AHS 3305 Practical 1 - Fleas, Lice, Flies, Ticks, Mites

Cellophane Tape Preparation

• Place a line of mineral oil on a glass slide

• apply CLEAR cellophane tape to skin to collect sample

• place adhesive surface of tape over mineral oil on glass slide

• scan microscopically with the 4x or 10x objective

• used to diagnose surface mites, fur mites, lice

Deep Skin Scrape Preparation

• apply a few drops of mineral oil on a glass slide

• dip #10 scalpel blade in oil (helps sample stick)

• squeeze area to be scraped between fingers

• hold scalpel blade perpendicular to skin

• scrape until oozing blood is seen

• smear sample onto slide, add more oil if needed

• place cover slip over sample and mineral oil

• scan under microscope with 10x objective

• used to diagnose burrowing mites

Superficial Skin Scrape Preparation

• apply a few drops of mineral oil on a glass slide

• dip #10 scalpel blade in oil (helps sample stick)

• squeeze area to be scraped between fingers

• hold scalpel blade perpendicular to skin

• scrape skin superficially to collect loose scales and crusts

• smear sample onto slide, add more oil if needed

• place cover slip over sample and mineral oil

• scan under microscope with 10x objective

• used to diagnose surface mites

Ear Swab Sample

• moisten cotton tipped applicator with mineral oil

• collect sample of ear debris with cotton swab

• place a few drops of mineral oil and debris on slide

• mix debris and mineral oil with wooden applicator stick until homogenous

• place coverslip (mineral oil should cover entire undersurface of cover slip)

• scan under microscope with 10x

• used to diagnose ear mites like Otodectes and Psoroptes

How is flea infestation diagnosed?

• you can look at lower back just above tail

• use flea comb to capture fleas and flea debris (feces)

• flea debris turn red when water is applied from digested blood from blood meals

Terms when animal is infested with parasite

• fleas = ectoparasitism

• lice = pediculosis

• flies = myiasis

• ticks = tick infestation

• mites = acariosis/acariasis

  • Demodex - demodicosis

  • Saroptes - scabies

  • Otodectes - Otoacariasis

What is the life cycle of a mosquito?

• Egg

• larva

• pupa

• adult

What is the life cycle of a tick?

• egg

• larvae

• nymph

• adult

Ctenocephalides felis

• Common name - cat flea

• Dx: using flea comb and wetting dirt with water

• Host: infests cats and dogs mostly, and mammals and birds

• Location: lives on the skin

• Zoonotic: yes, can take blood meals from humans but won’t infest them

• Life cycle:

  • egg

  • larva

  • pupa

  • adult

• 6 legs

• 3 body parts: head, thorax, abdomen

Echidnophaga gallinacea

• Common name - Poultry Sticktight Flea

• Dx: using flea comb and wetting dirt with water

• Host: cats, dogs, POULTRY, birds

• Location: on the skin

• Zoonotic: Yes, can take blood meals from humans but won’t infest them

• Life cycle:

  • egg

  • larva

  • pupa

  • adult

• 6 legs

• 3 body parts: head, thorax, abdomen

Trichodectes canis

• Common name - Dog chewing/biting lice

• Order: Mallophaga

• Dx: magnifiying lens, clear cellophane tape, microscopic examination

• Host: domestic dogs and wild canids

• Location: in and among hair of host

• Zoonotic: No

• Life cycle:

  • Egg (nits)

  • nymph

  • adult

• infestation called pediculosis

• transmitted direct contact and fomites

• highly host specific

• 6 legs, 3 body parts: head, thorax, abdomen

Felicola subrostratus

• Common name - Cat biting/chewing lice

• Order: Mallophaga

• Dx: magnifiying lens, clear cellophane tape, microscopic examination

• Host: cats and other felines

• Location: in and among hair of host

• Zoonotic: No

• Life cycle:

  • Egg (nits)

  • nymph

  • adult

• infestation called pediculosis

• transmitted direct contact and fomites

• highly host specific

• 6 legs, 3 body parts: head, thorax, abdomen

Linognathus setosus

• Common name - Dog sucking lice

• Order: Anoplura

• Dx: magnifiying lens, clear cellophane tape, microscopic examination

• Host: domestic animals except cats and birds

• Location: in and among hair of host

• Zoonotic: No

• Life cycle:

  • Egg (nits)

  • nymph

  • adult

• infestation called pediculosis

• transmitted direct contact

• highly host specific

• 6 legs, 3 body parts: head, thorax, abdomen

Melophagus ovinus

• Common name - Sheep Ked

• Obligatory (entire life cycle on host)

