Diagnostic Approach to the Pruritic Dog & Cat
Transcript of Diagnostic Approach to the Pruritic Dog & Cat
Diagnostic Approach to
the Pruritic Dog & Cat
Dr. Nuttawan SrifawattanaDermatology Clinic
Small Animal Hospital Chiang Mai University
Faculty of Veterinary Medicine, Chiang Mai University
Pruritic Skin Diseases in Dogs & Cats
Pathogenesis of Pruritus & Pruritic Threshold
Introduction01
Outline
Canine Pruritus & Canine Pruritic Score
Dermatological Approach, Differential Diagnosis & Management
Canine Pruritic Skin Disease02
Feline Pruritus & Dermatological Reaction Patterns
Dermatological Approach, Differential Diagnosis & Management
Feline Pruritic Skin Disease03
IntroductionPruritic Skin Diseases in Dogs & Cats
Pathogenesis of Pruritus & Pruritic Threshold
Canine
Pruritic
Disease
Ectoparasite
Allergic Dermatitis
Infectious Disease
Neoplastic Disease
Pruritic Skin Diseases
Feline
Pruritic
Disease
Ectoparasite
Allergic Dermatitis
Infectious Disease
Idiopathic
Pathogenesis of Pruritus
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PPT Presentation
Pathogenesis of Pruritus
https://www.researchgate.net/publication/275652472_Mediators_of_Chronic_Pruritus_in_Atopic_Dermatitis_Getting_the_Itch_Out/figures
Not a fixed level
Factors Raised threshold Lower threshold
Skin temperature Cooling Heating
Water content Moist skin Dry skin
Emotional status Calm Anxiety/Stress
Vary individually
Pruritic Threshold
Canine Pruritic
Skin DiseaseCanine Pruritus & Canine Pruritic Score
Dermatological Approach, Differential Diagnosis & Management
Canine Pruritus &
Canine Pruritic
Score
Dermatological Approach
Parasitic
Allergic
Autoimmune
Nutritional
Endocrine
Bacterial
Fungal
Degree of Pruritus
Differential Diagnosis
Ectoparasites
• Scabies
• Cheyletiellosis
• Fleas
Allergic dermatitis
• Flea allergy dermatitis
• Atopic dermatitis
• Food adverse reaction/Food intolerance
Infectious Disease
• Malassezia dermatitis
• Bacterial pyoderma
Neoplastic Disease
• Cutaneous lymphoma
Simple
Diagnostic
Test
The Skin Scraping The Scotch Tape Test Coat Brushing
Cytology Examination Trichogram Fungal Culture
Complex
Diagnostic
Test
An Elimination diet Intradermal Skin Testing Culture & Sensitivity Test
Skin Biopsy Blood Test Imaging Techniques
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Ectoparasite
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Sarcoptes scabieio Burrowing mite (Digging tunnel)
o Host: dog, pig etc.
o Location: epidermis (stratum corneum)
o Morphology:
Round
Unsegmented Pretarsi of legs I and II–
simple stalked pedicels and suckers
Dorsal spine with triangle shape of scale
Terminal anus
Clinical Signs
Picture
o Pruritus 10/10
o Positive pinna pedal reflex
o Papulocrustous eruptions
(Papules, yellow crust)
o Scaling , excoriation
o Erythema, alopecia
o Area : pinnal tips/margin, elbows,
ventral chest, abdomen, hock
o Hypersensitivity
(https://veterinarypartner.vin.com/default.aspx?pid=19239&catId=102899&id=4952007)
Diagnosis
o Skin scraping
o Serological test IgG
Sensitivity 83-92%
Specificity 89-92%
o Therapeutic trial
Kittichai wannasiri,DVM.
