Skin + Endocrine Flashcards
skin sampling techniques and there uses
Coat Brushing: flea faeces, cheyletiella
Skin Scrape: mites
Hair Pluck: mites, eggs, dermatophytes, hair structure
Cytology (tape): cell types, pathogens, neoplasia
clinical indications of a skin biopsy
suspect neoplasia, unusual/severe signs, persistent ulceration, no response to treatment,
skin biopsy selection and collection techniques
careful selection of lesion: (early lesion and undamaged)
carful removal: do not crush or surgically prepare site
sample centre of lesion not edge
Wheal
discrete focus of dermal oedema, if large called angioedema
5 patterns of inflammation in skin disease
Perivascular, Nodular, interface, Diffuse/interface, Panniculitis
Scale
Hyperkeratosis: increase in stratum corneum
Comedo
Dilated hair follicle plugged with keratinous and sebaceous debris
Papule
solid palpable skin elevation <1cm
Plaque: extension of papules
2 types of pustule
Intraepidermal Pustular Dermitis
Neutrophilic: pyoderma or sterile disease (Pemphigus)
Eosinophilic: ectoparasite or hypersensitivity
difference between ulcer and erosion
Ulcer is complete loss of epidermis, erosion is only partial loss
Folliculitis and Furunculosis
Folliculitis: inflammation of hair follicle
Furunculosis: inflammation and destruction of hair follicle
Crust
Accumulation of dried exudate on skin
Common causes of pruritic skin disease
Parasite: Cheyletiella, Sarcoptes, Trombicula
Microbial Overgrowth/Infection: Staph, Malassezia
Hypersensitivity: FBD, Atopic dermatitis, Food hypersensitisation
main mites effecting the Dog, Cat and Horse
Demodex(D,C,H), Sarcpoties(D), Chelyletiella(D,C), Trombicula(D,C,H)
July- September, sever pruritic
Trombicula, treatment:Fipronil
cause of walking dandruff on the dorsal trunk
Cheyletiella
Treatment : Dog (Amitraz) Cat (Fipronil)
Treatment of FBH
Flea Bite Hypersensitivity: Flea control, Antipruritic/anti-inflammatory (glucocorticoids)
Urticaria
Multiple wheals , HIVES
Atopic Dermatitis
Break in the skin barrier or exposure to allergen causing a secondary infection with Staphylococcus Pseudintermedius or Malassiezia Pachydermatis, causing erythema.
DDX for steroid resistant pruritic crusting lesions
Scabies, Pemphigus, Dermatophytosis, Cutaneous Lymphoma
Treatment for Sarcoptic mange
Amitraz, total body clip, prednisolone,
erosions, ulcers and hyperkeratosis on the paws, secondary pododermatitis also on muzzle and inguinal region
Superficial necrolytic dermatitis, Pemphigus foliaceous,
Red white and blue appearance on histology
Superficial necrolytic dermatitis: Poor prognosis
what is superficial necrolytic dermatitis often seen with
Hepatic disease(cirrhosis, vacuolar degeneration) or Pancreatic glucagonoma
3 types of pyoderma
Surface: Hot spots, intertrigo, Bacterial overgrowth
Superficial: Impetigo, follicultits
Deep: Furunculosis, Acne, PAIN
What is a Hot Spot and treatment
Pyotraumatic dermatitis, bacterial overgrowth with often underlying problem (otitis, anal sac, FBH)
treatment: topical antibacterial, systemic or topical anti-inflammatory, treat underlying cause
what is always indicated in deep pyoderma
Bacterial culture and sensitivity
Glucocorticoids are contraindicated!
