Clinical signs of sickness and disease – birds

Clinical signs in birds. What to look for.
Clinical signs in birds. What to look for.

What to look for as general signs of sickness and diseases of respiratory system, digestive system and reproductive reproductive system ….


Clinical signs are those changes in the body or behaviour that are considered to be abnormal. They are the external manifestation of a disease process. We can only guess at how the bird feels – a throbbing headache, wanting to be sick or the chronic pain associated with arthritic conditions. To further complicate matters, obviously looking sick will significantly increase the chance of being singled out by a predator. Consequently, a bird will do everything possible to look healthy despite an underlying disease problem. This still applies equally to highly inbred strains of birds as well as their wild counterparts.
As a broad generality when a bird looks obviously sick, it is probably nearer death than recovery.
A good stockman will notice the small signs that indicate a potential problem. This requires excellent observational skills and a good understanding of the normal behaviour of the birds.

General Signs of sickness

Many diseases will result in signs that may affect organ systems other than those that they are normally associated with. Other diseases can affect several organ systems simultaneously.
  • Mortality and Morbidity
    • A sudden death, increasing number of deaths, increasing number of sick birds
  • Posture
    • Separate from the flock, hunched up, fluffed up, head sunk, eyes closed
  • Breathing difficulties
    • Gasping, neck outstretched, tail bobbing, marked abdominal movements
  • Eggs
    • Changes in number, shell colour, shape and shell thickness
  • Loss of Body condition
    • Loss of weight, breast muscle mass, feather and skin condition
  • High body temperature
    • General or localised increase in temperature
  • Abnormal droppings
    • Watery faeces, excess urine, watery urates

Respiratory Signs

Upper Respiratory

  • Abnormal shaped nostril, purulent or serous discharge
  • Head shaking, scratching beak, open mouthed breathing, coughing, sneezing, yawning, neck stretching
  • Infra-orbital sinus swelling, s/c oedema
  • Frothy eye, sunken eye, dirty patches around the eyes or on the wing (elbow),
  • Longitudinal groove in beak
  • Loss of vocalisation, voice change

Lower respiratory

  • Open mouthed breathing, wings held away from the body, head and neck outstretched,
  • Increased respiratory rate
  • Laboured breathing, prolonged respiratory recovery time
  • Dyspnoea, coughing, open mouthed breathing
  • Tail bobbing
  • Cyanosis, depression

Enteric Signs

  • Regurgitation and vomiting,
  • Oral lesions,
  • Crop abnormalities,
  • Emaciation and cachexia,
  • Abnormal droppings – polyuria, abnormal urate colour, diarrhoea, blood, undigested food.

Abnormal Droppings

  • Urine :
    • Polyuria – little or no solid urates
  • Urine and Urates
    • Red, pink, brown discoloured
    • Yellow, green
  • Abnormal faeces
    • Liquid
    • Liquid black – ? Upper intestine
    • Brown
    • Other colours
    • Black little no urates
    • Black faeces with green urates
    • Fresh blood in or around

Reproductive Signs

  • Sounds
  • Behaviour
  • Smell
  • Body weight
  • Increase in morbidity and/ or mortality
  • Water consumption
  • Feed consumption
  • Feathering – loss of and dirty feathering, droppings on plumage, faeces staining at vent, urate staining/burning (red discolouration of the skin) below vent
  • Comb and wattle colour – loss/change of colour of the comb/skin of head/wattles, shrivelled comb/snood/wattles, dirty feet
  • Changes in colour and consistency of the faecal and caecal faeces to yellow-green-black, bloody, watery or frothy, faeces and watery urates


  • External:-
    • Loss of shell colour to white – thin shells – membrane eggs – loss of membrane
    • Shell defects pinholes, hairline cracks
    • Dirty or blood on eggs
  • Internal:-
    • Albumen – watery whites
    • Yolk – abnormal yolk colour or loss of colour

Musculo-skeletal and Nervous signs

  • Limping, lameness or leg deformities – problems of gait, conformational changes, limping, snatchy gait, inabilty to perch, loss of grip reflex, abnormal scales on legs
  • Swollen joints, tendons
  • Wing or leg fracture / dislocation
  • Loss of muscle mass
  • Ataxia, circling, twisted heads, head tilt, incoordination, ), torticollis
  • Drooping wings, paralysis (unilateral, bilateral, flaccid, wing, leg, tail)
  • Depression, failure to thrive
About David Parsons 19 Articles
David Parsons began his veterinary career in mixed practice which triggered his 39-year passion for poultry. Following positions as a veterinary research officer in the Poultry Department at the government’s Central Veterinary Laboratory and then as a poultry company veterinarian, he set up his own poultry veterinary practice in the southwest of England in 1985. He obtained his MSc in Applied Immunology in 1981, Certificate in Poultry Medicine and Production in 1989 and a Nuffield Farming Scholarship Trust to study the“Status of diseases specific to poultry and their control in Europe” in 1991.

He has been an Honorary External Lecturer at the University of Bristol Veterinary School on poultry medicine and production since 1999,a lecturer on the Institute of Animal Health’s poultry disease course since 2000 and is a regular monthly contributor of veterinary articles for backyard poultry keepers in the Practical Poultry magazine.