Dog and Cat 3 Flashcards
1
Q
What is the pathogensis of canine atopic dermatitis
A
- Not inhaled by actually route via percutaneous
○ Primary defect in your skin barrier -> allows allergens to get access to yours skin -> large exposure to allergens result in allergic response
§ Allergens especially allergens and dust mites could also be food allergy
§ Increase colonisation of bacteria such as staphylococcus that break down skin further and produce antigens that result in production of danger signals
□ Microbiome changes on the skin -> don’t get dampening down of danger signal (IL33, IL25) -> result in TH2 -> IgE production
OVERREACTION OF THE IMMUNE RESPONSE
2
Q
What are 5 factors that contribute to the atopic phenotype
A
- High IgE responder
- Low ceramide (lipid production in the skin)
- Low filaggrin expression (helps with sticking skin together)
- Claudin 1 mutation (retain water within the skin)
- TLR-2 mutation
3
Q
What are the 5 components of atopy
A
different components based on individual genome
1. Allergy
2. Barrier dysfunction
3. Infections
4. Behaviour
○ Itching behaviour can become a habit more likely to itch
○ Highly anxious dogs are more likely to clinically present as itching
5. Itch
○ Pathogenesis within the skin
○ Midbrain response -> itch or not to itch??
§ Itch to create mild pain signal to inhibit the itch pathway
□ If won’t stop then -> anxious dog, habit or infection
®Anxious dogs have high serotonin levels which inhibit the pain inhibitory pathways therefore keep itching
◊ IN THIS CASE NEED BEHAVIOUR DRUGS
4
Q
What increases the risk of developing atopy
A
- Urban life
- High human population density
- Increased average annual rainfall
- Adoption at the age of 8 to 12 weeks
- Regular bathing of young healthy dogs
○ Wash as infrequently as possible
○ Medicated shampoos should be used
5
Q
Describe the clinical presentation of the 3 levels of severity for atopi dermatitis
A
- Mild -> Disease in armpits, groin, ears, feet (moist areas) -> more effective skin barrier, most of the skin normal
- Moderate -> allergen penetration where skin isn’t moist -> everywhere that touches the ground -> less effective skin barrier
- Severe -> generalised disease all over the skin
Can get very bad
6
Q
Atopic dermatitis diagnosis what are the 3 main things involved
A
- Signalment
- Clinical signs
○ Generally present before 3 years old
○ Itchy and licking - face, leg and ventral abdomen - Exclusion of other DDx
○ Blood test for sensitisation DOESN’T WORK
7
Q
Diagnostic check list for atopic dermatitis
A
a. Could this be infection? -> multiple infections?? -> generally have secondary infection due to allergy
b. Could this be demodex? -> primarily not itchy disease but would be if infected
c. Could this be scabies? -> ALWAYS ON THE DIFFERENTIAL LIST
d. Could this be fleas? -> possible
e. Could this be contact allergy?
f. Could this be food allergy? -> NEEDS TO BE CONSIDERED
§ First symptom for food allergy dogs -> Ear infections
g. If this is atopy can I manage this or should I refer?
8
Q
Outline a diagnosic plan for atopic dermatitis
A
Step 1
- Resolve infection - DON’T MISS MRSP
○ If 2 weeks on antibiotics and not resolving -> CULTURE
- Bravecto/Nexgard/simpatico to rule out scabies/flea/Demodex
Step 2
- Still itchy when infection free and on isoxazolines - eliminated above
- Where itchy?
1. Contact areas affected = contact avoidance trail
2. Classical atopic areas = food elimination trial - BEEF most common food allergy in dogs,
9
Q
In terms of contact avoidance trails what is involved in the 3 types of dermatitis
A
1) Allergic contact dermatitis
- When moving through areas that have these allergens and come into contact with
- AVOIDABLE ALLERGENS -> keep off grass
○ Test to see whether dogs better if off of the grass for 3-4 days
2) Pollen atopic dermatitis
- Exposure through the skin and the pollen comes to you through the air
- NON-AVOIDABLE ALLERGENS
3) Atopic dermatitis
- Pollen, mites, fungi, bacteria
- NON-AVOIDABLE ALLERGENS
10
Q
In terms of a food elimination trail what should you feed - list 5 options
A
1) Hydrolysate diets -> Z/D royal canine etc -> inadequate
2) Restricted antigens diets -> extra things within, cross-contamination -> possible fail or food trial
3) Home-cooked diet -> novel protein +/- novel carbohydrate BUT WHAT IS NOVEL
® Cross-reactivity -> lots present within mammalian proteins, fish proteins -> if allergic to one thing may react to others
4) Anallergic diet -> royal canin - NO CROSS-CONTAMINATION
5) Crocodile meat -> LEAST cross-reactivity than other meats such as poultry and- NOT FULL PROOF
11
Q
In terms of a food elimination trail how long should you do it for and what is needed long term
A
□ Treat infection and flea control before start
