Ag Animal Dermatology Flashcards
1
Q
3 Basic Dermatology Tests
A
- Scrape
- Culture
- Biopsy
2
Q
Which LA species gets pemphigus foliaceus?
A
- Goats
3
Q
Appearance of pemphigus foliaceus
A
Widespread, crusty, pruritic lesion
4
Q
Pathophys of pemphigus foliaceus
A
- Type II hypersensitivity
- Autoantibodies against keratinocytes (glycocalyx)
- Intracellular junctions breakdown, blisters and acantholysis
5
Q
Diagnosis of pemphigus foliaceus
A
- Biopsy
6
Q
Treatment for pemphigus foliaceus
A
Steroids (prednisolone, dexamethasone)
- Taper dose over time
7
Q
Prognosis for pemphigus foliaceus
A
Unknown
- Rare
8
Q
What is urticaria?
A
- Transient swelling of skin (wheals) or mucous membranes
- Localized dermal edema
- Transudate of fluid from capillaries and small vessels
9
Q
Non-immune causes of urticaria
A
- Injury, thermal, solar
10
Q
Immune causes of urticaria
A
- Reaction to allergens
- e.g. penicillin, sulfas, aspirin, ingested/inhaled allergens
- MILK at dry-off
11
Q
Diagnosis for urticaria
A
- Physical examination and history
- Wheals “pit” +/- pruritus
12
Q
Treatment of urticaria
A
- Avoid allergen
- Corticosteroids
- Antihistamines
13
Q
What is angioedema?
A
- Angioedema: same as urticaria but involves SQ and is diffuse
- Still involves transudation of fluid from capillaries and small vessels
14
Q
Side effect of corticosteroids in pregnant cattle
A
- Abortion
15
Q
What are causes of contact dermatitis?
A
- Irritant (most common) and allergic
16
Q
Clinical signs of contact dermatitis
A
- Variable severity (mild itchiness to severe lesions)
- Erythema, edema, vesicles, erosion, ulcers, crusting, pigment changes
17
Q
Causes of contact dermatitis
A
Usually iatrogenic
- Bedding, tack, etc.
18
Q
Diagnosis of contact dermtatitis
A
- History is important
19
Q
Treatment for contact dermatitis
A
- remove source
- Symptomatic care
20
Q
What is Dermatophilus congolensis?
A
- Gram +, branching, filamentous, aerobic bacteria
21
Q
Type of division of Dermatophilus congolensis
A
- Longitudinal and transverse division
22
Q
***Classic appearance of Dermatophilus congolensis
A
Railroad tracks (parallel rows)***
23
Q
Other names of dermatophilosis (maybe not so important)
A
- Mycotic dermatitis, rain scald, rain rot, lumpy wool, strawberry footrot
24
Q
Type of infection with dermatophilosis
A
- Superficial bacterial infection
25
Type of infection with dermatophytosis
- Ringworm
| - Superficial fungal infection of keratinized skin by Microsporum, Trichophyton, etc.
26
Who gets dermatophilosis?
-Most all domestic mammals
27
Signalment with dermatophilosis?
- No predilection for age, sex, or breed
28
Where is dermatophilosis?
- Worldwide
29
Seasonality of dermatophilosis
- high moisture regions/conditions
| - Fall/winter
30
Risk factors for dermatophilosis
- Humid weather, warm or cool
- Prolonged rainy seasons (e.g. the PNW)
- Frequent spraying or dipping
- Crowding
- +/- worse in some breeds (Merino, based on the wool type)
- High fly and tick populations
31
Which tick is associated with dermatophilois?
- Amblyomma variegatum
| - Immunosuppression
32
Where is Dermatophilus congolensis thought to live?
- Soil
33
Main source of Dermatophilus congolensis
Chronic carrier animals
34
Spreading of Dermatophilus congolensis
- Contact, fomites, biting and non-biting flies
35
Where does Dermatophilus congolensis persist? For how long?
