Disease | Cause | Ages affected | Species | Mortality | Signs and Symptoms | Pathognomonic lesions | Control |
External parasites | Insects, arachnids | All | All | Usually low unless | Birds can become weak and unthrifty in heavily infested. Skin: Mites, ticks, fleas and lice can cause itching, loss of feathers. Reproductive: decreased egg numbers | According to type of external parasite | Cleaning of environment between flocks, pesticides applied to the bird and the environment |
internal parasites | Various worms | All but the most severe Disease is In young birds | All | Mortality is variable depending on the age of The birds, type and severity of infestation | Depression, failure to gain weight, anemia. Digestive: Diarrhea. | According to type of external parasite |
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Mycotoxicosis | Toxins | Young birds more severely affected | All although signs more severe in ducks | Variable | Nervous: difficulty walking, convulsions, feather picking Reproductive: Reduced fertility and hatch rates. Decreased egg numbers | Pale liver of birds, stomatitis | Remove contaminated food |
Vitamins & minerals deficiency | Unbalanced ration or secondary to some enteric diseases | All | All | Usually low in free-ranging birds. May be moderates to high in young, confined birds | Vitamin E: Death before 4 days of age Nervous: Difficulty walking and standing, 15-30 days of age Reproductive Decreased hatchability. Vitamin A: Slow growth, drowsiness, ad mortality. Respiratory: Discharge from nose and eyes. Reproductive decreased egg numbers and hatching, increased blood spots in eggs. | According to type of vitamin | Supplement vitamins in the water or feed. Add antioxidants to feed. Rotate feed. |