Avian Husbandry & Enrichment (JTA 2)

Question 1

How do birds thermoregulate?

Why are they more susceptible to heat stress?

What are the primary gross and clinicopathologic changes associated with heat stress in Australian doves and budgerigars?

Answer 1

• Birds thermoregulate physiologically (e.g dermal capillary dilation) or behaviorally (e.g. wing venting, gular fluttering)
• Birds are more susceptible to heat stress because they have high body temps, high metabolic rates, and rely on evaporative cooling
• Heat stress typically causes congestion, hemorrhage, thrombosis
• Congestion and lymphoid aggregates in liver, lungs, kidneys, and/or intestine were common in all groups
• Primary organ affected differed by species
• Lung congestion most common overall
• Myocardiocyte vacuolation and airway hemorrhage were only seen in doves
• Clinicopathologic changes varied by species and heat:
  
  • Budgies: increased heterophils and decreased PCV
  • Doves @ 35 C: decreased eosinophils

JAMS 2020. Organ Histopathology and Hematological Changes Associated With Heat Exposure in Australian Desert Birds

Question 2

Describe proper passerine husbandry in managed care and rehabilitation settings.

Answer 2

• Special Housing Requirements (F8):
  
  • Elevated perching opportunities above perceived threats.
  • Ample visual barriers (live or artificial plants) to reduce stress.
  • Chronic stress is a major problem.
    
    • Many common dz (candidiasis, asper, mycobacteriosis, atoxoplasmosis) are considered to be caused by opportunistic pathogens, assoc with immunosuppression from chronic stress.
  • Species specific temp, social dynamics, lighting, photoperiod, diets.
  • Nesting materials should avoid fine synthetic fibers/materials known to cause entanglement or leg constriction.
  • Small enclosures with wire mesh are known to cause feather damage (retrices and remiges).
  • Small enclosures if needed for transport should have smooth, solid walls vs wire mesh.

MMWS

• Ensure caging won’t cause feather damage
• Adult passerine BMR 65% higher than larger non-passerine species
• Other species with torpor – swifts, swallows, nightjars
  
  • Maintenance fluid volume during rehydration (typically birds 100ml/kg/d, some passerines 250-300ml/kg/d)
  • Easily imprinted species – corvids (jays, crows), galliform chicks