Avian spirochaetosis

Avian spirochaetosis is caused by Borrelia anserina

• Chickens, turkeys, pheasants, ducks and geese susceptible
• Transmitted by soft ticks of the Argas family, but also via contact with infected material such as blood and tissues
• Transmitted transovarially and trans-stadially via the tick population
• Outbreaks during peak tick activity during warm, humid conditions
• Fever, anaemia and wight loss occurs, with development of paralysis later
• Immunity is serotype specific
• Diagnosis using dark-field microscopy of buffy coat smears or immunodluorescence of blood or tissues
• Giemsa-stained smears and silver impregnation of tissues
• Isolation of borreliae by inoculation of embryonated eggs or chicks
• Antibiotic treatment
• Inactivated vaccines available