Dog and Cat 2 Flashcards
Skin infections causes what are the most common and more occasional agents
- Staphylococcus pseudintermedius (common) - all over the dogs skin most concentrated around mouth and nose
- Malassezia pachydermatitis (common) - over the skin
○ OPPORTUNISTIC - MRSP (increasing big problem)
- Other Staphylococcal spp or yeast (occasional)
- Pseudomonas (occasional)
List 4 reasons dogs have a higher prevalence of skin infections
- Higher skin pH
- Less epidermal lipids -> atopic dogs have even less
- No follicular lipid plug -> prevents topical chemicals getting into hair follicle
- Atopic dermatitis is common in dogs -> 10% of population
List 6 reasons dogs get skin infections
- Anatomical reasons - skin folds (increased environment for infection) - brachycephalic dogs
- Microclimate changes - swimming especially with thick coat dogs - not drying thoroughly
- Decreased exfoliation/follicular obstruction - long term corticosteroid therapy (stop turnover of skin cells (exfoliation))
- Decreased Immunity
- Self-trauma (scratching) - break the skin and liberate proteins that the agents can use
- Atopic dermatitis
What are the 3 main types of skin infections and
- Surface
○ Malassezia are almost always SURFACE infection
○ Skin fold pyoderma, hot spots, otitis - classic - Superficial - MRSP common
- Deep - usually painful not itchy
Surface infections what is the main clinical presentation and common areas
Common presentation - No papules, pustules or cellulitis - Hyperpigmentation - Can be greasy or scaly/dry depending on the dog - Hot spots -> rapid development, aggressive, intensely pruritic Common areas - Skin folds - Most areas - humidity - Thickened skin
What breed is important in terms of surface skin infections and what occurs
Westies - Breed variation ○ Something in the skin that reacts with the bacteria ○ Non-specific inflammation ○ Hyperproliferative skin - Clinical importance ○ Difficult to control colonisation ○ Cytostatic therapy?
For surface infections what diagnostic techniques used, treatment and maintenance/prevention
Cytology 1. Tape preps 2. Roll preps 3. Direct impression Treatment Surface infections do better with surface treatment (topical treatment) - topical anti-bacterial/fungal Maintenance/prevention - Surgery (anatomical problems) - Control environmental wetting - Treat underlying disease (eg atopy) - Shampoos ○ Pyohex conditioner ○ Malaseb (miconazole, chlorhexidine) ○ Mediderm (piroctone olamine)
superficial infections what are the 2 main causes and how to diagnose the different presentations
Causes - Folliculitis ○ Demodicosis ○ Dermaophytosis - Pustules ○ Pemphigus foliaceous ○ Contact allergy - lesions look like pustules BUT NOT PUSS Diagnosis - Pustules ○ direct smear - Papules ○ direct smears ○ blunt scrape - Crusts ○ direct smear - Annular scale (dry lesions) ○ tape cytology
In terms of treating bacterial superficial infections what is an important drug and how long administer and why
- Cephalexin 22mg/kg bid (Rilexine) - PRIMARY CHOICE AS WORKS FOR MRSP
Treat for at least 7 days AFTER clinical resolution MINIMUM of 3 weeks - Watch out for MRSP
MRSP - Methicillin Resistant Staphylococcus pseudintermedius how transmitted, why an issue and risk factors
- Cultured from veterinary clinics -> carrier dogs will shed in this environment, susceptible animals then pick this up, not an issue until selected for via antimicrobials
○ Issue when gets into clinic and - Generally staph sensitive to beta-lactam antibiotics
○ Resistant -> low affinity penicillin binding protein - beta-lactams don’t work
○ Resistant genes can be transferred and have areas in DNA where other resistant genes can insert
§ Generally multi-drug resistant - Risk factors - going into veterinary clinics (waiting room), giving beta-lactam antibiotics with corticosteroids/apequal, going to dog groomers, antibiotic ear drops (absorb some into bloodstream)
Deep skin infections how generally present, how occur, causes and treatment
- Usually painful not itchy
- Is an extension from superficial infection after follicular rupture
- Often mechanical reasons
○ Over bony points
○ Weight bearing interdigital areas
Treatment
○ 6-8 weeks antibiotics
○ Anaerobic PLUS staph activity
○ Deep culture
○ Choosing antibiotic
§ Must be able to reach infection
§ Clindamycin good empirical choice
□ Get into cells (neutrophils/macrophage with bacteria within)
□ Good for Anaerobic bacteria
□ Can miss MRSP
§ NO STEROIDS!!