□ MINIMUM 8 weeks
□ Total compliance needed -> try not to give any medications during this time
□ Anti-pruritic (oclacitinib - apoquel) can give with food trial but not all prednisolone
□ Re-assess BEFORE rechallenge and IF flare reported or after 14 days if no flare
□ Sequential rechallenge
12
Q
What are 6 important questions to ask with history with skin lumps and bumps
A
- When did you first notice it ○ Is this reliable - Has it changed - Painful or irritating - Any other masses (now, previously) - Other concerns - UV exposure risk
13
Q
What are important things to look for with physical exam in approaching lumps and bumps
A
- Signalment
○ Breed predispositions, UV exposure risk - Size - measure, can use your fingers as in-built callipers
- Location - be specific (leg is not specific)
○ Cutaneous vs subcutaneous - As move skin does mass move within
○ UV associated tumors - Fixed or mobile
- Appearance, texture
○ Round/irregular, raised/flat, pigmented, ulcerated, oedematous, firm/soft - Any other masses on skin
- Lymph nodes
○ Which one is the draining lymph node - assess that
14
Q
Diagnosis based on looks what skin lumps can you do with and what look like
A
1. Sebaceous adenoma/hyperplasia ○ Old dog warty appearance 2. Papilloma ○ Multiple in young dog 3. Fibropapilloma (skin tag) 4. Dermal Haemangiosarcoma - can be UV associated (sunbathing on ventral surface) 5. Squamous cell carcinoma ○ Appearance, breed disposition, location 6. Lipoma? - CANNOT Need to FNA it
15
Q
What are the 2 main diagnostic tests for lumps and what information does it provide
A
1. FNA and cytology ○ Needle off versus needle on ○ Screen slides § +/- definitive diagnosis, if not then: § Is it diagnostic for a clinical pathologist -> are there enough cells to make a diagnosis 2. Histopathology ○ Diagnosis ○ Margins ○ Other prognostic factors if applicable
16
Q
What are the 3 main options post diagnosis with lumps
A
- Surgery - in general for localised cancer is the best treatment
- Other
○ Radiation therapy - alone or adjuvant
○ Chemotherapy - alone or adjuvant - No treatment - still needs monitoring
○ Like sebaceous adenomas
17
Q
Canine cutaneous MCT presentation - what age and growth
A
- Breeds: boxers, retrievers, pugs, boston and pit bull terriers
- Can occur in young dogs
- Often slow growing, can vary
○ Changes day to day suggestive of MCT, due to histamine
§ Swell one day then decrease the next - repeat
○ Rapid growth, ulceration, systemic signs, suggestive of aggressive disease
18
Q
Canine cutaneous MCT what are the 2 main locations and diagnostic testings
A
Location
1. Muzzle/perioral
○ More likely to have LN metastasis at diagnostic than other sites
2. Subcutaneous
○ Unlikely to have aggressive behaviour
○ Some features may be predictive
Diagnosis
1. FNA usually diagnostic
○ Poorly granulated may be more challenging
○ May be suggestive of high vs low grade
2. Staging tests
○ Lymph node assessment recommended in every case
○ +/- ultrasound, liver, spleen FNA
If clinically aggressive features, cytology suggests high grade
19
Q
Canine cutaneous MCT list the 4 main prognostics factors
A
1) histolgic grade
2) margins
3) other histopathology features
4) stage - prognostic
20
Q
Describe the prognostic factor of canine cutaneous MCT histologic grade and margins
A
- Histologic grade
○ Two vs three-tiered systems
○ Low = better
§ 15-20% of low grade tumors may still have more aggressive behaviour
□ Therefore not necessary tells you the behaviour - Margins
○ Helps to predict risk of local regrowth but not 100% predictive - NOT METASTISE
§ Many low grade tumors never recur, some high grade tumours recur even through complete margins
21
Q
Describe how other histopathology features and staging helps with prognosis fro canine cutaneous MCT
A
- Other histopathology features
○ Mitotic index/mitotic rate
§ Per TEN high power fields, should be reported for every MCT
□ 0 = very good, predict benign behaviour
□ 7 = definitive for aggressive behaviour - depending on the scheme used
○ Other additional tests - unclear how to apply them
§ If all come back bad most likely bad and vice versa - Stage - prognostic
○ Distant metastasis
§ Metastasis -> grave prognosis
○ Lymph node metastasis
§ Still local disease -> can get good outcome for aggressive treatment
22
Q
What are the 3 main treatments for Canine Cutaneous MCT
A
- Local
○ Surgery
§ Wide vs planned marginal exicison
§ Only do if can excise ALL THE VISIBLE tumor
○ Radiation therapy - Systemic (chemotherapy)
○ Adjuvant for high-risk tumours
○ Known distant metastasis
○ Non-surgical primary tumour (+/- radiation therapy) - Supportive care medications
○ Anti-histamines - with every case
§ Don’t need to do before FNA
