T2 Exam Flashcards
Corneal Ulcer Classification
Superficial/uncomplicated
Complicated
- Non-healing >7days
- Penetrating
- Perforating
Corneal ulcer diagnosis
History, CS, ocular exam, positive fluorescein stain
How to treat a superficial, small, non-complicated ulcer sustained <2days ago?
- ABs e.g. chloramphenicol, tricin
- Systemic analgesia e.g. phenylbutazone
- Atropine (once off)
revisit in 2-3days
Corneal ulceration surgical options?
- debridement of melting and stromal abscesses
- Grafting
- Temporary tarsorrhaphies
- Enucleation
Steps when presented with a pruritic horse. (6)
- Skin scraping (superficial & deep)
- ectoparasites
Positive: treat
Negative: ascaricidal trial - Fungal culture
- detrmatophyte
Positive: treat
Negative: rule out - Bacterial infection
- cytology of papule fluid
- AB trial - Consider allergies
- insect bite trial - Adverse food reactions (food allergy)
- elimination diet - Atopic dermatitis
- serological/intradermal allergy testing
- response to therapy
Drugs for pain relief in a colic case
xylazine: 0.4-0.6mg/kg IV
(double dose for IM)
Flunixin 1.1mg/kg
- Only if we have a diagnosis otherwise masks pain so can’t cage prognosis
Fluid Therapy Calculation
Deficit= %dehydration x BW
Maintenance= 60ml/kg/day (adult)
= 100ml/kg/day (foal)
Ongoing losses= estimated NG reflux, Diarrhea frequency x volume
First half within first 3-6hrs (~5-10l/hr)
second half within 24hrs (1-2l/hr)
How much fluid would a 500kg horse require if its 10% dehydrated with high volume diarrhoea (1L every 2hrs) in the first 24hrs?
Deficit
= 0.1 x 500
= 50L
maintenance
= 0.06x500
= 30L
Deficit
= 1 x 12
= 12L
total = 92L
What are the radiographic signs of physeal dysplasia? (7)
- Physeal widening
- Irregular physis outline
- Sclerosis
- Bone lipping
- Asymmetry of metaphysis
- Wedging of epiphysis
- Asymmetry of cortical bone
At what age must you correct angular limb deformities of the Fetlock and Carpus/Tarsus?
Fetlock = 30-60days (closes ~90days)
Carpus/Tarsus = 6weeks-4m (closes around 6m)
Pyrrolizidine Alkaloid Toxicosis pathogenesis.
PAs alkylate nucleic acids and protein prevents cell division and protein synthesis results in formation of MEGALOCYTES. Fibrous tissue replaces parenchyma when megalocytes die = liver fibrosis CHRONIC NODULAR LIVER HYPOPLASIA
PA toxicosis Histopathological findings (3)
megalocytosis, bridging portal fibrosis and biliary hyperplasia.
Common plants containing PAs
- Paterson’s curse (Echium plantagineum)
- Rattlepod (Crotalaria crispata)
- Ragwort (Senecio spp) - not in AU
CS of hepatobiliary disease (6 common/6 uncommon)
Common = Icterus, weightloss, depression/lethargy, anorexia, colic, fever.
Less common = photosensitization, diarrhea, ventral oedema, ascites, encephalopathy, bleeding diathesis.
Liver enzymes for hepatocellular injury
AST, SDH, GLDH
Liver enzymes associated with Biliary injury/cholestasis
GGT, ALP
Suspected causes of Neonatal Maladjustment Syndrome
Maternal disease e.g.
- anaemia, lung/cardiac disease, cardiovascular shock (toxemia)
Placental disease
- premature placental separation, placental insufficiency, placentitis
Stage II labour
- placenta previa (red bag delivery), uterine inertia, dystocia, oxytocin
5 main differential for sick looking foals
- Sepsis
- Uroperitoneum
- Neonatal maladjustment syndrome
- Neonatal isoerythrolysis
- Prematurity
Most important bacterial cause of sepsis in foals
E.coli
In what circumstance would a horse with cardiac disease be unsafe to ride?
