium anatis • Staphylococcus sp. • Streptococcus sp.

38. Avian Bacteria (Cont) • Enterococcus sp. • Ornithobacterium rhinotracheale • Erysipelothrix rhusiopathiae • Pseudomonas aeruginosa • Klebsiella pneumoniae • Riemerella anatipestifer • Avibacterium (Haemophilus) paragallinarum • Yersinia pseudotuberculosis • Spirochetes • Listeria, Neisseria-like • others

39. Colibacillosis • any one of the syndromes in poultry caused by E. coli • colisepticemia, air sac disease(CRD), peritonitis, coligranuloma, salpingitis, omphalitis/yolk sac infection, cellulitis, osteomyelitis/synovitis, swollen head syndrome and panophthalmitis • enteritis with AAEC, eae gene present • ceca most commonly involved • common in turkeys, others; chickens, pigeons, quail, partridges, pheasants, ducks, ostriches, psittacines, passerines, etc.

40. Omphalitis (Yolk stalk)

41. Omphalitis (yolk sac infection)

42. Hemorrhagic omphalitis

43. Fibrinous pericarditis, perihepatitis and airsacculitis Fibrinous pericarditis

44. Synovitis

45. Cellulitis Salpingitis

46. Typhlitis – Turkey poult

47. Attaching effacing E. coli (AEEC)– Turkey poult

48. Avian Salmonellosis • A large group of acute or chronic diseases caused by one or more members of the genus Salmonella • Majority of salmonella are ubiquitous • Some are host specific • S. dublin in bovine, S. abortus equi in equine, S. choleraesuis in swine • S. Pullorum and S. Gallinarum in chicken

49. Avian Salmonellosis • Pullorum disease in poultry - S. Pullorum • Typhoid disease in poultry - S. Gallinarum • Paratyphoid in poultry, ducks, pigeons, wild birds, psittacines, passerines, etc. • 10-20 species; S. Typhimurium, S. Enteritidis, S. Heidelberg, S. Anatum, S. Derby, etc. • Arizonosis in turkey poults - S. arizonae • also in chicks, ducklings, psittacines, passerines, etc.

50. Pullorum Disease