TreatmentEMA Approved Extra-label
Sarolaner (Simparica®) 2.5 mg/kg POIsoxazolines : Fluralaner,
afoxolaner , lotilaner
Selamectin (Revolution® ) Spot on
Moxidectin (Advantage multi®) Spot on
Ivermetin 0.2 mg/kg
q14ds SCOne application/administration : repeat
after one month
Cheyletiellosis
o Walking dandruff
C. blakei in cat
C. parasitivorax in rabbit
C. yasguri in dog
o Morephology: oval shape and the
body has a "waist"
o Cheyletiella dermatitis
o Length of life cycle: 3-5 wks
o In contact and Zoonosis
Clinical Signso Skin scales
o Moving dandruff
o Cat can induce dorsal crusting,
generalized miliary dermatitis
Diagnosis
o Scotch tape technique
o Superficial skin scraping
o Flea combing
o Hair plucking
http://www.pugdogclubofamerica.com/skin-5.html
Treatmento Milbemycin oxime 2 mg/kg weekly
o Selamectin weekly
o Moxidectin weekly
o Fipronil spray
o Amitraz 250 ppm
o Selenium sulphide washes
Flea
Life Cycle
5%
10%
35%
50%
Ctenocephalides canis
o 7-8 similar length of genal combs spine อนัแรกของ genal
ctenidium จะสัน้กว่า spine อนัท่ีสอง
o 16 pronotal combs
o Hind tibia; 2 long bristle between postmedian & apical setae
o Poor host for D. caninum
Ctenocephalides felis
o ช่ือสามญัว่า หมดัแมว (cat flea)
o พบได้ในแมวทัว่ไป แต่อาจพบได้ในสนัุขเลี้ยงด้วย
o มีหลาย subspecies Ctenocephalides felis felis
7-8 similar length of genal combs
16 pronotal combs
Hind tibia; 1 long bristle between postmedian & apical setae
How important it is ???
oSucking blood causing Anemia
(puppy & kitten)
o Intermediate hosts of Rickettsia
felis & Bartonella spp.
o Itching and scratching (pruritis &
Dermatitis) and hair loss
oFlea bite allergic dermatitis
Stage 3
In animals that are allergic to the flea saliva, the
reaction is more pronounced, causing intense
itching. Scratching may
cause increased inflammation and hair loss.
Stage 1
Normal skin
Stage 2
When a flea bites, it injects a
small amount of saliva into the skin, causing
an inflammatory reaction
Stage 4
Bacterial infection is a common sequela to skin
trauma caused by scratching.
Clinical signs
o Non allergic animal
Irritation
Pruritus
o Allergic animal
o Flea bite allergy
Allergic Dermatitis
Caused by Flea
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Allergic Dermatitis
Flea triangle
Atopic Dermatitis
Adverse Food Reaction
Ctenocephalides felis
Ctenocephalides canis
Hypersensitivity to flea salivary
antigens (dose dependent
hypersensitivity)
Severity of flea bite allergy
depend on individual
hypersensitivity
Flea Allergy
Dermatitis
Rule Out Allergy Rule Out Flea
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Allergy
o Adverse food
reaction
o Atopy
o Flea bite allergy
Flea therapeutic trial for 4 weeks
May take until week 8-12 to see the improvement
in severe and chronic cases
Symptomatic anti-pruritic therapy is necessary
Lumbo-sacral region
All pets in the same household need to be treated
Flea Control
Adverse Food Reaction
Hypersensitivity type I (also III
and IV)
Allergen : Glycoproteins of MW
between 10-70 kD.
Most common : Beef , Daily
product, Chicken , wheat and soy
Young dog , all breed
Non seasonal pruritus
Only partially responsive to
steroid
Erythema , papule, secondary
lesions (periocular , ventral
pinnae , around mouth)
Abdomen, perianal area , legs,
paws
Otitis externa
GI sign 10-15%
Adverse Food Reaction
Diagnosis :
Elimination diet with New source of protein / carbohydrate or Commercial food based on hydrolyzed protein
Elimination diet
(8 weeks)
Improve response
Challenge (2 weeks)
Clinical signs re-appear
Food allergy
Remains without clinical signs
Rule out
No response
Rule out
Food allergy/ Intolerance
Favrot’s criteria5 criteria should be fulfilled
Age at on set<3 years
Mostly indoor
Alesional pruritus at onset
Corticosteroid responsiveness
Affected front feet
Affected ear pinnae
Non-affected ear margins
Non-affected dorso-lumbar area
Canine Atopic Dermatitis
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Infectious Disease
Canine
Pyoderma
Phylum: Firmicutes
Class: Bacilli
Order: Bacillales
Family: Staphylococcaceae
Genus: Staphylococcus
Facultative anaerobic
Gram-positive
Cocci in clusters (grape-like cocci)
Colonize at mucocutaneous junctions
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Staphylococcus pseudintermedius
Classification
Deep pyoderma
Surface pyoderma
Mucocutaneous pyoderma
Superficial pyoderma
Antibiotic TreatmentTopical Therapy Systemic Therapy
Antiseptic Shampoo
• Benzoyl peroxide
• Chlorhexidine
• Salicylic acid
First Tier
Cephalexin 22-30 mg/kg q8-12h PO
Amoxicillin-clavulanic acid 15-30 mg/kg q8-12h PO
Clindamycin 5.5-11 mg/kg q12h SC,PO
Sulfamethoxazole-trimethoprim 15-30 mg/kg q12h PO
Antibiotics Topical
• Mupirocin
• Polymyxin B
• Fusidic acid
• Amikacin gel
Secondary Tier
Cefovecin 8 mg/kg once SC
Enrofloxacin 5-20 mg/kg q24h PO
Marbofloxacin 2.75-5.5 mg/kg q24h PO
Doxycycline 5-10 mg/kg q12-24h PO
Alternatives
• Herbs, Fruits, etc.
