Genitourinary Flashcards
List 6 differentials for urinary incontinence in a young, spayed bitch
Hormonal-responsive (post-spay) incontinence
Ectopic ureters
Lower or Upper motor neuron disorders or reflex dyssynergia
Urge Incontinence (inflammation or infection)
Anatomic outflow obstruction (paradoxic incontinence)
Behavioral incontinence (submissiveness)
What’s the most common type and location of ectopic ureters? What percentage of patients are affect by bilateral disease?
The most common location for termination of ectopic ureters is in the urethra, although termination in the uterus and vagina can occur. Ectopic ureters are classified as intramural (the ureter enters the bladder wall at a normal anatomic position, but a portion of the ureter extends submucosally within the bladder wall before it enters the urethral lumen; Fig. 24.14A) or extramural (the ureter bypasses the bladder to enter the urethral lumen; Fig. 24.14B). Bilateral ectopic ureters occur in more than one-third of dogs (some reports have suggested more than 90%). Other abnormalities noted in some dogs include double ureteral openings (i.e., where the ureter opens in the bladder plus more distally; Fig. 24.14C) and ureteral troughs (Fig. 24.14D). Ureteral ectopia is much less common in cats.
What are the diagnostic options for the diagnosis of ectopic ureters? Which one is the most reliable diagnostic option?
Excretory urogram (based on radiographs), ultrasonography, cystoscopy and CT excretory urography.
CT excretory urography is the most sensitive method for diagnosis of ectopic ureters, and if available, should be considered the imaging modality of choice
What procedures are most commonly used for the treatment of intramural and extramural ectopic ureters?
Neoureterostomy (for intramural)
Ureteroneocystostomy (for extramural)
What is the overall prognosis, in percentage of patients that remain fully continent, after surgically corrected ectopic ureter?
Past reports suggest that as few as 30% of patients are fully continent postoperatively; however, 72% of male and female dogs with surgically-corrected ectopic ureters were continent in a 2012 study.
Many dogs with ectopic ureters have functional abnormalities of the urinary bladder or urethra. Obtaining urethral pressure measurements before surgery and after initiating diethylstilbestrol, estriol, or phenylpropanolamine therapy (see p. 666) may help predict the likelihood of continence after surgery. Siberian huskies are particularly prone to postoperative incontinence because of a high incidence of concurrent urethral sphincter incompetence. These dogs may respond to diethylstilbestrol, estriol, alpha-adrenergic agonists, or imipramine. If bladder hypoplasia is present, incontinence may continue until the bladder enlarges and properly functions as a reservoir. Dogs with ureteral troughs may have a poorer prognosis than dogs with nondistended intramural ectopic ureters. Failure to resect a ureterocele may result in continued incontinence and UTI.
Minimally invasive option for the treatment of intramural ectopic ureter’s
Cystoscopically-guided laser ablation
What are the functions of the pelvic nerve
Provides parasympathetic motor innervation to the bladder detrusor muscle (General visceral efferent) and Sensory innervation (General visceral afferent)
“The preganglionic neurons are located in the sacral spinal cord segments. Preganglionic axons synapse with ganglionic neurons at the pelvic ganglia and within the wall of the bladder.”
Excerpt From
Veterinary Surgery: Small Animal Expert Consult
Spencer A. Johnston VMD, DACVS & Karen M. Tobias DVM, MS, DACVS
https://books.apple.com/us/book/veterinary-surgery-small-animal-expert-consult/id1250368401
This material may be protected by copyright.
What are the functions of the pudendal nerves and where do they originate?
“The pudendal nerves supply somatic innervation (motor [general somatic efferent] and sensory [general somatic afferent]) to the external urethral sphincter, perineal musculature, and anal sphincter and skin of the perineum (sensory). The neurons that give rise to the pudendal nerve are derived from the sacral spinal cord segments.”
Excerpt From
Veterinary Surgery: Small Animal Expert Consult
Spencer A. Johnston VMD, DACVS & Karen M. Tobias DVM, MS, DACVS
https://books.apple.com/us/book/veterinary-surgery-small-animal-expert-consult/id1250368401
This material may be protected by copyright.