§ Re-assess each 2 weeks
§ Beware foreign bodies
What are some causes of repeat and recurrent infection
repeat - environmental riggers, anatomical reasons, foreign bodies, underlying disease recurrent infection - Atopy - Demodicosis - Other hypersensitivity diseases - Endocrinopathies - Keratinisation defects
Dermatophytosis - ringworm what are the 3 main types, animal within, does it fluroesces and zoonoses
Microsporum canis (cat) - Kittens, long haired cats (Persians) - Hair fluoresces - ZOONOTIC Trichophyton metagrophytes (rodents, GPs) - Dogs that hunt, rural exposure - Doesn't fluoresces - Not zoonotic Microsporum gypseum (soil) - Dogs that dig (face and forelegs)
3 ways to diagnose dermatophytosis and treatment
Diagnosis
- Wood’s lamp -> fluorescents so good for Microsporum
- Culture - good for Microsporum canis and trichophyton NOT MICROSPORUM GYPSEUM
- Biopsy - good for Microsporum gypseum
Treatment
- anti-fungal
- treat for 14 days past negative culture - ZOONOSIS
Give 5 indications for ovariohysterectomy
- Elective -Desexing/Population control
- Reduction of mammary neoplasia risk
- Treatment of behavioral conditions
- Treatment of other medical conditions
- Council registration
What is standard practice for desexing females, what occurs in shelters and claims for this
- Standard practice to desex females at age of about 6 months - before first or second oestrus
- More recently shelters 8-12 weeks -> debatable
○ Claimed decreased stress and operative time.
○ Assurance that the animal is desexed when it is re-homed.
○ Anaesthetic risk?
○ Decreased maturation of external genitalia
○ Increased incidence of oestrogen responsive urinary incontinence.
○ Increased risk of bony neoplasia in giant breeds?
What is an important difference with desexing female in season and what important if have a litter
○ Uterus more friable and increased blood supply - need to be confident with ligatures and haemostasis
○ Oestrogen can have a detrimental effect on haemostatic mechanisms.
○ If possible delay for 4 weeks after the onset of pro-oestrus.
§ Desexing an early pregnant bitch is easier than in season.○ After a litter, wait until 3 weeks after weaning to allow mammary tissue to involute.
How does the risk of mammary neoplasia change based on when spay
- Reduction in risk is a major benefit of canine OHE/OVE: (Lifetime risk of Mammary Neoplasia)
○ 0.5% if spayed cf intact before first oestrous -
○ 8% if spayed cf intact after the first oestrous
○ 26% if spayed cf intact after the second oestrous
○ No decrease in risk if spayed after 4 oestrous cycles
Entire cats have 7x the incidence of mammary tumours cf spayed queens
What are the 3 main ligaments of the female reproductive system and what connect
1) The broad ligaments consist of the mesovarium, mesosalpinx and the mesometrium.
2) The suspensory ligament is the cranial continuation of the broad ligament from the ovary –coalesces into a distinct band which inserts on the middle and ventral thirds of the last two ribs.
3) The proper ligament attaches the ovary to the uterine body - between ovary and uterine horn
Blood supply of the female reproductive tract what are the 2 main arteries and connections
1) Ovarian artery is a direct branch off the aorta.
§ The ovarian artery supplies the ovary and cranial aspect of the uterus
○ The right ovarian vein drains into the caudal vena cava.
○ The left ovarian vein drains into the left renal vein
2) Uterine artery
○ Branch of the internal pudendal artery
○ Positioned on the lateral aspect of the uterine body bilaterally
○ Enters the mesometrium at the level of the cervix
Anastomoses between the ovarian and uterine arteries are believed to exist
what are the lymphatics and innervation of the female reproductive tract
Lymphatics - Drain to the hypogastric and lumbar lymph nodes Innervation - Hypogastric plexus - sympathetic Pelvic nerves - parasympathetic
what is an important difference with canine and feline ovaries in terms of neutering
- Canine ovaries are difficult to expose (if on heat easier) and the cervix is easily mobilised
- Feline ovaries are easily exposed and the cervix is less mobile
ventral midline vs flank for neutering which better and why
- Ventral midline is MY preference over flank:
○ Better access to peritoneal cavity if problems occur
○ Can check haemostasis
○ Access to right ovary can be difficult through flank approach
○ Anecdotally increased incidence of seroma with flank procedures ( 3 x muscle layers)
○ BUT Flank approaches commonly performed in UK and at some welfare centresand private practices - Flank -> can be done depending on the clinic, generally done if have mastitis
what are the 7 main steps in ovariohesterectomy up to clamping ovary
1) express bladder
2) Canine - at or 1-2cm caudal to the umbilicus extending 5cm -> more cranial if younger due to suspensory ligament
- Feline - 3-4cm incision centred over the midpoint between the cranial rim of the pelvis and the umbilicus
3. Finding uterine horns
○ lies ventral to the rectum and dorsal to the bladder
4. Spay hook - introduce hook parallel to the body wall and rotate 90 degrees and move toward the midline
5. Exteriorise ovary –right is more difficult.
○ Stretch, break or cut suspensory ligament
6. Ligate the ovarian pedicle –create a window in the mesovariumcaudal to the ovarian vessels and triple clamp with Carmault-Rochester forceps.
7. 3 clamps proximal to ovary if possible otherwise one clamp between the ovary and uterus
Steps 8 - 13 in ovariohesterectomy starting after 3 clamp method
- Tie into the crush
- Selection of suture size depends on the amount of fat in the pedicle and your confidence in your ligature.
○ Dog 0 –2/0, cat 2/0 –3/0
○ Consider slipknot or Miller’s knot - Transect the ovarian pedicle and hold the pedicle in forceps without tension before releasing into the peritoneal cavity.
- The broad ligament may be cut or broken down with fingers.
- Avoid the uterine vessels.