Third Tier
Amikacin 15-30 mg/kg q24h SC
Vancomycin
Carbapenems
Malessezia Dermatitis
Yeast Infection
Medication
Itraconazole : 5 mg/kg sid duration at
least 1 month
Topical treatment
2% Ketoconazole cream
Shampoo
• 2% miconazole
• 2-4% chlorhexidine
• 2% ketoconazole
• 2% chlorhexidine +
1%ketoconazole
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Neoplastic Disease
Cutaneous Lymphoma
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Diagnostic Approach to the Pruritic Dog
Fleas or lesions suggestive of FAD
Rule out ectoparasite
Skin scraping
Hair microscopy
Serology/Treatment
Investigate secondary infections
Rule out Adverse Food Reaction
Atopic dermatitis
Test in vibo (IDST)
Test in vitro (serology)
Flea control
Scabies treatment
Specific treatment
Adequate treatment
Feed Adequate Food
Decide most
Adequate therapy
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Management of Pruritus
Multimodal ManagementShot term/Acute flare/ Supportive care Long term control
Antihistamine (30%)Oclacitinib acid/
ApoquelCorticosteroid/Prednisolone
Oclacitinib acid/ApoquelLokivetmab/
CytopointLokivetmab/Cytopoint
Control secondary infection Cyclosporine
Antihistamine
Antihistamine used in CanineAntihistamine Dose
Hydroxyzine HCl (Atarax®) 2.2 mg/kg q8-12h
Diphenhydramine (Benadryl®) 2.2 mg/kg q8-12h
Chlorpheniramine (CPM®) 0.2-0.8 mg/kg q8-12h
Clemastine fumarate (Tavist®) 0.05-0.1 mg/kg q8-12h
Amitriptylyne (Elavil®) 2.2 mg/kg q12h
Loratadine (Claritin®) 10 mg/kg q24h
Fexofenadine (Allergra®) 15-20 mg/kg q24h
Cetirizine (Zyrtec®) 1 mg/kg q12-24h
Oclacitinib acid/Apoquel
Lokivetmab / Cytopoint
Corticosteroid / Prednisolone
Corticosteroid / Prednisolone Prednisolone 0.5 mg/kg twice daily then reduce dose 50% every 7 days,
then alternate day
Safe annual dose: 30 x Body weight(kg) = mg of prednisolone per year
(need to divided to daily dose)
Be aware of PU/PD, Iatrogenic cushing’s, Cystitis, Hepatomegaly, DM, GI
ulcer, Calcinosis cutis
Cyclosporine
Feline Pruritic
Skin DiseaseFeline Pruritus & Dermatological Reaction Patterns
Dermatological Approach, Differential Diagnosis & Management
Reaction Patterns
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01 02 0403 05
Head and
neck pruritus
Self-induced
alopecia
Eosinophilic
plaque
Indolent
ulcer
Eosinophilic
granuloma
Reaction Patterns
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06 0807
Linear
granuloma
Miliary
dermatitis
Urticaria
pigmentosa like
dermatitis
Head and Neck Pruritus
Back
Self-induced Alopecia Back
Eosinophilic PlaqueEosinophilic Granuloma
Back
https://veterinary-practice.com/article/dealing-with-feline-allergic-
skin-disease
Indolent Ulcer
Back
https://veterinary-practice.com/article/dealing-with-feline-allergic-skin-disease
Linear Granuloma
Back
https://veterinary-practice.com/article/dealing-with-feline-allergic-skin-disease
Miliary Dermatitis
Back
https://www.cliniciansbrief.com/column/1000-words/miliary-dermatitis
Urticaria Pigmentosa-liked Dermatitis
Back
Differential Diagnosis
Ectoparasites
• Otodectes cynotis,Notoedres cati
• Demodex ,Trombiculid mite
• Flea , lice
• Sarcoptes
Allergic dermatitis
• Environmental , Food, Flea saliva
• Contact, Intestinal parasite (Immune
response : rare)
Infectious Disease
• Dermatophyte
• Bacteria
• Virus : Herpes virus
Idiopathic/Neurogenic
• No underlying cause
• Cannot identified
• Psychogenic
Ectoparasite
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Parasite cause of feline itching
Flea
Chyletiella
Demodex gatoi / Demodex Cati
Notoedres
Otodectes
Mosquitoes
Demodex Demodex gatoi
Short body
Stratum corneum
Scale ,alopecia, erythema
Demodex Cati
Follicular demodicosis