Describe the origin, synapses and functions of the hypogastric nerve
“The hypogastric nerve supplies sympathetic innervation to the internal urethral sphincter, the pelvic (parasympathetic) ganglia, and the detrusor muscle. The preganglionic neurons are located in L1 through L4 spinal cord segments. Preganglionic axons course through splanchnic nerves to synapse with their ganglionic neurons in the pelvic plexus. Postganglionic sympathetic axons course in the hypogastric nerve. Sympathetic input to the pelvic ganglia inhibits the ganglionic parasympathetic neurons during urine storage. The hypogastric nerve also contains sensory fibers (general visceral afferent) from the bladder wall and is involved in bladder nociception. Descending motor information includes inhibitory and excitatory upper motor neuron input to the detrusor muscle and urethral sphincters.61”
Excerpt From
Veterinary Surgery: Small Animal Expert Consult
Spencer A. Johnston VMD, DACVS & Karen M. Tobias DVM, MS, DACVS
https://books.apple.com/us/book/veterinary-surgery-small-animal-expert-consult/id1250368401
This material may be protected by copyright.
Describe the mechanism of urine storage and the development of UMN bladder as a result of T3-L3 myelopathy
“Normal urine storage and voiding are accomplished by both reflexive and conscious input.61 Urine storage is accomplished by beta-mediated detrusor muscle relaxation, alpha-mediated internal urethral sphincter tone, and cholinergic (nicotinic)-mediated external urethral tone. To empty the urinary bladder, adrenergic input to the bladder is decreased, allowing increased detrusor muscle activation and decreased internal urethral sphincter tone. Cholinergic stimulation via the pelvic (parasympathetic) and pudendal nerves (skeletal innervation) results in detrusor muscle contraction and external urethral sphincter relaxation, respectively.
With damage to the upper motor neurons affecting the urinary bladder, the sacral spinal cord segments supplying the pelvic and pudendal nerves remain intact. The transmission of ascending and descending information to and from the brain is decreased or lost. The result is an upper motor neuron bladder in which there is urinary incontinence with increased detrusor muscle and external urethral sphincter tone, presenting as a large, firm bladder that is difficult to express and may overflow as intraluminal pressure overwhelms the urethral sphincters”
Excerpt From
Veterinary Surgery: Small Animal Expert Consult
Spencer A. Johnston VMD, DACVS & Karen M. Tobias DVM, MS, DACVS
https://books.apple.com/us/book/veterinary-surgery-small-animal-expert-consult/id1250368401
This material may be protected by copyright.
What class of drugs is commonly used for treatment of upper motor neuron bladder? Give two examples.
“Pharmacologic intervention targets relaxation of the internal urethral sphincter and may include alpha-adrenergic antagonists, such as phenoxybenzamine (0.25 to 0.5 mg/kg q12h to q24h, PO) or prazosin (1 mg/15 kg q8h to q24h, PO). Prazosin is advantageous in that it has a more rapid onset and is more specific for alpha-1 receptors.6”
Excerpt From
Veterinary Surgery: Small Animal Expert Consult
Spencer A. Johnston VMD, DACVS & Karen M. Tobias DVM, MS, DACVS
https://books.apple.com/us/book/veterinary-surgery-small-animal-expert-consult/id1250368401
This material may be protected by copyright.
What class of drug is typically used for therapy of lower motor neuron bladder in dogs? Give one example
“ In dogs with bladder atony, a parasympathomimetic such as bethanechol (2.5 to 25 mg total dose q8h, PO) may be used in addition to an alpha-1-adrenergic antagonist after therapeutic levels of the alpha-1-adrenergic antagonist have been reached. Bethanechol may cause vomiting, diarrhea, excessive salivation, and anorexia”
Excerpt From
Veterinary Surgery: Small Animal Expert Consult
Spencer A. Johnston VMD, DACVS & Karen M. Tobias DVM, MS, DACVS
https://books.apple.com/us/book/veterinary-surgery-small-animal-expert-consult/id1250368401
This material may be protected by copyright.