- In multiparous, pregnant or mature dogs there may be large branching vessels that require ligation. - Check abdominal cavity for haemorrhage - normal to have some bleeding
- Linea alba closure –interrupted or continuous monofilament absorbable (1 –3/0) egpolydioxanone. Ensure closure incorporating rectus sheath.
○ Best NOT to use chromic catgut in a continuous manner
What are 5 important complications of ovariohysterectomy
1) haemorrhage - most common (70%)
2) wound healing complications - sutuer reaction, seroma
3) ovarian remnant syndrome - NEED TO REMOVE ENTIRE OVARY
4) urinary incontinence - 11-20%
5) weight gain - 26-38%
Ovariectomy V Ovariohysterectomy
- Historical preference in Australia, the UK and the US for ovariohysterectomy in the bitch and the queen
- Due to concerns regarding uterine disease post-operatively when exogenous hormonal therapy has been administered for:
- no significant differences between techniques were discovered for incidence of:
○ endometritis/pyometra
○ urinary incontinence
○ obesity.
What is the most importnat pre-op consideration with casearian and desex or not
- Time from anaesthetic induction to delivery of pups should be as short as possible - therefore as much prep needs to be done before induction
- Anaesthesia–maximise dam safety / minimise foetal depression.
Desex or not? Controversy.
○ May prolong anaesthesia/SxVS save a subsequent procedure. Loss of circulating volume?
○ Take longer to recover -> need to stay in longer at the clinic BUT want the mum and pups to go home and start nursing as soon as possible
○ If won’t return to desex then should do it
What are the 10 main steps in a casearaian
- Ventral midline approach, 2 –3cm cranial to and 5 –6 cm caudal to the umbilicus.
○ Take care not to damage the abdominal contents particularly the gravid uterus. - Pack off the uterus from the abdominal cavity with laparotomy sponges
- Incise the uterus in an avascular area within the body that will allow removal of foetuses from both horns.
○ Sometimes multiple incisions will be required. - Gently milk each foetus to the uterine incision
- Break through foetal membranes and clamp the umbilicus 2-3cm from its base
- Rub foetuses vigorously to stimulate breathing
○ Give supplemental warmth and O2 - CHECK ALL FOETUSES ARE REMOVED
○ Especially check the uterine body and vagina - A Cushing or Lembertpattern is recommended with synthetic absorbable monofilament suture.
- The uterus is thoroughly lavaged before being returned to the abdomen.
- Change gloves and instruments and close the abdomen
What are the 3 main complications of casaearians
- Haemorrhage–intrauterine (oxytocinor ovariohysterectomy) or peritoneal (ligature failure)
- Infection –especially if long procedure or gross contamination of peritoneal cavity.
- Foetal or maternal death.
Vaginal oedema/hyperplasia when occur, what occurs, how present, what breed more suscepible and treatment
- During oestrogenic phase (oestrus and proestrous)
- Vaginal mucosa becomes swollen allowing a transverse fold to prolapsethrough the vulva
- Presents as a large mass protruding through the vulva
- Exposed tissue predisposed to dessication, ulceration and trauma
- Esp. Brachycephalic breeds
- Regresses spontaneously during the luteal phase but interferes with breeding and may recur during parturition resulting in dystocia.
Treatment - OVH provides permanent relief.
- Other treatments include:
1. excision of the prolapse (haemorrhage) - not common
2. conservative (lubrication, sugar water to help reduce oedemaand manually try to reduce followed by purse string suture)
3. pharmacologic induction of ovulation (GnRH or hCG)
Vaginal prolapse how common, breed predisposed, how differeniate with hyperplasia, what occurs and treat
- Rare
- Brachycephalic breeds predisposed
- Differentiated from hyperplasia by circumferential prolapseof the vagina. Must also be differentiated from tumour–careful examination +/-biopsy
- Occurs after forced separation during mating or in the advanced stages of parturition due to excessive straining.
- If recognised early an attempt can be made to reduce the prolapsehowever amputation is often necessary.
Neoplasia of vulva/vagina benign or malignant most commonly, what type generally and treatment
- 70 –80% benign
- Most common leiomyoma, fibromaor lipoma.
- Malignant: leiomyosarcoma
- Surgical excision is treatment of choice.
what are the 3 main issue with entire males
○ Population control ○ Unwanted behaviour: § Aggression § Marking § Mounting ○ Disease: § Testicular Neoplasia § Prostatic disease (Prostatitis, BPH, Prostatic cysts) § Perineal hernia § Perianal adenoma
List 6 main reasons for castration
- Population control:
- Prevention of behavioural issues
- Prevention / Treatment of testicular tumours
- Prevention / Treatment of prostatic disease:
○ Benign Prostatic Hypertrophy/Prostatitis/Cysts
○ Exception of prostatic neoplasia (androgen independent in most dogs) - Primary/adjunctive therapy of perianal adenoma
- Treatment of Testicular torsion
Timing for castration what is optimal age and why
- Traditionally believed 6-9 months as optimal age:
○ Avoids perceived problems of anaesthesia in young animals
○ Performed prior to development of sexual maturity:
○ Population control
○ Undesirable male behaviour
○ Evidence?
