Ticks are responsible for the transmission of numerous diseases of man and animals in many parts of the world. Wild birds are frequently infested and may carry the parasites for considerable distances when migrating. The fowl tick Argus persicus is the best known species to be found on birds. Argus refiexus commonly occurs on pigeons. While some have quite strict host requirements, others are satisfied with a wide range of warm-blooded creatures: man, mammals, and birds. Different species of tick occur in different areas of the world depending upon temperature, humidity, type of vegetation and terrain. In cage and aviary birds, infestations are mainly sporadic and usually acquired from poultry, wild birds or mammals.

Ticks, like mites, are acarine arthropods. They possess eight legs except in the first larval stage of the life cycle when they have six. They are all blood suckers and vary in size from 3-15 mm. in length being broadly oval, round or pear-shaped, according to species and whether or not they have recently fed on blood. Two main groups occur, the hard or ixodid ticks which have a horny shield on their backs, and the soft or argasid ticks. Hard ticks are parasitic, mainly as larvae or during the nymphal intermediate stages; they do not occur so frequently on birds as the soft ticks.

The latter can cause considerable trouble by blood-sucking and by transmitting diseases. Important infections which they are capable of transmitting include spirochaetosis due to Borrelia and agyptianellosis (Aegyptianella pullorum infection) of poultry, the latter disease also affecting some psittacine birds. Adult ticks may be found on birds around the head and neck, the vent and thinly feathered parts of the body and also on the limbs. When engorged they appear as small, blue to deep red colored grape-like structures firmly embedded in the skin by their mouth parts. They are often present in bunches or small groups. When starved, for example on the ground or elsewhere, they appear as wizened, dehydrated, raisin-tike objects. After feeding on a suitable host soft ticks lay about 20 to 10,000 eggs, usually in the vicinity of the bird, in cracks and crevices or under dry sand or soil. The eggs hatch within 10 days to several months depending upon the temperature, the larvae wait for a host to approach close enough to attach themselves to some part of the body.

The larvae then feed for several days, moult once or twice into eight legged nymphs over a period of weeks or several months and eventually moult and become adults. The females attach themselves to hosts, sucking large amounts of blood and at least quadrupling their size in the process. They then mate and lay eggs, and the life cycle is repeated. Any stage may survive for 6 to 12 months or even more, whilst lying in wait for a victim. Ticks must be numerous in order to cause appreciable illness or unrest and moderate infestations may be overlooked in a brief examination because the larvae are little bigger than mites. Even a few adults, however, are sufficient to produce considerable anemia. Signs to be expected include weakness, loss of weight, reduced growth, ruffled plumage, poor appetite, restlessness and even diarrhea.

Treatment and control:
As soft ticks feed mainly at night and often retreat into hiding by day, they can be checked by spraying the bird at night with suitable acaricides at two week intervals. Thorough spraying of the entire building, and especially shady areas in the flight and aviary itself, with an acaricide should be carried out whenever the accommodation can be cleared of birds for some days or weeks. Individual adult ticks on birds are very difficult to remove. Any attempt to pull them off usually leaves the head embedded in the skin and this may rapidly become an infected wound or abscess. A chloroform or ether-soaked pad placed over the parasites will sometimes induce them to loosen their grip a little, and they may then be gently eased off or alternatively pulled away suddenly using a pair of fine-pointed curved forceps. Both young and adult stages may die attached to the skin as a result of acaricidal treatment and these too, may produce unpleasant wounds. Suitable treatment may clear premises for a matter of months, but prophylactic spraying or painting at least every 3 months is desirable in areas where ticks are common.


E-Mail: berniehansen@sympatico.ca



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Hamilton & District Budgerigar Society Inc.