Common infectious diseases and parasites of poultry and pet birds: causes, signs and prevention

First confirm which animal you are dealing with. The same disease name is handled differently in different species, and copying what is done for another species can do harm. This article is compiled from the poultry, reptiles and amphibians, and bird chapters of the veterinary reference, with the source noted entry by entry.

Highly pathogenic avian influenza (HPAI)

• Cause: Viral infection; zoonotic and a notifiable disease
• Signs: Dullness, sudden heavy losses across the flock, cessation of laying, neurological signs
• Work-up: Report to the authorities, after which officials take samples for confirmation; keepers should not handle suspected cases themselves
• Treatment direction: This falls under statutory notification and culling, not home treatment
• Prevention: Keep wild and migratory birds away, apply biosecurity measures

Colibacillosis

• Cause: Bacterial infection, often secondary to another disease or to stress
• Signs: Diarrhoea, respiratory signs, reduced activity
• Work-up: Bacterial culture
• Treatment direction: Antibiotics require a veterinary prescription
• Prevention: Environmental hygiene, fewer stressors

Salmonellosis

• Cause: Bacterial infection; contaminated drinkers and feeders are a common route
• Signs: Diarrhoea, reduced activity, spread through the flock
• Work-up: Faecal culture
• Treatment direction: Antibiotics require a prescription (zoonotic; see column 9)
• Prevention: Disinfect drinkers and feeders regularly

Aspergillosis

• Cause: Aspergillus infection of the airways and air sacs
• Signs: Laboured breathing, tail bobbing, change of voice
• Work-up: Endoscopy, imaging, blood tests
• Treatment direction: Antifungal drugs require a prescription, and the course is long
• Prevention: Avoid damp mouldy litter, maintain good ventilation

Coccidiosis

• Cause: Protozoal infection of the intestine
• Signs: Diarrhoea, weight loss, reduced activity
• Work-up: Faecal microscopy
• Treatment direction: Anticoccidial drugs require a prescription
• Prevention: Environmental hygiene, keep droppings out of drinking water and feed

External parasites: red mite and lice (Dermanyssus gallinae and others)

• Cause: Poor environmental hygiene, hiding in the crevices of perches
• Signs: Restlessness at night, feather damage, anaemia in heavy infestations
• Work-up: Inspect perch crevices at night, examine feathers under a microscope
• Treatment direction: Antiparasitic drugs and environmental treatment need veterinary or professional guidance
• Prevention: Clean perch crevices regularly, treat the environment

Respiratory infection

• Cause: Unsuitable temperature and humidity
• Signs: Audible breathing, mucus or froth at the nostrils and mouth
• Work-up: Auscultation, imaging
• Treatment direction: Antibiotics require a prescription
• Prevention: Maintain a suitable temperature and humidity gradient

Newcastle disease

• Cause: Viral infection; a notifiable disease in some regions
• Signs: Respiratory signs, neurological signs (twisted neck), a sharp drop in laying
• Work-up: History assessment, laboratory confirmation (PCR / serology)
• Treatment direction: No specific drug; supportive care. If it is suspected, see the reporting obligation in column B
• Prevention: Vaccination (according to the local programme), quarantine of newly introduced birds, limited contact with wild birds

Limits of this content

This article brings together several entries on the same species from the veterinary reference: 8 entries and 8 source anchors in total (see the evidence chain). The sources listed at the end are the authoritative references cited by the chapters covered here; the mapping is chapter-level and does not mean that every sentence traces back to a particular listed source. This content is for education and does not replace diagnosis and prescription by a practising veterinarian; in an emergency, seek veterinary care immediately. Sources are noted entry by entry from the reference corpus (see the evidence chain at the end); it has not been clinically reviewed by a named veterinarian.