what causes over 90% of canine superficial pyoderma
staphylococci pseudintermedius
also 60-80% deep pyoderma
how long should treatment for pyoderma last
Deep 4-6 weeks or 2 weeks beyond CS
Superficial: 3 weeks or 1 week beyond CS
Dermatophilosis
Mud Fever/Lumpy wool: bacterial infection spread by fleas and ticks
causes of alopecia
Inflammatory( parasite, bacterial, fungal or sterile)
Non-inflammatory (coat colour- linked, Endocrine)
Traumatic
Panniculitis
inflammation of subcutaneous fat and connective tissue
causes of nodules
granulomatous inflammation( sterile or infectious) Neoplasia, depositional diseases, trauma (haematoma)
main causes for hyperpigmentation
Chronic allergic skin disease or endocrine disease
most common autoimmune disaese
Pemphigus foliaceus
Phemphigus Foliaceus main CS and Cause
Pustules and crust on face/neck/feet and whole body
intrepidermal pustular disease caused by an autoimmune attack on the desmosomes causing loss of intracellular connections
main vesicular diseases of farm animals
Foot and Mouth !!! swine vesicular disease
small ulcers on cats face/limbs causing widespread lesions 7-10 days later, vesicles/crusting/ulcers
Hunting cat in Autumn
Feline poxvirus infection (cowpox)
should resolve in 4-6 weeks in a healthy cat
treatment of autoimmune skin disease
topical steroids, Vitamin E, tetracycline, low dose steroid
2 main ectoparasites of horses and where they effect
Chorioptes: Limbs and Tail
Psoroptes: Head and Ears
worm causing tail rubbing in a horse
Pinworm
cause of papules and crusting on the dorsal or ventral mid line of a horse
Insect bite hypersensitivity (sweet itch)
most likely Culicoides
How is sweet itch treated
Management: Avoid (stable 4pm-8am, rug/hoods, windy)
Repel (synthetic pyrethroids), Anti-inflammatoys
cause of aural plaques on a horse
Papillomavirus
Therapy: observation
Dermatophilosis
Bacterial skin infection (mud fever, greasy heal)
causes paint brush effect, alopecia on dorsum and limbs
cause of hirsutism, laminitis, PU/PD and hyperhydrosis
PPID (Pituitary Pars Intermedia dysfunction)
Therapy; PERGOLIDE
causes of photosentisation in horses
St John’s Wort or liver disease
multiple nodular lesions around the saddle area or neck in spring/summer
collagenolytic granuloma, leave alone or surgical excision and give systemic glucocorticoids
Most common equine skin neoplasm
Sarcoids: entire biopsy followed by topical chemotherapy , imiquimod cream
Are Guinea Pig louse zoonotic
No
cause of scaling and crusting on a rabbit
Cheyletiellosis: Ivermectin
main lice affecting cattle
Biting: Bovicola Bovis
Sucking: haematopinus eurysterus
Treatment for lice
Best to treat in Autumn: ML pour-on or injection
cause of head and tail mange in cattle
sarcopties ( ML pour on)
cause of sheep scab
Psorotes Ovis: pustules and matted fleece
treatment with plunge dip or ML pour-on
only mite and louse of Pigs
Mite: Sarcopties
Louse: Haematopinus Suis
cause of lumpy wool
Dermatophilosis: bacterial infection
Treatment: dry conditions, systemic AB, topical chlorhexidine scrubs
causes of otitis
FB, Parasites, Atopic dermatitis, cutaneous food hypersensitivity, S . Intermsdius or Malassezia
main causes of recurrent chronic pruritic otitis externa
Allergic skin disease or bacterial/yeast overgrowth
Cushings Disaese
Hyperadrenocorticism: Pituitary dependent (80%) or adrenal dependent (20%)
CS for Cushings disease
PU/PD, excellent appetite, exercise intolerance, abdominal distension, coat changes, symmetrical alopecia and hyper-pigmentation, anoestrus
Sensitivity
likelihood an infected animal will be positive
few false negatives
Specificity
likelihood that a uninfected animal will be negative
few false positives
how is Cushing’s tested for
ACTH stimulation test or a low dose dexamethasone suppression test
How to differentiate between pituitary and adrenal dependent hyperadrenocortisisum
Pituitary dependent has a 4 hour suppression on dex test but rises back up at 8 hours.
Adrenal never suppresses
concerns over both test for cushings
ACTH : false negatives
Lox dose dex: false positives (stress)
treatment for hyperadrenocortisism
Trilostane (inhibits cortisol synthesis) or Mitotane (lysis of adrenal gland) or surgically
cause of increased supraorbital fat in a 13 year old pony
PPID
cause of generalized obesity especially around crest and tail base. test for it
Equine metabolic syndrome
Oral glucose test: fast overnight give 1g/kg glucose and take blood 2 hours later >85 IU/ml= insulin dysfunction
treatment for equine metabolic syndrome
Weight loss: 1.5% body weight of poor hay
increased exercise, pergolide and trilostane
cause of sudden onset neuro signs in a dairy cow: walking in circles, wandering, head pressing , licking and apparent blindness
Ketosis
Primary:VFI too low for energy requirement (post calving)
Secondary: any condition causing loss of appetite (LDA/RDA, lameness, mastitis or metritis)
treatment for ketosis
IV dextrose 100g fast or 200g slow
cause of fatty liver syndrome
loss of BCS from >4 to 2: NEFA getting stored in liver
treatment: Fluids and dextrose drench
causes for a downer cow
Hypocalcaemia, Hypomagnesaemia, Hypophosphataemia, acute toxic metritis/mastitis/ peritonitis, Fat cow syndrome
time period for a downer cow
if longer than 24 hours = poor prognosis
sciatic nerve damage, muscle necrosis
48 hour euthanasia
happy dower cow or creeper cow
Hypophosphataemia
