Urinary and ophthalmics Flashcards
What is the definition of acute renal failure?
Advanced decline in glomerular filtration rate over hours to days.
What are the broad causes of acute renal failure?
Haemodynamic, nephrotoxic, interstitial nephritis, obstructive nephropathy
What are the clinical signs of acute renal failure?
Diarrhoea
SIRS/MODS
Myopathies
Colic
Fever
Urine output (oliguria, anuria, polyuria)
What is the approximate daily water intake for a horse?
50ml/kg/day
What biochemistry markers are useful in assessing urinary tract function?
Azotaemia, BUN: creatinine ration, electrolytes, protein and albumin, muscle enzymes, glucose
What conditions are typically seen alongside chronic renal failure?
Hypercalcemia and hypophosphatemia
What are the clinical signs of chronic renal failure?
Weight loss, PU/PD, ventral oedema, poor appetite, dull hair colour, dental tartar
What clinical pathology is seen with chronic renal failure?
Increased creatinine
USG 1009 - 1014
Casts, tubular casts, neoplastic cells, leukocytes
Proteinuria
Hypercalcemia, hyponatraemia, hypochloraemia, hyperkalaemia
Hypoalbuminemia
Anaemia
How do you manage the chronic renal failure case?
Steroids once ensured infection under control
Avoid toxic insults
Plenty of fresh water
What can cause myoglobinuria?
Muscle injury, nephrotoxic insults
What can cause haemoglobulinuria?
Intravascular haemolysis and renal damage
What is the typical urine production of the horse?
15-30ml/kg/day
What are some physiological causes of PU/PD?
Excessive dietary protein, salt consumption, drug administration, high environmental temperature
What are some pathological causes of PU/PD?
Psychogenic polydipsia, hepatic insufficiency, sepsis, renal medullary solute washout, diabetes mellitus/insipidus
What are some iatrogenic causes of PU/PD?
IVFT
Diuretics
Corticosteroid administration
Sedation with A2-agonist
Excess dietary salt
What is the typical presentation of corneal ulceration?
Usually painful
Blepharospasm
Ptosis
Conjunctival swelling
Inflammation and discharge
Corneal opacity
What is the typical presentation of secondary uveitis?
Myosis, empyema, hyphaemia, synechiae.
Iris prolapse and fibrin in anterior chamber
Do you use steroids with corneal ulcers?
NO
What is the normal corneal epithelium turnover?
7 days - heals 0.6mm/day
How do you control myosis?
Topical atropine until mydriasis then maintain.
Dark environment, mask +/- contact lenses +/- lubricants
What are the two types of viral keratitis?
Type 1 - Dendritic pattern
Type 2 - Multifocal pattern
What are the main viral cause of keratitis?
EHV-2
How do you treat viral keratitis?
Idoxuridine for 7 days - every 2hrs for 2 days then every 6 hours.
What antifungals can be used to treat fungal keratitis?
Voriconazole, clotrimazole
What are the clinical signs of immune-mediated keratitis?
Neovascularisation, oedema, cellular infiltration, anterior uveitis, transient ulceration, minimal discomfort
How do you treat immune-mediated keratitis?
Dexamethasone, calcineurin inhibitors, doxycycline
What is the main cause of blindness in equine opthalmology?
Uveitis
What are the secondary issues associated with uveitis?
Synechiae, iris rests, changes in pigmentation, reduction in size of corpora nigra, cataracts, retinal detachment, glaucoma, blindness
What are the 6 layers of the cornea?
- Mucus/tear-film layer
- Epithelium
- Basement membrane
- Stroma
- Descemet membrane
- Endothelium
What colour is a normal tapetum?
Green, yellow, red or blue - reflective
What colour is the normal non-tapetal fundus?
Brown or red
What is the most common nerve block used in equine ophthalmology?
Auricolopaebral
What is commonly used to dilate the pupil?
Tropicamide
What is the normal IOP reading for an equine eye?
14 - 22mmHg
What are the topical anaesthesias used in the eye?
Tetracaine or proxymetacaine (proparacaine)
What is a normal reading on a Schirmer tear test?
> 10mm
