Common Ecto And Endo Parasites

Question 1

Ectoparasite types

Answer 1

Fleas
Lice
Ticks
Mites

Question 2

Fleas

Answer 2

• fleas are wingless insects with laterally compressed bodies
• six legs adapted to jumping - unique for ecto, able to move well, onto other animals/environment
• average 2mm long (vary with species) easy to identify
• two common species
  ~ Ctenocephalides felis (cat flea) most common in UK and infestation cat/dog/rabbit/small rodent/ferret and man
  ~ Ctenocephalides canis (dog flea) found on some dogs in uk (more unusual than cat fleas on dogs) and most common flea on dogs in Ireland

Question 3

Lice

Answer 3

• small wingless insects
• occur in large numbers on many comp animals inc dogs, cats,
• host specific so lice infestation of one host species does not pose a risk for other species of host

Question 4

2 key types of lice

Answer 4

Sucking lice

• pointed head with piercing proboscis and feed regually on blood
• Linognathus setosus (canine sulking louse)
• slim head small mouth parts

Chewing lice

• broad head baring strong chewing mouth parts and feed on epidermal scales scurf and wool
• Trichodectes canis (canine biting chewing louse)

Question 5

Ticks

Answer 5

• not insects
• arachnids
• 8 legs as adults and are flattend dorsoventrally with hard shell on the back
• no wings
• limited movement with legs
• ixodes ricinus - commonly seen in companion animals but known as sheep tick

Question 6

Mange mites

Answer 6

• some species specific, some preference
• mange = skin disease of domestic animals caused by a number of different mites and described under those headings e.g. sarcoptic, demodectic
• entire life cycle takes place on animal or w/in its skin, many stages remain infective for several days of animal
• thus detect animal to animal contact is not always nescasary for transmission (via enviro)

Question 7

Otodectes

Answer 7

• ear mites
• common in doga nd cat
• otitis external (inflammation of external ear canal) of ten due to or irritated by ear mites
• ear protects itself by produce wax that blocks ear, anaerobic bacteria perfect environment to grow, fungal infections

Question 8

Cheyletiella

Answer 8

• surface living mites
• infect dog/cat where it cause pruritus and hair loss with dry scalling of skin
• Cheyletiella yasguri = most common in dog
• Cheyletiella parasitovorax common cause of alopecia in rabbit and guinae pig

Question 9

Sarcoptic mange (more focus)

Answer 9

• zoonotic = humans can be infected from dogs

- sarcoptes scabiei

Question 10

Demodectic mange

Answer 10

• demodex lives in hair follicles and sebaceous glands
• hard to tell apart but many different species for many mamalas
• demodex canis
• demodex cati
• cigar shaped - live in cavities adapted to get in

Question 11

Tapeworms and roundworms examples

Answer 11

• Diplydium caninum
• taenia species
• echinoccocus granulosus
• toxocara canis and cani

Question 12

Tapeworms

Answer 12

• flat tape like segmented body
• each segment is self contained, containing one or two sets of male/female repro organs = fertilised eggs in each segments
• further down body release end segment, pass out into faeces, split and spill eggs for animal to ingest

Question 13

Diplydium caninum

Answer 13

Tapeworm

• primary host in dog and cat
• intermediate host is the flea

Question 14

Taenia tapeworms

Answer 14

• primary = dogs and more commonly cats (hint i host)
• intermediate = birds, small animals
• I needs to be ingested for infection

Question 15

Echinococcus granulosus

Answer 15

• primary = dog
• intermediate = the usual intermediate host is sheep but any mamal in contact with dogs can become an i host including man
• zoonotic

Question 16

Roundworms

Answer 16

• vary in size from fine thread like to resemble common earthworms and several cm
• no segments and tend to be white/pinkish brown