- Crusts (in environment)
| - Up to 3.5 years
36
Pathophysiology of dermatophilosis
- Moisture --> defect in stratum corneum
- Zoospores germinate --> mycelia proliferate in the living layers of the epidermis
- Inflammatory response (neutrophils/PMNs
- Organisms eliminated via re-epithelialization
37
What causes the clinical signs of dermatophilus?
- The inflammatory response
38
Major issues with dermatophilosis in cows
- Decreased production (Moses lake case)
- Hide damage
- Epizootic death
39
Major issues with dermatophilosis in sheep
- Decreased fleece/skin value
- Interferes with shearing
- Lamb deaths
40
Is dermatophilosis zoonotic?
- Yes
41
Clinical signs of dermatophilosis in cattle - distribution
- Neck, top line, udder, limbs, ventrum
42
Clinical signs of dermatophilosis - appearance
- Thick, horn-like brown crusts (crusted paintbrush)
- "Paintbrush" (hair stick together in variable sized lesions)
- Moist grey/pink "granulation" tissue under crusts
- PAINFUL*****
- Not pruritic
43
Clinical signs of dermatophilosis in sheep - distribution
- Initial lesions on wool-less areas of face, legs, scrotum
| - Later wooled areas
44
Clinical signs of dermatophilosis in sheep - appearance and other issues
- pyramid-shaped, thick, pigmented crusts, discolored wool
- Heavy losses in lambs
- Secondary fly strike
- Fatal pneumonia
45
Clinical signs of dermatophilosis in goats - location
- Starts at ears, crusts can block ear canals
- External nares
- Dorsal midline, medial thighs
- Appearance same as cattle and sheep
46
Diagnosis of dermatophilosis
- Scrape/impression smear***
- Culture
- ELISA
- FA
47
Where to do the scrape/impression smear for dermatophilosis?
- Under crusts
| - He thinks that impression smears are more successful because you don't disrupt things as much
48
What to look for with a scrape/impression smear with dermatophilosis?
- Stain and railroad tracks (look at the pictures)
49
What is the most important aspect of dermatophilosis treatment?
- Remove predisposing factors (**SINGLE MOST IMPORTANT ASPECT OF RX**)
- Mitigate moisture**
- Reduce external parasites
- Optimize animal health (nutrition, stress, etc.)
50
Antibiotics for dermatophilosis - which ones? and when to administer?
- Can try in some animals
- Single, high dose (e.g. Penstrep, erythromycin, tetracycline)
- Treat prior to shearing (8 weeks so lesions healed by shearing)
51
Topical treatments for dermatophilosis?
- Chlorhexidine sprays
- Povidine iodine spray
- Iodine shampoo (imaging in 1000 head herd)
52
Withdrawals for topical treatments**
- Still need to be considered!
| - FARAD
53
Infectious agent of ovine proliferative dermatitis AKA strawberry footrot?
- Dermatophilus congolensis
54
Who gets ovine proliferative dermatitis? WHen do they get it?
- Lambs in summer
55
Morbidity in ovine proliferative dermatitis
- High morbidity
| - Primary losses are decreased weight gain
56
Where does D. congolensis come from with ovine proliferative dermatitis?
- Organism or scabs in soil
57
Where are the lesions for Strawberry footrot?
- Lower leg
| - Coronet to stifle
58
Clinical signs of strawberry footrot
- Small, coalescing scabs
- Scabs grow, wart like, hair loss
- Under scabs is a bloody, fleshy mass (strawberry-like)
- Not painful unless inter-digital, but he thinks it's painful
59
Treatment for strawberry footrot
- Same
| - Bath would be appropriate here - walk them through a footbath
60
Control of strawberry footrot
- Quarantine
| - Rest paddocks can help, but if they stay moist, the organism can live for years
61
Folliculitis
- Inflammation of hair follicles
| - AKA superficial pyoderma
62
Furunculosis
- Severe inflammation of follicles
- Ruptured follicles, "boils"
- Inflammation of adjacent dermis and SQ
63
Impetigo
- Infection causing subcorneal pustules, but not follicles
| - Pustules that aren't in the follicles
64
Who gets folliculitis/furunculosis/impetigo?
- Goats and cattle
65
Signs of folliculitis/furunculosis/impetigo? - distribution
- Udder, abdomen, perineum
66
Pain/pruritus in folliculitis/furunculosis/impetigo?