Eyelids, periocular,Head,neck
Treatment
Stop any Glucocorticoid
Bravecto
Lime sulfur
www.veterinaryimagebank.com
:Demodex cati
https://vet360.vetlink.co.za/training/diagnosis-treatment-of-demodicosis-in-dogs-cats/
Demodex gatoi
Demodex Cati
http://citeseerx.ist.psu.edu :
Demodex gatoi
Notoedres catiFeline Scabies
Morphology similar to Sarcoptes scrabiei
except the anus position (dorsal anus)
Skin hyperkeratinization
Treatment
Selamectin (6-12mg/kg every 4 week)
Moxidectin (2.5-5 mg/kg every 2-4 week)
Lime Sulphur dips
Fipronil spray
Week 4Week 2Week 0
OtodectescynotisLocation: Ear canal (external), Ear pinna
Length of life cycle: 3-4 weeks
Clinical signs
Pruritus and self induced alopecia
Associated with otitis externa
Dry blackish granules
Erythema and excoriations
Severity in TM rupture : vestibular signs
Diagnosis Ear swab (liquid paraffin mounts)
Treatment Topical otic preparations
***Thiabendazole ****
Monosulfiram
Permethrin
Selamectin (spot on labelled dosage)
Moxidectin (spot on labelled dosage)
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Infectious Disease
Fungal Infection
Microsporum Canis Microsporum gypseum
Trichophyton
mentagrophytes
Localized Infection Generalized Infection
1-5 small circumscribed
Treatment: Topical treatment
o Shampoo (miconazole,
ketoconazole, chlorhexidine
+ miconazole)
o Cream, Spray
5 or more lesions
Treatment: Topical and Systemic treatment
o Ketoconazole
o Itraconazole
Fungal Infection
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Allergic Dermatitis
Distribution pattern
Feline Food allergy
Genetic predisposition not require
• 0.22 to 6% of cats with dermatologic signs
• 17 to 22% of cats with GI signs •
Cats mean age 4-5 years (range 3 mo to 11 yr)
Allergen
> 4000 Dalton
Reported Food Allergens in cat
Proteins Grains Others
Beef Barleys Commercial food
Chickens Corn Clam juice
Fish Cod liver oil
Dairy product Food additives
Horse meat Food preservatives
Lamp
Pork
Diagnosis
R/O ectoparasites
R/O food allergies
R/O infections
• Investigate for “offending”
allergens
• Serum IgE testing
• Intradermal testing
Feline Atopic Dermatitis
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Idiopathic
Neurogenic
Idiopathic/Neurogenic
Twitchy cat syndrome
Neurologic ?
Behavioral?
Rippling of skin over back
Over grooming , Growling, hissing, biting at back or tail,
running and hiding
Rule out ectoparasites, allergies, neurological disease
Treatment trials
Gabapentin
Amitriptyline
Phenobarbital
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Management of Pruritus
Avoidance
Managing Microbial infection/overgrowth
Medical treatment of Itching
Antihistamine
Glucocorticoid
Cyclosporine
***Apoquel ***
Management of Feline Pruritus
Antihistamine used in cat
Antihistamine Dose
Chlorpheniramine (CPM®) 2-4 mg/cat q12h
Diphenhydramine (Benadryl®) 2.2 mg/kg q12h
Clemastine fumarate (Tavist®) 0.68 mg/cat q12h
Amitriptylyne (Elavil®) 0.5-1.0 mg/kg q12h
Cetirizine (Zyrtec®) 5 mg/cat q24h
Cyproheptadine 2 mg/cat q12h
Glucocorticoid used in cat
Prednisolone 2 mg/kg PO q 24h then EOD
Methylprednisolone 1.6 mg/kg PO q24h then EOD
Dexamethasone 0.2 mg.kg PO q24h then EOD
Cyclosporine
7 mg/kg SID (5-10 mg/kg)
Clinical improvement typically between 2-3 weeks
Steady state around 4-6 weeks
Recommended that cats have serology evaluated for
Toxoplasma , FeLV or FIV
Prior to initiating therapy and periodically during treatment
Oclacitinib acid
Janus kinase inhibitor
Decreases production of IL-31
At higher doses may cause bone marrow suppression
Precautions
Do not use in FeLV or FIV + cats
Indoor cats only and avoid feeding raw meats
Thank YouFor your attention