• Non-myiasis producing fly

• Biting fly → anemia

• Dx: Looking through wool/fleece

• Host: Sheep and goats

• Location: Deep within the sheep’s wool or goat’s fleece

• Zoonotic: No

• Transmitted: Direct contact

• Flattened and wingless and resemble ticks

• Females lay 1 larva (no eggs)

• Life cycle:

  • Larva

  • Pupa

  • adult

• Infestation called melophagiosis

• 6 legs

Cuterebra

• Obligatory

• Myiasis producing fly

• Bot

• Dx: looking for swollen, cyst-like subcutaneous lesions

• Host: Rabbits, rodents, dogs, cats, sometimes humans

• Location: Areas around head and neck (subcutaneous abscesses)

  • can be in nasal and oral cavities

  • can migrate to brain (fatal)

  • MIUST BE CAREFUL REMOVING or fatal

  • anaphylaxis

• Zoonotic: Yes, but rare

• Transmitted: Direct contact with 1st stage larvae

• Life cycle:

  • Egg

  • Larva

  • Pupa

  • adult

• larvae covered with tiny black spikes

• Infestation called cuterebrosis

Oestrus ovis

• Common name - Nasal Bot Fly

• Obligatory

• Myiasis producing fly

• Bot

• Dx: Looking for the large brown bot going through nostrils

• Host: Sheep and goats

• Location: Nasal chambers

• Zoonotic: Yes

• Transmitted: Adult female lays larvae in nares

• Life cycle:

  • Females squirt larvae into nostrils

  • Larvae crawl into frontal sinuses → feed on mucosa

  • return to nostrils → fall to ground, pupate → adults

• black oral hooks

• infestation is called oestrosis

Gasterophilus intestinalis

• Common name - Horse bots/Horse boy fly

• Obligatory

• Myiasis producing fly

• Adults causes fly worry

• Bot

• Dx: Looking for female flies around horse in fall and feces with tiny larvae and dark-brown bots

• Host: Horses

• Location: Attached to gastric mucosa (stomach)

• Zoonotic: No

• Transmitted: Adult female lays eggs on horse legs, they groom themselves, and larvae hatch and penetrate mucosa

• larvae may cause inflammation and interfere with digestion

• Life cycle:

  • fly deposits eggs to hairs

  • hatching triggered by warmth and moisture during grooming

  • larvae enter mouth → migrate through oral tissue → swallowed

  • attach to gastric mucosa, remain for months

  • exit in stool → pupate (visible bots) → adults

• infestation is called gasterophilosis

Hypoderma

• Common name for larvae - warbles, grubs

• Common name for flies - bot fly, warble fly, gad fly, heel fly

• Obligatory

• Myiasis producing fly

• Adults cause gadding

• Dx: Looking for swelling on back and looking for gadding

• Host: Ruminants, occasionally horses, sometimes humans

• Location: In large boil-like cysts in back of cow and through tissue

• Zoonotic: Yes

• Transmitted: Adult female flies from host to host

• larvae migrate through tissue and makes hides downgrade from larval damage and causes green “butcher’s jelly” which decreases money

• Life cycle:

  • fly attaches eggs to hair during summer

  • larvae enter through hair follicles or wounds (from biting flies)

  • migrate to back → forms warbles with breathing hole (palpable under skin)

  • emerge, fall to ground, pupate → adults

• infestation is called hypodermosis

How are maggots different?

• They live in soiled, or wounded tissue

Rhipicephalus sanguineus

• Common name - Brown Dog Tick/Kennel Tick

• Hard tick

• Family: Ixodidae

• Host: Dogs, sometimes humans

• Location: Attached below hair coat, external ear canal and between toes

• Transmitted: direct contact in infested environment

• Zoonotic: No, but can cause tick paralysis

• Life cycle:

  • Eggs

  • Unfed larvae

  • Goes on 1st host

  • Fed larvae, unfed nymph

  • Goes on 2nd host

  • Fed nymph, unfed adults

  • Goes on 3rd host

  • Fed male and female adult

• Parasitizes at larva, nymph, and adult stage

• Has an inornate, uniformly reddish-brown scutum

• The head has prominent lateral extensions that give it a hexagon looking structure

• 8 legs

• infestation called acariasis/ixodidosis

Dermacentor variabilis

• Common name - The American Dog Tick

• Hard tick

• Family: Ixodidae

• Host: Small mammals, dogs, humans

• Location: Attached to skin when feeding (head/neck)

