Bovine Dermatology Flashcards
1
Q
What are the differentials for pruritic skin in cattle?
A
- Ectoparasites
- Photosensitization
- Fungal/bacterial infections
- Fusarium, Aspergillus, leptospirosis
- Pseudorabies
- Dermatophytosis
2
Q
What is Pediculosis? cause, appearance, etc
A
- Caused by Lice
- Biting - Mallophaga
- Damalinia bovis
- Sucking - anoplura
- Haematopinus eurysternus
- Linognathus vinus
- Biting - Mallophaga
- Distribution:
- Neck & tail to generalized
- Sucking lice also have facial distribution (muzzle/ears)
- Appearance:
- Excoriation -
- alopecia
- ulcers
- dryness/scale
- Excoriation -
- Sequelae:
- Hide damage
- weight loss
- anemia
- trichobezoar formation
- Dx: look for lice
- Tx:
- Suckers - Injectable avermectin
3
Q
What are the causes of Mange in cattle?
A
- Mites:
-
Choriptes bovis
- Leg mange, Foot and tail
- Surface, non-burowing
- have funnel feet
-
Psoroptes ovis
- Sheep scab mite
- Body mange
- Surface, non-burrowing
- Whisker legs
-
Sarcoptes scabiei
- Head mange
- surface, burrowing
- look “stumpy”
- Zoonotic
-
Demodex bovis & ghanesis
- Hair follicles & glands
- Most host-specific
- Non-pruritic (nodular)
-
Choriptes bovis
4
Q
Which causes of mange are most host specific?
A
Demodex >> chorioptes > sarcoptes > psoroptes
5
Q
Which causes of mange are the itchiest?
A
psoroptic & sarcoptic >> chorioptic >> Demodex
6
Q
how is mange diagnosed
A
- Skin scrape
- Dermatohistopathology - rarely picks up mites, shows characteristic lesions
7
Q
What is Chorioptic mange? distribution, appearance, etc
A
- Most common
- Surface, non-burrowing
- Risk factors:
- stalled animals in winter
- stocking density
- dairy
- Distribution:
- lower hind limbs
- perineum
- tail
- scrotum
- dead skin cells
- Appearance
- papule
- erythema
- scale
- crusts
- ulcers
- alopecia
- Sequelae
- weight loss
- Secondary skin infection
- decreased production
- DX: skin scrape
8
Q
What is Psoroptic mange?
A
- Debilitating pruritis
- Surface, non-burrowing
- Control is challenging
- Risk factors:
- Beef
- cold months
- Distribution
- Withers & tail to generalized
- Appearance:
- Crusted popular lesions
- lichenification
- Sequelae
- irritability
- weight loss
- secondary skin infection
- decreased production
- Death (>40% of body)
- Dx:
- skin scrape
- Histopath: Hyperplastic eosinophilic dermatitis
9
Q
What is Sarcoptic mange?
A
- Debilitating pruritis
- Surface, burrowing
- Distribution:
- face, pinna & neck to generalized +/- udder cleft
- Appearance:
- papule, scaling, crusting, ulceration
- alopecia, lichenification, and hyperkeratosis
- Sequelae:
- lymphadenopathy
- weight loss
- ill thrift
- pyoderma
- Dx: Deep skin scrape
10
Q
What is Demodectic mange
A
- Skin follicles, sebaceous and sweat glands
- Dame to neonate transmission
- Not pruritic
- Distribution:
- face
- shoulder
- brisket
- neck
- Appearance - nodular
- Sequelae - secondary pyoderma
11
Q
Does a negative skin scrape rule out mange?
A
NO
12
Q
How is mange treated/managed
A
- Topical acaricides 10-14 day intervals; 4-6x
- lime sulfur, doramethrin, deltamethrin, coumaphos, diazinon, malathion, toxaphene
- Injectable Ivermectin - limited efficacy
- Isolate infected animals
- Decontaminate environment bedding
- Notify officials
13
Q
What are the differentials for masses and bumps in cattle?
A
- Papilloma
- Squamous cell carcinoma
- Demodectic mange
- Dermtophitosis
- Pemphigus Foliaceus
- Cutaneous lymphoma
- Stephanofilariasis
- Pseudocowpox
- Insect bite hypersensitivity
14
Q
What is Papillomatosis
A
- Caused by Bovine papilloma virus - 2 (BPV-2)
- Affects skin, reproductive, urinary, and GI
- Distribution:
- head, neck, & withers
- teats
- penis
- Appearance:
- white/tan/gray protruding masses with dry/horny surface
- Sequelae:
- decreased hide quality
- undesirable at shows
- decreased hide quality
- Tx:
- self-limiting
- manual removal
- cryotherapy
15
Q
What is Squamous Cell Carcinoma?
A
- Malignant neoplasia of Keratinocytes
- “Cancer eye”
- Risk factors:
- UV light
- altitude
- non-pigmented skin
- tropical climate
- Distribution:
- Ocular - lateral limbus/lower lid/3rd eyelid/medial canthus
- Branding keratoma, back, pinna, limbs
- Premalignant appearance:
- white hyperplastic plaque/papilloma
- Malignant appearance:
- Proliferative or ulcerative
- invasive, irregular nodular, pink, erosive, foul odor, necrotic
- Dx:
- patient factors, gross appearance
- Histopathology
- Tx:
- surgical excision
- laser therapy
- Cryotherapy
16
Q
What is Dermatophilosis “rain scald”
A
- Agent: Dermatophilus congolensis
- G+ aerobe, non-acid-fast, branching, filamentous
- Infective stage: Zoospores
- Disease triad: Carrier + moisture + skin abrasions
- Risk factors for decreased resistance:
- prolonged rain / hosing
- immunosuppresion
- bugs
- UV light
- excessive grooming
- Risk factors for decreased resistance:
- Transmission: Chronic carriers, flies, ticks, fomites
- fall and winter months
- Distribution:
- dorsum, distal extremities, muzzle
- generalized
- Appearance:
- thick crusts with moist concave skin beneath
- +/- pain
- Sequelae:
- generalized disease
- superficial folliculitis
- Dx:
- Grossly
- Impression smear/cytology
- railroad track cocci
- Histopathology - layer cake
- parakeratoic stratum corneum
- dried serum
- degenerating neutrophils
- Tx:
- Keep dry
- Oxytetracycline LA-200 (20 mg/kg IM)
- PPG
- Remove crusts, wash w/ betadine
- Contagious!
