Equine Med- Derm 2

wilsbach's version from 2016-04-13 14:11

Viral+bact skin dzs

Question Answer
what 2 viruses can cause skin dz in the horse? Papillomavirus, EHV-3
what is this? Papillomatosis (warts)
what is going on here? How worried are you about this particular horse at this particular time? EHV-3. this is just residual. White plaques around vulva-- has been infected with EHV3- not infective anymore, but this wont go away
how are papillomas transmitted?might be congenital. equine papillomavirus (‘everywhere’) via contact. (not zoonotic)
is there an age predilection for papillomas? mainly in younger horses (1 to 4-years old)
what does papilloma look like/ where is it usually on the body? multiple wart like lesions, mainly head, incidentally elsewhere
how do you dx papilloma?diagnosis on clinical presentation (it looks like a wart)
how do you tx papilloma?they usually just go away by themselves- treatment isnt warranted (unless they are super bad and preventing nursing or sthing, you can try to sx remove)-- cryosurgery, surgery, creams
what is the name for rain scald?Dermatophilosis\
most common bact skin dz?Dermatophilosis (rain scald)
5 types of bact skin dzs(1) dermatophilosis (2) Folliculitis / furunculosis (3) Abscesses (4) Bacterial dermatitis / Pastern dermatitis (5) Cellulitis
who is particularly prone to Bacterial dermatitis / Pastern dermatitis?white legged/hooved horses
how does dermatophilosis present?(rain scald) presents as painful pink lesions, can have awful crusting and pruritus. <--this is a particuarly severe case.
what is the bacteria which causes dermatophilosis?(rain rot) caused by Dermatophilus congolensis
how does poor management lead to problems with rain scald?moisture, also high temperatures--> maceration of skin--> bacteria can penetrate and colonize. (might see on dorsum a lot bc rain would hit their back a lot)
Dermatophilus congolensis-- what kinda bact is this?(causes rain rot) its a is a gram+ branching actinomyces (Actinomyces colonies form fungus-like branched networks of hyphae)
how do you dx dermatophilosis?Bacterial culture with dry swab or swab in culture medium.
how do you treat dermatophilosis? improvement of the management!!! removing crusts (painful!) clip as far as possible (it's anaerobic, want good exposure), repeated bathing and drying. What about abx??? Strong considerations: systemic abx have poor skin penetration and can really mess with a horse's GI. They are also expensive. You can consider oral TMPS (AS LONG AS THE HORSE IS EATING WELL-- if they are painful and its causing them not to eat, the oral TMPS can cause GI disruption/diarrhea). So she's really not a fan-- in class she said wash with neodyne and chlorhex- an topical abx not necessary- if can elim crusts and wash horse, will elim itself
how contagious is dermatophilosis? should you be isolating them? disease is not highly contagious but it is sensible to isolate affected horses
why is she mentioning MRSA? (multidrug resistant staph aureus)BECAUSE YOU AS A VET ARE A CARRIER-- and it can jack a horse up. If there is a wound thats not healing, consider this.
common signs of an abscess? pain, heat, swelling, inflammation
3 types of bacteria which are major causers of abscesses?Streptococcus equi (strangles- looooves making abscesses), Corynebacterium pseudotuberculosis (pigeon fever- big abscesses in their pecs), Clostridium spp. (im injections)
which bact is the main asshole when it comes to IM inj abscesses?clostridium
do you need to have an abscess opened to let it heal?depends on the infection. some its important we open area. like with clostridium need to open bc is anaerobic. with clostridium see signs of emphysema as well.
does heat packing an abscess help ripen it to open it?Eh, no actual evidence this works, but its great to keep the owner busy.
Bacterial dermatitis, pastern dermatitis--> who are the two main bact that cause this?Staphylococcus spp, Dermatophylus congolensis (rain rot)
what is the major problem in pastern dermatitis, aside from the fact its a nasty leg?it is PAINFUL, which means its bad news for performing horses who will show dec performance.
what are some predisposing factors/initial insults for pastern dermatitis?(remember, staph sp or dermatophilus congolensis) Photosensitization, Long hair (feathers in draft horses), Cellulitis +- lymphangitis
what management is important in helping with pastern dermatitis?keep it clean and dry! (common prob in rainy season) if photosensitization might be a problem, keep indoors/ use sunscreen. Clipping might help keep it dry and clean, but some owners will NOT want to do this (think feathered fresians)
some diff ways to approaching pastern(bacterial) dermatitis/ deep foliculitis?topically (creams with steroids, abx...), systemically (abxs, more on other card), or both...
what are some systemic abxs you can consider for tx pastern dermatitis?procaine penicillin (IM), sodium/potassium penicillin G (IV/IM), trimethoprim sulfonamides (PO(often prescribes bc owner can give PO)/IV) ceftiofur-natrium (IM)------ all other antibiotics only after sensitivity testing!
uhhhh dude you should not put a pressure bandage too tight around a horse's tail. Esp too tight or wet bandage.History taking is important on this one. Also if you see swelling in the area after they left the bandage on-- dont say its gonna be ok. it's prolly gonna get a lot worse.

