Fleas and Mites

small, wingless, bilaterally flattened insects

What are the general characteristics of fleas?

nope!

Are fleas host specific?

males and females

When it comes to fleas, who feeds on blood?

Adults will feed, copulate, and lay eggs on host

the rest of the life cycle is in the environment

What part of the fleas life cycle is spent on the host vs. in the evironment?

Ctenocephalides felis

Pulex irritans

Xenopsylla cheopis

Echid

What are the fleas of veterinary importance?

they jump on host for feeding, have several blood meals a day, mate on host, lay eggs on host, and the eggs will eventually fall into environment. While in the environment, they undergo 3 larval stages

Describe the life cycle of the cat flea

feeds on organic material

What does Ctenocephalides felis feed on?

Dipylidium caninum

Acanthocheilonema reconditum

What pathogens can be transmitted by cat and dog fleas?

Nuisance (stress)

Flea allergy dermatitis

Anemia

What are the direct effects of a cat flea infestation?

Clinical signs of pruritis and alopecia.

Combing to detect presence of fleas and/or flea dirt

How do you diagnose flea infestations in dogs and cats?

insecticide drugs - clean the environmnet: sanitation/pest control

How do we control and prevent cat fleas?

Nuisance

Flea Allergy Dermatitis

Anemia

What are three direct impacts of Ctenocephalides?

IH for Dipylidum caninum

Acanthocheilonema reconditum

Bartonella henselae (cat scratch fever) and other rickettsiae of importance

What are three indirect impacts of Ctenophalides?

They are the main vectors of the Plague - Yersinia pestis

What is the medical and veterinary importance of Pulex and Xenopsylla?

Xenopsylla: has mesopleural rod on the 2nd thoracic segment.

Pulex: No mesopleural rod on the 2nd thoracic segment

Both do not have combs like Ctenocephalides

What characteristics distinguish between Pulex and Xenopsylla and Ctenocephalides?

the domestic chicken

What is the host preference of Echidnophaga?

severe infestations may cause anemia, death. They cause ulcerations at their attachment sites.

What is the veterinary importance of Echidnophaga?

they are microscopic, very small, in size

mouthparts are attached anteriorly

Have no basis capitulum or scutum (like ticks have)

What are some key characteristic of parasitic mites?

incomplete

Mites go through what kind of metamorphisis?

Sarcoptes

Notodres

Demodex

List the burrowing mange mites

Psoroptes

Chorioptes

Otodectes

List the non-burrowing mange mites

Sarcoptic mange and Notoedric mange respectively

What disease(s) are caused by Sarcoptes and Notoedres mites?

Severe pruritus

hyperkeratosis

alopecia

What are the main clinical signs of Sarcoptes in dogs?

younger

Is sarcoptes more common in younger or older dogs?

transmitted via direct contact/fomite

female mites burrow under skin and lay eggs

larvae mature in skin, destroying th e skin and causing Severe pruritus, hyperkeratosis, alopecia

Describe the pathogenesis of Sarcoptes in dogs

humans, horses, cattle, ferrets, pigs, wildlife

What are other hosts of Sarcoptes, besides dogs?

o Crusty lesions on head, ears

o Pruritus, hyperkeratosis, alopecia

o Self-trauma

What are the main clinical signs of Notoedres in cats?

o History, Clinical Signs (location of lesions)

o Superficial skin scrapings

o Visualization of mites and eggs: Mites are round, microscopic - use light microscope with mineral oil

o Clinical diagnoses: treatment, remission of lesions (since not finding mites does not rule out infection)

How do we diagnose infestations caused by Sarcoptes and Notoedres mites?

Chorioptic mange

What disease is caused by Chorioptes?

o itchy legs, foot mange, greasy heel

o Foot and tail mange in cattle, sheep, and goat

What are the main clinical signs for Chorioptes?

Occurs superficially in keratin layer, mites feed on the epidermal tissues

Describe the the pathogenesis of Chorioptes. What is the site of infection?