List 11 risk factors for the development of urinary tract infections in patients with spinal disease
Gender
Incomplete avoiding
Elevated intravesical pressure
Prior dexamethasone administration
Mucosal damage associated with catheter insertion
Catheter contamination
Proximity of the retry to sources of virulent microorganisms
Retrograde flow of urine from the collection system to the bladder
Normal to alkaline urine pH
Low urine osmolality
Pre-existing conditions (cystic calculi, hyperadrenocorticism, diabetes mellitus, immune compromise)
Explain the phenomenon of “spinal walking”
“Spinal walking involves the use of pelvic limb reflexes, trunk “muscles, and any remaining upper motor neurons to generate a gait as opposed to conscious voluntary walking. Most of these dogs will not develop urinary and fecal continence.”
Excerpt From
Veterinary Surgery: Small Animal Expert Consult
Spencer A. Johnston VMD, DACVS & Karen M. Tobias DVM, MS, DACVS
https://books.apple.com/us/book/veterinary-surgery-small-animal-expert-consult/id1250368401
This material may be protected by copyright. ”
Ammonium urate calculi - Most common breed and disease process to lead to this type of calculus? What is the bio chemical reason for this breeds predisposition to this type of calculus?
Ammonium urate stones are most common in Dalmatians and in dogs with congenital portosystemic vascular shunts.
Dalmatians do not convert most of their metabolic urate to allantoin and thus excrete the bulk of nucleic acid metabolites as relatively insoluble urate. The net result is that only 30%–40% of urate is converted to allantoin in Dalmatians compared with ~90% in other breeds.
What are the electrolyte and cardiac consequences of prolonged urethral blockage? What EKG abnormalities may be observed?
Prolonged urethral blockage leads to severe hyperkalemia, metabolic acidosis and post-renal azotemia. Hyperkalemia may lead to life-threatening cardiac arrhythmias due to its effect on cardiac electrical conductivity. These may begin as bradycardia and spiked T-waves, progressing to depressed R-waves, prolonged QRS and PR intervals and ST segment depression.
In what species are circumcaval ureters occasionally observed and possibly responsible for benign ureteral obstruction?
Cats
Patients undergoing renal biopsy should receive IV fluids before during or shortly after the procedure. What’s the rationale for this practice?
“Administering fluids before, during, and shortly after biopsy to initiate and maintain a mild diuresis may reduce formation of blood clots in the renal pelvis, which could cause obstruction and further loss of GFR. ”
Excerpt From
Small Animal Surgery E-Book
Theresa Welch Fossum DVM, MS, PhD, Dipl ACVS
https://books.apple.com/us/book/small-animal-surgery-e-book/id1367916984
This material may be protected by copyright.
When obtaining renal biopsies, what is the minimum number and size of samples to be submitted? What tests should you request, how should the samples be stored and to which laboratory should you submit the sample?
“at least two samples larger than 10 mm or three samples smaller than 10 mm are recommended.
“Cut the sample into three sections; place one in 10% neutral buffered formalin solution for light microscopy, one in glutaraldehyde for electron microscopy, and freeze one for immunofluorescence.”
Request light microscopy, immunofluorescence, and electron microscopy
International Veterinary Renal Pathology Service, a joint collaboration of Texas A&M University and The Ohio State University.”
“The minimum numbers of glomeruli considered necessary for accurate diagnosis of glomerular disease are as follows: 5 to 10 for light microscopy, 1 to 2 for electron microscopy, and 3 to 5 for immunofluorescence. ”
Excerpt From
Small Animal Surgery E-Book
Theresa Welch Fossum DVM, MS, PhD, Dipl ACVS
https://books.apple.com/us/book/small-animal-surgery-e-book/id1367916984
This material may be protected by copyright.
In cases of generalized diffuse kidney disease, which kidney is typically preferred for biopsy? Why?
