Bacterial and Fungal Diseases of Pet Birds

1. Culture and Inflammatory Response

• Culture Results: Nearly uniform culture results (>80%) indicate a significant bacterial presence.
• Host Inflammatory Response:
  • Cytology:
    • Increased inflammatory cells noted.
    • Phagocytized bacteria observed.
  • Complete Blood Count (CBC): Shows toxic changes in heterophils.
  • Protein Electrophoresis: Useful for further analysis.

2. Primary vs. Secondary Infections

• Importance of Differentiation:
  • Secondary infections can perpetuate disease processes.
  • Laboratory testing often does not effectively distinguish between primary and secondary infections.
  • Primary infections are typically diagnosed by ruling out other diseases.

3. Secondary Bacterial Pathogens

• These pathogens often breach the body's defenses:
  • Abnormal presence of autochthonous flora.
  • Mixed cultures from flock isolations.
  • Concurrent isolation of viruses or Chlamydophila.
  • Identification of predisposing factors, such as Vitamin A deficiency or tumors.
• Treatment of underlying issues does not always restore health.

4. Primary Bacterial Pathogens

• Typically identified without concurrent infections:
  • No other microbes present (e.g., viral, Chlamydophila, or other bacteria).
  • Can reproduce specific diseases experimentally.

5. Host Range

• Salmonella spp.:
  • Host-adapted strains include S. pullorum and S. gallinarum.
• Avibacterium paragallinarum: Causes infectious coryza in chickens.
• Mycobacterium spp. and Yersinia pseudotuberculosis: Both are zoonotic.

6. Clinical Signs

• Signs are often non-specific:
  • Highly pathogenic bacteria can cause septicemia and sudden death.
  • Chronic infections vary depending on the affected site.

7. Collection Sites for Diagnosis

• Upper respiratory tract.
• Gastrointestinal tract.
• Joints and bones.
• Trachea, lungs, and air sacs.
• Abscess sites.

8. Therapy and Control

• Antimicrobials:
  • Aminoglycosides are used orally but not systemically absorbed.
  • Klebsiella spp. show resistance to certain penicillins like Zosyn.
• Environmental management and addressing predisposing factors are crucial.

9. Bacteria of Concern

• Common Pathogens:
  • Escherichia coli
  • Klebsiella spp.
  • Salmonella spp.
  • Acinetobacter baumannii
  • Listeria monocytogenes
  • Pasteurella spp.
  • Pseudomonas spp.
  • Staphylococcus spp.
  • Mycobacteria.
  • Toxin producers.
  • Spiral bacteria.

10. The Enterobacteriaceae Family

• Members can be normal in the gastrointestinal tract but not in respiratory or reproductive sites.
• Includes Gram-negative rods like Escherichia coli, Klebsiella, Salmonella, and others.
• Frequent Isolates:
  • Enterobacter spp. typically require a compromised host.

11. Escherichia coli

• A significant avian pathogen, common and diverse in its virulence.
• Transmission routes are various.
• Associated diseases include pneumonia, enteritis, and septicaemia.

12. Klebsiella spp.

• Characterized by a protective mucoid capsule.
• Primarily affects respiratory and gastrointestinal systems.

13. Salmonella spp.

• Notably Salmonella enterica serotype Typhimurium.
• Often leads to asymptomatic carriers, especially in birds.

14. Acinetobacter baumannii

• Emerging as a multi-drug-resistant pathogen in humans.
• Rarely isolated from birds but noted in some studies.

15. Listeria monocytogenes

• A Gram-positive rod found in various environments.
• Can cause multi-organ inflammation in birds.

16. Pasteurella spp.

• Associated with avian cholera and can lead to severe septicemia.

17. Pseudomonas spp.

• An opportunistic pathogen linked to various infections in birds.

18. Staphylococcus spp.

• Most are normal flora; however, pathogenic strains like S. aureus can cause serious infections.

19. Enterococcus faecalis

• Part of the intestinal flora, can cause respiratory issues in birds.

20. Mycobacteria

• Typically associated with wasting diseases and granulomatous lesions.

21. Toxin Producers

• Certain bacteria, like Clostridium perfringens, produce toxins leading to severe gastrointestinal issues.

22. Spiral Bacteria

• Linked to upper respiratory infections in young cockatiels, identified by cytology.

23. Fungal Diseases

• Often challenging to diagnose and treat, except for Candida infections.

24. Aspergillus spp.

• Ubiquitous and opportunistic, often affecting the respiratory tract.

This comprehensive overview highlights key aspects of bacterial and fungal diseases in pet birds, emphasizing the importance of accurate diagnosis and effective treatment strategies. Racing Pigeon Laboratory Testing . Donal Barry