What are the 2 main surgical castration techniques and which is preferred
- Open Castration
- Preferred method:
○ All structures can be visualised
○ Ligatures applied directly to vessels without interposed tunics. - closed castration
what is the difference between open and cloased castration
- Initial technique similar to open BUT
○ Tunica albuginea NOT incised
○ Testicle and cord separated from surrounding soft tissue attachment
○ DOUBLE (slippery tunic) ligature technique:
§ Proximal ligature into crush
§ Distal transfixation ligature - Closure and incision identical identical:
○ Avoid suturing the urethra!!
○ Prescrotal incision
○ 2 layer closure –incorporate raphe
feline castration how occurs and what is scrotal ablation and what used in
FELINE - 2 scrotal incisions and testicular exposure (gentle pressure), scrotal incision heal via second intention healing - just leave to drain Scrotal Ablation - Cutting around the scrotum - Indicated in: ○ Mature dogs with pendulous scrotum ○ Cosmetic ○ Dogs with scrotal/testicular neoplasia ○ Dogs with scrotal/testicular infectious dz
List 5 complications associated with castration and 2 ways to prevent
○ Scrotal bruising / haematoma - proper ligation of vessels ○ Haemorrhage ○ Dermatitis ○ Infection / Abscess ○ Persistent Priapism in cats Prevention: ○ Good surgical technique ○ Prevention of self-trauma -> loose sutures
Cryptorchidism when know, where occur more and the 3 main consequences
- Practically dx > 6mths.
- Right testicle +/-more commonly affected
- Polygenetic inheritance suspected (avoid breeding)
Consequences
○ Fertility:
§ Bilaterally affected animals –sterile
§ Unilaterally affected animals –sub-fertile
○ Neoplastic transformation:
§ Dogs: 9.2-13.6%
§ Cats: ?
○ Testicular torsion:
§ Increased mobility
§ Increased mass associated with neoplasia
Cryptorchid what are the 2 main surgicial techniques and how to choose
- Confirm the location: (abdominal v inguinal)
○ Palpation
§ only accurate in 48% cats
§ Fat, Lymph nodes(better to do under sedation) - Ultrasound when available as very accurate
1. Open - incision adequate for visualization
2. laparoscopy
what are the 3 most common testicular neoplasia and which most common in cryptorchids
a. Sertoli Cell Tumours
b. Interstitial Cell Tumours (akaLeydig)
c. Seminomas
- In cryptorchids Sertoli Cell Tumours & Seminomas are most common
What are 4 ways to diagnose testicular neoplasia
1) Examine both testicles –bilateral involvement frequent and assess prostate
2) Staging:
○ Thoracic (CT/Radiography)
○ Abdominal imaging CT/U/S)plus local imaging of testis,
○ CBC for myelotoxicity and coagulation assessment
3) Histopathology via excisional biopsy:
○ Confirms diagnosis
4) For high breeding value animals:
○ Testicular sampling:
§ FNA and biopsy may be performed for definitive
Sertoli cell tumours what is the main clinical presentation, treatment and metastasis
- Feminization syndrome in 16-39%:
○ symmetrical alopecia
○ squamous metaplasia of prostate with increased risk of cystic change and abscessation•
○ pendulous prepuce,
○ penile atrophy, - Feminization generally reversible with removal of oestrogenic source–unless mets present
- Metastatic sites: (2-10%)
○ LN –medial iliac, sublumbar, inguinal
○ Lungs, Liver, Spleen, Pancreas, Kidneys
Interstitial cell/leydig tumourswhat occurs and metastasis and what is good about seminoma
- Increased testosterone production: ○ Perineal hernia ○ Perianal adenoma/adenocarcinoma - Metastasis: ○ Uncommon but reported in LN, Lung ○ Prognosis excellent with orchidectomy seminoma - prognosis good in absence of metastases (rate 6-11%)
What are the 2 main clinical signs of prostatic disease and 4 important diagnosis techniques
clinical signs 1) constipation 2) urethral bleeding/discharge Diagnostic approach 1) history of reproductive status 2) palpation - symmetry 3) radiography - size, shape, location, mineralisation 4) ultrasound - size, symmetry, margination, echogenicity
4 indications for surgery of prostate what is important organ to use and important consideration with castration
Indications: ○ Biopsy ○ Prostatic Abscess ○ Cystic Disease ○ Prostatic neoplasia Omentalisation - to seal the prostate - Omentum: ○ Vascular supply ○ Lymphatic drainage ○ Immuno-competent Cells Castration does not prevent, not androgen based
Complete Prostatectomy when use
- Malignant neoplasia sole indication:
○ Bladder / urethral TCC
○ Prostatic adenocarcinoma
Phimosis what is it, causes, results in and treatment
- Inability to extrude the penis: ○ Preputial oriface too small Causes - Congenital: ○ Narrowed preputial opening ○ Persistent frenulum - Acquired: ○ Trauma ○ Infection ○ Surgical scarring ○ Neoplasia LEADS TO - urine pooling, balanoposthitis, erectile pain Surgical Therapy - Enlargement of a narrowed Preputial os performed via v-shaped incision on the dorsal surface and apposition of mucosa to skin - A Slightly over-enlarged orifice created as narrowing is anticipated with healing
Paraphimosis what is it, causes, cliinical signs and treatment
- Inability of the penis to retract within the prepuce:
Causes - same as phimosis
clinical signs - penis can become engorged
treatment aimed at replacement of the penis:
○ Lubrication
○ Hyperosmolar solutions
○ Local cold therapy
○ Temporary surgical enlargement of the preputial os - Recurrence is common:
Surgery of penis when most common, clinical signs and treatment
- Most common in young male brachycephalic dogs:
○ Abnormal urethral development?