The right kidney is technically easier (less mobile)
Describe the technique for nephrectomy with emphasis on the necessary precautions pertaining to the placement of vascular ligatures
“Grasp the peritoneum over the kidney and incise it. Using a combination of blunt and sharp dissection, free the kidney from its sublumbar attachments. Elevate the kidney and retract it medially to locate the renal artery and vein on the dorsal surface of the renal hilus (Fig. 24.3). Identify all branches of the renal artery. Double ligate the renal artery with absorbable suture (e.g., polydioxanone, polyglyconate, glycomer 631, poliglecaprone 25) or nonabsorbable suture (e.g., cardiovascular silk) close to the abdominal aorta to ensure that all branches have been ligated. Consider placement of a transfixation suture if the artery is larger than 3 to 4 mm in diameter. Identify the renal vein and ligate it similarly. The left ovarian and testicular veins drain into the renal vein and should not be ligated in intact dogs. Avoid ligating the renal artery and vein together to prevent the formation of an arteriovenous fistula. Ligate the ureter near the bladder with a simple encircling ligature. Remove the kidney and ureter and, after procuring appropriate culture specimens, submit them for histologic examination.”
Excerpt From
Small Animal Surgery E-Book
Theresa Welch Fossum DVM, MS, PhD, Dipl ACVS
https://books.apple.com/us/book/small-animal-surgery-e-book/id1367916984
This material may be protected by copyright.
Describe the nephrotomy technique with emphasis on the possible methods of closure
“Locate the renal vessels and temporarily occlude them with vascular forceps, a tourniquet, or an assistant’s fingers. Mobilize the kidney to expose the convex lateral surface. Make a sharp incision along the midline of the convex border of the kidney capsule, then bluntly dissect through the renal parenchyma, ligating renal vessels as necessary (Fig. 24.5). Culture the renal pelvis. Remove the calculi and flush the kidney with warm saline or lactated Ringer’s solution. Assess the ureter for patency by placing a 3.5-Fr soft rubber catheter down the ureter and flushing it with warm fluids. Close the nephrotomy by apposing the cut tissues and applying digital pressure for approximately 5 minutes while restoring blood flow through the renal vessels (sutureless technique). As an alternative, appose the capsule with a continuous pattern of absorbable suture material (see Fig. 24.5). If adequate hemostasis is not achieved, or if urine leakage is a concern, place absorbable sutures through the cortex in a horizontal mattress fashion (see previous comments and Fig. 24.5). Then, suture the capsule in a continuous pattern with absorbable suture. Replace the kidney in its original location. Sutures may be placed in the peritoneum where the kidney was elevated to help stabilize it…]”
Excerpt From
Small Animal Surgery E-Book
Theresa Welch Fossum DVM, MS, PhD, Dipl ACVS
https://books.apple.com/us/book/small-animal-surgery-e-book/id1367916984
This material may be protected by copyright.
You represented with a large breed female dog of 10 months of age with a history of intermittent urinary incontinence. This dog was spayed three months ago. Besides hormone related sphincter incontinence, what is your second most likely differential diagnosis?
Ectopic ureters
A skilled ultrasoundnographist will be able to diagnose ectopic ureters by identifying and following the ureter past the level of the trigone. What is currently considered the test of choice for the diagnosis of urogenital abnormalities?
“CT excretory urography is the most sensitive method for diagnosis of ectopic ureters, and if available, should be considered the imaging modality of choice (Fig. 24.18). In a recent study comparing CT findings with cystoscopic and/or surgical findings, reviewers correctly identified 20 of 20 (100%) ureters as normal or ectopic based on the CT findings.6 Common abnormalities observed in dogs with intramural ectopic ureters include lack of a normal ureterovesicular junction, a urethral-ureteral orifice location, and lack of ureteral divergence.”
Excerpt From
Small Animal Surgery E-Book
Theresa Welch Fossum DVM, MS, PhD, Dipl ACVS
https://books.apple.com/us/book/small-animal-surgery-e-book/id1367916984
This material may be protected by copyright.