Fungal skin dzs, environmental

Question Answer
Dermatophytosis (DONT CONFUSE WITH DERMATOPHILOSIS, DIPSHIT)--> what is very important that you need to know as a vet about this?ZOONOTIC (its ringworm!)
why does dermatophytosis cause alopecia?(ringworm!) invade hair shaft --> weaken hair
what are the two species of ringworm which affect horses?Trichophyton-species (Trichophyton equi), Microsporum-species
Sooo what is this? dat rangwurmmmm (dermatophytosis)
CSs of dermatophytosis? Where does it tend to be on the horse?Common at tack area, no pruritus. See circles of alopecia.
dx ringworm? microscopy & fungal culture-- remember to sample AT PERIPHERY!! Clean area with alcohol first to prevent overgrowth of commensal bacterial in the area.
tx ringworm?self limiting / antifungal TX
prevention of dermatophytosis?vaccination Insol Dermaphyton®
what is a pressure sore called?decubitus
urine and diarrhea can cause what skin prob?Contact dermatitis
saddle eczema or saddle/bridle sores are common names for what problem?contact dermatitis
explain primary vs secondary photosensitizationPRIMARY is when the horse ingests a plant which photodynamic pigment which then causes the photosensitization. SECONDARY is when there is liver problems in the horse so it cannot process any of the photodynamic pigments in regular foods and these accumulate and cause phototoxicity
what are the 6 different types of sarcoids?(1) occult (2) verrucose (word means "covered with warty elevations") (3) fibroblastic (4) nodular (5) mixed (6) malignant
NAME THAT SARCOID!!! fibroblastic (looks like they got blasted all right)
NAME THAT SARCOID!!! malignant
NAME THAT SARCOID!!! verrucose (remember this means warty like)
what are the 4 clinical forms of melanoma?(1) melanocytic naevus (FOALS) (2) Melanocytoma (<5yr) (3) dermal melanoma (>10yr) (4) malignant melanoma (any color)
which type of melanoma do foals get?Melanocytic naevus. (kinda mole-like lesion)
which type of melanoma do <5yr old horses get?melanocytoma
which type of melanoma do horses >10yr get?dermal melanoma
which type of melanoma can basically any color horse get?malignant melanoma
what are some risk factors for SCC?poor skin pigmentation and chronic exposure to UV light (possibly- there was a ? at the end of this)
how does SCC behave?malig- often metastasize (lungs) in older horses
2 predilection locations for SCC?genitalia, eye/head
what is the most common cause of SEVERE pruritus in horses?insect hypersensitivity
akas for insect hypersensitivty?sweet itch, summer itch, queensland itch
which breeds are more prone to insect hypersensitivity?greater in ponies, shire, and friesians (she also mentioned icelandic horses have genetic predilection)
is there seasonality to insect hypersensitivity?yes- when the culicoides midges are around (so summer)
what type of dx is alopecia areata?immune mediated!!
explain the pathogenesis of alopecia areataT-lymphocytes attack own hair matrix--> local or systemic hair loss.
how does alopecia areata present?local or systemic hair loss with NO PAIN, NO PRURITUS.
how do you tx alopecia areata?NO TX- hair may return within mo-yrs
in general for skin stuff, tx often involves what type of drugs?corticosteroids