Gauteng Smallholder Gauteng Smallholder November 2011 | Page 31

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ANIMAL HEALTH
species, on the other hand,
have only one host.
Not all species of ticks are
found in Gauteng. What is
interesting though is that
climate change is bringing
about expansion of the ranges
of certain species of tick.
K Amblyomma hebraeum –
the bont tick is typically found
in short pasture. (“Bont” is
Afrikaans for “colourful”.) It is
known as a bont tick because
of its bright contrasting
colours. Amblyomma
hebraeum transmits Ehrlichia
ruminantium (heartwater) to
domestic and wild ruminants,
Theileria mutans (benign
bovine theilerioses) to cattle
and Rickettsia africana, the
cause of African tick-bite fever
in humans. The larvae of A
hebraeum are probably more
responsible than any other
tick for tick bites in humans.
Research published earlier this
year by the Onderstepoort
Journal of Veterinary Research
draws attention to the fact
that horses do not receive the
same anti-tick control
measures as cattle. “Horses
on the same property as other
livestock may thus serve as a
reservoir of infestation and
escape the sometimes
rigorous acaricidal control
regimens applied to cattle.”
K Rhipicephalus
decoloratus - African blue
tick is most active in
December to January and
March to July. It can be widely
dispersed on the host,
although the adults prefer
flanks and underbelly, while
the immatures are found
mostly on the ears, neck and
dewlap.
Rhipicephalus decoloratus
transmits Babesia bigemina
and Anaplasma marginale to
cattle and Borrelia theileri, the
cause of spirochaetosis, to
cattle, sheep, goats and
horses.
K Rhipicephalus
appendiculatus - Brown ear
tick is a uniform brown colour
and can be found on cattle,
goats and horses. This tick is
the main vector of Theileria
parva, the causative organism
of East Coast fever in cattle.
K Rhipicephalus evertsi
evertsi – the red legged tick is
found throughout South
Africa. Rhipicephalus evertsi
evertsi transmits the causative
organisms of equine
piroplasmosi, ovine
theileriosis and Babesia caballi
to horses. It also transmits
Anaplasma marginale, the
causative organism of
anaplasmosis in cattle.
K Hyalomma rufipes – A
large, coarse bont-legged tick
that is drought and heat-
tolerant. The long mouthparts
cause tissue damage in cattle
and sheep and secondary
bacterial infections may lead
to abscess formation. It can
transmit Anaplasma marginale
to cattle causing bovine
anaplasmosis or gallsickness
and also Babesia occultans
causing benign babesiosis in
cattle; it can cause equine
piroplasmosis in horses and
donkeys; it can also transmit
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