§ Should do before surgery -> needs time to take affect
○ Antacids - histamine can lead to stomach ulceration
§ If large and ugly then use this as well
○ Any bulky MCT
23
Q
Feline MCT what are the 3 main sites and which are more likely
A
- Primary sites: skin > spleen (in dogs would be metastasis from skin) > GIT
1) Cutaneous
2) feline splenic MCT
3) Feline GI MCT
24
Q
Cutaneous feline MCT general character, how many generally present and treatment
A
○ Most are benign, histopathology does not always correlate well with behaviour
§ Histiocytic subtype in young cats may regress
○ Multiple = associated with splenic MCT
§ Staging recommended
○ Treatment: surgery for all
25
Feline splenic MCT how common and treatment
○ MCT one of the most common cause of feline splenic disease
○ Clinical signs non-specific
○ Splenectomy recommended even if evidence of liver or peripheral blood involvement
§ +/- chemotherapy
26
Feline GI MCT clinical signs, character, treatment and prognosis
○ History of non-specific GI signs
○ Metastasis common
○ Typically treated with surgery and/or chemotherapy
○ Prognosis used to be thought to be very poor, more recent study suggests better than thought (even with corticosteroids alone)
27
Give some examples of canine soft tissue sarcoma and why are they grouped together, general presentation and the 2 main diagnostic techniques
- AKA spindle cell sarcomas, spindle cell tumours, soft tissue mesenchymal tumours
- Group of tumours with different cells of origin but similar behaviour
- Subcutaneous mass - firm, usually well-defined
Diagnosis
1. FNA may or may not be helpful
○ Aspiration techniques may be better
○ Rule out other causes
2. Biopsy histopathology
○ Small mass - consider excisional
○ Larger - incisional recommended
28
For canine soft tissue sarcoma what are 2 important tests in staging and list the 2 prognostic factors
Staging
1. Thoracic imaging - chest radiographs or CT
○ CT allows primary tumour imaging also
2. LN evaluation if enlarged, known high grade or clinically aggressive tumour
Prognostic factors
1. Histopathologic grade (1/2/3; low/int/high) - PROGNOSITC
2. margins - risk of regrowth
29
What are the two main prognostic factors for canine soft tissue sarcoma and how prognostic
1. Histopathologic grade (1/2/3; low/int/high) - PROGNOSITC
○ Grade 1,2 = <15% chance of metastasis
○ Grade 3 = 3 40-50% chance of metastasis - after removal
○ Mitotic index alone is also prognostic (>9 = worse)
2. Margins
○ Risk of regrowth - varies with grade
§ 1,2 - many do not regrow even if narrow/incompletely excised
§ 3- 75% regrow with narrow margins, 30% if incomplete
□ If the case second surgery, OR radiation therapy OR THEN monitor
30
List the 4 main treatment options for canine soft tissue sarcomas and why choose
1. Surgery - as long as hasn't already metastasised
2. Adjuvant radiation therapy if incomplete margins post-op and secondary surgery is not an option
3. Chemotherapy - consider if high grade; known metastasis
4. Non-resectable tumor - consider RT and chemo
31
Feline injection site sarcoma where more common what is the general presentation and what is concerning, how to remember this
More common USA - rabies vaccine maybe
- Rapidly growing mass at site of injection
- 3,2,1 - should be evaluated as concerning
○ Mass present 3 or more months post vaccine/injection
○ Mass is >2cm
○ Mass is growing more than 1 month post vaccine/injection
32
Feline injection site sarcoma what are the 2 main diagnostic techniques and staging
Diagnosis
1. FNA - rule out other causes, not always definitive Dx for ISS
2. Incisional biopsy not excisional!!!! - IMPORTANT
○ Aggressive (referral) first surgery = better outcomes
Staging
- Thoracic imaging - CT often ideal for imaging primary tumour also
○ Do metastasis to the lungs
33
Feline injection site sarcoma what are the 4 main treatment options and what is important
1. Surgery: refer!! DON'T DO IN GENERAL PRACTICE
○ Time for recurrence after surgery in general practice is 2 months
2. Adjuvant radiation therapy post-op, or for palliation if non-resectable
3. Chemotherapy - adjuvant can be considered, alone may help slow progression if non-resectable
4. Other, non-injection associated STS in cats treat as for dogs
34
Canine mammary tumours (MGT) what are the 4 main factors
1. Age > 7-8 years
2. Hormone exposure - intact female, spayed later in life
○ Reduced risk if before 2nd oestrus cycle/ 4 year old
3. Breed - smaller dogs, springer spaniel, English setter
○ BRCA mutations in springers detected
4. Weight - increased risk of overweight at 1 year of age
35
Canine mammary tumours what is the general clinical presentation
- Mass - usually palpable on exam but may not be noticed by owner until quite large