What causes other than ectopic ureters should you rule out in young versus older patients prior to considering tests for ectopia?
- Behavioral (submissive) incontinence
- Urge incontinence
- Neurogenic incontinence
- Hormonal responsive incontinence
“Ureteral ectopia should be seriously considered in any young animal presented for incontinence or any older animal which has had incontinence since it was young. Behavioral incontinence is also common in young animals because of exaggerated submissiveness. Other causes of incontinence include urge incontinence (associated with inflammation or infection), neurogenic disorders (e.g., lower and upper motor neuron disorders or reflex dyssynergia), anatomic outflow obstruction (e.g., paradoxic incontinence), and urethral sphincter incontinence (e.g., hormone-responsive incontinence). Behavioral, urge, neurogenic, and hormone-responsive incontinence should be eliminated before tests for ectopia are considered in older animals.”
Excerpt From
Small Animal Surgery E-Book
Theresa Welch Fossum DVM, MS, PhD, Dipl ACVS
https://books.apple.com/us/book/small-animal-surgery-e-book/id1367916984
This material may be protected by copyright.
What are the three most common drugs utilized in the treatment of urinary sphincter leakage?
Phenylpropanolamine (alpha-adrenergic agonist, weak beta adrenergic agonist. Leads to the release of norepinephrine and inhibits norepinephrine reuptake in the postsynaptic membrane, thereby increasing smooth muscle tone)
Ephedrine (Al[ha and beta adrenergic agonist, also promoting the release and inhibiting the reuptake of norepinephrine. POTENTIALLY LETHAL AT 10 MG/KG)
Diethylstilbestrol (synthetic estrogen)
What precautions (4) should always be taken when performing a nephrectomy?
1) explore the entire abdomen, particularly the opposite kidney for evidence of disease
2) locate the contralateral ureter to make sure it is not inadvertently ligated
3) remove the entire ureter associated with the kidney being removed
4) handle the neoplastic kidney very carefully and ligate the renal vein first to prevent seating of neoplastic cells via the vasculature or a directly into adjacent tissue
What are the most common complications associated with nephrectomies? (4)
Hemorrhage
Urine leakage
AKI in patients with pre-existing CKD
Inadvertent ligation of the contralateral ureter
What is the most common cause of hydronephrosis?
Ureteral outflow obstruction 
Renal abscesses are rare in dogs. What diseases are they commonly associated with and what is the most commonly isolated bacterial agent?
“Although few cases have been reported in dogs, renal abscesses have been associated with pyelonephritis, hyperadrenocorticism, diabetes mellitus, and renal biopsy. Most renal cortical abscesses are unilateral and Staphylococcus spp. is the most commonly isolated causative agent in dogs and cats.”
Excerpt From
Small Animal Surgery E-Book
Theresa Welch Fossum DVM, MS, PhD, Dipl ACVS
https://books.apple.com/us/book/small-animal-surgery-e-book/id1367916984
This material may be protected by copyright.
Perinephric abscess is often associated with significant mortality despite aggressive therapy (drainage, surgical intervention, antibiotics). Provided that the condition can be diagnosed expediently and that renal function remains adequate, what is the recommended treatment for these lesions?
Nephrectomy
Urinary obstruction and uroperitoneum are considered medical emergencies, not surgical emergencies. Why?
“Urinary obstruction and uroperitoneum are medical emergencies, not surgical emergencies. Hyperkalemia associated with these conditions makes the animal prone to cardiac arrhythmias; therefore fluid and electrolyte abnormalities should be corrected before anesthesia.”
Excerpt From
Small Animal Surgery E-Book
Theresa Welch Fossum DVM, MS, PhD, Dipl ACVS
https://books.apple.com/us/book/small-animal-surgery-e-book/id1367916984
This material may be protected by copyright.
