ectoparasites

Species

Biting/chewing (round heads – feed on skin/hair):

·    Bovicula bovis – found on the head

Sucking (pointy heads – feed on blood):

·    Linognathus vituli – found around head area

·    Haematopinus eurysternus – found around the horns

Impacts: - only if high burden

·    Itching, rubbing, licking

·    High burden of sucking = anaemia

·    Decreased BCS/DLWG

·    Damaged skin/fleeces

Lifecycle

Simple and direct – all on host

Impacts

·    Itching, rubbing, licking

·    High burden of sucking = anaemia

·    Decreased BCS/DLWG

·    Damaged skin/fleeces

Diagnosis

·    See with naked eye

·    Usually affect animals that have something else going on – consider underlying diseases

Treatment

·    Pour on synthetic pyrethroid - deltamethrin

·    Pour on ML - ivermectin

·    Injectable ML – ivermectin

·    Treat all cows In direct contact

·    Treat, then again in 2w to kill any nymph (as no tx for eggs)

Impacts

·    Act as vectors for disease:

o  Pinkeye

o  Onchocerca

o  Bovine papilloma virus

§ Transmission: abrasions, direct contact, flies (act as vectors)

·    Cause irritation ® decreased DLWG, yield

Warble fly

·    Hypodermic bovis, Hypoderma lineatum

·    Lifecycle – lay eggs on hair in summer ® larvae hatch and migrate to oesophagus/spine ® migrate under skin in spring ® mature for 30d then drop off

Impacts:

·    Gadding behaviour – flies harass cattle

o  Cattle become restless (® physical injuries) and depressed (® decreased growth/production)

·    Ectopic migration and paralysis

·    Damage caused by warbles – downgrade of hide due to perforations of skin by larvae

·    Reduced reproduction – cattle wont stand to be mated when larvae under skin in spring

Treatment: injectable ML – ivermectin

Species

·    Chorioptes spp. – surface mite

Clinical signs

·    Chorioptic mange – tail, leg, scrotal mange

Diagnosis

·    Deep skin scrape (edge of lesion)

Treatment

·    Synthetic pyrethroid – permethrin

·    Pour on ML – ivermectin

Most common species

·    Ixodes ricinus – 3 host life cycle

Impacts

·    Act as vectors for disease – e.g. Babesia, Q-fever, Lyme disease, tick borne encephalitis

·    Cause small inflammatory/granulomatous lesions when bite ® secondary bacterial infection

·    Poor BCS, weight loss, reduced milk yield

·    Hide/fleece damage ® reduction in quality

·    Intense irritation

Diagnosis

·    History

·    Skin examination

·    Skin scraping

Control

Host control:

·    Pour on pyrethroids or MLs

Environmental control:

·    Avoid tick borne pastures during spring

·    Improve pasture to decrease tick population, e.g. drainage

Babesia

Clinical signs:

·    Pyrexia

·    Severe haemolytic anaemia

·    Haemoglobinuria

·    Death

Animals affected:

·    Calves usually resistant and develop immunity

·    If see disease, usually if naïve animal brought into endemic disease