○ Increased intra-abdominal pressure (dyspnoea, excitement) –reduces venous return from penile veins? - Clinical signs:
○ Haematuria
○ Bleeding from penile tip
○ Licking
○ Red-purple mass (urethral mucosa) protruding from distal penis
○ DDxTCC, TVT, SCC - sertoli cell or transitional cell carcinomas
Treatment:
○ Castration (reduction of sexual excitement and dominance mounting)
○ Correction of Brachycephalic Syndrome - Penile surgery if (painful, bleeding):
penile neoplasia how common, clinical signs, diagnosis and treatment
- Uncommon in dog, rare in the cat
- CSx:
○ Licking
○ Urethral Discharge - Diagnosis:
○ Impression smear, FNA, Biopsy - Treatment Modalities:
○ Chemotherapy (TVT)
○ Radiation therapy - NOT IN VIC
○ Surgery:
§ Partial penile amputation -> Malignant tumours on distal penis
§ Larger diffuse tumours -> Penile amputation + scrotal or perineal urethrostomy
What are 3 important ophthalmic examinations to do in a light room
1) distance exam - assess symmetry, size, position, check for redness, dicharge, swelling
2) palpate bony orbit, retropel globe
3) assess vision in light room
○ Dogs can hide their vision lost quite well, horses can also adapt to low vision if in a stable environment
○ Asses via:
i. Menace response
ii. Moving object, visual placing
iii. Dazzle reflex - bright light into the eye - detect the light and blink
□ Important for hyphaemia, cataract, inflammation -> testing whether the retina is still attached
iv. Obstacle course exam
v. Palpebral reflex and other CN responses
Dark room opthalamic exam what are the 9 tests to conduct
- PLR (pupillary light reflex) -> consensual light responses (opposite eye), any anisocoria (look at evenness of pupils)
○ Retina or optic nerve disease - Eyelids
- Third eyelid -> press on the top of globe to passively expose in horse and dogs, cats can control the movement
- Conjunctiva
- Sclera
- Anterior segment: Cornea, AC, Iris
- Measure IOP (intra-ocular pressure) with tonometer
○ Need to use local anaesthetic (why collect samples at the beginning) - Dilate pupil (tropicamide!): Lens, viterous, fundus exam
- Fluorescein staining - PERFORMED LAST
Collecting diagnostic samples from the eye what is important to do
- Evaluate eyelid, conjunctiva and globe
- Determine which diagnostic samples required
- STT and MC&S need to be performed at beginning of exam as other examination procedures may affect their results
what is important with eye exams of cats
○ Place at edge of exam table -> looking down -> unlikely to be prolapsing their third eyelid at this point
○ Measure BP in all cats >8-10years of age -> pick up early changing as high BP can lead to blindness in end stages
What are the 2 types of examination techniques of the eye, how conduct and when to use
- Focal illumination
○ Using the light source -> move left and right and up and down
○ Help examine the different levels and tissues of the eye -> highlight region of interest - Retroillumination - helps to localise lesions within the eye and give character
○ Examination tool not a test
○ Use light source shinning into eye, bouncing off tapetum and reflects back to you
○ Highlights lesions and helps determine whether solid or liquid (solid light doesn’t come back)
What is aqueous flare, where frequently occur, what is important to diagnose
uveitis - determine whether the eye is inflamed
○ Frequently occurs with anterior segment disease in horses
○ Focal light essential to detect aqueous flare -> need the slit beam at 45 degree angle
§ Separate eye tissues and determines whether cells in anterior chamber
§ Should see black (aqueous humour) however if dusty/speckled -> cells present
List 4 important tests during opthalamic exam
1) schirmer tear test
2) corneal cytology
3) tonometry
4) fluroescein staining
Schirmer tear test when performed, how perform and normal
○ Performed in all cases presenting with ocular discharge and conjunctivitis -> especially dogs (maybe not cat and horse)
○ Reduced by GA and sedation
○ Performed at beginning of exam
○ Must contact cornea - lateral eyelid -> lower eyelid lateral canthus
○ Usually well over 20ml -> 15ml is the minimum
Corneal cytology what used for and what need to perform
○ Invaluable diagnostic aid/test ○ Detects infection, chronic/acute disease, antibiotic selection ○ Topical anaesthesia ○ Blunt end of scalpel blade ○ Place on slide and Diff Quick
Tonometry what important for, what does it so and what do you need
○ Essential to determine the difference between uveitis (really low) and glaucoma (really high) -> can present the same
○ Measure IOP in both eyes - IOP rarely varies > 5mmHg between two normal eyes
○ Sedation, nerve blocks and head position can affect IOP but clinically insignificant
Fluorescein staining when perform, where place, what is normal and when abnormal
○ Use pre-package sterile strips
○ Apply to all eyes at the end of your exam so as not to interfere with other testing
○ Place strip on bulbar conjunctiva - DON’T TOUCH CORNEA
○ Don’t use too much false positive staining common, irrigate eye until fluorescein stops flowing from eye
○ Should pass into distal NLD in 5-10mins
