Lower Tract Anatomy
Name the area in the bladder where the ureters open into the bladder in a functionally healthy animal.
What is the trigone area?
Explain the difference between Renal cysts and hydronephrosis.
What is renal cysts = congenital tubular defects, cortical & collecting tubules; hydronephrosis = expansion of the renal pelvis by fluid due to lower urinary tract obstruction?
What is the most common cause of UTIs?
Bacteria, i.e. E. coli
What are the two types of urinary incontinence and why is this important when prescribing drugs? Which is more common in females.
Storage disorders: (females more likely to experience) normal post-voiding residual volume-> urethral sphincter mechanism incompetence
Voiding disorders: Larger post-voiding residual volume; central nervous system abnormality, mechanical outflow obstruction, or atonic bladder
Depends on which aspect of the bladder/organ we need to target i.e. muscle vs sphincter
What blood sample is needed to measure pCO2?
arterial blood
There are two arteries that supply blood to the bladder; name the primary artery.
What is Caudal vesical artery?
(other one is the umbilical artery)
An owner is concerned about their new foal, about a week old. The foal is eating/drinking normally and they haven't noticed a change in behavior. The owners main concern is they have noticed fluid dripping from the umbilicus. What pathological reason could be causing the leakage from the umbilicus region.
What is a patent urachus?
Name the parasite we are concerned about with UTIs. Name the intermediate host. Treatment protocol.
Pearsonema spp.
Earthworm
Fenbendazole & Recheck/treat until test is negative
What drug would we likely utilize to reverse bladder atony in cases of acute overdistention?
Hint: its a muscarinic agonist
Bethanechol
What organic compounds may increase the anion gap? Inorganic compounds?
Organic: Lactic acidosis (i.e. lactate); ketoacidosis (i.e. ketones)
Inorganic: Increased PO4 & SO4 (renal failure *relatively common*)
Using the terms below match the muscle with its nerve.
Pudendal nerve, pelvic nerve, or hypogastric nerve
Detrusor muscle, smooth muscle sphincter, & striated Urethralis muscle
Detrusor Muscle = Pelvic nerve (Parasympathetic)
Smooth Muscle Sphincter = Hypogastric nerves (Sympathetic)
Striated Urethralis muscle = Pudendal nerve
Urolithiasis is not completely understood however we do know some things can increase the risk. What are some things that can predispose an animal to urolithiasis?
reduced water intake, urinary pH (alkaline), urease-producing bacteria, abnormal conc. substance in diet (P, Mg, Oxalate, Silicic acid)
The bacteria causing cystitis, left untreated, can lead to ascending pyelonephritis. There is one species (we discussed) that cystitis-pyelonephritis can lead to mortality; affected animals may be found dead. What species is this?
Pigs
To manage urolith formation there are a couple compounds (different uses) that can be administered in food to alter the pH. What are these substances, how do they affect pH, and why does this help?
Potassium citrate: increases pH (makes urine more alkaline); complexes with calcium to form more soluble salts and reduces irritation of bladder and urethra
Ammonium chloride: decreases pH (makes urine more acidic); useful in management of struvite uroliths
What percentage of sodium is reabsorbed in the proximal tubule? Loop of Henle? Distal Tubule/Collecting Duct?
PT: 70% (angiotensin II contributes)
LOH: 20-25%; thick ascending (Na+-K+-2Cl- symporters)
DT & CT: aldosterone increases expression of Na+-K+ pump and transporters
In males, there are two anatomical specifications in different species that can lead to further obstructions.
Name the anatomical structure in pigs.
Name the anatomical structure(s) in ruminants.
What is the S-shaped sigmoid flexure in pigs and ruminants?
What is the urethral process in ruminants?
This form of neoplasia arises from leftover embryonic tissue. Very rare, found in young, large breed dogs. What is it?
Rhabdomyosarcoma
In which species can empirical therapy, in lieu of a culture, be justified? Situation dependent?
Dogs with suspected sporadic cystitis; particularly those with limited previous antimicrobial exposure
Cats=all cases should have culture
Which antimicrobial is often the first line of defense in small animals when treating a UTI?
Amoxicillin-Clavulanate
We may prescribe this diuretic when there is edema or cardiac, hepatic or renal origin; also used to manage early stages of CHF. We would not use this in patients with severe renal disease. What drug am I?
Thiazide or thiazide-like diuretic (Chlorothiazide)
Explain the Micturition process starting with filling and storage. Voiding.
Stretch receptors in bladder send afferent signals along pelvic nerve which activates hypogastric nerve to urethra -> postganglionic neurons release NE which activates B(3)-adrenergic receptors allowing relaxation. NE also stimulates a-1 adrenergic receptors in urethra which prevents urine leakage.
Pelvic nerve->lumbar spinal cord->cerebral cortex/hypothalamus: if situation=appropriate for urination then signals go through pelvic nerve -> releases ACh at postganglionic parasympathetic neurons. ACh binds to M3 receptors stimulating contraction.
An owner brings their 2 year old dog into the clinic because they won't stop leaving small pee puddles around the house. Fluffy is potty trained, the owner is worried it may be a UTI. The CBC, Chem & urinalysis do not show signs of an infection and based on the history it seems Fluffy may suffer from urinary incontinence. You suggest taking a radiograph to confirm basic functionality, what may you find on the radiograph?
Ectopic ureter is causing the intermittent urinary incontinence
Name the clinical signs of cystitis vs the clinical signs of pyelonephritis.
Cystitis (LUT): foul-smelling urine, stranguria, hematuria, and pollakiuria
Pyelonephritis (UUT): Fever, depression, anorexia & vomiting, and renal/back pain
Fluffy, 10 yr old FS, presents to the clinic for urinary incontinence. Fluffy is on zero other medications and is otherwise healthy. When Fluffy goes outside to pee she is still able to empty her bladder but occasionally urine appears to leak out and it's becoming more frequent leading you to believe Fluffy suffers from USMI.
To prevent leakage we want to prescribe Fluffy a drug that will improve sphincter function and increases smooth muscle tone. Fluffy does not have any additional underlying conditions so we are unconcerned with any adverse affects. What drug would we prescribe? What may we mention to owners that they may notice (adverse effects)?
Phenylpropanolamine
AE: increased BP & HR, GI upset or restlessness
Rank these am most emergent to least emergent.
Dead Cow
Hypovolemic Cow
Dehydrated Cow
1. Hypovolemic
2. Dehydrated
3. Dead