Fowlpox is a slow-spreading viral infection that affects most bird species, including all commercial forms of poultry. It occurs in both a wet and dry form. The wet form is characterized by plaques in the mouth and upper respiratory tract while the dry form is characterized by wart-like skin lesions that progress to thick scabs. The disease may occur at any age of the bird, at any time. Mortality is usually not significant unless respiratory involvement is severe. Fowlpox can cause depression, reduced appetite, and poor growth or egg production. The course of the disease in the individual bird takes three to five weeks.
Birds often get Fowlpox when they are older.
What causes Fowlpox?
It is caused by an avian pox virus.
Infection occurs through skin abrasions or bites, through the respiratory route, and possibly through the ingestion of infective scabs.
How is Fowlpox transmitted?
By direct contact of infected chicken with healthy chicken or wild birds.
Bites from mosquitoes, flies, and mites, on a chicken with active Fowlpox, will carry this to the next bird it bites. Fomi.tes, that is, inanimate objects such as equipment can also be involved in the transmission. The virus is highly resistant in dried scabs and under certain conditions may survive for months. Mosquitoes can harbor the infective virus for a month or more after feeding on affected birds and can subsequently infect other birds. Recovered birds do not remain carriers. A flock may be affected for several months as fowl pox spreads slowly.
What are the signs of Fowlpox?
Birds develop blisters around the head, inside the beaks and eyelids. The blisters are also found under the wings and on the feet. The blisters grow rapidly, turn yellow then dark brown. After 2-4 weeks the blisters dry up and become scabs. The birds have a clear discharge from the beak and eyes. They have pus around the eye and may have pus coming out of the nostrils. Some birds have a thickened membrane inside the mouth. Birds are depressed, have a poor appetite and a drop in egg production.
Symptoms resemble comb wounds from fighting birds only that wounds do not spread but fowl pox spreads.
Most birds recover but fowl pox reduces resistance to other diseases.
A few birds develop more severe disease, quickly become thin and may die.
What is the treatment for Fowlpox?
There is no known treatment for this disease.
How to prevent and control Fowlpox?
Prevention is through the vaccination of replacement birds. Where preventative vaccination is used, all replacement chickens are vaccinated when the birds are six to ten weeks of age, and one application of fowl pox vaccine results in permanent immunity. Vaccination of broilers is usually required especially when the mosquito population is high or infections have occurred previously. Chicks may be vaccinated as young as one day of age.
During outbreaks, unaffected flocks and individuals may be vaccinated to help limit the spread.
If there is evidence of secondary bacterial infection, broad-spectrum antibiotics may help reduce morbidity and mortalities.
As mosquitoes are known reservoirs, mosquito control procedures may be of some benefit in limiting spread in poultry confined in houses. Control of mites and lice using effective insecticides proves to be beneficial.