A disease is defined as a state of deviation (of an animal) from normal state of health. Diagnosing a disease through observation of external symptoms such as eyes, nostrils, body posture, appetite etc is called ante-mortem. Below are various external symptoms which can be observed to diagnose a disease in poultry.
BODY
- Emaciation - Off-feed; nutritional deficiencies; lymphoid leukosis;enteritis; gizzard impaction; tuberculosis
- Stunted, uneven growth - Gizzard impaction; bluecomb disease; alfatoxin poisoning; synovitis; contaminated hatching egg
- Swellings - Ruptured air sac; edema
- Twitching, muscular spasm - Botulism; infectious bursal disease
- Trembling - Epidemic tremors; encephalitis (brain damage)
- Paralysis - Botulism; Marek's disease; arthritis; aflatoxin poisoning; epidemic tremor
- Dehydration - Acute lack of water; coccidiosis; infectious bursal disease; nutritional imbalance-dietary salts
- Nervousness - Hysteria; drug intoxication; Newcastle; fungus infection
- Lying on breast, legs paralyzed - Algae poisoning; acute lack of water; yellow jasmine poisoning; botulism; drug toxicity
FEATHERS
- Moist under wing - Infectious coryza
- Loss of feathers - Molting
- Deposits at base of shafts - Lice or mite eggs
- Soiled hackle feathers - Infectious coryza, eye infection
- Feathers picked - Lice; nutritional deficiency-methionine; birds not debeaked
- Depigmented - Nutritional deficiencies-lysine, iron or folic acid
- Broken on upper thigh - Self picking
- Feather eating - Nutritional deficiency-methionine
SKIN
- Pigmentation excessive - Poor production; high pigment intake
- Nodules, mainly legs - Marek's disease
- Nodules over vent - Flukes (rare)
- Moist, necrotic, edematous - Necrotic dermatitis, exudative diathesis
- Darkened, purplish - Erysipelas; fowl cholera
- Crusted areas - Erysipelas; scab; gangrenous dermatitis
- Scabby hip - Self picking, inflicted by other birds
- Gangrenous, green - Hemmorhage; arthritis; gangrenous dermatitis
- Vent irritated - Northern fowl mite; lice (occasionally)
- Pale - Anemia; nutritional deficiencies-iron, copper, or vitamin
HEAD
- Swollen, puffy - Ruptured air sac; infectious coryza; injury; Newcastle disease
- Mottled, red and white margins - Frozen
- Eruptions, nodules - Fowl pox
- White, scaly, powdery - Favus
EYES
- Watery - Infectious coryza
- Blindness - Fowl pox; aspergillosis; Arizona paracolon; paratyphoid
- Watery, red, inflamed, closed - Laryngotracheitis; ammonia burn; Newcastle disease;
NUTRITIONAL DEFICIENCY
- Cataracts - Epidemic tremor
- Crusts on eye lids - Nutritional deficiency-vitamin A; fowl pox
- Pupil irregular, blindness - Marek's disease
- Blood in eye - Hemorrhagic anemia
- Large, swollen - Mycoplasma infection
FACE
- Swollen - Infectious coryza; Newcastle disease; nutritional deficiency-vitamin A; E. coli
- Darkened, purplish - Erysipelas; fowl cholera; septicemia; injury
- Nodules - Fowl pox
NOSTRILS
- Discharge - Infectious coryza; chronic respiratory disease; infectious bronchitis; influenza
MOUTH
- Pustules - Nutritional deficiency - vitamin A
- Crusts at margins - Nutritional deficiencies - pantothenic acid or biotin
- Beak soft, rubbery - Nutritional deficiencies - vitamin D or calcium-phosphorus imbalances
- White coat over tongue and in mouth - Wet form of fowl pox
- Ulcers - Mycotoxins; chemical injury
WATTLES
- Swollen, bulbous - Infectious coryza; fowl cholera
- Nodules - Fowl pox
NECK
- Paralysis (limber neck) - Botulism; yellow jasmine poisoning
- Twisting - Newcastle disease; fowl cholera; brain infection; improper injection of Marek's vaccine
- Retracted over back - Newcastle disease; nutritional deficiency-thiamin
- Retracted under breast - Nutritional deficency-vitamin E; Newcastle disease
- Scabby necrotic areas - Improper injection of drugs; other injury
LEGS
- Paralysis - Marek's disease; botulism; heat stoke; epidemic tremor; cage layer fatigue; vitamin E deficiency algae poisoning; yellow jasmine poisoning; acute lack of water
- Rough, scaly - Fowl pox; scaly leg mite
- Bowed, weak - Nutritional deficiency-vitamin D; osteodystrophy
- Bone bends - Nutritional deficiency-vitamin D
- Joint swelling - Infectious synovitis; paratyphoid; pullorum; zinc deficiency; staphylococcosis; tenosynovitis; arthritis
- Tendon at hock displaced - Perosis (nutritional deficiency-manganese or choline)
- Stilted gait - Tenosynovitis
- Shank depigmented - Nutritional deficiency-vitamin A; coccidiosis; any low grade slow disease (for any length of time)
- Toes twisted - Genetic
FEET
- Joints fixed - Tenosynovitis
- Swollen foot pad - Infectious synovitis; bumblefoot
- Toes curled - Nutritional deficiency-riboflavin; genetic; management deficiency
- Foot pad cracked, dermatitis - Nutritional deficiency-biotin or pantothenic acid; management deficiency
- Bird walks on toes - Tenosynovitis
DROPPINGS
- Profuse - Enteritis; excess roughage in diet
- Bloody - Cecal coccidiosis; Newcastle disease
- Green - Feed intake low; bile not diluted
- Sulfur yellow - Blackhead
- Light yellow or yellowishgreen - Fowl typhoid; fowl cholera
- Foamy - Intestinal parasites (protozoa)
EGG PRODUCTION
- Sudden severe drop - Newcastle disease; infectious bronchitis; laryngotracheitis; influenza-A, mycotoxin, mismanagement (no lights, feed, or water)
- Unsatisfactory - Infectious coryza; fowl cholera; chronic respiratory diseases; diet deficiencies; gizzard impaction; fowl pox; hepatitis; lice; mites; ascarids; capillaria; lymphoid leukosis; coccidiosis; enteritis; pullorum; fowl typhoid; aflatoxicosis; adenovirus infection; toxins
- Egg wrinkled, depigmented - Necrotic enteritis; infectious bronchitis
- Production pause - Epidemic tremor
- Poor shell quality - Newcastle disease; infectious bronchitis; adenovirus infection; diet deficiency; T-2 fusariotoxin
DEATH
- Instant, few or no prior signs - Aortic rupture; acute lack of water; fowl cholera; overheated, fatty liver hemorrhagic syndrome
- High mortality-producing diseases - Fowl cholera; erysipelas; exotic Newcastle disease; acute coccidiosis; aflatoxin; botulism; poison; fatty liver hemorrhagic syndrome
