FELINE DERMATOLOGY
Introduction Compound follicles – greater number of secondary hairs Less contact dermatitis Epidermis – very thin Careful with topical therapy – shampoos Lack melanocytes except on lip, footpad, nose, scrotum and circumanal Lentigo Simplex Dorsum of tail – collection of sebaceous glands Feline stud tail Inflammatory response different Less folliculitis Response to steroids, decreased (higher doses)
Feline Acne Comedones to folliculitis/furunculosis to chin edema Etiology – unknown. Seborrheic disorder? Infection – secondary in more chronic cases
Feline Acne Clinical signs Comedones
on chin and lips Erythematous papules and pustules Folliculitis/furunculosis/cellulitis of chin with hemorrhagic exudate Pruritus variable Severity of disease variable Fat Chin – swelling – part of EGC
Feline Acne Diagnosis Clinical
signs Rule out demodex, dermatophyte, contact (?), Malassezia derm and food allergy – if pruritic Bacterial culture/sensitivity if exudative Biopsy(?)
Feline Acne Treatment DO
NOT OVERTREAT!!!!!!!!!!! Do nothing if black heads (pick it off) Clip, warm soaks and gentle washings Systemic antibiotic for pustular/infected Recurrent cases – Topical Vitamin A?
Mycobacterial Infections Higher bacteria – mostly saprophytes Non tuberculosis/non leprosy – atypical Atypical Ubiquitous
saprophytes – classified according to culture characteristics Can be opportunists Type IV – rapid growing M. fortuitum most common
Atypical Mycobacterial Infections Clinical signs Single
or multiple SQ nodules, ulcerate and drain Chronic non-healing and draining wounds, non-responsive to surgery or antibiotics Both types tend to recur and cause dehiscence of suture line – may enlarge after attempt to “cut it out”
Atypical Mycobacterial Infections Diagnosis Can
be difficult History Culture – special media – alert lab; Sensitivity Biopsy – special stains – very few organisms! – Pyogranulomatous panniculitus
Atypical Mycobacterial Infections Treatment Antibiotics
– based on C & S; however invivo and in-vitro don’t always match Aminoglycosides – toxicity Sodium iodide therapy? Lamprene 8 mg/kg SID Long term fluoroquinolone – Not Baytril – retinal problems/blindness
Sporotrichosis Cats are unique – high numbers of organisms Zoonotic potential highest in cats Handle carefully
Flea Allergy Dermatitis Clinical signs – not as classic as dogs Lumbosacral dermatitis – like dogs Facial or generalized pruritus Self-inflicted alopecia Bald
belly cat
******Miliary dermatitis Miliary dermatitis – collar only
Cutaneous Reaction Pattern Based Diagnosis Cats respond to cutaneous insults in a limited number of ways Diagnosis helped by recognizing reaction pattern – use to make DDX list Most patterns have similar list – but order of probability is different
Cutaneous Reaction Pattern Based Diagnosis Miliary dermatitis Eosinophilic Granuloma Complex Head and Neck Pruritus Scaling/Crusting Self-inflicted alopecia
Cutaneous Reaction Pattern Based Diagnosis Miliary dermatitis Eosinophilic Granuloma Complex Head and Neck Pruritus Scaling/Crusting Self-inflicted alopecia
Miliary Dermatitis Very common clinical presentation VERY LONG DDX LIST
Miliary Dermatitis FLEA ALLERGY Food allergy Atopy Otodectic mange Cheyletiellosis Trombiculidiasis Notoedric mange Demodectic mange Dermatophytosis Staph folliculitis
Pediculosis Ticks Cat fur mite Drug eruption Internal parasitism Hypereosinophilic syndrome Biotin deficiency Fatty acid deficiency Hormonal Idiopathic
Miliary Dermatitis Clinical Signs Papule surmounted by a crust Edematous – exudes serum Distribution is variable Pruritus is variable/self inflicted alopecia
MILIARY DERMATITIS Diagnosis Clinical signs Search for underlying etiology – initially.. Skin
scrape Ringworm culture Fecal exam Flea allergy test/flea control
MILIARY DERMATITIS Further work up Antibiotics for several weeks Food allergy trial Intradermal skin test CBC Response to ivermectin Intestinal parasite deworming Discontinue drugs Biopsy?