Crusty ears, pruritis, otitis

What are the main clinical signs of Psoroptes?

mites feed on skin and lymph exudated, resulting in crusty scabs

Describe the pathogenesis of Psoroptes

Pruritus

Otitis externa

Cerumen resembles coffee grounds

What are the main clinical signs of Otodectes?

non,-burrowing mite of the ear canal causing pruritus and otitis externa (not much more on pathogenesis in lecture)

Describe the pathogenesis of Otodectes

rabbits and sheep

What are the common domestic hosts for Psoroptes?

horses, cattle, sheep and goat

What are the common domestic hosts for Chorioptes?

dogs, cats, and ferrets

What are the common domestic hosts for Otodectes?

consider host species

history, clinical signs

view mites from ear swab and collection of crusts under dissecting microscope

What information or diagnostic tools do we utilize to diagnose Psoroptes?

consider host species

history, clinical signs

superficial skin scraping, crusts

view superficial, larger mites under dissecting microscope

What information or diagnostic tools do we utilize to diagnose Chorioptes?

history, clinical signs: cerumen resembling "coffee grounds"

ear swab cytology

visualization of mites: small, not microscopic in size. use light or dissecting microscope, otoscopy, videoscopy

What information or diagnostic tools do we utilize to diagnose Otodectes?

alopecia, erythema, non-pruritic

What are the main clinical signs of demodicosis in dogs?

through direct contact from mother to neonate

What is the mode of transmission for demodicosis in dogs?

No - only spread via direct contact from mother to neonate

Is demodicosis contagious?

Demodex lives in the hair follicles and sebaceous glands. They normally do not cause any problems unless there is an overpopulation.

They will cause folliculitis, destroy the follicles (alopecia)

Usually only occurs in young animals (localized) or in immunosuppressed dogs (general), which has a genetic predisposition

Describe the manifestations/pathogenesis of demodicosis in dogs. What explains alopecia as a clinical sign? What makes one dog prone to it over another?

localized: young animals, lesions are small & well-defined, usually on face/paws

general: may affect young or old dogs (related to immunosuppression), lesions are generalized, which predisposes skin to bacterial infections.

What is the difference in presentation of localized vs. general demodex?

history, clinical signs

deep skin scrapings (mites are in hair follicle)

visualization of characteristic mites and eggs

mites are microscopic - must be viewed with light microscope

Clinical diagnosis - treatment with remission of lesions

What information or diagnostic tools do we utilize to diagnose infestations caused by Demodex?

nope!

If no demodex mites are found from a deep skin scraping - does this rule it out as a possibility?

o Sarcoptic: extremely contagious, pruritic

o Demodectic: not contagious, naturally occurring, non-pruritic

What are the main differences in transmission and signs of sarcoptic and demodectic mange in dogs?

Dogs, cats, rabbits

What species may be hosts for Cheyletiella?

Walking Dandruff

What is the common name(s) of the infestation of Cheyletiella?

Exfoliative alopecia, scaling, pruritus

What are the clinical signs of walking dandruff?

Examine for small, moving mites on skin surface: No scraping needed, but you can view on dissecting microscope

How do we diagnose walking dandruff?

pruritus and dermatitis

appearance or orange granular material (mites) on animal

visualization of these signs

What are the clinical signs of chiggers? How do we diagnose chiggers?

only the larval stage

What stage of chiggers is parasitic?

Ornithonyssus:

o Always on host

o Cause anemia, exsanguination

Dermanyssus:

o Nest-dwelling, only go onto host at night to feed

o Can cause anemia, skin irritation

What are the biological differences of Ornithonyssus and Dermanyssus in poultry?

o found at base of feathers, particularly on vent - Can cause anemia, exsanguination, and death

What are the clinical signs of Ornithonyssus in poultry?

Can cause anemia, skin irritation, decreased productivity

What are the clinical signs of Dermanyssus in poultry?