Sheep blowflies and ticks Flashcards
What is myiasis?
Infestation of organ/tissues by the larvae of dipteran flies (in family oestridae)
What are 3 examples of myiasis species (family Oestridae)
Hypoderma spp
Gasterophilus
Oestrus ovis
What is the species of the blowfly?
Lucilia sericata
Are blowflies (Lucilia sericata) facultative or obligatory myiasis? What can they initiate?
Facultative cutaneous myiasis
Can initiate flystrike
What are the morphological features of adult blowflies (Lucilia sericata)?
Dorsal bristles
Blue green metallic body
What are the morphological features of Lucilia sericata?
Smooth segmented worms (Freaky!)
Anterior oral hooks containing enzymes for feeding
Rear end has breathing spiracles
What is the lifecycle of blowflies? (Lucilia sericata)
L1 hatch and moult to L2 and L3, feeding on tissue
L3 fall to ground to pupate
Do blowflies cause wool loss? What do they cause?
No wool loss
Sheep nibble at wool = dark and oily
What is the species that is Bluebottles?
Calliphora vicina
What is the difference between primary and secondary species of flystrike?
Primary - initiate strike e.g. blowflies
Secondary - cannot initiate strike, e.g. Calliphora vicina
What is flystrike?
Infestation of sheep by Lucilia sericata (blowflies) and Calliphora vicina (bluebottles)
What species are affected by flystrike?
Sheep
Rabbits
Birds
When are animals particularly susceptive to flystrike?
If debilitated, dirty or wounded (disease)
What does flystrike cause in sheep?
Anorexia, dullness, isolation, pyrexia, tachycardia, loss of condition and appetite
Describe the lifecycle of the flies that cause flystrike
Larvae spend 3-4 days on host and cause rapid tissue damage (life threatening)
Flies breed in rotting flesh
What part of the body does flystrike mainly affect?
Body Tail Penile sheath Foot Rump Horns
What host factors affect flystrike?
Skin folds Wool length/thickness Scour Tail length - dock Wounds - treat footrot
What environmental factors affect flystrike?
Warm weather
Summer rain
Abundance of blowflies
What can be used to prevent flystrike in sheep?
Diazinon dips
Cypermethrin
Cyromazine
What is an advantage and disadvantage of using cyromazine to treat flystrike?
Advantage -doesn’t damage host tissues
Disadvantages - not an adulticidal or ovicidal
What can be used to treat flystrike in rabbits?
Cyromazine
Permethrin
What is the name of the nasal bot fly in sheep?
Oestrus ovis
Do oestrus ovis produce eggs? How do they produce osspring?
Larviparous - deposit larvae not eggs
When are nasal bot flies (oestrus ovis) most active?
July
Larvae ecdysis happens over winter and spring
What are the morphological features of oestrus ovis?
Dark greyish speckled body, segmented
Vestigial mouthparts
Describe the pathogenesis of oestrus ovis?
Adult fly lays larvae in nose
Larvae feed in nasal passages and sinuses
Moult to L2 in nasal passage, moult to L3 in sinuses
L3 move to nostrils and sneezed out
Purpariate on ground and fly emerges 3-8 weeks later
How is oestrus ovis (nasal bot fly) diagnosed? How is it controlled?
Clinical signs
Ivermectin
What are the welfare issues associated with nasal bot flies?
Nasal discharge
Sneezing
False gid (bot migrates to brain)
Scrapie - affects nervous systems
What species are affected by Nasal bot fly (oestrus ovis)
Mainly sheep
Can be humans and other animals
What is the most common tick in sheep?
Ixodes ricinus
What pathogens do Ixodes ricinus transmit in sheep?
Louping ill - zoonotic virus, vaccine available
Tick pyaemia - young lambs, joint infection by staph aureus
Anaplasma phagocytophilium - gram -ve bacteria