List three steps that should always be taken when performing a cystotomy
1) obtain a sample of mucosa for a bacterial culture
2) check the Apex for diverticulum and excise if present
3) Pass a urinary catheter down the urethra to verify patency
Describe the surgical approach and recommended therapy for a transected membranous (pelvic) urethra
“Perform a caudal ventral midline abdominal incision and, if necessary, a pubic symphysiotomy or bilateral pubic and ischial osteotomy (see later). Locate the transected ends of the urethra and debride them. Minimize dissection around the urethra and bladder to prevent damage to the vascular or nerve supply to these structures (Fig. 25.11). Suture the ends with six to eight absorbable interrupted sutures over a transurethral catheter (preferably a Foley catheter or other soft catheter). Leave the catheter in place for 7 to 10 days. If the urethral tissues do not hold suture because of prolonged urine extravasation and subsequent tissue devitalization, delayed repair is indicated. Place a transurethral catheter to divert urine flow for 5 to 7 days. If a catheter cannot be placed from the penile orifice into the bladder, pass a catheter from the bladder into the traumatized tissue, tie it to a catheter placed from the penile urethral orifice, and use it to pull the penile catheter into the bladder. If the urethra does not heal completely in 7 to 10 days, or if stricture occurs, resect the urethral ends and suture them over a catheter, as described for primary repair.
”
Excerpt From
Small Animal Surgery E-Book
Theresa Welch Fossum DVM, MS, PhD, Dipl ACVS
https://books.apple.com/us/book/small-animal-surgery-e-book/id1367916984
This material may be protected by copyright.
Describe the technique for closure of a pre-scrotal urethrotomy
“Using 4-0 or 5-0 monofilment absorbable matetial, Place the first layer in the urethral mucosa and corpus spongiosum, then appose subcutaneous tissue and skin with simple interrupted sutures or a continuous subcuticular suture pattern.”
Excerpt From
Small Animal Surgery E-Book
Theresa Welch Fossum DVM, MS, PhD, Dipl ACVS
https://books.apple.com/us/book/small-animal-surgery-e-book/id1367916984
This material may be protected by copyright.
What are the four types of urethrostomy performed in dogs?
“Depending on the site of the lesion, ureterostomy can be prescrotal, scrotal, perineal, or prepubic in dogs.”
Excerpt From
Small Animal Surgery E-Book
Theresa Welch Fossum DVM, MS, PhD, Dipl ACVS
https://books.apple.com/us/book/small-animal-surgery-e-book/id1367916984
This material may be protected by copyright.
What is the recommended length of an urethral incision for urethrostomy?
“The length of the urethral incision should be six to eight times its luminal diameter. ”
Excerpt From
Small Animal Surgery E-Book
Theresa Welch Fossum DVM, MS, PhD, Dipl ACVS
https://books.apple.com/us/book/small-animal-surgery-e-book/id1367916984
This material may be protected by copyright.
Describe the technique for a perineal urethrotomy in the dog
“For perineal urethrotomy, make a midline incision over the urethra, midway between the scrotum and the anus. (A) Identify the retractor penis muscle, elevate it, and retract it. (B) Separate the paired bulbospongiosus muscles at their raphe to expose the corpus spongiosum. (C) Incise the corpus spongiosum to enter the urethral lumen. (D) Close the urethra with simple interrupted absorbable sutures. Place the first layer in the urethral mucosa and corpus spongiosum; appose subcutaneous tissue and skin with simple interrupted sutures or a continuous subcuticular suture pattern.”
Excerpt From
Small Animal Surgery E-Book
Theresa Welch Fossum DVM, MS, PhD, Dipl ACVS
https://books.apple.com/us/book/small-animal-surgery-e-book/id1367916984
This material may be protected by copyright.
Why is perineal urethrostomy rarely ever performed in dogs?