- Painful but not pruritic
67
Which bacterium are most common with folliculitis/furunculosis/impetigo? ?
- Coagulase positive Staph spp (especially S. aureus, S. pseudintermedius)
68
Diagnosis for folliculitis/furunculosis/impetigo?
Culture, biopsy
69
Treatment for folliculitis/furunculosis/impetigo?
Antibiotics (parenteral)
70
Appearance of folliculitis/furunculosis/impetigo?
- look at the pictures
71
What is hairy heel warts?
- Infectious contagious dermatitis of digital skin
| - Important cause of lameness
72
WHo gets hairy heel warts?
- Mostly dairy cattle
| - 1st and 2nd lactation, near parturition or freshening
73
Where do hairy heel warts usually manifest?
- Hind feet*** (80% of the time on the hind, plantar aspect)
74
Clinical signs of hairy heel warts
- Hind feet
- Raised, oval, demarcated, +/- filiform, red/brown/grey
- Tends to be in the interdigital area
- Foul odor!
- EXTREMELY painful
75
How contagious is hairy heel warts?
- Spreads rapidly
76
Risk factors for hairy heel warts
- Muddy, wet conditions
| - Introduction of new animals (carriers?)
77
What causes hairy heel warts?
- Associated with numerous obligate anaerobes
- Treponema spp. often found
- Mode of transmission unknown
78
Treatment for hairy heel warts
- Topical antibiotics such as tetracycline powder (extralabel drug use!; unless cow isn't lactating)
- Parenteral antibiotics (PPG, ampicillin, Ceftiofur?)
- Footbaths
- Improve hygiene (stalls, bedding, alleys, etc.)
- Reduce stocking rate
- Disinfect trimming equipment
79
What is the label for ceftiofur?
- BRD, metritis, "footrot" (F. necrophorum/B. melaniogenicus)
80
Etiology of papillomatosis
- Bovine papilloma virus
- At least 6 strains (BPV 1, 2)
- Single viral type associated with lesions
- >1 type can infect an animal
81
What determines the distribution and appearance of papillomatosis?
- Distribution and appearance related to strain
82
Papillomatosis in horses, goats, and sheep
- 1 strain recognized in each species thus far
| - BPV genome found in equine sarcoids
83
Are the different strains of BPV cross-protective?
- No
84
When are animals most susceptible to papillomatosis?
- Young most susceptible
85
Transmission of papillomatosis
- Contact
- Usually need abrasions (wire, thorns, etc.)
- Perianal via rectal exams, etc.
- Single viral type associated with lesions
86
Significance of papillomatosis
- Aesthetic
- Milking (teats)
- Breeding (perineum)
- Sale/transfer (health certificates)
87
Clinical signs of papillomatosis in cattle
- Teats: may obstruct milking
- Perianal: breeding difficulties
- Oral: eating difficulties
- Reticular: chronic bloat
- Penile: paraphimosis, phimosis, etc.
88
Treatment of penile warts
- Debride it and get rid of it
- They will clean it up, and put a a ring block
- Lidocaine and cut off the wart
- Have to avoid the dorsal nerve of the penis (would not be able to ejaculate)
- Ventral side is the urethra
They use a hyfercator, which is a thermal instrument that will burn it off
89
Clinical signs of papillomatosis in goats
- Common on udder, un-pigmented skin
90
Clinical signs of papillomatosis in sheep
- Rare
| - Face and legs
91
Papillomatosis and fomites**
- Be cognizant of transmission
- We can be the fomite
When you're vaccinating animals, have some hygiene between animals
92
Treatment for papillomatosis
- Often none
- Remove if a show animal
- Surgical removal (cryotherapy, hyphrication or heat)
- Many "farmer" treatments that are ineffective
- Vaccinate with commercial or autogenous vaccine
93
Who gets ringworm AKA dermatophytosis?
- All species (cattle and horses especially)
94
Most common species for ringworm and who gets it
- T. verucosum
| - bovine, ovine, caprine
95
Risk factors for ringworm
- Contact (group housing)
- Infected housing
- High humidity
- Young animals
- Carriers
- Fomites (grooming, interchangeable equipment, etc.)
