Causes: Ticks are large mites belonging to the super-family Ixodoidea of the Acarina. Ticks inhabiting poultry houses belong to the family Argasidae.

Effects: Losses caused by tick infestation are threefold- loss of host blood, which may cause death; reduced productivity associated with anaemia, but also possibly due to toxic substances produced by the tick; transmission of avian diseases.

The fowl tick is the most important poultry ectoparasite in many tropical countries, being a limiting factor in successful rearing of standard breeds of poultry. Turkeys usually suffer even more than chickens; recently hatched poults and chicks show the highest mortality. These ticks cause skin blemishes on turkeys, reducing price.

Ticks are large mites belonging to the super-family Ixodoidea of the Acarina. Unengorged adults of most common ticks are 2-4 mm long, but fully engorged females may reach more than 10 mm. However, unengorged tick larvae are similar in size to adult mites. Ticks inhabiting poultry houses belong to the family Argasidae.

The fowl tick is capable of transmitting the highly pathogenic spirochete Borrelia anserine in many tropical and temperate parts of the world. Tick-borne avian spirochetosis has been reported in chickens and turkeys in the United States; epizootics of avian spirochetosis in Arizona are associated with infestations by the flow tick.

Fowl ticks have been reported to transmit Aegyptianella pullorum and fowl cholera (Pasteurella multocida) in some regions of the world. All postembryonal stages of the common fowl tick have been found infected with A. pullorum in some areas. However, in other areas transmission of fowl cholera was not shown even though fowl ticks harboured P. multocida for 25 days. Aegyptianellosis has not been reported from the Americas.

Tick paralysis in chickens, a flaccid, afebrile motor paralysis, may result from attacks by A. persicus as well as by A. walkerae in Africa. Aetiology of this sporadic disease is not understood, but most probably a specific paralytic toxin is contained and transmitted in the tick salivary secretions. Clinical signs may be confused with botulism, neural signs of Marek’s Disease, transient paralysis of Newcastle disease, and possible conditions caused by other bacterial or chemical toxins.

Birds suffer chiefly from attacks of these ticks during the warm dry season. Loss of blood may reach proportions of a fatal anaemia; at least there may be emaciation, weakness, slow growth and lowered production. Ruffled feathers, poor appetite and diarrhoea are signs suggesting tick infestation.

Mature blood-engorged females measure about 10 mm x 6 mm. Unfed ticks are relatively easily recognised by their flattened ovoid shape and tan to reddish brown colour.

Females may lay a total of 500-875 eggs in four or five separate batches but require a blood meal before laying each batch of eggs. Eggs are laid in sheltered crevices, including bark of trees. The complete life cycle takes about 7-8 weeks during warm weather and longer during cold seasons. Fowl ticks remain inactive in cracks and crevices during cold weather, and adults may live without a blood meal for more than 4 years.

Diagnosis is made by identification of ticks on the birds, and by clinical signs.

Control requires treatment of premises because adult and nymphal ticks are on their hosts only a short time and then hide in the surroundings. The litter, walls, floors and ceilings must be sprayed thoroughly – forcing spray into cracks and behind nest boxes.

Outdoor runs and feed troughs, woodpiles and tree trunks may be treated suing approved insecticides. Other methods for fowl tick control include use of metal construction, elimination of tree roosting, using roosts suspended form ceilings and converting to cage operation.

Frequent inspection is necessary to combat ticks before their numbers increase to a harmful level. Fowl ticks are rare in modern, large commercial cage-layer operations.

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