Fowl pox: Why you need to know about disease

Sick chicken in a farm

Fowl pox is a poultry disease that affects chickens, turkeys, pheasants, and even ducks. It is primarily a disease of older birds and is characterized by the appearance of warts or blisters on the skin surfaces of the head, wattles, and comb. The disease can also spread to the skin covering the back and legs.

This form of fowl pox is called the cutaneous type and rarely results in death. Affected birds typically recover within two weeks without any treatment. The other form of the disease causes similar lesions on the mucosal (inner) surfaces of the buccal cavity and respiratory linings. In rare cases, it can affect internal organs such as the liver and kidneys. This is called “wet pox” and may cause mortality rates of up to 50 percent in non-vaccinated flocks.

How the disease is spread

The primary method of spreading pox microorganisms between poultry flocks is through biting insects. The point of entry can vary from broken skin to the respiratory or oral route. Fowl pox-causing microorganisms can be transported from one flock to another by shared equipment, trucks, and other means. Insects such as flies, mites, fleas, and mosquitoes are well-known carriers of these disease-causing microbes. The virus responsible for fowl pox is highly resistant and can survive for months in a poultry house if it is not properly cleaned, disinfected, and rested for 21 days.

How to tell when a flock is infected

As with any other poultry disease, a farmer may observe loss of appetite (inappetence), depression, poor growth rates, and a drop in egg production if the birds are in production. If you are observant, you may notice pimple-like swellings on the unfeathered skin of the head, neck, wattles, comb, legs, and feet. Over time, these wet pimples or blisters dry up and form scales, scabs, and warts on the skin surface. The cutaneous type of fowl pox is not a fatal disease, and with a little tender loving care, affected birds given access to a well-balanced feed and plenty of potable water tend to recover within two weeks. For severe lesions, topical application of a 70 percent tincture of iodine solution can help. If neglected, affected birds may eat less, waste away, reduce egg production, and some may eventually succumb. If slaughtered, the skin may appear to have pimples, wart-like growths, and be unappealing to consumers.

How to control the disease

There is no known treatment for fowl pox, and affected birds tend to recover on their own if there are no secondary bacterial infections. For severe lesions, you can spray the affected areas with iodine or vetmycin spray. To control the disease, you must vaccinate birds at 5-6 weeks of age using live vaccines applied through a wing web stab. The vaccines were first introduced in 1926, and the good news is that where farmers vaccinate their flocks diligently, fowl pox has been permanently eradicated.

As soon as the previous flock has been cropped or depleted, the flock house and equipment must be thoroughly cleaned and disinfected. It is important to allow the house to remain empty for at least two weeks before placing the next flock. This allows time to reduce the build-up of disease-causing organisms and to prepare the house effectively for the next flock.

After cropping (slaughter or sale of birds), ensure that you clean the house and disinfect it using recommended disinfectants available from any agrovet, poultry center, or veterinary shop in your area. Do NOT administer antibiotic treatment for any disease without advice from a vet. If you are running sites with different age groups, ensure physical separation of the units, and manage them independently in terms of resources and staff.

You can also use ultraviolet zappers to kill flying insects. These devices are used outside the poultry shed and in stores where eggs or poultry are processed. They are electric and attract flies with ultraviolet lights, killing them by electrocution.

[For more information, contact Watson Messo, Head Vet at Kenchic PLC, at [e-mail]]