L24 - Fleas and Lice

Control and treatment of what parasites is the largest small animal health issue?

Fleas

What species is known as the cat flea?

Ctenocephalides felis

What stages of Ctenocephalides felis are parasitic?

Adults, larvae feeds in environment on dander, dried feces etc.

What species is known as the dog flea?

Ctenocephalides canis

What species is known as the false human flea?

Pulex simulans

What parasite is a suspected vector for FeLV?

Fleas

How long is the life cycle of the flea?

3 weeks

Can fleas survive in the environment without a blood meal?

Yes, survives long periods of starvation

How are flea infestations controlled?

• Must be directed at all stages of life cycle

• Fleas on primary and secondary host

• Larval stages off hosts

• Prevent reinfestation

How does Frontline (Fipronil) kill fleas?

• Spread via body’s sebum

• Blocks GABA-regulated chloride channels

How does Advantage (imidacloprid) control fleas?

CNS impairment and death of fleas via nicotinic acetylcholine receptors

How do isoxazolines kill fleas?

CNS impairment by inhibition of GABA

How does Revolution (selemectin) control fleas?

Stimulates GABA-regulated chloride channels → muscular paralysis and death (similiar to ivermectin)

How does Capstar (nitnpyram) control fleas?

Ties up nicotinic receptors and kills fleas (>90% elmininated in 24 hrs)

How does Comfortis (spinosad) control fleas?

Binds nicotinic acetylcholine receptors → hyperexcitation paralysis leads to death

How does Seresto Collars control fleas?

Synergistic neurotoxcity on adults → Imidacloprid + Flumetrhin

How does Vectra 3D (Dinotefuran) control fleas?

Inhibits nicotinic acetylcholine receptors → CNS impairment

• Permetherin → tick repellant (cats don’t have this ingredient)

• Pyriproxifen → prevents fleas from hatching

How does Nexgard (afoxolaner) control fleas? Analogs: Bravecto and Simparica

Blocks GABA-gated chloride channels → neurologic paralysis

What products kill or repel fleas from reinfestation?

1. Frontline

2. Revolution

3. Advantage

4. Nexgard

5. Comfortis

What products kill residual flea eggs and larvae in the environment?

1. OTC products with methoprene/pyriproxyfen → Frontline Plus and Advantix

2. Revolution

3. Program

What kind of lifecycle do lice have?

Direct

What’s different in the morphology of sucking vs. chewing lice?

Chewing → head wider than thorax, only lice on birds and cats

Sucking → head more narrow than thorax

What type of lice causes hypoproteinemia?

Sucking Lice

Sucking lice

Chewing lice

Sucking lice

Chewing Lice

What is the term used for lice infestation?

Pediculosis

What are the typical targets of pediculosis? What season is typical?

• Young animals

• Winter months (more hair coat) → less UV radiation, more crowding, less nutrition

What treatment can be used for lice in companion animals?

• Fipronil

• Imidacloprid

• Selamectin

• Isoxazoline (off label)

What treatment can be used for lice in livestock animals?

• Macrocyclic lactones

Is animal lice zoonotic?

No! Humans get lice from other humans, not their animals

How are humans treated for lice?

• OTC pyrethroid products

• Nit removal is cruical → comb them out

What type of lice is only on birds and cats, not found on other species?

Chewing lice

What type of “true bugs” fall under the Hemiptera category?

1. Reduviid bugs (kissing or assassin bugs)

2. Bedbugs

What species are known as bed bugs?

Cimex lectularius

What bug is an intermediate host for Trypanosoma cruzi?

Reduviid bugs (kissing/assassin)

What species do bed bugs target?

Rabbits, poultry and pigeons