Livestock Urinary - VanMetre Flashcards
This is a normal structure, an outpocketing of the urethral lumen located at the level of the ischium.
Urethral recess
This is the skin appendage from which the penis extrudes during breeding.
Sheath
This is the thick mucosal lining (actually stratified sq epith) of the interior of the sheath. This mucous membrane reflects onto the penis
Prepuce
Why is it nearly impossible to pass a retrograde urinary catheter into the bladder of a male of castrated male ruminant, camelid, or pig?
The catheter will almost always become enlodged in the urethral recess
This is a common site for urinary calculi to become lodged and obstruct the urethra in cattle - due to its narrow diameter and abrupt change in direction
Sigmoid flexure
This is the narrowest part of the urethra in small ruminants (sheep and goat); urinary calculi tend to become lodged at this site. The second most common site in small ruminants is the _____
- Urethral process “Pizzle”
2. Sigmoid flexure
Why are female ruminants, pigs, and camelids less likely (rare actually!) to have urethral obstruction from calculi?
They have much shorter urethras, which are not surrounded by a fibrous tunic which allows them to easily distend
The ______ _______ is caudal and ventral from the urethral orifice in female ruminants, pigs, and camelids
Urethral diverticulum
*Can help you find the urethral orifice during palapation
Occasionally, the urachus (conduit for urine to exit the fetal bladder in utero) will remain open post-partum. What is the term for this?
Patent urachus
This should be kept in mind when evaluating a neonate with evidence of a UTI
Pigs, camelids, and small ruminants have a smooth, bean-shaped kidney similar to those of humans and domesticated animals. Which species has a lobulated kidney?
Bovine!
How do you collect urine in cattle? Cows vs bulls
Cows: Gently rub the perineum immediately ventral to the vulva - cow usually has to be standing
Cattle: lightly rub the preputial mucosa (sick your finger in the prepuce… yuuuuck)
How do you collect urine in a sheep?
Hold off its nose - the sheep typically urinate once they begin to struggle against the restraint
Normal USG in ruminants/camelids
pH?
Protein?
1.020-1.050
pH is usually alkaline (7-8.5)
usually negative for protein, but a trace + on urine dipstick is common
When would ketones be elevated?
Negative for ketones in the normal animal; ketones can be elevated in postpartum dairy cows in a negative energy balance or small ruminants with pregnancy toxemia
What is the common name for Ulcerative Posthitis? What causes it? If the penis is involved, what is a more appropriate description?
Pizzle Rot!
Corynebacterium renale
Balanoposthitis
This bacteria is part of the normal flora of prepuce of small ruminants, and it proliferates under conditions of high urea in the urine
Corynebacterium renale
- high protein feeds induce high conc of urea in urine
(e. g. alfalfa hay, legume hay) - the extra nitrogen is metabolized to urea
How do you treat pizzle rot?
Remove high protein diet!
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Systemic antimicrobial
Penicillin) therapy and or/topical Abx ointment (triple antibiotic
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This is a sporadic metabolic disease of intact and castrated male ruminants, camelids, and pigs. ____ form from precipitation of urinary minerals. Obstruction usually occurs in the _____
Urolithiasis
Calculi
Urethra
What are the major risk factors for urolithiasis?
- Dietary mineral imbalance - Ca, Mg, Pi
- Water intake - dry weather, unpalatable water, freezing
- Castration - smaller urethral diameter
- Gender - males»_space;» females
Phosphatic Calculi. These urolits are usually ____. They are finely granular, white to brown, and easily crumbled. Typical signalment is feedlot calves and lambs, show animals, on a high-grain diet, and pet goats on inappropriate diets.
Phosphatic Calculi - STRUVITES
Why are high grain diets a risk factor for phosphatic calculi (struvites)?
They are inherently high in phosphorus and low in calcium, they alsoinduce less rumination (cud chewing) & Less salivation (saliva normally aids in Pi excretion) so less saliva = more Pi excreted in urine
These are commonly found in range animals in the western US and Canada. The calculi are firm, beige to tan, and usually spherical
Silicate Calculi
The native rangeland grasses have high silicon content. Intermittent water deprivation assoc’d with grazing arid rangeland causes concentrated urine and silic acid precipitates to form silicate calculi
These are common with high Ca diets such as clover and alfalfa hays or pastures, and when commercial diets designed for lactating animals are used in non-lactating animals. These stones are typically gold in color and resemble BBs.