96
Clinical signs of ringworm in cattle
- Thick, grey, rounded, coalescing crusts
- Moist (initial) --> dry
- Alopecia, dandruff
- Mostly head, neck, perineum (general distribution)
97
Clinical signs of ringworm in sheep
- Lesiosn on head, non-wooled areas
- Round hairless lesions with grey crust
- Regress spontaneously at 4-5 weeks but persists in a herd
98
Clinical signs of ringworm in goat
- Lesions, similar to sheep, but cover more body
99
Ringworm in people
- Superficial fungal infection
- Tinea corporis (any area, all ages)
- Tinea cruris (inguinal area)
- Tinea pedis ("athletes foot")
100
Diagnosis of ringworm
- Skin scraping
- Smear see spores, hyphae
- Culture on DTM and color change
- Some infected hairs fluoresce with Wood's lamp (both false positives and false negatives)
101
Treatment for ringworm
- Spontaneous recovery common
| - Individual vs group treatment
102
Individual treatment for ringworm
- Not common
- Brush off scabs
- Apply iodine solutions or lime sulfur rinse, bleach rinse, enilconazole rinse (Canada, Europe)
103
Treatment for groups of animals
- Captan (orchard fungicide)
- 1:300 sprayed twice 1-2 weeks apart
- 1:150 sprayed on facilities (barn, feeders, wood, etc.)
- Bleach solutions
- Captan you must be careful with withdrawals
- SYstemic sodium iodide or griseofulvin (but griseofulvin is expensive and a teratogen)
104
Control of ringworm
- Isolate and treat affected
- Disinfect housing
- Destroy bedding
- Vaccines may have success in Europe but not available in US
105
Host specificity of lice
- They are typically host specific
106
Biting lice vs sucking lice names
- Mallophaga (biting or chewing lice)
| - Anoplura (sucking lice)
107
Specific mallophaga lice in cattle
- Damalinia
108
Specific anoplura lice in cattle
- Haematopinus, linognathus
109
When do you see lice?
- Winter (typically)
110
What's the medical term for lice?
- Pediculosis
111
Diagnosis of pediculosis
- Pruritus
- See lice
- Dry, scaly skin, alopecia
- Phytobezoars weight loss
112
Treatment for pediculosis
- Topical (coumaphos, malathion, pyrethrins, lindane, methoxychlor)
- They try to avoid OPs in lactating animals so stick with pyrethrins
- Ivermectin
113
What's the medical term for mite infestation?
- Acariasis
114
Psoroptic mange - who gets?
- Cattle and goats
115
Appearance of psoroptic mange
- Crusty papular lesions, on head and neck
116
Diagnosis of psoroptic mange
- Pruritus, scrape, biopsy
117
Treatment of psoroptic mange
- Ivermectin
| - Reportable in cattle in US
118
Chorioptic mange distirubtion
- Alopecia, crusts, scales
| - - Hind limbs, tail, perineum
119
Dx of chorioptic mange
Pruritus, scrape, biopsy
120
Tx of chorioptic mange
- Ivermectin
121
Reportability of mites
- Report all of them basically if you see one
122
Sarcoptic mange - what's unique?
- Zoonotic
| - Mites can live off the host***
123
Appearance of sarcoptic mange
- Scaling, crusts, alopecia, self trauma
| - Head and neck (or generalized)
124
Dx of sarcoptic
- Pruritus, scrape, biopsy
125
Tx of sarcoptic mange
- Ivermectin
126
Demodectic mange - who gets?
- Goats and cattle
127
Demodectic mange - where are the lesions?
- Nodular lesions (zits) on head and neck
128
Dx of demodectic mange
- Pruritus
- Scrape
- Biopsy
129
Treatment of demodectic mange
- Amitraz, ivermectin (tought to treat, may regress spontaneously)
130
Stephanofilariasis - what is it?
- Filarial dermatitis via female horn fly
131
Where does stephanofilariasis end up?
- Ventral midline
132
Appearance of stephanofilariasis?