- Diastolic murmurs
- Aortic regurg until proven otherwise
- Risk of ventricular ectopy
- Systolic murmurs
- mitral valve regurg may lead to AF
- Bilateral murmurs
- VSD unsafe in unrestrictive
- Uncommon/sudden-onset murmurs
What are the types of perineal lacerations and their management?
First degree
- superficial mucosa and muscles of labia and vestibule
- local wound care e.g. AB’s, AI’s
- most will heal spontaneously
Second degree
- constrictor vulvae muscle & perineal body only
- debridement, superficial suturing, Caslick’s
- AB’s and AI’s
Third degree
- perineal body, anal sphincter and rectum
- delay corrective surgery for 6 weeks
- manual daily evacuation of vagina
- surgery = 2 stages
1. recreate shelf between rectum and
vagina
2. tension relieving sutures to restore
perineal body
What are the 4 grades of rectal tears?
Grade 1: mucosa & submucosa
Grade 2: mucosa, submucosa & muscular
layer prolapse
Grade 3: all layer except serosa (subtype
a) or mesentery (subtype b)
Grade 4: full thickness tear
Management of type 1 & 2 rectal tears?
CAREFULLY evacuate rectum and pack defect
Conservative management
- BS AB’s e.g. pent & gent
- tetanus toxoid
- flunixin
- supportive care e.g. IVFT
- Fast + stool softeners
Management of type 3 & 4 rectal tears?
REFER to surgical facility
Surgical management
- in-dwelling rectal liner
- suture per rectum
- colostomy
- laparoscopic repair
- euthanasia if extensive contamination
IgG levels in foals and what levels indicate successful passive transfer vs partial vs failure?
> 8g/L = PROTECTED
4-8g/L = PARTIAL PROTECTION (protected if well and in a clean environment
<4g/L = FAILURE of passive transfer
When should you check passive transfer levels in foals?
<24hrs of age
maximum absorption <6hrs
What are the complications associated with castration?
- Hemorrhage
- Oedema/swelling
- Infection (can lead to scirrhous cord)
- Herniation/Evisceration
- Hydrocoele
- Persistent masculine behaviour
What is the drug of choice to treat AF in horses?
Quinidine Sulphate
What are the consequences of Quinidine Sulphate toxicity?
Non-cardiac
- colic/diarrhoea/inappetence
- stertor/nasal oedema
- weakness/ataxia
Cardiac
- SVT
- Hypotension
- VT
How do colic signs appear in a horse vs a foal?
Horse:
- recumbency
- stretching
- bruxism
- flehmen response
- arching of neck
- flank watching/biting
- pawing
-kicking at belly
- rolling
- posturing to lay down
- sweating
- posturing to urinate
Foal:
- Lie on their back
- bruxism
How to diagnose foal meconium impaction?
Black to dark brown, pasty - firm faeces
Passage should be completed by 48hrs
Diagnostic test:
- digital rectal palpation
- US/RADS for a proximal compaction
How to diagnose foal meconium impaction?
Black to dark brown, pasty - firm faeces
Passage should be completed by 48hrs
Diagnostic test:
- digital rectal palpation
- US/RADS for a proximal compaction
Management of a meconium impaction
Supportive care
- IVFT or oral fluids if CS consistent with dehydration.
- Analgesia e.g. flunixin or meloxicam
- Enema e.g. soapy water then acetylcysteine
How to administer an enema in a foal
- warm soapy water
- foal in lateral recumbency
- lubricated foley catheter
- 500ml-1L for 50kg foal
- administered by gravity flow
- max twice!
What to do if fluid enema fails in a foal with a meconium impaction?
Acetylcysteine enema
- decreases viscosity of meconium
- kept in place for 30-45mins with foal sedated in lateral recumbency.
- excellent prognosis
