Disease	Cause	Ages affected	Species	Mortality	Signs and Symptoms	Pathognomonic lesions	Control
Velogenic viscerotropic Newcastle Disease (VVND)	Virus	All	Most domestic birds	Mortality may reach 100% but often lower in ducks	Sudden mortality, often with few or minimal signs Nervous: Balance & walking problems, twisted necks Respiratory: gasping, difficulty breathing, swelling of the head Digestive: diarrhea Reproductive: decreased egg numbers	Prominent hemorrhages occur throughout the digestive tract especially in the mucosa of the proventriculus and gut-associated lymphoid tissue	Vaccination, biosecurity
Highly Pathogenic Avian Influenza (HPAI)	Virus	All	Most domestic birds	Mortality may reach 100% but often lower in ducks and pigeons	Sudden mortality, often with few or no signs Respiratory: gasping, swelling of wattles & combs Nervous: tremors of the head and neck Digestive: diarrhea, thirst Reproductive: soft-shelled or shell-less eggs, decreased egg numbers	subcutaneous hemorrhages and edema of the head. Vesicles may be present on the comb and wattles.	Biosecurity, depopulation, (vaccination)
Duck viral enteritis (duck plague)	Virus	All, although adults more severely affected	Wild and domestic ducks and geese	5- 100% with the highest mortality in older birds	Sudden mortality, often with few or no signs Digestive: watery diarrhea, decreased appetite, thirst Reproductive: decreased egg numbers Nervous: difficulty walking, tremors Respiratory: pasted eyelids, nasal discharge	Free blood in the body cavity. Hemorrhages of the ovary in mature ducks. Free blood in the lumen of the intestine.	Biosecurity, (vaccination)
Pigeon paramyxovirus (PPMV)	Virus	All	Pigeons	Mortality may reach 100%	Adults neglect squab, resulting in their deaths. Nervous: Balance & walking problems, twisted necks, head tremors, inability to fly Digestive: diarrhea, thirst	Mild conjunctivitis and tracheitis are observed	Vaccination, biosecurity