External Parasites Flashcards
Ctenocephalides spp adults look like?
3-4mm in lenth, flattened laterally with powerful strong legs for leaping & piercing sucking mouth parts
Ctenocephalides spp life cycle
Egg, Larvae, Pupae, Adult
Ctenocephalides spp eggs look like?
0.5mm in size, white in color & oval in shape
Ctenocephalides spp definitive host?
Dog
Ctenocephalides spp can cause?
Irritation, itching, loss of body condition, flea allergy dermatitis, flea anemia,
disease transmission - hemobartonellosis in cats, dipylidium, & plague
Ctenocephalides spp is diagnosed by?
seeing flea dirt/dander/poop in the fur coat
Plague is caused by?
A bacteria maintains in rodent populationsl
Is a flea an insect or arachnid?
Insect
True/False: Plague is One of the oldest diseases afffecting man
True
Plague is caused by?
• Caused by a bacteria maintained in rodent populations
• Causative Agent: Yersinia pestis
Plague syndrome
◦ Human:
‣ Fever
‣ Chills
‣ Myalgia
• Muscle Pain
‣ Sore Throat
‣ Headache
‣ Lymph Node Enlargement
• Bubonic
‣ Septecemia with development of pulmonary disease
◦ Animals:
‣ Rodents:
• Become ill and die
‣ Cats:
• Fever
• Dyspnea
◦ Difficulty breathing
• Nasal Discharge
• Swollen Lymph nodes
• Septicemia
• Incubation Period:
◦ 2-6 days
• Transmission:
◦ Bite of an infected rodent flea
◦ Handling tissues or fluids of infected animals
◦ Inhalation of airborne bacteria from cats or humans w/ pulmonary disease
Plague is diagnosed how?
Diagnosis:
◦ Culture of lymph nodes aspirate, blood, sputum, & CSF
Plague Treatment, Control & Prevention
◦ Antiobiotics - Penicillin since its a gram + organism
• Control/Prevention:
◦ Prevent human contact w/ wild rodents
◦ Uses insecticides/repellents when entering wildlife habitats
◦ Wear gloves when hunting or handling wildlife
◦ Keep dogs/cats from hunting wild rodents
◦ Vaccinate Individuals at risk
Otodectes cynotis
• Common Name:
◦ Ear Mite
• Adult:
◦ 0.4mm
◦ Dorsoventrally flattened
◦ Considered an Arachnid
‣ Has 8 legs
◦ Femals are larger than male mites
• Clinical Signs:
◦ External Otitis
◦ Sticky brown exudate from the ears
• Diagnosis:
◦ Examine debris from external ear canal
• Control:
◦ Clean Ears
◦ Apply miticide
• Lifecycle: 18-21 days
• Life stage: Egg - larval (6 legs) - Nymph (8 legs) - Adults (8 legs)
• Live entire lifecycle on the host
• Spread by direct contact
Cheyletiella spp
• Common Name:
◦ Fur Mites
◦ Walking Dandruff Mites
• Adults:
◦ 0.5mm in length
◦ Have a hook like palpi
• Defenitive Host:
◦ Most cats
◦ Dogs
◦ Can be infest humans which will cause itching but they do not thrive on humans
• Can cause Alopecia dermatitis
• Diagnosised by
◦ Skin Scraping
◦ Cellophane Tape Method
• Control:
◦ Apply Miticide
• Lifecycle:
◦ Spend their entire life cycle on the host
Sarcoptes scabiei
• Common Name:
◦ Mange Mite
• Adults:
◦ 0.3-0.5mm in
◦ Burrows tunnel into the skin
• Causes severe dermatitis
◦ Alopecia
◦ Skin Trauma
◦ Leathery skin texture - dry thickened skin
◦ Ulcers
• Diagnosis:
◦ Deep Skin Scraping
‣ These mites will burrow faster than you can scrape
• Control:
◦ Apply Miticide
◦ Itch Relief medication
◦ Clip Hair
◦ Bathe
• Head, Shoulders & Neck - they like locations where the animal cannot reach
• Definitive Host: Dogs
• Tranmission:
◦ Direct Contact
◦ Zoonotic
◦ Can be transmitted to humans through direct contact which would cause a rash for a short amount of time
Demodex spp
• Considered an: Arachnid
• Considered a Mite
• Common Name:
◦ Follicular Mange Mite
• Adult:
◦ 0.25mm long
◦ Cigar Shaped
◦ Found in hair follicles and sebaceous glands
• Normal Skin Flora until large numbers occur than that is when issues begin to appear
• Causes severe dermatitis
• Diagnosis:
◦ Deep Skin Scraping
• Control/Treatment:
◦ Treat w/ topical or systemic Miticide
◦ A lot of topical flea medications have miticide included to make treating/prevention easier
• Sharpei commonly have Demodex issues especially due to the multiple skin folds
• Often leads to secondary skin infections
• Demodex overgrowth can be caused due to physiologic stress and/or immunosuppressant disorder
◦ Important to address the underlying immunosuppressant disorder
Biting Lice:
• Family: Mallophaga
• Surface Dwellers
• Host specific - lives on the host for their entire lifcycle
• Spread by direct contact
◦ Including bedding
• Can live a short amount of time off the host which is why dealing with infected bedding can transmit the lice
• Considered Insects - 6 legs
Trichodectes canis
• Common Name:
◦ Dog Biting Louse
• Considered an insect
◦ Has 6 legs
• Adults:
◦ 2-4mm in length
• Egg:
◦ 0.5-1mm in length
• Can serve as an intermediate host for: Dipylidium caninum (The Flea Tapeworm)
• Can cause irritation, dermatitis, & rough hair coat
• Diagnosis:
◦ Examine hair coat for adults, nymphs, and eggs ———->
◦ This is where the saying “nit picking” comes from
• Control:
◦ Apply topical insecticide