• Transmitted: direct contact with life stage at tip of infested vegetation

• Zoonotic: Yes

• Life cycle:

  • eggs hatch into 6-legged larvae

  • larvae feed on 1st host

  • larvae molt into nymphs after leaving 1st host

    • can feed on humans and transmit disease

  • nymphs feed on 2nd host

  • nymphs molt into adults after leaving 2nd host

    • can feed on humans

  • adults attach to 3rd host for feeding and mating

  • adult female drop off host to lay eggs

• Parasitizes at larva, nymph, and adult stage

• only inhabits grassy, scrub-brush areas

• has an ornate scutum that is dark brown with white striping

• has a rectangular base of head and white markings on dorsal shield

• short mouthparts and festoons

• 8 legs

• infestation called acariasis/ixodidosis

Dermacentor andersoni

• Common name - The Rocky Mountain Wood Tick

• Hard tick

• Family: Ixodidae

• Host:

  • Larval and nymph stages: small rodents

  • Adult stage: dogs, horses, cattle, goats, sheep, humans

• Location: Attached to skin surface (head/neck)

• Transmitted: direct contact with infested vegetation

• Zoonotic: Yes

• Life cycle:

  • eggs hatch into 6-legged larvae

  • larvae feed on 1st host (rodents)

  • larvae molt into nymphs after leaving 1st host

  • nymphs feed on 2nd host (rodents)

  • nymphs molt into adults after leaving 2nd host

  • adults attach to 3rd host for feeding and mating (large mammals)

  • adult female drop off host to lay eggs

• Parasitizes at larva, nymph, and adult stage

• ornate tick

• female has small scutum and male has big scutum

• short palps and hypostome

• 8 festooned legs

• infestation called acariasis/ixodidosis

Ixodes scapularis

• Common name - Deer Tick/Black Legged Tick

• Hard tick

• Family: Ixodidae

• Host:

  • Larval and nymph stages: mice and voles

  • Adult stage: horses, dogs, deer, and humans

• Location: Attached to host when feeding, in environment when not feeding

• Transmitted: direct contact with life stage on tip of vegetation

• Zoonotic: Yes

• Life cycle:

  • eggs

  • larvae feed on 1st host (small mammals/rodents)

  • larvae leave host and molt into nymphs

  • nymphs stay dormant for seasons

  • nymphs feed on 2nd host

  • nymphs leave host and molt to adults

  • adults feed on 3rd host

  • adults leave host and female lays eggs

• Parasitizes at larva, nymph, and adult stage

• lacks festoons and inornate

• mouthparts are long and anal groove surrounds anus anteriorly

• 8 legs

• infestation called acariasis/ixodidosis

Amblyomma americanum

• Common name - The Lone Star Tick

• Hard tick

• Family: Ixodidae

• Host:

  • Larval and nymph stages: ground birds

  • Adult stage: cattle, horses, sheep, dogs, and humans

• Location: Attached to host when feeding (head, belly, flanks, ears)

• Transmitted: direct contact with infested vegetation

• Zoonotic: Yes

• Life cycle:

  • eggs

  • larvae feed on 1st host

  • larvae leave host and molt into nymphs

  • nymphs feed on 2nd host

  • nymphs leave host and molt to adults

  • adults feed on 3rd host

  • adults leave host and female lays eggs

• Parasitizes at larva, nymph, and adult stage

• has a white spot on the apex of its scutum

• 8 legs

• infestation called acariasis/ixodidosis

Otobius megnini

• Common name - Spinose Ear Tick

• Soft tick

• Family: Argasidae

• Host: Livestock, dogs, people

• Location: External ear canal

• Transmitted: Direct contact with infested environment

• Dx: otoscope

• Zoonotic: No, but can infest humans

• Life cycle:

  • eggs

  • larvae feed on host and molts into nymph

  • nymph molts into adult then leaves the host

• Parasitizes at larvae and nymph stages only

• mouthparts may not be visible when looking at dorsal aspect

• almost violin shaped

• nymph covered with tiny backward-projecting spines

• larval stage has stout, tiny spines

• 8 legs

• infestation is called otoacariasis

Sarcoptes scabiei

• Common name - Scabies mite

• Burrowing mite

• Dx:

  • blood test - ELISA

    • positive 2-4 weeks after infestation

    • can react to dust mites - false positive

  • reference lab - IDEXX

  • in-house test - Heska

  • superficial skin scrape

  • cellophane tape preparation

• Host: species specific, can affect dogs (canis), pigs (suis)