○ Monitoring for at risk dog - when they come in for annual vaccines
- Caudal > cranial glands, often multiple at diagnosis
- Inflammatory mammary carcinoma is a specific subset - present with diffuse involvement which can look like severe mastitis, systemically ill
○ Clinical diagnosis shouldn't need histopathology
36
Canine mammary tumours what 2 diagnosis is important and 4 staging tests
Diagnosis
1. FNA - not always definitive for malignancy but should identify epithelial origin and rule out other causes
2. Histopathology - benign/malignant, subtype of carcinoma, grade, other features such as vascular or lymphatic invasion, margins
Staging
- Recommended prior to surgery in most cases
1. Lymph nodes - palpation/imaging AND sampling
○ Axillary or inguinal lymph node
○ Difficult to predict drainage pattern
2. Lungs - chest radiograph or CT (more sensitive)
3. +/- abdominal imaging
4. CT may be beneficial for full staging to evaluate all LN, chest, abdomen and other mammae
37
Canine mammary tumour what are the 2 treatment options and for which types
1. Surgery - primary tumour and LN ideally
○ If distant metastasis then surgery may or may not be of benefit (palliation)
○ Wide enough to completely remove the tumour
○ Regional mastectomy if multiple tumours
○ NOT for inflammatory mammary carcinoma
○ +/- OHE
2. Chemotherapy
○ Adjuvant (following surgery) for high-risk tumours
○ Distant metastasisi (systemic disease)
○ Best agent
○ NSAIDS
38
What are the 3 main prognostic factors for canine mammary tumours
- Histologic grade, lymphatic invasion
- Size (<3cm best) -> DON'T WANT TO IGNORE, get them small
- LN involvement/other metastasis
39
Feline mammary tumours what is the general character and 3 risk factors
- 80-90% are malignant
Risk factors
1. Age: > 7-9 increased, mean 10-12 years
2. Hormone exposure:
○ if spayed <1 year old 90% risk reduction
○ May be no benefit if > 2 years olf
○ Exogenous progestins - DDx fibroepithelial hyperplasia
3. Breed: Siamese
40
Feline mammary tumours what is the general clinical presentation and the 2 diagnosis
Clinical presentation
- Mass - often noted quite later, may be ulcerated
- PE: as for dog, multiple tumours common
Diagnosis
- FNA recommended to r/o other causes
- Up to 90% malignant in cats (vs approx. 50% in dogs)
- Histopathology: benign/malignant, subtype of carcinoma grade, margins, invasion
41
Feline mammary tumours staging when occur and 3 prognostic factors
```
Staging
- Recommended prior to surgery
- Diagnostic tests as for dogs (imaging, LN, evaluation)
Prognostic factors
- Histopathology
- Size <2cm
- Stage (metastasis)
```
42
What are the 2 main treatment options for feline mammary tumours
1. Surgery
○ More aggressive than for canine MGT
○ Uni (for single) or bi-lateral (multiple/bilateral tumours) chain mastectomy
○ May be stages
§ Mastectomy = improved survival time -> lumpectomy/mammectomy alone
2. Adjuvant chemotherapy
○ Adjuvant in high risk tumours, any case with distant metastasis
○ Usually doxorubicin-based
43
Digial tumours in dogs and cats what most common
- Dogs
○ Melanoma, SCC most common
○ Staging with LN evaluation and thoracic imaging recommended
○ Treatment - surgery (digital amputation) if no obvious metastasis
○ Melanoma higher risk of metastasis, consider adjuvant treatment
- Cats
○ Unlikely to be primary
○ Most commonly - lung carcinoma that has metastasised to the digit
§ Radiograph chest before amputate the digit
44
What is special about dog and cat skin vs humans
- Direct cutaneous arteries and veins supply subdermal plexus – panniculus muscle - skin much more mobile
○ Panniculus = Cutaneous trunci (abdomen) and platysma (head)
- Allow significant movement of skin during reconstructive procedures
45
What are tension lines and how to use them
- Tension lines - predominant pull of fibrous tissue
- Make incisions and close wounds parallel to tension lines to minimize skin tension
- Wound/incision closure across or perpendicular to tension lines results in wide gaping and large ‘dog ears’.
- Wound/incision closure diagonally across tension lines results in a curvilinear closure.
46
List the 3 stages in skin healing and how many days does it last
Stage 0: Immediate response to wound: Blood clot
Stage 1: Inflammation/debridement (1-3 days)
- Vasoconstriction > AA cascade > vasodilation and vascular fluid leakage, release of cytokines > Neutrophils and monocytes migration > phagocytosis and enzymatic destruction of bacteria and debris.
Stage 2: Repair/proliferative (4 – 12 days)
Stage 3: Maturation/remodelling (mths - yrs) - wound already closed
- Type III Collagen is replaced by type I through cross-linking of collagen fibres, development of interwoven arrangement of fibres and deposition of the fibres along lines of stress.
