Page 221 - The Veterinary Laboratory and Field Manual 3rd Edition

190 Susan C. Cork and Mani Lejeune

R. (Boophilus) annulatus transmit Babesia bigemina (Figure 3.45), camels, sheep, goats and horses
and B. bovis. R. (Boophilus) decoloratus ticks trans- as well as humans but specific subspecies are not
mit B. bigemina and rickettsial species (Anaplasma commonly zoonotic.
marginale and A. centrale), see Table 3.9. A summary of the mites of veterinary impor-
tance is given in Table 3.10 (above) and two
species are illustrated in Figure 3.44. Some non-
tick control parasitic, or free-living, mites such as members
of the Trombiculidae (that is, harvest mites)
Animal health authorities will develop their own may also cause irritation in individual animals
tick control guidelines but some basic principles but the infestation is usually transient. Mites
are outlined below. may also be found in stored food (for example,
Glycyphagus sp. and Acarus sp.) and in human
1 Identify the species of tick(s) present. dwellings, for example, the house dust mite
2 Treat infested livestock with a suitable prod- (Dermatophagoides pteronyssinus), which feeds on
uct (acaricide). flakes of loose epidermal tissue and may result
3 Move livestock to a ‘clean’ (that is, tick free) in allergy in certain individuals.
pasture after treatment.
4 Clear overgrown pasture/scrub to remove the
environmental stages of tick development.
5 If ‘clean’ land is not available, acaricide treat-
ment may need to be repeated every 2–3
weeks. 7

3.9 Mites and mange

Parasitic mites are small arachnids which can
cause mild or severe skin damage depending
on the species of mite, the level of infestation
and the underlying health status of the host.
Mite infestations are associated with skin irrita-
tion and hair loss; severe infections are usually
clinically obvious and cause discomfort and
itching. The latter often results in secondary
trauma, the formation of scabs and concurrent
bacterial infections. Mite infestation is some-
times referred to as mange. Some species, such
as the sheep scab mite (Psoroptes ovis) may cause
significant morbidity in livestock and economic
loss due to wool or pelt damage and poor body
condition. Many mites, for example, Chorioptes
sp., are not strictly host specific, for example, Figure 3.44 Ventral view of two species of adult
Chorioptes bovis may infect cattle, sheep, goats mites. (A) Psoroptes sp. mite; (B) poultry ‘red mite’
and horses. Sarcoptes scabiei infects pigs, dogs Dermanyssus gallinae.

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