Chicken farmers are reporting a return of Fowl pox, a disease whose symptoms include the development of skin lesions, warts or blisters or growths around the head, mouth, upper respiratory tract, on the skin and the legs.
The disease used to be a problem in most poultry producing countries several years ago but following the discovery of vaccines, its spread dramatically reduced and, in some instances, it was eliminated. In Kenya, the disease was very limited because its diagnosis and control is straightforward. But of late, we have started seeing re-emergence of Fowl pox infection in chicks as young as three weeks of age.
The question experts are asking is; what went wrong? Are farmers getting complacent?
Cause of fowl pox
Fowl pox is caused by a virus that belongs to the Avipox genus. It is like Turkey pox, Pigeon pox or Quail pox. It is, however, different from the human or mammalian pox - what we usually refer to as smallpox.
The disease is worldwide and in Kenya, it is mostly restricted among the local or Kienyeji population of chickens that are not traditionally vaccinated before point of lay.
How does Fowl pox spread
The affected chicken with Fowl pox will spread the disease if they are in direct contact with a healthy bird. Once on the skin surface, the virus can only penetrate through a wound or broken skin where it multiplies and causes the disease.
This, therefore, means that farmers should always avoid bringing chickens from unknown location closer to your valuable flock.
It is also known that certain biting insects such as mosquitoes can transmit the disease from one infected bird to the other. Very warm climates like the one in our country can also rapidly spread the infection among chicken populations that are very close together.
Please note that Fowl pox is a disease of poultry and cannot affect human beings. Keeping flocks in poor sanitary conditions, dusty environment fuels the spread of Fowl pox infection.
Consequences of this infection
Once these viral organisms enter a chicken, they attack the cells especially on the surface of the skin or epidermis and cause cancer-like growth on the surface of affected parts of the head, comb, wattles, legs and skin.
The birds cannot feed and drink water, which affects their general performance and leads to poor growth, drop in egg production and, in severe cases, death.
Clinical signs of fowlpox
Fowl pox is predominantly a poultry disease and does not affect workers in contact with sick chickens. These lesions are easy to identify on the parts of the birds with no feathers of the head, neck, legs and feet. These signs start slowly and spread gradually through the flock.
This form of Fowl pox is called cutaneous type and will rarely kill, affected birds recover within two weeks without any treatment.
How to control and manage Fowl pox attack
There is no known treatment against Fowl pox and the disease can only be prevented through vaccination. Live vaccines are available that can be administered through the wing web.
The vaccine is inoculated on the skin of the wing web using a bifurcated needle that has a groove that holds the content of the vaccine fluid.
Please get an experienced health expert to administer the vaccine appropriately.
To check if the vaccination was successful, look at the vaccination site seven to 10 days after vaccination for nodular swelling. Vaccinations should be done at about six to seven weeks of age for the long living birds. As a rule of thumb, do not vaccinate sick birds.
[ The writer is Head Vet at Kenchic, [email protected]]