47
What are the 3 stages in stage 2 of skin healing and describe
Stage 2: Repair/proliferative (4 – 12 days)
1. Granulation – Macrophages & fibroblasts, angiogenesis.
2. Contraction - Fibroblasts produce an amorphous ground substance and collagen.
○ The wound edges move inwards until the force applied by the myofibroblasts equals the tension on the wound or contact occurs -> will reach at point at which it cannot contract anymore
3. Epithelialization - Epithelial proliferation provides surface coverage of the wound.
○ This phase will not progress with the presence of infection, necrotic tissue or foreign material - stay in inflammation stage
48
Surgical drain what is the goal how achieve and how long leave in place
Drain’s Goal:
○ Reduce fluid accumulation (seroma formation) between skin and underlying tissues
§ Large dead space
§ Area of high motion
○ Contaminated or infected wounds continuing drainage
- Length of time in place: remove as early as possible to minimise risk of infection (1-2ml/kg/d)
○ If leave longer than 4-5 days
49
List 3 main types of drains and what type are they
1) penrose drain - passive
2) jackson-pratt drain - active
3) butterfly catheter and vacutainer - GREAT
50
Penrose drain – Passive how work and what is important to do
- Cheap latex
- Gravity dependent -> need to put it in ventrally
- Anchor proximal in SC space with suture and exit ventrally through separate stab incision
- Fluid drainage proportional to surface area
- Bandage to avoid environment soiling
51
Jackson-Pratt drain – Activewhat type of syste,, important characteristics, what good for and disadvantages
- closed system
- Fenestrated tube and grenade reservoir collection
- Reduced risk of ascending infection
- Less environmental contamination
- Non-gravity dependent
- Good for higher volume drainage
- Requires air-sealed cavity - disadvantages
○ Not used for small puncture wounds in the skin
Can measure and assess fluids - GREAT
52
What are 4 main processes that involve closure of skin
1. Intentional skin incision (e.g. surgery)
2. Lacerations
3. Bite wounds / abscesses
4. Open wounds
○ e.g. burns, shearing injuries, large mass resections
53
what is important with skin closure of large areas in high motion areas
- For mass removal, large dead space or surgery in high motion areas (joints, elbow, flank) -> may need to address tension or potential for seroma formation due to dead space.
54
Define a laceration, what is important with closure
- Sharp, linear, ‘clean contaminated’ wounds
- Lavage
- Debridement /En bloc excision (excising the wound - skin and subcutaneous tissue like removing a tumour - creating a CLEAN wound)
- To manage tension:
○ Deep & superficial S/C and skin sutures OR
○ S/C, intradermal and skin sutures
55
Seroma define, what result in and treatment
- A S/C accumulation of protein-enriched serum under a closed wound
- Often result of poor dead space closure or in area of high motion
- Excellent medium for bacterial growth
○ BUT Isolated from cellular immune responses -> unless puncture through
○ Will go from clean -> contaminated -> infected -> abscess - then need to treat as abscess
- Generally self-limiting (reabsorbs within few weeks)
- Do NOT drain – risk of introducing infection
- Address the seroma -> put a drain within in
56
Abscess what caused by, what do you do before treatment and treatment
- Caused by
○ Penetration (e.g. FB like grass awns or bite wound)
○ Infection (e.g. anal gland abscess, SSI)
- Clip liberally and aseptic prepare for surgery
- Sample (centesis or swab) for C&S!!! - culture and sensitivity
○ IMPORTANT FOR ANTIBIOTIC RESISTANCE
1. Puncture and drain abscess (look for a FB (foreign body))
2. Lavage with 0.9% NaCl and debride necrotic tissue
3. Place a drain!!!
4. Start empirical antimicrobial'
- IF STILL RECCURING -> need to search for foreign body (grass seed) -> ultrasound, MRI, CT
57
What is the difference between cat and dog bite wounds and what is common and important
- Cat bite wounds
○ Small pointed straight teeth
○ Small deep wound, seal quickly
○ Often lead to abscesses
- Dog bite wounds
○ Large curved teeth
○ Greater penetration, laceration and crushing
- All bite wounds are contaminated
○ Mixed bacterial population in mouth/skin
- Often external trauma is ‘tip of the iceberg’
○ ‘Big dog – Little dog’ attacks
§ Large area of little dog affected
§ Little dog shaking causing shearing injuries and possible entry into thoracic or abdominal cavity
58
Dog bite what is the initial management
- Assess whole patient and stabilize
○ Shock, blood loss, respiratory distress
○ IV Fluids, Oxygen, analgesics
○ Diagnostic imaging
§ especially around bones -> fractures
§ abdominal cavity -> penetrate the gut -> Free fluid -> increased opacity
- Minimize further contamination
1. Sterile hydro gel on wound before clipping
2. Liberally clip hair around puncture wound
3. Gently cleanse skin around wound with warm saline and surgical preparation solution
4. Lavage the wound
59
Dog bite wounds what are the 10 steps in the treatment
- Explore wound
1. Bite wounds should be explored under general anaesthesia when patient stable
○ Be prepared for exploratory laparotomy or thoracotomy
2. IV antibiotics (e.g. cephalosporins)
3. Excise puncture wounds and extend incision in region of viable skin
4. Probe all pockets
5. Debride wound edges and devitalized tissues with sharp dissection
6. Lavage with 0.9% NaCl
7. Collect swab samples for C&S after lavage
8. Place a drain
9. Primary close skin if possible
- If contamination still present or unable to close, then treat as open wound follow with delayed primary or secondary closure
10. Analgesia and antibiotics
60
Open wound management what are they a result from and what does it cover in skin healing
- Open wounds are generally the result of a shearing injury or large skin defect (e.g. burn wound or large tumour excision)
- Open wound management covers the Inflammation and Repair phases of wound healing:
• granulation tissue
• Re-epithelialization
• Wound contraction
61
Open wound management what are the 4 steps within
1. Lavage - Pulsatile lavage, gravity flow, or manual (8 psi) delivery via a 35-60 ml syringe with an 18-19 gauge needle
2. Debridement - make wound grossly lean - mechanical, chemical, surgical (sharp dissection)
3. bandage
4. tie over bandage
62
Bandaging open wounds how often needs to be changed in the different conditions and how many layers of bandage
○ Daily or twice daily dressing changes initially in infected wound
○ Changes every 2-3d during inflammation stage for non-infected wound.
