Other symptoms are twisted necks, paralysis, loss of balance and circling movements of the head. Vaccines are available, however many countries insist upon a complete slaughter of birds in affected yards to control any further outbreak. Newcastle Disease is particularly dangerous as it can affect nearly all kinds of birds. Mareks Disease affects young birds between the ages of 9 to 16 weeks. It is caused by a strain of herpes virus.
Birds develop drooping wings, lameness and paralysis, particularly of the legs.
Another strain of the virus causes internal cancerous growths resulting in quick death, often with no prior warning signs. Mortality in both strains is very high. Birds which survive the disease become carriers and once Mareks has appeared in your flock, it becomes virtually useless to hatch chicks under hens, an incubator being the only safe way to avoid chick losses. There is no cure for Mareks Disease however day old chicks can be vaccinated. Fowl Pox is usually transmitted by mosquitoes.