Frequently causes unacceptable urine scalding
The surrounding cavernous tissue is large at this location, and hemorrhage can be profuse
The urethra is deep at this location, making it difficult to obtain a tension free closure between skin and mucosa (may result in dehiscence)
Describe the technique for perineal urethrostomy in cats
“Place a purse-string suture in the anus, and catheterize the penis if possible. Place the cat in dorsal or ventral recumbency. If the cat is placed in dorsal recumbency, pull the pelvic limbs forward to improve access to the perineal region. Dorsal recumbency allows for cystotomy and perineal urethrostomy without having to reposition the cat. Make an elliptical incision around the scrotum and prepuce, and excise them. Place an Allis tissue forceps on the end of the prepuce or around the catheter to help manipulate the penis. Free the penis and the distal urethra from the surrounding tissue on either side (Fig. 25.22A). Extend the dissection ventrally and laterally toward the penile attachments at the ischial arch. Elevate the penis dorsally, and sharply sever the ventral penile ligament. Then, transect the ischiocavernosus muscles (see Fig. 25.22B) and the ischiourethralis muscles at their insertion on the ischium to avoid damaging branches of the pudendal nerves and to minimize hemorrhage. Reflect the penis ventrally to expose the dorsal surface. Locate the bulbourethral glands proximal and dorsal to the bulbospongiosus muscle and cranial to the severed ischiocavernosus and ischiourethralis muscles (see Fig. 25.22C). Avoid excessive dorsal dissection to prevent damage to[…]”
Excerpt From
Small Animal Surgery E-Book
Theresa Welch Fossum DVM, MS, PhD, Dipl ACVS
https://books.apple.com/us/book/small-animal-surgery-e-book/id1367916984
This material may be protected by copyright.
Ureterocolic anastomosis are considered salvage procedures in cases of trigone neoplasia when complete cystectomy is necessary. These procedures are typically avoided in favor of stenting techniques due to the high risk of complications. List the most common complications associated with the procedure?
“Complications associated with ureteral anastomosis in the bowel include reabsorption of electrolytes and nitrogenous waste products, upper UTI, and neurologic dysfunction. Azotemia, hyperammonemia, hyperchloremia, and metabolic acidosis are also common after these procedures.”
Excerpt From
Small Animal Surgery E-Book
Theresa Welch Fossum DVM, MS, PhD, Dipl ACVS
https://books.apple.com/us/book/small-animal-surgery-e-book/id1367916984
This material may be protected by copyright.
List a commercial xenograft that has been successfully used with minimal complications for the reconstruction of large portions of the urinary bladder in dogs
“porcine small intestine submucosa grafts”
Excerpt From
Small Animal Surgery E-Book
Theresa Welch Fossum DVM, MS, PhD, Dipl ACVS
https://books.apple.com/us/book/small-animal-surgery-e-book/id1367916984
This material may be protected by copyright.
What are the recommended methods for treating a partial urethral laceration (urethral continuity not completely disrupted) versus a complete urethral laceration? What are the expected healing times and possible complications?
If urethral continuity is not completely disrupted, the urethra will regenerate in as little as seven days. Urinary diversion via urethral catheter or tube cystostomy are indicated to avoid urine extravasation. Urine leakage, particularly if infected, can delay healing and promote periurethral fibrosis and stricture.
When complete transaction of the urethra occurs, primary anastomosis over an indwelling catheter should be performed to decrease the likelihood of stricture formation. The catheter should be left in place for 3 to 5 days. 
Proteus mirabilis is known to produce a different urinary environment in comparison to E. coli. What is the difference? How does it matter when it comes to choosing a suture material for the closure of the urinary bladder or urethral defect?
“Most sutures appear to lose tensile strength faster in alkaline urine (such as that seen with Proteus infections) than in infected acidic urine or sterile urine. Polyglycolic acid, polyglactin 910, and poliglecaprone 25 are rapidly degraded in infected urine; polydioxanone, polyglyconate, and glycomer 631 are acceptable for use in sterile bladders and in those infected with E. coli. However, use of any suture that is degraded via hydrolysis may be risky when the bladder is infected with Proteus spp. (see also p. 61) because monofilament absorbable sutures have been shown to degrade within 7 days in Proteus mirabilis-inoculated urine in vitro.”