- Absent in animals with block nasolacrimal duct, lazy nasolacrimal duct or hair media canthus
What are the 2 main nerve blocks in the horse when examining the eye and where to block them
- Auriculopalpebral nerve provides motor supply to orbicularis occuli muscle (branch of CN VII)
- caudal ramus of mandible
- dorsal zygomatic arch
- cranial zygomatic arch/caudal frontal process
- frontal nerve provides sensation to the upper eyelid and dorsal periocular skin (branch of CNV)
Blocking both nerves provides total akinesia and analgesia to upper eyelid - as emerges from supra-orbital forramen
Fundus examination what is important
- Completes ophthalmic examination
- Large variation in normal
- Coat colour, age, breed can all affect appearance of fundus
- Disease state adds further complexity
What is different between direct and indirect ophthalmoscopy
Direct ophthalmoscopy
- Real, upright image
- Highly magnified
- Peripheral lesions difficult to visualise -> alright for horse as most lesions near the optic nerve
Indirect ophthalmoscopy
- Difficult to learn - commitment and practice
- Projected (left to right), upside down image of fundus -> need to remember to localise
- Good for scanning fundus of lesions
Direct ophthalmoscopy used to “hone-in” on any pathology
What are the 3 main causes of discharging eye
3 main causes
- Increased ocular discharge - increase in lacrimation
- Impaired drainage
- Both increased production and impaired drainage (RARE)
Define epiphora, punctal atresia, dacryocystitis, entropion and blepharitis
Epiphora - overflow of tears from impaired drainage or excess production of tears
Punctal Atresia - absence of one or more puncta in eyelids
Dacryocystitis - inflammation of the nasolacrimal sac/duct
Entropion - turned in upper or lower eyelid(s)
Blepharitis - inflammation of the eyelids
Define conjunctivitis, corneal ulceration, uveitis and keratoconjunctivitis sicca
Conjunctivitis - inflammation of the conjunctiva
Corneal ulceration - defect of corneal epithelium with or without loss of stroma
Uveitis - inflammation of the uvea i.e. iris, ciliary body and/or choroid
Keratoconjunctivitis sicca - inflammation of the cornea and conjunctiva in dry eyes
Corneal cytology what useful for, most common issues in dogs and cats and what helps with
- Useful in all cases of blepharitis (inflamed eyelids and conjunctivitis)
- Acute or chronic
- Bacteria present (dogs); Chlamydophila inclusions (cats)
- Helps with TREATMENT decision making
Flushing the nasolacrimal duct what use and what if unsuccessful
- Use a human cannula or make your own
○ Modified hypodermic needles (bend 45 degree angle and cut sharp end and blunten) - Apply topical local anaesthesia - alcaine
- Firm restraint
- Gentle flush and watch response
- If unsuccessful: GA and explore with monofilament suture
Epiphora (watery ocular discharge) what possible causes and how to differentiate with tests
Differential diagnosis
- Block nasolacrimal duct, punctal atresia?
- Conjunctivitis - allergic, bacteria, viral, UV radiation (solar)
- Surface irritation - ectopic cilium, distichiasis, trichiasis
- FB?
- Lazy nasolacrimal duct or hair medial canthus -> generally in brachycephalic dogs
Tests
- STT
- Conjunctival cytology
- Fluorescein passage to nose - good to do due to unilateral discharge
- Nasolacrimal duct flush or explore under GA
Upper and lower eyelid erythema, oedema and alopecia what possible causes and how to differentiate with tests
Differential diagnosis
- Bacterial, fungal, viral, parasitic, immune=mediate blepharitis
- Neoplasia - MCT, LSA, sebaceous adenoma, lipoma
- Inflammatory conditions - nodular fasciitis, histiocytosis
Tests
- Skin scraping
- Sticky-tape cytology
- Incisional biopsy
- Deep tissue MC&S
Entropion (when eyelid rolls in medial) what causes and tests to differentiate
Differential diagnosis
- Entropion - primary (congenital) or secondary (chronic scar tissue formation)
- Trauma
- Conjunctival FB
- Corneal ulceration -> if present hard to know which came first, if adjacent to inward eyelid then likely entropion occurred first
- Feline herpes virus infection
Tests
- Apply topical anaesthesia - entropion may resolve ‘indicating spastic entropion’ is present
○ Even if it is spastic still will need surgical intervention
- Fluorescein stain - is there concurrent ulceration
Entropion how common, what caused by and treatment
- Entropion is a common condition of young and older dogs and cats
○ Certain breeds prediposed: Rottweiler, sharpie, Labradors, great dane, Weimaraner, mastiff
○ In many young cats entropion is secondary to FHV conjunctivitis and corneal ulceration
○ In older dogs and cats it occurs secondary to orbital fat atrophy and enophthalmos
Treatment - Treat primary cause if present EG FHV, trauma, FB
- Tacking (tacking sutures) in young animals <12 weeks
- Surgical correct of eyelid position
○ Skin and muscle resection
KCS (kerato-conjunctivitis sicca) or dry eye what tests needed to diagnose, how common and treatment
common in dogs
○ Certain breeds are predisposed: Cavaliers, West highlands, bulldogs, pugs, cocker spaniels
○ Dogs with DM and older dogs predisposed
○ Cats with FHV
Tests
- STT!!!!
