PATHOLOGY - Equine Urinary Disease Flashcards
(75 cards)
Describe the appearance of normal urination in a male horse
When male horses urinate, they will be in a stretched, lordotic (inward curvature of the lumbar spine) position, the tail will be elevated and the penis will be out of the sheath. Urination in horses requires abdominal contraction, and there should be a brisk stream of urine which won’t contaminate their limbs due to their posturing. Male horses may grunt when urinating, this is normal and not a sign of pain
Describe the appearance of normal urination in a female horse
When female horses urinate, they will be in a stretched lordotic position, the tail will be elevated and there should be a brisk stream of urine which which won’t contaminate their limbs or perineum due to their posturing
How does urination differ in horses in oestrus?
When female horses are in oestrus, they will have pollakuria
How much water should a horse intake per day?
2 - 4 litres of water per kg of dry matter consumed per day
When is a horse classified as polydipsic?
A horse is classified as polydipsic if they are drinking more than 100ml/kg/day
What is one of the first signs of polydipsia in the horse?
Hard faeces
What are the differential diagnoses for PUPD in horses?
Psychogenic polydipsia
Secondary renal medullary washout
Hyperadrenocorticism
Chronic renal failure
Diabetes insipidus
What is the most common cause of PUPD in horses?
Psychogenic polydipsia
What causes psychogenic polydipsia in horses?
Psychogenic polydipsia is usually due to boredom, environmental changes or feeding changes in horses
What is secondary renal medullary washout?
Renal medullary washout is a condition where the normal osmotic gradients between the renal interstitium and the renal tubules are reduced due to a loss of sodium, resulting in an inability to concentrate urine. This loss of sodium can be caused by long term psychogenic polydipsia as excessive water intake will dilute sodium levels in the blood, and result in the loss of both water and sodium in the urine. Horses with renal medullary washout and psychogenic polydipsia usually concentrate their urine in response to the gradual restriction of water, achieved via a water deprivation test
What is the gross appearance of normal adult equine urine?
Normal adult equine urine will appear pale yellow to brown, slightly turbid and viscous
Why does normal adult equine urine appear turbid and viscous?
Horses have a large quanitity of mucus in their urinary tract which causes the urine to be viscous, and horses excrete a lot of calcium crystals into their urine due to their diet being so high in calcium, causing the urine to be turbid
When is urine specific gravity (USG) classified as hypersthenuric in an adult horse?
Urine specific gravity above 1.020 is classified as hypersthenuric
What is the gross appearance of normal foal urine?
Normal foal urine will appear yellow, watery and translucent
Why do foals typically have dilute urine?
Foals should typically have dilute urine as they have a higher intake of fluids, primarily milk, which is high in water content. As a result they should be producing dilute urine
What can be indicated if a foal produces more concentrated urine?
If a foal produces more concentrated urine, this can indicate they are not getting sufficient fluid intake
Which urinary tract diseases are seen in young horses?
Patent urachus
Ectopic ureters
Rectovaginal fistula
Rectourethral fistula
Polycystic kidney disease
Renal agenesis
Most of these are congenital diseases
What is the key sign of ectopic ureters in horses?
Urinary incontinence in a young horse can be a key sign of ectopic ureters
More common in fillies
Which urinary tract diseases are more commonly seen in older horses?
Neoplasia
Urolithiasis
What are the most common forms of bladder neoplasia seen in horses?
Bladder squamous cell carcinoma
Bladder transitional cell carcinoma
Which history questions can be benefial to ask when investigating equine urinary tract disease?
Have there been any recent dietary changes?
Has the horse been moved from pasture to stabling?
Is the forage the horse is being fed high in calcium?
Is the horse being given any supplements (such as calcium supplements)?
Is the water intake adequate?
Does the horse have access to salt blocks?
Has there been any recent environmental changes?
Has there been any recent trauma?
Are any of the other horses affected?
Could the horse have had access to any toxins?
Is the horse being treated with NSAIDS?
Why is it important to establish if the horse has had any recent dietary changes or has been moved from pasture to stabling?
Dietary changes and movement from pasture to stabling can cause a dramatic drop in water intake in horses (which could increase the risk of urolithiasis, and impaction if thinking in terms of colic)
Why is it important to determine the quantity of calcium in a horse’s diet?
Equine diets are already very high in calcium so it is important to determine if the owner has been providing high calcium forage or supplements as this could contribute to the development of further calcium carbonate crystals in the urine and increase the risk of urolithiasis
Which toxins can cause urinary tract disease in horses?
Red maple
Acorns
Aflatoxins