• Location: tunnel in superficial epidermis

• Transmitted: direct contact, spread easily

• Zoonotic: Yes

• Life cycle:

  • female mites burrow into skin and form tunnels and eggs are laid

  • larvae and nymphs grow in tunnels

• causes extreme pruritus

• crusts at edges of ears, elbows, face, abdomen

• oval shape

• each leg has a sucker on ends of legs and connected by a pedicel

• infestation is called sarcoptic mange

Demodex

• Burrowing mite

• Dx: deep skin scrape

• Host: species and host specific, domestic animals and humans

• Location: hair follicles and sebaceous glands of the skin

• Transmitted: direct contact, and by dam and neonate

• Zoonotic: No

• Life cycle:

  • adult mites in hair follicles and lay eggs in follicles and glands

    • can be transmitted to nursing puppies

  • eggs hatch into 6 legged larvae in follicles

  • larvae molt to nymph

  • nymph molt to adult

• causes localized or generalized demodicosis

• unique cigar shape

• causes hair loss, skin thickening, pustules

• infestation is called demodicosis or red mange

Psoroptes cuniculi

• Common name - Ear canker mite of rabbits

• Surface mite

• Dx: ear swab or superficial skin scrape or cellophane tape preparation

• Host: rabbits, also can affect horses, goat, sheep

• Location: skin surface, live in waxy discharge in ears

• Transmitted: direct contact

• Zoonotic: No

• Life cycle:

  • spent on one host, eggs molt into larvae

  • larvae molt into nymphs

  • nymphs molt into adults and live in ear canal

• corn flake appearance

• have long, jointed pedicels with suckers

• dark internal area in center

• infestation is called psoroptic mange

Otodectes cynotis

• Common name - Ear mite

• Surface mite

• Dx: ear swab or superficial skin scrape or cellophane tape preparation or otoscope

• Host: dogs, cats, ferrets (most common cat and dog mite)

• Location: external ear canal (also tail head region)

• Transmitted: direct contact, very contagious

• Zoonotic: Yes, but rare

• Life cycle:

  • eggs

  • larvae

  • nymph

  • adult

• ear debris resemble coffee grounds

• very pruritic

• short, unjointed pedicels with suckers on end of legs

• anus is terminal

• infestation is called otodectic mange

Notoedres (cati)

• Common name - (cati) Feline scabies mite

• Burrowing mite

• Dx: superficial skin scrape or cellophane tape preparation

• Host: felines and sometimes rabbits

• Location: superficial layer of dermis but can also be around pinna, face, neck, and feet

• Transmitted: direct contact

• Zoonotic: Yes

• Life cycle:

  • eggs

  • larvae

  • nymph

  • adult

• smaller than Sarcoptes

• long, unjointed pedicels

• crusts mainly on head, neck, feet

• anus is dorsal

• infestation is called notoedric mange

Which parasites are zoonotic?

• Ctenocephalides felis

  • cat flea

• Echidnophaga gallinacea

  • poultry sticktight flea

• Cuterebra

  • wolves, warbles

• Oestrus ovis

  • nasal bot fly

• Hypoderma

  • ox warbles, cattle grubs

• Dermacentor (andersoni and variabilis)

  • The Rocky Mountain Wood tick and The American Dog tick

• Otobius megnini

  • Spinose Ear Tick

• Sarcoptes scabiei

  • Scabies mite

• Amblyomma americanum

  • The Lone Star Tick

• Ixodes scapularis

  • The Deer Tick/Black Legged Tick

• Otodectes cynotis

  • ear mite

• Notoedres cati

  • cat scabies mite

Which parasites aren’t zoonotic?

• Trichodectes canis

  • dog chewing lice

• Felicola subrostratus

  • cat chewing lice

• Linognathus setosus

  • dog sucking lice

• Melophagus ovinus

  • Sheep ked

• Gasterophilus intestinalis

  • Horse bot fly

• Rhipicephalus sanguineus

  • The Brown Dog/Kennel tick

• Demodex

• Psoroptes cuniculi

  • Ear canker mite of rabbits

How can you tell ticks apart?

• Short mouthparts:

  • Dermacentor

  • Rhipicephalus sanguineus

    • Both have festoons

    • Rhipicephalus has a hexagonal shaped head

• Long mouthparts:

  • Amblyomma americanum

  • Ixodes scapularis

    • Only Amblyomma americanum has festoons