- Cytology - secondary to bacterial conjunctivitis?
- Fluorescein stain
- MC&S - unlikely to be necessary
Treatment
1. Clean eyes
2. Optimmune (works best when tear reading 8ml and above -> need to treat EARLY), cyclosporin, or tacrolimus eye drops/ointments
3. Topical preservative free lubricants - applied regularly
4. Topical antibiotics
5. Canthoplasty (narrowing of eyelid opening) or PDT surgery in refractory causes
BEWARE -> brachycephalic breeds with KCS are prone to deep corneal ulceration
Distichiasis how to diagnose how common and treatment
common cause of epiphora in dogs
Diagnose
- Magnification to find the distichiasis (extra hairs on the eyelid margin coming into the eye)
Treatment
1. Transconjunctival excision in thick-eyelid breeds
2. Cryosurgery in thin-eyelid breeds
3. freeze the glands in dogs with think eyelids
Orbital abscess what tests are important and treatment
Tests - Physical palpation - OPEN MOUTH - Retropulsion - Examination or mouth - Orbital ultrasound, CT or MRI - Exploratory surgery Treatment - Exploratory surgery located the foreign body - Dental abscess are common cause of cellulitis or abscess, so make sure you examine the mouth
List 6 signs of a sore eye
- Blepharospasm
- Weeping eye
- Rubbing the eye
- Sleeping more than usual
- Protects the eye
Allergic response - hair loss of lid hair, ocular mucopurlent discharge and ulcerative keratitis treatment
Allergic
1. Anti-inflammatory drugs - topical, systemic
2. Antibiotics if ulcerative - cephalexin 22 mg/kg BID, clindamycin
Ulcerative
- surgery - debride and conjunctivitis graft
Ulcertative keratitis treatment options
- Surgery - debride with cotton bud/high speed -> extensive epithelial loss
- Bandage contact lens
- Third eyelids flap/temporary tarsorrhaphy not usually necessary
- Topical antibiotic +/- topical atropine
Supportive therapy - pain relief, anti-inflammatory
Fungal infection of cornea treatment
- Topical anti-fungal medication - voriconazole
- Anti-inflammatory medication
- Possible surgery
Eosinophilic keratitis and feline keratitis nigrans treatments
Eosinophilic keratitis
Treatment
- Topical anti-inflammatory/immunomodulating medication
- Dexamethasone drops
- Cyclosporin
Feline keratitis nigrans (corneal sequestration)
- Can be secondary to feline herpes virus keratitis (especially Persians)
Treatment
1. Treat primary cause
2. Artificial tears (for comfort)
3. Medical therapy unrewarding
4. Surgery - keratectomy with “button” graft, pedicle graft or corneoconjunctival transposition
Anterior uveitis what caused by generally in dogs and cats and treatment
- Cat - neoplasia (lymphoma), FIP virus, toxoplasmosis, FeLV, cryptococcosis
- Dog - neoplasia (lymphoma), uveodermatological syndrome
Treatment - Treat primary cause
○ Toxoplasmosis, cryptococcosis - Anti-inflammatories/immunomodulating medication - topical, systemic
- Secondary glaucoma or phthisis bulbi common
Surgery - enucleation
Glaucoma what treatment
- Treat primary cause
- Reduce production of aqueous
- Increase outflow (PG analogues)
- Pain relief
- Surgery - enucleation
What are the 3 main reasons clients seek advice with fleas
- No current flea control (non-allergic)
○ Routine flea control
○ Flea seen - Failing flea control (non-allergic)
- Itchy Dog! (allergic)
○ May not see fleas as scratch them off and the saliva heptins can last 2 weeks
Non-allergic pets may NOT be significantly pruritic
Routine control flea products work well with what of the follow conditions
1) If used as directed
1. Correct medication interval
2. Correct application technique
3. Correct timing with shampoos/swimming
4. Correct dose for each pet
5. All pets in the house treated
2) if expectations are accurate
1. Efficacy often drops at the end of the month
2. Speed of kill is not instantaneous
3. environemntal fleas can persist >140d
4. closed environment = easier to control
In terms of speed of kill of flea products what is needed to eliminate flea allergy dermatitis and products that do this
anything that works within 4 hours advantage/advocate - cats comfortis - dogs capstar - dogs and cats Activyl - best for flea allerge
What is delayed emergence and how is it important for control
Delayed emergence - IMPORTANT
§ Egg to new adult within 14 days if climatic conditions are perfect
□ 75% humidity, 25-26 degree Celsius
§ If not perfect can stay in pupated version for a few months (hard to kill)
□ Stay underneath furniture, underneath steps -> where protected
§ When emerge stay in area near the light
§ 5-6months from time to start flea control to when will no longer have fleas at home
What control is appropriate for closed vs open environmental with and without fleas for dogs and cats
i. Closed Environment § No fleas □ no control needed § Occasional departure □ Dogs: IGR only (e.g. Lufenuron) ® If clients not flea phobic, otherwise all the adulticides ok ® Cats: Selamectin (Revolution) q28d, Activyl, Comfortis ii. Open Environment § Dogs: □ All adulticides OK if not flea phobic □ Flea phobic need rapid speed of kill § Cats: □ Selamectin q28d, Activyl, Comfortis - need continuous control
Failing flea control what are the reasons
IS IT REALLY FAILING? - delayed emergence or other causes of pruritis 1. Atopic dermatitis 2. Food allergy 3. Scabies 4. Bacterial pyoderma 5. Malassezia dermatitis FAILING 1. poor compliance 2. access to flea nests 3. untreated animals - wildlife 4. others - wetting/shampooing - avoid daily swimming, gentle shampoos 5. resistance - rare possible organophosphates, pyrethroids
Access to flea nests what need to determine and what is important for control in each area
○ Need to determine if
§ Inside the home
§ Outside the home
1) Inside infestation -> prolonged emergence
§ Will probably be under the couch
□ Vacuum underneath furniture to cause adult to emerge, then spray and do the same thing in 1 month
§ How to tell if in the house?? -> wear long white socks, bright light near the dogs bed and walk past, fleas will hatch and latch onto white socks
§ Will reproduce all year round so need flea
2) Outside infestation -> indefinite emergence!
