Ectoparasites Flashcards
What is a parasite?
Lives at the expense of another organism (host) long term, without causing immediate death of the host
What are some detrimental effects of host-parasite relationships?
Anaemia, tissue damage, inflammation, allergic responses, weight loss
What is tagmatization?
Formation of segmented hosts (usually head/thorax/abdomen different sections)
What are the layers of the exoskeleton (deepest-superficial)
Basement membrane –> epidermis –> endocuticle –> exocuticle –> epicuticle (with waxy layer)
Through which structures do ectoparasites respire?
Spiracles and tracheoles (stigmata in ticks/mites)
What is the mouthpiece of a mite called?
Gnathosoma
What is the body of a mite called?
Idiosoma
What are the symptoms of scabies (sarcoptes)?
Intense itching and inflammation, hair loss, crusts of dried exudate, hypersensitivity
Which species typically get sarcoptic mange?
Dogs and pigs, rarely seen in livestock/cats/horses
Where do dogs typically get sarcoptic mange infestation?
Pinnae, elbows, ventrum
What is otodectes cyanotis/what gets it?
Ear mites, hosts are cats/dogs/other carnivores (e.g. foxes)
What/where is demodicosis?
Demodex mites, obligatory, deep in dermis (only found via deep skin scraping/hair plucks)
How are demodex mites usually passed on?
From dam to young with suckling,
What are Cheyletiella?
Large zoonotic mites, can infect rabbits/cats/dogs, can survive 10 days off host
Do male or female ticks have the larger shield?
Males
What is the activity called where ticks are looking for a host?
Questing
What is the most common tick in the UK
Ixodes ricinus
How many hosts does Ixodes ricinus have by the time it grows to adult size?
3
What is the basic life cycle of the flea?
Egg –> larva –> pupa –> adult
How can fleas also transmit Dipylidium caninum (tapeworm)?
Larvae will feed on organic debris including tapeworm segments
What provides stimulation for pupae to emerge from cocoon?
Increasing temperature or mechanical pressure
How long can pupae remain dormant for?
Up to 6 months (but usually only 5-10 days)
What are the 2 types of lice?
Sucking louse and chewing louse
How to tell which type of louse?
Sucking louse = small head
Chewing louse = large flat round head
What is Trichodectes canis?
Chewing louse of dogs - found in puppies head/neck/tail
Which ectoparasites can also be intermediate hosts for Dipylidium caninum?
Fleas and chewing lice (dogs)
What is Gasterophilus spp.?
Flies found on horses
What is a myiasis affecting rabbits?
Rabbit strike (Lucilia sericata)
What are some possible infestations in rabbits?
Blowfly strike Myxomatosis Mange mites Coccidia Encephalitozoon coniculi
What is canine leishmaniosis? Where does it come from?
Myiasis, carried by sand flies, from abroad (mediterranean)
What are Culicoides midges?
Sweet itch, found on horses worldwide
Vectors of many viruses and nematodes
What is different about the life cycle of a midge?
Larva are aquatic
