Fowl Pox 

Fowl pox is a virus caused by the Avipoxviruses that effects avian species. Once contracted, it causes a reduction in productivity for chicken (Gallus gallus domesticus) and is highly contagious amongst flocks (Yehia et al., 2023). The virus is transmitted through open wounds by direct contact between infected birds and healthy birds, exposure to bedding dust containing the pathogen or through vectors such as fleas, ticks and other bitting insects (Xin et al., 2026). This is not a notifiable disease.

Identification and Diagnosis 

Fowl pox presents in two different forms: cutaneous form and diphtheritic form. The cutaneous form of fowl pox presents as dry scabs and growing lesions on exposed skin such as the comb and wattles (Tizard, 2020). These lesions can form around the eyes causing eye inflammation and discharge. The diphtheritic form, which is less common and more life threatening, presents as larger lesions which are grey or yellow in colour specifically targeting the mucous membranes around the mouth and through the upper digestive and respiratory systems (MacLachlan and Dubovi, 2016). These can cause respiratory distress in the chickens resulting in coughing or gasping and can ultimately lead to chocking and suffocation.

Other clinical symptoms which can be observed are reduced appetite (which can be caused by the lesions around the mouth and throat), weight loss and fever. Behavioural changes which can be observed include a decrease in productivity such as reduced egg laying and poor growth rates, lethargy and sudden depression (Elshwihdi et al., 2025). As well as itching, rubbing and pecking infected areas (Hockaday, 2024).

Diagnosis for fowl pox is done first by physical examination, then tissue samples are taken to be tested to rule out any bacterial infections. The tissue is also used and tested under a microscope using eosinophilic staining to observe any changes in the cytoplasm of cells. If any inclusion bodies are observed, it confirms a diagnosis of fowl pox (Sawale et al., 2012).

Treatment 

For fowl pox, there is no specific cure for the virus. For the cutaneous form it usually takes it course in three to five weeks and the focus during that time is supportive and preventive care (Skinner, 2008). For the diphtheritic form, the mortality rate is high and the treatment is centred around supportive care.

Prevention and control 

Fowl pox has no cure, so prevention and control is vital to minimise the risk of exposure. These methods are sustainable and while there is no legislation on fowl pox, these are good practices to have in place in accordance with the Animal Welfare Act 2006.

-Vaccination

This is the most effective way to prevent fowl pox. Vaccinations happen at 12-16 weeks of age and will create herd immunity in the flock (Butcher and Rossi, 2018).

-Biosecurity and hygiene

Biting insects are one of the leading causes of fowl pox. To help minimise the presence keep up with good hygiene in the coops, use window screens to keep out bugs and remove any standing water (Mohamed et al., 2024).  

-Quarantining and Isolation

When getting new members of the flock or once a chicken is infected, isolating them to avoid pathogen spread is important. This cuts of transmission routes to the rest of the flock.