Categories Of Diseases in Poultry

- Category 2 Diseases

Disease	Cause	Ages affected	Species	Mortality	Signs and Symptoms	Pathognomonic lesions	Control
Newcastle Disease (lentogenic or mesogenic)	Virus	All	Most domestic birds	Low, except in very young birds where mortality may reach 20%	Signs may vary by species. There may be no signs in waterfowl. Respiratory: sneezing, coughing, difficulty breathing Nervous: twisted necks Reproductive: decreased egg numbers	Mild conjunctivitis and tracheitis are observed. Recovered flocks show septicemia and air-sacculitis due to secondary infection with E. coli	Vaccination, biosecurity
Low Pathogenicity Avian Influenza (LPAI)	Virus	All	Most domestic birds	Usually, < 5% but may be up to 60% in turkeys.	Signs vary by species and infecting virus. There may be no signs in waterfowl. Respiratory: sneezing, coughing, wheezing Reproductive: decreased egg numbers	tracheitis, pulmonary edema and if secondary bacterial infection occurs, air-sacculitis is observed.	Biosecurity, depopulation, (vaccination)
Infectious laryngotracheitis (ILTV)	Virus	All but mostly in adults	Chickens	Usually 10-20% but may be very mild < 2% mortality or very severe > 50% mortality	Respiratory: nasal discharge, difficulty breathing, coughing, bloody mucus Reproductive: decreased egg numbers.	severe hemorrhagic tracheitis with the presence of blood clots which may obstruct the glottis resulting in asphyxiation.	Vaccination, biosecurity
Infectious bronchitis virus	Virus	All but most severe in chicks	Chickens	0-25%	Birds may be depressed with ruffled feathers. Respiratory; gasping, coughing, sneezing, wet eyes Reproductive: thin-shelled, rough and misshapen eggs, decreased egg numbers	Hyperemia of the trachea and accumulation of mucus in the nasal cavity	Vaccination, medication for secondary bacteria
Marek's Disease	Virus	Usually, 3-30 weeks of age	Chickens	0-30% in unvaccinated flocks	Unthriftiness, failure to gain weight. Nervous: paralyzed in one or both legs or wings, difficulty stanning pale eyes.	Unilateral enlargement of nerves of the sciatic plexus	Vaccination
Avian Leukosis	Virus	> 30 weeks of age	Chickens	Usually, < 3% although it may exceed 20% in some cases	Unthriftiness, weight loss, enlarged abdomen Reproductive: decreased egg numbers	Internal organs contain white or grey nodules which are cancerous lymphoid tissue that has spread from the bird’s bursa.	Chicks from clean flocks, biosecurity
Duck virus hepatitis	Virus	Young, < 6 weeks	Ducks	Close to 100% in ducklings 1< wk. old. 50% in 1-3 wk. old, very low in > 4 wk. old	Death may be the first sign of disease. Nervous: birds fall on their sides, kicking	enlargement of the liver with punctate or ecchymotic hemorrhages	Isolation of young ducks, (vaccination)
infectious bursal disease	Virus	Mostly 3-6 weeks	Chickens	Usually 0-25% but in some cases, may be up to 100%	Prostration and death Digestive: vent picking, soiled vent feathers, whitish or watery diarrhea	Dehydration and muscular hemorrhages, In acute cases the characteristic lesion comprises enlargement of the bursa of Fabricius	Vaccination, biosecurity
Avian Encephalornye-litis	Virus	Mostly 1-3 weeks	Chickens	May reach 50% in young birds	Nervous: difficulty walking, paralysis, tremors	No gross lesions are observed, Incoordination and lateral recumbency	Vaccination
Fowl pox	Virus	All, except newly-hatched	Chickens, turkeys	< 5% in skin form; 10-50% in respiratory form.	Poor weight gain. Skin: scabby, raised pocks on the face Digestive: loss of appetite Respiratory: nasal discharge, difficulty breathing	Pink focal lesions occur on the comb and wattles and non-feathered portions of the body	Vaccination, biosecurity

Fowl cholera	Bacteria	Birds >4 weeks are most susceptible	Chickens, ducks, geese, most birds	10-90% mortality. Mortality is highest in turkeys, ducks.	Death may be the first sign of disease. Respiratory: Gaping, difficulty breathing Digestive: diarrhea, especially in ducks	enlargement of the spleen and liver with punctate hemorrhages of the viscera including the heart	Medication, remove reservoirs, vaccination
Omphalitis	Bacteria	Birds less than 2 weeks old	Any	Variable.( May reach 100% )	Late incubation mortality. Navel is inflamed and the abdomen is distended.	Enlarged yellow yolk-sac, typical of omphalitis in a 3 day old chick.	Medication, hatchery sanitation
Mycoplasmosis	Bacteria	All	Chickens, pigeons, turkeys	Very low.	Respiratory: facial swelling, nasal discharge, coughing, foamy eyes Reproductive: Decreased egg numbers, decreased hatchability Skeletal: joint swelling.	Acute foamy Caseous air-sacculitis	Vaccination, biosecurity
Chlamydiosis	Bacteria	All	Ducks, pigeons, turkeys	Variable, but severe cases may have 5-30% morality	Depression, weakness. Nervous (young ducks): trembling. Imbalanced gait Respiratory: swollen eyelids, nasal discharge, difficulty breathing Digestive (young ducks): yellow-green diarrhea.	Fibrinous pericarditis and perihepatitis, Hepatomegaly and splenomegaly, air-sacculitis	Medication, biosecurity
Infectious Coryza	Bacteria	All, disease most severe in mature birds	Chickens	Rapid onset and high mortality.	Respiratory: Facial swelling, especially around the eyes, nasal discharge, rales. Digestive: loss of appetite, sometimes diarrhea. Reproductive: decreased egg numbers	Severe conjunctivitis and inflammation of the periorbital fascia. Chronic cases show serous to caseous sinusitis.	Vaccination, remove reservoirs, biosecurity.
Trichomoniasis	Protozoa	Young birds	Pigeons	Can be up to 50% without treatment	Young birds lose weight and may die. Digestive: thick, yellow areas inside the mouth, difficulty closing mouth		Sanitation, medication
Coccidiosis	Protozoa	Young birds, older birds become immune	Most although the coccidian of one species do not infest other birds	Variable depending on how severe the case is and the type of coccidian	Depression, weakness, decreased weight gain, dehydration. Digestive: may have mucoid or bloody diarrhea.	Hemorrhage interspersed with white foci visible through mucosa	Self-immunization, medication
Histomoniasis	Protozoa	Turkeys: 3-12 weeks. Chickens: 4-6 weeks	Turkeys, chickens	Mortality is generally low in chickens <30% but higher in turkeys (up to 70%	Depression, weakness Digestive: loss of appetite, yellow feces in turkeys, blooding droppings from chickens	thickening of caecal mucosa, petechial haemorrhages, and hepatic granulomas	Medication, put birds on wire or cement