Mosquitoes and related insects can carry a range of disease-causing pathogens that affect farm animals. During the wet season, mosquitoes serve as the primary source of infection on various farm animals including poultry birds. Mosquitoes spread diseases by ingesting disease pathogens when they feed on infected birds and transmit them to healthy birds. Thus during the rainy season and in mosquito infected areas, farmers are advised to protect themselves and their poultry birds from mosquito bites. Farmers should not wait until their poultry birds show symptoms of infection to act. Farmers should be proactive and prevent disease-causing pathogens from multiplying, as it is rather difficult and expensive to treat an infected flock. 

Poultry diseases caused by mosquitoes: 
The most common poultry disease transmitted by mosquitoes to poultry is referred to as Fowl Pox. Fowl Pox differs from Chicken Pox that affects humans. The main symptoms of Fowl Pox are lesions observed on the featherless parts of the bird such as on combs, wattles, ear lobes, eyes and around the beak, etc. It should be noted that mosquitoes could harbour the virus for a month or more after feeding on infected birds and eventually play a significant role in spreading the virus from one flock to another. Affected young birds are stunted in growth whereas laying birds experience a drop in egg production. Poultry birds of all ages that have oral or respiratory system infections as a result of the disease have difficulty eating and breathing, and thus poor appetite can be observed among the infected flock. 

Prevention & control: 
Poultry farmers are advised to make all efforts to reduce the risk of poultry bird exposure to mosquitoes. Although, it may be nearly impossible to completely prevent poultry birds from being bitten by mosquitoes, exposure should be minimized at all cost. Prevention should start with the clearing of grass around the coop and the disposal of old tins, tyres, and other forms of garbage that can hold water, as stagnant water can become a breeding site for mosquitoes. Farmers can also smoke their poultry coop with traditional herbs such as the boiling of mango leaves, bitter bush, etc. Alternatively, synthetic remedies available in shops can also be used. 

 Vaccination is also considered effective, which can be performed using wing–web vaccination methods. The vaccination of broilers against this disease is usually not required unless there is a history of fowl pox outbreaks on the farm. Poultry birds are vaccinated against fowl pox when the birds are six to ten weeks of age. One application of fowl pox vaccine results in permanent immunity. 

In conclusion, farmers should take note that there is no treatment for this condition. The disease may resolve itself. Thus, it is imperative for farmers to control any mosquito infestation and sanitize their premises. The virus is highly resistant in dried scabs and may survive for months on contaminated premises. Moreover, poultry birds showing unusual symptoms should be isolated to avoid cross-infection to healthy birds. Sick birds should be promptly reported to the nearest veterinarian for disease confirmation, as most poultry diseases have similar clinical signs and require experts that can perform differential disease diagnosis. 

*This article is compiled by Emilie Abraham, Technical Officer within Agribank’s Agri Advisory Services Division.