Ca Carbonate
These occur in animals eating high Ca diet. There may be some additional risk by ingestion of plants containing ___ = such as rhubarb, peanuts, pig weed, and lambs quarters. Overzealous dietary supplementation with _____ acid (vit C) can promote these.
Ca oxalate
oxalate
Ascorbic acid
- this is metabolized in the liver to oxalate, which is excreted in the urine
What is the “Pet Small Ruminant Rule”
Any ill male small ruminant or wether is BLOCKED until proven otherwise!!
What do you think when an owner says their animal is constipated?
Constipation in food animals is VERY rare - they may have mistaken stranguria for constipation
Uroliths cause _______ on US
Acoustic shadowing
Pt has pitting edema along the prepuce, in the inguinal tissues, or within the ventral abdominal wall. The affected tissues are warm and painful initially; however, with time there is tissue necrosis and they may be cool and non-painful. The animals are usually dehydrated and depressed, they are azotemic. their breath smells of ammonia
Rupture of urethra
Blood results with uroabdomen
hyponatremic, hypochloremic, hyperkalemic, severe azotemia
DDx for Uroabdomen - 5 F’s
- Fat - omental fat deposits
- Fluid - free in the abdomen
- Fetus - pregnancy
- Flatus (flatulence)
- Food
Partial urethral obstruction can lead to hydronephrosis - how? what is this?
urine is able to dribble out, which spares the urethral or bladder from rupturing - but pressure builds up in the bladder. This pressure can transfer up both ureters to both kidneys. If sustained for too long the nephrons are crushed under the fluid pressure.
Grave prognosis - should US kidneys to evaluate prior to sx or major workup
How to treat urolithiasis in ruminants?
Difficult to catheter - cant flush out
if its a struvite you can infuse bladder with Walpole’s solution to acidify and break down
Either sx or humane euth
Why put salt on feed?
Increase salt intake –> increases thirst –> more water intake = more dilute urine
***MUST be done responsibly (always access to water)
Ascending UTI:
- urethra to bladder?
- bladder to one or both ureters?
- ureters to kidney(s)?
- cystitis
- ureteritis
- pyelonephritis
UTI and Cornyebacterium renale
Confined cattle UTIs: Vulva to vulva contact
aka contagious bovine pyelonephritis
UTI caused by E coli
Souces of infection are most commonly due to fecal contamination. Damage to lower urinary tract defenses or heavy urogenital contamination with feces increases the risk of ascending UTI with coliforms.
How to differentiate cystitis from pyelonephitis (brief)
CBC: Inflammatory leukogram
CASTS of WBCs/debris on sediment
*if azotemia exists, this implies bilateral involvement
The ___ kidney is palpable per rectum in adult ruminants, and lies on the roof of the abdominal cavity, roughly ____
Left
On midline
How does vaginal palpation aid in the diagnosis of pyelonephritis?
Can frequently feel distended ureters(s)
UTI Tx in food animals: you much select an Abx with _____ concentrations in the urine.
You may need to treat for __________ period of time
Rough rule: ___ wk min for cystitis; ___ wks for pyelonephritis
Whats the best?
high
extended
1 wk
2 wk
Penicillin, ampicillin, or sulfonamides
Other than ascending infection, how can the kidneys be infected?
Hematogenous nephritis
What agent is notorious as a hematogenous “kidney-infector”
which spp is often affected?
Lepto!
Primarily cattle
What is host-adapted?
Strain of agent sets up shop in the host, but doesnt want to kill the host.
This is a host-adapted agent of cattle. Who is susceptible?
Leptospirosis hardjo
Fetus!
What are non-host adapted?
These cause more severe damage!
These cows are SICK
Reminder to review (NAVLE)
Bracken Fern
Nephrotoxin plants
Non-plant nephrotoxins
Renal amyloidosis