- Alopecia, crusting, nodules, ulcers
- Ventral midlien
- Mild pruritus
133
Treatment of stephanofilariasis
- Typically not
| - Ivermectin? Not approved
134
Three types of photosensitization
1. Primary
2. Secondary
3. Congenital
135
Primary photosensitization
- Criculating photodynamic agents - activated by UV light
- Emits energy and damages tissues
- This is something they ingest
- e.g. St. John's wort
136
Secondary photosensitization
- Toxins, bacteria, viruses, neoplasia --> damages liver --> phylloerythrin (degraded chlorophyll) not conjugated --> acts as a photodynamic agent
- Carbon tetrachloride is the poster child for secondary
137
Which photosensitization carries a better prognosis: primary or secondary?
- Primary
138
Congenital photosensitization
- Aberrant pigment synthesis
- Porphyria
- Rare
139
Which plants cause primary photosensitization?
- St. John's wort (hypericum perforatum)****
- Possible Lady's thumb
- Buckwheat (Fagopyrum)
- Wild carrot
- Perennial rye grass
- Burr trefoil
140
Drugs that cause primary photosensitization
- Sulfonamides, tetracyclines, phenothiazine, thiazides, etc.
141
Where do you often see lesions for primary hypersensitization?
- White areas
142
Treatment of photosensitization
- Eliminate source of photo agent
- Avoid sunlight
- Antibiotics (secondary pyoderma)
- Wound management/debridement
- SYmptomatic for liver disease
143
Photosensitization diagnosis
- Diagnostic is if you take them out in the sunlight for a few minutes and they get very frantic
- Get them back in the shade, and they calm down
144
Prognosis for primary, secondary, and congenital photosensitization (i.e. porphyria)
1. Primary = favorable
2. Secondary (hepatogenous) = poor
3. Porphyria = poor
145
What's the biggest problem with lice?**
- Itching and irritation
- The animals are constantly grooming themselves and licking themselves, so you also end up with other issues (like phytobezoars, etc.)
146
Contagious ecthyma common name
Orf
147
Contagious ecthyma - what's one of the big concerns for this
- Zoonotic
| - You do need an abrasion, but it's pretty bad
148
Contagious ecthyma - what type of virus? What is the significance?
- Poxvirus
| - Can last for a long time in the environment
149
Who gets orf?
- Sheep and goats mostly
| - Also camelids, wild sheep and goats, musk ox, etc.
150
Morbidity and mortality of orf in adults vs lambs
High morbidity, low mortality in adults
- Mortality can be high in lambs (they can starve if the lesion is around the mouth)
151
Risk factors for orf
- Dry seasons
- Access to wild ruminants
- Surgical procedures (any sort of procedure)
- FPT (malignant form)
152
Transmission of contagious ecthyma
- Contact (animals, inanimate objects)
- Stable in the environment (it's a poxvirus!!!)
- Lives in crusts up to 12 years
- Farms that have it will have it for awhile
153
Significance of contagious ecthyma
- Can't nurse
- Fly strike
- secondary bacterial infections
154
Clinical signs of contagious ecthyma (typical)
- Ulcers and scabs at mucocutaneous junction!
- eyelids, lips, nostril, coronet, gingiva, teats, etc
- EXTREMELY PAINFUL!***
- Progressive
155
Malignant form signs of contagious ecthyma
- Spreads to trachea, lungs, esophagus, etc.
| - Happens with FPT
156
Recovery from contagious ecthyma
- Spontaneous recovery in 2-3 weeks
| - Unless there's a secondary issue going on
157
Progression of contagious ecthyma***
- Papular --> vesicular --> pustular --> proliferative, coalescing, scabbed lesion
158
Signs of contagious ecthyma in lambs
- Reluctance to nurse, walk, be nursed
159
Diagnosis of contagious ecthyma
- History and clinical signs (progressive, painful, mucocutaneous lesion that has a high morbidity)
- SErology
- Viral ID (EM, culture)
160
Differentials for orf
- Sheep pox and goat pox
- Blue tongue
- Ulcerative dermatosis
161
How to differentiate Blue tongue from orf**
- Blue tongue mostly around the mouth
| - **Blue tongue is in the fall; orf is in the spring
162
How to differentiate Sheep and goat pox from Orf?