○ Change every 4-7d during repair stage.
○ 3 layers of bandage
63
Describe the 3 layers of bandaging with function and type
1. Primary/contact - most important layer
§ Adherent vs. non-adherent
§ Hyperosmolar/ Alginate/ debridement dressing if exudative
§ Topical antibiotic ointment/silver/ hydrophilic dressings for inflammation/repair stage.
2. Secondary layer
§ Absorb wound exudate, blood, and debris away from the wound
§ Secure the contact layer to the wound and provide limb support and wound protection
3. Tertiary layer
§ Secure the other bandage layers in place
§ Provide pressure support
§ Protect the middle layer from contamination -> as long as it stays dry than inside won't become infected
64
Tie over bandage in open wound management what useful for, how place
○ Useful in high mobility or difficult to bandage locations.
○ Place simple interrupted loop sutures around wound
○ Apply contact layer and absorptive layer
Hold in place with umbilical tape
65
List and describe the 7 ways to deal with tension in skin closure
1) pre-suture - bring skin closure together
2) undermining - NEEDS TO BE DONE TO PREVENT DEAD SPACE
3) S/C sutures, walking sutures - stretching skin
4) tension releasing incisions - extremities used
5) tension relieving sutures - vertical and horizontal (may compromise blood supply - not done) mattress sutures
6) plasty techniques - V to Y plasty (mild tension), X plasty (Scar tissue)
7) skin flaps/grafts - based on subdermal plexus
66
Skin flaps/grafts what are the 2 types and types within
1) Local flaps
1. pedicle advancement flap
2. rotation flap
3. transposition flap
4. skin fold flaps - elbow and flank
2) Axial pattern flaps
§ Based on direct cutaneous arteries
§ Thoracodorsal, superficial cervical, caudal superficial epigastric, deep circumflex iliac
§ Relies on blood supply within the skin -> up to rotation of 180 degrees
67
List 5 indications for ear surgery
1) Aural haematoma
2) Pinna trauma / lacerations
3) Neoplasia – Pinna / ear canal
4) Otitis externa
○ Lateral wall resection
○ Total ear canal ablation
5) Otitis interna and media
○ Total ear canal ablation and lateral bulla osteotomy
○ Ventral bulla osteotomy
68
Ear describe the vascular supply, motor innervation, sensory innervation
• Vascular supply
- The great auricular artery, a branch of the external carotid arising adjacent to the bulla.
• Motor innervation
- Facial nerve exits the skull via the stylomastoid foramen and crosses immediately ventral to the horizontal ear canal.
• Sensory innervation
- Vagus nerve
69
What is different with middle ear in cats and dogs
- In cats, more distinct separation of the chambers into a larger ventral cavity and a smaller dorsal cavity
These are nearly completely separated by a bony septum with a small slit like communication between them - when doing some bulla surgeries need to remove this for lavage
70
What are 4 important things in pre-surgical assessment for the ear
1) clinical signs assocaited with ear pathology - pain response, head shaking, discharge, thickening, head tilt, circling - NEED TO DOCUMENT BEFORE SURGERY
2) otoscopic exam
○ Determine if tympanic membrane is intact, and whether it’s grossly normal
3) Cytology
○ Indication of the types of organisms present
4) Imaging
○ Skull radiographs - open mouth rostro-caudal view to image tympanic bullae
○ CT or MRI can more accurately determine the nature and extent of the disease
71
Aural haematoma what is a common cause and what occurs without treatment
- Vigorous head shaking secondary to acute or chronic otitis externa or foreign bodies.
- Shear forces result in the creation of dead space and rupture of vessels. Blood fills the space created between skin and cartilage.
- If no treatment -> scar tissue formation, contraction, distortion of the pinnae - cosmetically bad and in cats
○ In cats -> medial movement of the ear which can block the external canal -> further increasing otitis externa
72
Describe the 3 steps in treatment for aural haematoma
1. Cut medial aspect - S shape, straight line or bunch incisions-> can break the fibrin formation
2. Close the dead space that you formed -> parallel sutures, parallel to incisions (which is parallel to blood supply)
3. Bandage the ear to the head for 5-7 days to help prevent further trauma from head shaking or scratching.
- Take care when removing the bandage with scissors to avoid cutting the pinna.