§ Requires ongoing adulticides
Flea bite hypersensitivity history clues, clinical signs and diagnosis
- Historical clues ○ Spring / Summer exacerbation ○ Inadequate flea control ○ Fleas not always seen! - Primary lesion ○ Crusted papules ○ Mainly around base of tail, dorsum and caudal thighs ○ HOWEVER - these days generally - Diagnosis ○ Therapeutic trialling >2 weeks § Nitenpyram 1mg/kg q24h (best) § Other options - Spinosad q14d
Short and long term control of flea bite hypersensitivity
○ Short term
§ As per trialling -> with capstar as above
§ Clear infections if present
§ Short term prednisolone/Apoquel if required
§ Environmental flea treatment
□ Not as important
○ Long term
§ Other pets in house
□ Dogs: IGRs +/- adulticide
□ Cats: Selemectin /Comfortis/Activyl
○ Allergic pet
§ Dogs: Nexgard, Simparica, Bravecto, Comfortis, Activyl
§ Cats: Selamectin , Comfortis and Activyl
Scabies what caused by and characteristics of this cause
- Sarcoptes scabei var canis ○ Obligate parasite ○ Subspecies relatively host specific § Var canis – foxes, cats, humans ○ Burrow through stratum corneum ○ Can survive up to 3 weeks off host § Longer at low TdegreesC
Scabies what causes the disease and lesions found
Disease - Hypersensitivity to mite antigens - Pruritus is low until seroconversion Lesions - Primary ○ Papules ○ Hyperkeratosis - Secondary - from pruritus - Distribution- sparsely haired regions ○ Lateral elbows & margins of pinnae ** ○ Lateral hock ○ Ventral abdomen ○ Periocular ○ Generalised
Scabies diagnosis and treatment
Diagnosis
- Superficial skin scrapes
○ Papules
○ Elbows, pinnae
Only find mites 10% of the time!
- Therapeutic trials
○ Revolution 0, 2w, 4w
○ Nexgard, Simparica (only one registered) or Bravecto - isoxazoline (active ingredient)
Treatment
- Acute
○ As per treatment trial for 6 weeks
○ Antibiotics if secondary infection
○ +/- Prednisolone 0.5mg/kg 3-5 days only if not infected
○ Warn clients of possible worsening first week
- Long term
○ May not be required depending on exposure
○ Otherwise Revolution or Advocate monthly
○ Nexgard monthly or Bravecto each 3 months
Demodex cause, transmission and what does disease result from
- Aetiology: D. canis
- Obligate parasite
- Transmitted at birth
- Present in all dogs
- Disease results from
○ Genetic / immunological factors -> most common in young animals
§ Most common -> pugs, bull terriers
○ Concurrent disease -> more common in adults
§ Corticosteroid and apoquel use is a common signs
○ Immunosuppressive drugs
What are the 5 main predisposing factors for demodex
1) Juvenile - <18 - 36 months ○ Risk factors: breed, body condition, oestrus 2) Adult - >4yo ○ Risk factors: hyperadrenocorticisim, hypothyroidism, leishmaniasis, neoplasia, immunosuppressive drugs ○ 50% idiopathic? 3) Mean age onset ○ 4.2-5.8 years 4) Breeds ○ Terriers, esp WHWT 5) History ○ Chronic disease (esp. AD) ○ Prior decrease immune drug use ○ Young onset with no underlying causes
Demodex lesions and diagnosis
Lesions - Folliculitis - Hyperpigmentation - Hyperkeratotic -> comedomes ○ Young dog with comedomes - If really deep infections can have pseudomonas contamination - Scaly ears -> could be Demodex or otitis Diagnosis 1. DEEP skin scrapings 2. Trichograms - periocular, paws 3. Exudative/pustular samples
