Omphalitis is a condition characterized by infected, unhealed navels in young fowl. It is noncontagious and associated with excessive humidity and marked contamination of the incubator.
The affected chicks or poults usually appear normal until a few hours before death. Depression, drooping of the head, and huddling near the heat source usually are the only signs. The navel is inflamed and fails to close; a scab may be present. Opportunistic bacteria (coliforms, staphylococci, Pseudomonas spp , and Proteus spp ) are often recovered. Proteolytic anaerobes are prevalent in outbreaks. The yolk sac is not absorbed and often is highly congested or broken; peritonitis may be extensive. Edema of the sternal subcutis may be seen. Mortality often begins at hatching and continues to 10-14 days of age, with losses up to 15% in chickens and 50% in turkeys. Chilling or overheating during shipment may increase losses. Persistent, unabsorbed, infected yolks often produce stunted chicks or poults.
There is no specific treatment; the disease is prevented by careful control of temperature, humidity, and sanitation in the incubator. Only clean, uncracked eggs should be set. If dirty eggs are washed and set, the risks of omphalitis and other problems during incubation are markedly decreased. Sanitizing detergents must be used according to directions if eggs are washed. Time, temperature, and frequent changes of water are as critical as the concentration of sanitizer in both wash and rinse water. The rinse should be warmer than the wash water but not >140°F (60°C).
The incubator should be cleaned and fumigated thoroughly before the hatching season and between hatches. Fumigation must be done with closed vents at high temperature and humidity. Thirty mL of 40% formaldehyde and 15 g of potassium permanganate per 20 cu ft (0.6 m3), or paraformaldehyde (in the strength recommended by the manufacturer) in a heating device, should be used. The machines are readily contaminated after fumigation unless the exterior of the machines and the rooms in which they are located are cleaned and disinfected.