Week 8 - Dermatology Flashcards
CS of skin dz in rabbits and rodents
Pruritus
Alopecia without pruritus
Scaling
Nodules
What can cause Pruritis in rabbits and rodents?
Parasites
Environment
◦Contact – bedding
Neoplasia
What Parasites cause pruritic in rabbits and rodents?
Rabbit: Psoroptes cuniculi (otitis externa!!)
Guinea Pig: Trixacarus caviae
Rats and Hamsters: Notoedres muris
Rabbits
◦ Sarcoptes scabiei
◦Leporacarus gibbus
Rats and mice
◦ Mites: Myobia musculi, Myocoptes musculinus, Radfordia ensifera, Liponyssus bacoti
◦Louse/Lice: Polyplax spinulosa, P serrata
Guinea Pigs
◦ Mites: Chirodiscoides caviae
◦Lice: Gliricola porcelli, Gyropus ovalis
What are the Louse/Lice parasites for rats and mice?
What what organisms are they vectors for/what do the lice carry?
Polyplax serrata (mice)
Polyplax spinulosa (rats)
Organisms:
◦ Mycoplasma (Haemobartonella) muris
◦ Encephalitozoon cuniculi
◦ Eperythrozoon coccoides
How do you TREAT mites or lice?
- Selamectin (Revolution®)
◦ 15 mg tube: rabbits < 2.3 kg
◦ 45 mg tube: rabbits > 2.3 kg
◦ 2 drops (60 mg/ml): mice
◦ Repeat in 2 weeks - Isoxazolines
◦ Fluralaner [Bravecto®] in rabbits 25mg/kg - Ivermectin (0.2 – 0.4 mg/kg) - q2 weeks, 2-3x, SQ or PO (Only SQ in guinea pigs: difficulty with GI absorption)
Do NOT use fipronil (Frontline®) on rabbits (or hedgehogs) !! – will cause illness
What can cause Alopecia w/out Pruritis?
Dermatophytes
Barbering / shedding
Demodicosis (most common in hamsters)
Endocrine dz
What are some examples of Dermatophytes?
Trichophyton mentagrophytes
Microsporum canis
Microsporum gypseum
How do you DIAGNOSE dermaotphytes?
fungal culture, trichogram, Wood’s
lamp, biopsy
How do you TREAT dermatophytes?
Lime sulfur 2% topical, 1:32 dilution (0.2 liters in 3.8 liters [1/2 cup in 1 gallon] of water), 2x/week for 1 month
0.2% enilconazole (Imaveral®: Janssen) weekly for 3 weeks
(may be toxic due to ingestion)
What should you avoid with chinchillas that have otitis?
Aminoglycosides (oto-neuro-toxicity)
What causes Demodicosis in Hamsters?
Demodex aurati
◦Long, follicular
Demodex criceti
◦Short, stratum corneum
How do you TREAT Demodicosis in hamsters?
Rx ivermectin (0.3 mg/kg) SQ q 7 to 10 days
or PO q24h x ?
Fluralaner 25mg/kg q 60 days x2
What common Endocrine issue happen in small mammals that affect dermatitis?
Hyperadrenocorticism (most common in
hamsters)
Cystic ovaries (most common in guinea pigs)
Diagnosis of both probably done most easily with ultrasound
What causes scaling and crusting in small mammals?
Cheyletiella sp mites
Venereal spirochetosis (rabbit syphilis): Treponema paraluiscuniculi
Guinea pig scaling of the pinnae:
hypovitaminosis C
What does Treponema paraluiscuniculi do clinically?
Crusts, erythema, edema, vesicles, ulcers,
proliferative lesions; face and perineum
Painful, not pruritic
Metritis, abortion and neonatal death
Rabbit syphilis is NOT zoonotic
How do you DIAGNOSE Treponema paraluiscuniculi in rabbits?
Microscopic visualization of T paraluiscuniculi
from scrapes on dark field, with special silver
stains on biopsy
Serology (OK to use human lab)
How do you TREAT Treponema paraluiscuniculi?
Penicillin G (40 - 80 000 IU/kg SC, q 1 week
x 3) resolution in 1-3 weeks.
Monitor for signs of antibiotic-associated
enterotoxaemia. Treat all exposed rabbits.
Chloramphenicol 55 mg/kg q 12 h per os
for 4 weeks
Azithromycin 30 mg/kg/day per os 1-2
times daily for 15 days
What causes scaling and crusting in small mammals?
Sebaceous adenitis
Cutaneous lymphoma (hamsters, rabbits,
guinea pigs and mice – usually with severe alopecia)
Thymoma
How do you TREAT scaling and crusting in small mammals?
◦Retinoids?
◦Antibiotics if secondary infections are
present
◦Cyclosporin A (5 mg/kg) and medium chain
triglycerides q24 h
Chelitis occurs in guinea pigs. What is chelitis? How do guinea pigs get chelitis?
dry and inflamed lips
Rough forage and/or acidic fruit
Hypovitaminosis C
Pox virus
What are the causes of Nodules in small mammals?
Infectious
◦ Pododermatitis
◦ Myxomatosis
◦ Abscesses
Neoplastic
◦ Trichofolliculoma
What is Pododermatitis?
Sore hocks
w/ Rabbits & guinea pigs (rats)
Infection, wire cage bottom, obesity, females
(rabbits), neutered (rabbits), hypovitaminosis
C (guinea pigs)
Treat underlying causes as well as infection
What is Myxomatosis?
caused by Myxoma (pox) virus
Arthropod transmission
Morbidity and mortality high in pet rabbits,
approaching 100%
Incubation 8 to 21 days.
CS of Myxomatosis
Edema of the head, ears, eyelids and genitalia, milky oculonasal discharge
Myxomas: firm, non-pruritic, erythematous
nodules
Lethargy, fever
What is Otitis Externa?
- Inflammation of the external ear canal epithelium +/- pinnal dermatitis
-pinnal derma can occur without otitis externa - Incidence up to 20 % in dogs
- Less common in cats at 6 -7%
What does the pinna do?
- Latin for fin or wing
- Plate of cartilage covered w/ epithelium
- Wide variability in conformation
- Mobile, channels vibrations
- Aids in directional hearing
- Vascular for heat exchange