Parasitology - Exam 1 Lectures 1 --> 3

Question 1

What is myiasis? What causes the different stages of myioasis?

Answer 1

• Myiuasis is the infestation of the larval stage of the fly (AKA **fly strike)
• Blowflies ** –> cause facultative myiasis where a specific host is NOT required and even a dead host can be used
• Note that there is an EXCEPTION WITH screwworms since they cause obligate myiasis
• Bots cause obligate myiasis where a specific host is required to reproduce

Question 2

With regards to arthropods, discuss how this is broken donw

Answer 2

Main categories include insects and arachnids

• insects: flies, lice, and fleas
• arachnids: mites and ticks

Question 3

With regards to blowfly miasis, what is the treatment for sheep vs dogs?

Answer 3

Clip and clean the area, remove the maggots mechanically:
- Sheep: organophosphates, macrocyclic lactones, spinosad are effective; apply directly to the affected region
- Dogs: Administer nitenpyram orally; apply insecticides like topical macrocyclic lactones

Question 4

Whats the species that causes blowfly myiasis? Discuss this disease

Answer 4

Screwworms, known as cochliomyia hominivorax cause obligate myiasis and eats the lioving tissue. This is a reportable foreign animal disease

Question 5

Regarding flies, what is myiasis and what flies are inbcluded in this?

Answer 5

• 1) Blowflies (AKA bottle flies)
• 2) Bot flies
• Both bloth flies and bot flies causes myiasis

Myiasis is when the larval stage of the fly causes damage to the animal host

Question 6

what is the lifecycle for blowfly myiasis

Answer 6

Question 7

What is the ‘fly strike’ in regards to blowfly myiasis

Answer 7

Blowfly myiasis - fly strike –> infestation with the larval stage

• warm, wet, soiled, smelly things attract blowflies

Question 8

Discuss the progression of the fly-strike in regards to blowfly myiasis

Answer 8

Question 9

What are some prevention methods for blowfly myiasis

Answer 9

• Sanitation - enviornmental and animal
• Crutch (remove woool from back legs and tail) and dock (shorten tail) sheep
• Treat primary causes of diahhrea: 1)internal nematode parasite control and 2) coccidiosis control
• get rid of adult flies

Question 10

Discuss screwworms

Answer 10

• cochliomyia hominivorax known as screworms
• a special blowfly that causes obligate myiasis that eats a living tissue
• reportable foeign animal disease

Question 11

what is the lifecycle of screwworms and discuss the progression of it

Answer 11

1) Larcae feed on the healthy tissue in and around the world
2) Massive tissue destruction:
- swecondary effects: A) secondary blowefly strike B) bacterial infection C) death

Question 12

discuss the treatment for screworms

Answer 12

Treatment –> clip and clean around the wound
- apply insecticide
- Nitenpyram

Question 13

Discuss the specific genus of bot flies for each species

-

Answer 13

• hypoderma sp –> Cattle
• Oestrus ovis –> sheep
• Gastrophilus sp –> Horse
• Cuterebra –> rodents, dogs and cats

All of these are species of Bot flies

Bot flies: do not feed (during the adult stage), only reproduce

Question 14

what is the difference between bot flies asnd blow flies

Answer 14

Bot flies are different from blow flies because bot flies cause an obligate myiasis

Question 15

Discuss the lifecycle of Bot flies

Answer 15

Question 16

Discuss the life cycle of bot flies, specifically the hypoderma species

Answer 16

Hypoderma –> warble flies, cattle grubs, heel flies, gadlies (these all refer to hypoderma of the cattle

adult fliy lays eggs on cattle hairs > larvae penetrate skin > migrate to back > emergy and fall to ground to pupate

Life cycle:
- June –> July: adults emerge and lay eggs on the front legs of cattle. Eggs hatch, and larva penetrate the skin
- August –> December: Larva migrate though submucosa and grow as they migrate
- January-February: bots accumulate around esophogus and spinal cabnal and form ‘warbles’ on the back
- March –> May: Bots fall to the ground and pupate
-

Question 17

Botv flies: Hypoderma species –> discus the effects on the host

Answer 17

**Worry –> ** flies bother cattle to the poont where they dont graze properly resulting in poor growth and poor production
**Meat and hide damage: **results in something called Butchers jelly

Question 18

Discuss the treatment for the hypoderma species of bot flies

Answer 18

• Macrocyclic lactones are highly effective –> Ivermectin, eprinomectin, moxidectin
• Timing of treatment is cruical –> Treat as soon as possible after adults lay eggs in the fall
• do NOT treat after January

Question 19

What is the proper name for the Bot flies, specifically the sheep nasal bot. ALso discuss its lifecycle

Answer 19

• ## Oestrus ovis –> Sheep nasal bot

Question 20

What are the effects on the host of the sheep Nasal Bot (Bot flies)

Answer 20

• Summer sheep hiding noses

Question 21

discuss the effects, diagnosis, and treatment for Oestrus ovis, the sheep nasal bot

Answer 21

• Minor mucosal irritation from the larva –> usually asymptomatic
• Diagnosis: Direct observation of larvae (usually found in water troughs)
  ; no specific clinical signs (mild upper respiratory tract signs
  Treatment
• Macrocyclic lactones very effective but usually not necessay

Question 22

What is the proper name for the horse bot fly (Bot flies) and also discuss its lifecycle

Answer 22

• ## Gastrophilus

Question 23

For Bot flies (gastrophilus), discuss the effects on the host, diagnosis, and treatment

Answer 23

• Effects on host: usually asymptomatic; ulceers at site of attachment
• Diagnosis: infection is usually assumed (confirmed via endoscopy); can find eggs on the fur and larvae on the mouth
• Treatment: Macrocyclic lactones in the fall

Question 24

what is the proper name for the rodent bot fly (bot flies)

Answer 24

• Cuterebra
• life cycle is missing along with effects on the host, treatment, and diagnosis