Health management of poultry
TC Tolenkhomba and Prava Mayengbam
Contd from prev issue
Avian Encephalomyelitis: Signs commonly appear during the first week of life and between the second and third weeks. Affected chicks may first show a dull expression of the eyes, followed by progressive incoordination, sitting on hocks, tremors of the head and neck, and finally paralysis or prostration. Some may refuse to walk or will walk on their hocks. In advanced cases, many chicks will lie with both feet out to one side (prostrate) and die. All stages (dullness, tremors, prostration) can usually be seen in an affected flock. Feed and water consumption decreases and the birds lose weight. In adult birds, a transitory drop (5-20 percent) in egg production may be the only clinical sign present. However, in breeding flocks, a corresponding decrease in hatchability is also noted as the virus is egg- transmitted until hens develop immunity. Chickens which survive the clinical disease may develop cataracts later in life.
Treatment: There is no treatment for outbreaks. Infected birds should be removed, killed and incinerated. Recovered chicks are unthrifty.
Prevention:Vaccine is available.
Egg Drop Syndrome: There are no reliable signs other than the effects on egg production and egg quality. Healthy-appearing hens start laying thin-shelled and shell-less eggs. Once established, the condition results in a failure to achieve egg production targets. Transient diarrhoea and dullness occur prior to egg shell changes. Fertility and hatchability are not affected.
Treatment: There is no successful treatment. Induced molting will restore egg production.
Prevention:Prevention involves a good biosecurity program.
Fowl Cholera: Fowl cholera usually strikes birds older than 6 weeks of age. In acute outbreaks, dead birds may be the first sign. Fever, reduced feed consumption, mucoid discharge from the mouth, ruffled feathers, diarrhoea, and laboured breathing may be seen. As the disease progresses birds lose weight, become lame from joint infections, and develop rattling noises from exudate air passages. As fowl cholera becomes chronic, chickens develop abscessed wattles and swollen joints and foot pads. Caseous exudate may form in the sinuses around the eyes. Turkeys may have twisted necks.