73
Laceration of the ear what healing present and treatment
- If only one skin surface is involved, lavage, debridement and primary repair may be indicated
- Second intention healing can result in acceptable healing.
Treatment
- When a full thickness injury is present, primary repair is indicated
- Suture both skin surfaces and cartilage layer
○ Vertical mattress suture -> deep for subcutaneous and superficial for skin apposition
- The ear margins should be reapposed first
74
Neoplasia of external ear what are common types and when biopsy
- Chronic wounds SHOULD BIOSPY as could be neoplastic
- The more frequent types include:
○ Squamous cell carcinoma
○ Haemangioma / Haemangiosarcoma
○ Basal Cell Tumour
○ Mast Cell Tumour
○ Histiocytoma
○ Sebaceous Adenoma
75
Squamous cell carcinoma what present as, contributing factors, risk factors, treatment
- Squamous cell carcinoma frequently present as chronic non-healing wounds which may be cracked and bleeding.
- Thin hair covering and unpigmented skin is a contributing factor.
- White cats have a 13.4 X greater risk of SCC than coloured cats.
- Surgical treatment may require partial or complete pinnectomy +/- vertical canal resection depending on the extent of the disease.
- Incomplete excision will frequently result in recurrence in a short time frame.
- Small lesions may be treated via a variety of other local modalities such as cryotherapy, laser ablation or local radiation therapy
76
Sub-total and total pinnectomy when indicated, what important and the 3 steps
- Sub-total and total pinnectomy may be indicated for trauma or neoplastic disease.
- Appropriate surgical margins are important for neoplastic disease - otherwise recurrence
1. Excise the tissue to be removed
2. Pull skin on the convex surface of the pinna over the edge of the cartilage and suture with 4-0 or 5-0 monofilament, non-absorbable suture in a simple continuous pattern.
3. Ink the cut edges for histopathology margin assessment for neoplastic disease cases
77
Lateral wall resection how common, indications, when not indicated and success rate
- Opening the lateral ear canal - REALLY RARE
- Indications:
○ Facilities management of otitis externa that is controlled with medication (improves ventilation, reducing moisture, humidity and temperature)
○ Removal of benign neoplasia of vertical canal
- NOT indicated if stenosis of canal is present or in Cocker Spaniels
- Success rate 35-50%
78
Total ear canal ablation when indicated, what involved and the 3 general steps
- Indicated for end stage otitis externa / media
- Hyperplastic, stenotic vert. and horiz. canals
- Removal of entire ear canal and lateral bulla osteotomy to drain bulla
1. Cutting outside surface of the cartilage down to the tympanic bulla
• Need to stay close to the cartilages to avoid blood vessels and nerves
○ Facial nerve near the tympanic bulla
2. Lavage bulla
3. Take culture and sensitivity
79
What are 5 potential complications for total ear canal ablation
1. Facial nerve damage
○ Pulsing of facial nerve 12-24 hours after
2. Haemorrhage
3. Can have some hearing after surgery - but cannot hear before surgery
4. Fistulation if tissue left in situ
○ Can occur even 2 years post-operative surgery
5. Horner's syndrome -> reported up to 40% of cats post op
○ May damage the tympanic bulla
80
List some clinical signs of anal sac disease
- Scooting
- Licking and biting the anal area and tail base
- Discomfort in sitting
- Painful defecation
- Tenesmus
- Draining tract when abscess ruptures
81
Anal sacculectomy what are the 2 main indications and the 2 main techniques
Indications:
○ Recurrent anal sacculitis/ impaction / abscess
○ Neoplasia
1) Closed technique for neoplasia
2) open technique can be used for inflammatory conditions
82
what occurs with close and open tehcnique of anal sacculectomy
CLOSED
Excising the sac WITHOUT ENTERING THE LUMEN
Fill the sac if too small and can't get access to
- Probe, string, gel, tape etc.
Incision over anal sac -> not into the anus
Duct is ligated
Sac is removed
OPEN
- Complete removal with the duct and orifice
- Incision on the anus and the skin in the end
83
Anal sac adenocarcinoma presentation, main clinical sign and treatment
○ Large, invasive subcutaneous mass
○ Hypercalcemia
§ Paraneoplastic syndrome
§ It and lymphoma most common cause of this
Treatment:
- Correct hypercalcemia prior to anaesthesia or surgery
○ Especially due to cardiovascular issues
○ Cause calcinuria -> steroids
- Wide surgical excision of primary mass along with enlarged sublumbar lymph nodes
○ Dissection of sublumbar lymph nodes carefully as right near the aorta
- Chemotherapy/ radiotherapy follow surgery -> advisable
84
Perianal adenoma how common in males and what associated with in females and typical behaviour and appearance
- Most common perianal tumor in intact male dogs
- Androgen dependent
○ Often have concurrent testicular tumor (interstitial cell tumor)
- In females related to Cushing's disease so always test for
- Typical behaviour and appearance
○ Slow-growing
○ Non-painful
○ Freely moveable
○ May occur on tail head, prepuce or scrotum
○ +/- ulcerated
○ Diffuse form
85
Perianal adenoma treatment and prognosis
- Treatment
○ Conservative/marginal resection + castration
○ Castration alone for diffuse form
○ Castration + cryosurgery for small lesions
- Always submit for histopathology!!