- Sheep and goat pox are more virulent
- Also have pyrexia
- Also have rhinitis
163
How to differentiate ulcerative dermatosis from Orf?
- Leg and lip ulcer
164
Treatment for Orf******
- DO NOT DEBRIDE*** (Delays healing)
- Support (tube feed young)
- Soft palatable feeds
- Prevent secondary bacterial infections
- Cryosurgery (not as much)
- Intralesional steroids, chemotherapeutics (not universal)
165
Is Orf reportable?
- Yes in WA (within 24 hours)
166
Control of Orf
- Isolate early cases
| - Vaccination
167
Vaccination of Orf
- Ineffective if incidence already high
- Local, autogenous most effective (in the axilla)
- Once you start, you have to continue from then on out
- Annual of 6-8 weeks lambs (pre-lambing ewe vaccination ineffective)
168
Fly strike - what's the problem?
- Serious loss to sheep in terms of life and wool
169
Which species of fly cause fly strike?
- Green bottle fly
- Black blow fly
- 2° screw worm (Cochliomyia macellaria)
170
Pathophys of Fly Strike
- Female flies attracted to decaying matter (wounds, feces, etc.)
- Screwworm larvae can feed on live tissue!
- Larvae feed on necrotic tissue
171
Treatment of fly strike
- Management ("crutching")
- Shearing
- Wound management
172
Crutching
Shearing the perineal area and back of the udder so that it's clean when they lamb
173
Which genus is the screwworms?
- Cochliomyia hominivorax
174
Appearance of Cochliomyia?
- 3x the size of the house fly (green/blue)
| - Previously in Southern USA and Mexico (eradicated)
175
What's the main problem with screwworms?
- Larvae are aggressive, feed on living tissue
| - Cavernous lesions, liquefaction, necrosis, death!
176
Treatment with screwworms (historical vs contemporary)
Historic: OPs
Contemporary: Fipronil and doramectin
177
Florida Keys Outbreak
- Key deer
- Irradiated pupae
- Male sterile but active
178
Fipronil and yellow jackets
If you have yellow jacket problems
Put fipronil in the spam and the yellow jackets take it back to the next
Day one you'll lose 90%
Day 3 is 98%
179
What's the main problem with hypoderma?
- Loss to cattle industry (millions of $)
| - Loss of hide (holes in the hide)
180
Two species of hypoderma?
- H. bovis
| - H. lineatum
181
Where is H. bovis?
- N and S USA
182
Where is H. lineatum
- Prefers warmer climates
183
Appearance of cows being attacked by hypoderma?
- They're literally running away
184
When are hypoderma active and laying eggs?
- Spring and summer
185
Where do the hypoderma lay their eggs?
- Rear limbs (Heel flies)
186
Where do hypoderma lineatum and hypoderma bovis over-winter?
- H. lineatum (esophagus)
| - H. bovis (spinal canal) - RULE out for an acutely down animal
187
At what time of the year do L1 larvae hibernate in the animal? When do they migrate toward the dorsum
- L1 larvae stay through fall/winter
| - Late winter - migrate toward dorsum
188
What drugs for treatment of Hypoderma?
- OPs
| - Macrocyclic lactones (doramectin, ivermectin, moxidectin)
189
When should you NOT treat Hypoderma?
- Between Oct 1st and March 1st
190
Crowpeck
- Birds often land on the backs of animals
191
Miscellaneous
look at the images
192
Eliophora
- Crusting lesions
| - Filarial worm of white tailed deer that can cause crusting lesions in the wrong host
193
Frostbite - where in Cattle?
- often on the feet
- Can be ears, tails, etc.
- Calves when they lay down will have one back leg exposed, which is why one back leg is usually frostbitten
194
Treatment for frostbite
- Aloe vera (thromboxane inhibitor)
| - NSAID
195
Treatment for wounds
- Debridement
- Systemic antibiotics
- Kept it clean
- Dress with sugar and betadine mixture