MILIARY DERMATITIS Treatment Treat underlying disease Steroids (rule out demodex, dermatophyte, staph) 1 mg/lb prednisone daily then taper 10 – 20 mg Depo-medrol EOM or less! Ovaban/Megace????? YUCK
Cutaneous Reaction Pattern Based Diagnosis Miliary dermatitis Eosinophilic Granuloma Complex Head and Neck Pruritus Scaling/Crusting Self-inflicted alopecia
SYMMETRICAL ALOPECIA Self-inflicted alopecia- MUCH MORE COMMON THAN….. Non self inflicted alopecia Self –inflicted Pruritic
(VERY COMMON)***** Psychogenic (MUCH LESS COMMON)
SYMMETRICAL ALOPECIA Various areas affected Ascertain if hair loss is self inflicted Historical
information: owner noting licking, chewing etc.. History or hair balls or constipation Derm exam: hair epilation, broken hair, dermatitis? Exam hairs microscopically E-collar (usually not needed)
SYMMETRICAL ALOPECIA If self-inflicted then: pruritic vs psychogenic Explore pruritic disease first Skin scrape, fungal culture, fecal exam, flea test/control If no answer then.. Food trial, skin testing, ivermectin response, deworming
SYMMETRICAL ALOPECIA Treatment Treat underlying pruritic disease After extensive search then try steroids Steroids
may help to differentiate between pruritic and psychogenic alopecia
SYMMETRICAL ALOPECIA Psychogenic High strung breeds: Siamese, Burmese, Abyssinian, Himalayan Historical informationchange in physical or mental environment R/O self inflicted pruritic
PSYCHOGENIC Alleviate the stressor Mood modifying drugs Most commonly used Prozac
(Fluoxetine) Elavil (Amitriptylline)
Taper gradually
NON SELF INDUCED ALOPECIA Temporary stresses: antimitotic drugs, surgery, high fever Systemic Disease Cushing’s Diabetes Hyperthyroid Advanced kidney disease Chronic hepatic disease Paraneoplastic alopecia
Cutaneous Reaction Pattern Based Diagnosis Miliary dermatitis Eosinophilic Granuloma Complex Head and Neck Pruritus Scaling/Crusting Self-inflicted alopecia
HEAD AND NECK PRURITUS Extremely pruritic!!!! May need steroids initially or placement of E- collar because of self trauma Difficult to make diagnosis DDX: Otodectes, Notoedres, Food Allergy, Atopy, Flea Allergy, Dermatophyte, Demodex, Other Ear Disease
SEBORRHEIC DISEASE Total body seborrhea: systemic disease, chronic inflammatory dz, FeLV, FIV, malnutrition, environmental problem, endocrinopathy Sticky cat syndrome – idiopathic Localized seborrhea: feline acne and stud tail
SEBORRHEIC DISEASE Stud tail Most common – intact males Comedones/inflammation of dorsal sebaceous glands Treatment: ignore, wash with benzoyl peroxide, treat with antibiotics, treat with ketoconazole
PLASMA CELL PODODERMATITIS Rare idiopathic disease Footpad swelling – sometimes ulceration May occur with hyperglobulinemia, lymphocytosis, GN Soft non-painful pad swelling, pads balloon and then collapse, may then ulcerate and be painful
PLASMA CELL PODODERMATITIS Diagnosis Histopathology: massive plasma cell infiltration R/O neoplasia, autoimmune Treatment: glucocorticoids, possibly gold salts
LENTIGO SIMPLEX Orange cats: Macular areas of hyperpigmentation Lips, eyelids, gingiva and nose Completely asymptomatic
STEROIDS Cats harder to pill More resistant to adrenal suppression Don’t respond as well to oral steroids Iatrogenic Cushings is rare Commonly use long acting injectables: Depo-Medrol, Vetalog
MEGESTEROL ACETATE Megace, Ovaban More effective antiinflammatory agent than steroids in the cat Mood altering MANY SIDE EFFECTS: adrenal suppression, PP, PU/PD, personality changes, pyometra or stump pyometra, mammary gland cysts or hyperplasia, DM