- Prognosis:
○ Good
○ >90% cured with castration and mass removal
Recurrences may be adenocarcinoma
86
Perineal adenocarcinoma diagnostic work up what involved and 3 treatmetn options
Diagnostic work-up
- Rectal exam
- Abdominal ultrasound
- Chest radiographs for metastasis
- +/- advanced imaging (CT, MRI) to assess degree of invasiveness
Treatment
- Aggressive surgical removal with margins if possible
- Radiation therapy may be required if margins are incomplete
- Do not respond to castration
87
Perineal adenocarcinoma what is the typical behaviour and appearance
- Can look similar to perianal adenoma
○ Cytology may not differentiate between perianal adenoma and adenocarcinoma
- Usually more rapidly growing, invasive and may be painful
- Occurs in intact males, castrated males or females (non-androgen dependent)
- Metastasize to sublumbar lymph nodes
88
Perineal adenocarcinoma prognosis in terms of lymph node involvement, local recurrence, future lifespan
- 15 % will have lymph node metastasis
- Local recurrence common w/ conservative Sx
- Prognosis variable - staging is important!
○ <5 cm diam. and no metastasis, 2 year survival
○ Worse with metastasis to lymph nodes or lungs, 2 month survival
- Surgery or surgery + XRT provides excellent local control
89
Amygdala is its general role and what role does it play with stress
- Limbic system
- Regulates emotional behaviours
- Regulates activity of HPA axis
- With stressors -> primes your brain to be ready for threats -> on edge
90
define stereotypies, compulsions and what makes a compulsive disorder
- Stereotypies: repeated motor patterns
- Compulsions: fixation on a goal
- Repetitive, exaggerated, sustained
- Out of context behaviours
- Interferes with normal functioning
91
What are the 4 main causes of compulsive disorders
1. Physical Stimuli
○ Irritations (lesions, sutures, allergy)
2. Conditioning
○ Owner inadvertently reinforces (e.g. attention)
3. Genetics
○ Breed Predispositions
4. environmental/psychological - largest trigger
92
Environmental triggers what are the main ones, and what result in
○ Stress, anxiety, frustration, conflict
○ Personality (e.g. fearful), disease or other behavioural problems that increase stress and irritability
○ Result in displacement or redirected behaviours
1. Trigger situation -> stress, conflict, frustration, anxiety
2. Displacement behaviour in trigger situation
3. Displacement behaviour generalised to different triggers/context
4. Displacement behaviour emancipated from triggers - interferes with normal function or causes injury
93
Psychological stressors what is the main one and how occurs
Lack of control and predictability
□ Inconsistent owner interactions
□ Lack of training and inconsistent commands
□ Inappropriate use of punishment
□ Inconsistent routine
□ Frustrated in meeting social, interactive and exploratory needs
94
What is important about stressors that lead to different tolerance levels
○ Stressors are additive
§ Threshold theory - accumulative of all the stressors
□ Can also help if you treat one or two stressors may
§ One stressor may initiate compulsive response, but other stressors maintain the behaviour
□ Look for multiple causes
95
List 5 examples of compulsive diorders in dogs
1. Locomotion
○ Circling, tail chasing, pacing, jumping, chasing light, freezing
2. Oral
○ Chewing legs, feet, self-licking, air or nose licking, flank sucking, scratching, chewing or licking objects, polydipsia, pica, ‘fly’ snapping
3. Aggression
○ Self-directed aggression – growling at hind end, attacking legs, hind end or tail, attacking food bowl, or other objects
4. Vocalisation
○ Rhythmic barking or whining
5. ‘Hallucinations’
○ Startling, staring
96
List 8 differential diagnoses for for compulsive disorders
1) CNS lesions - circling
§ Brain stem, and forebrain (larger circling), vestibular (one side only)
2) seizures
3) gastro-intestinal
4) sensory neuropathies - reduced pain in distal extremities
5) musculo-skeletal
6) dermatological
7) conditioned behaviour - attention seeking - only in owners presence
8) acute conflict behaviour - only in response to trigger
97
what are the main differences between seizures and compulsive disorders
§ Different pathogenesis and history of development
§ Aware of environment - not aware if seizures
§ Distractible
§ No post ictal phase -> hangover phase
98
What are the 9 compulsive disorder criteria
1. Out of context
2. Excessive
3. Unusual target objects
4. Repetitive, sustained
5. Conscious
6. Usually can be interrupted (strong stimulus needed sometimes)
7. No post ictal stage
8. Owner does not need to be present
9. Generalised to any situation with high arousal
99
List the 3 main treatment of behavioural problems
1. Management
2. Modification
3. Medication