Excerpt From
Small Animal Surgery E-Book
Theresa Welch Fossum DVM, MS, PhD, Dipl ACVS
https://books.apple.com/us/book/small-animal-surgery-e-book/id1367916984
This material may be protected by copyright.
Emergency surgery is rarely ever indicated for patients with urinary bladder or urethral rupture caused by trauma. What initial approach should be taken in these patients?
“Immediate surgery is contraindicated in animals with uroabdomen that are hyperkalemic or uremic. In general, emergency surgery is rarely appropriate for animals diagnosed with uroabdomen. Patients should first be treated medically to normalize electrolytes and acid base, and to decrease circulating nitrogenous waste products. Intravenous fluids should be given and abdominal drainage and urethral catheterization performed (see p. 699). A large over-the-needle catheter (14-gauge) can be placed in the ventral abdomen under local anesthesia (sedate if necessary) to allow drainage for 6 to 12 hours. This will stabilize most animals with previously normal renal function.”
Excerpt From
Small Animal Surgery E-Book
Theresa Welch Fossum DVM, MS, PhD, Dipl ACVS
https://books.apple.com/us/book/small-animal-surgery-e-book/id1367916984
This material may be protected by copyright.
When urine leaks into the abdominal cavity, some nitrogenous waste products and electrolytes are reabsorbed across the perineal membrane while others are not due to their molcular size. Explain what happens to BUN creatinine and potassium in these cases. How can measurement of these parameters help us diagnose uroabdomen and what are the “cutoff” values for each?
“Urea rapidly equilibrates across the peritoneal surface, whereas larger molecules (e.g., creatinine) cannot pass back into the bloodstream, and they remain concentrated in the abdominal fluid.
“Diagnostic
Creatinine: Abdominal fluid: peripheral blood ≥2
Suggestive
Creatinine: Abdominal fluid: peripheral blood >1 but <2
Potassium: Abdominal fluid > peripheral blood”
Excerpt From
Small Animal Surgery E-Book
Theresa Welch Fossum DVM, MS, PhD, Dipl ACVS
https://books.apple.com/us/book/small-animal-surgery-e-book/id1367916984
This material may be protected by copyright.
What is the reported incidence of uroabdomen versus hemoabdomen in dogs with a traumatic pelvic fracture (2016 study)
Uroabdomen: 3.6%
Hemoabdomen: 32.5%
What are the alpha blocker and the somatic muscle relaxant typically utilized to decrease urethral sphincter tone?
Phenoxybenzamine
Diazepam
What is the prognosis for patients diagnosed with urinary bladder rupture secondary obstruction?
Possibly guarded because most of the urinary bladder may be necrotic
Explain the pathophysiology of struvite calculi formation due to UTI’s in dogs
“UTIs with urease-producing bacteria are an important cause of struvite calculi in dogs. These bacteria split urea to ammonia and carbon dioxide. Hydrolysis of ammonia forms ammonium ions and hydroxyl ions, which alkalinize the urine and decrease struvite solubility. Bacterial cystitis also increases organic debris, which can serve as a nidus for crystallization. Female dogs tend to have more struvite-containing calculi than male dogs, most likely owing their propensity for UTIs. Feline struvite formation usually occurs without UTI.”
Excerpt From
Small Animal Surgery E-Book
Theresa Welch Fossum DVM, MS, PhD, Dipl ACVS
https://books.apple.com/us/book/small-animal-surgery-e-book/id1367916984
This material may be protected by copyright.
What are possible risk factors for the development of calcium oxalate cristaluria/calculi?
Defective tubular resorption of calcium
Primary hyperparathyroidism
Lymphoma
Hypervitaminosis D
Diet rich in oxalates (high carbohydrate content)
Any condition leading to acidic urine or hypercalcemia
Urate calculi are more commonly observed in what breed? What is the pathophysiology for such tendency?
What disease condition (congenital) can also lead to the formation of these calculi?
Dalmatians
Ammonium acid urate is derived from metabolic degradation of endogenous purine ribonucleotides and dietary nucleic acids. A normal dogs these by products are converted into allantoin for excretion (>90%). Dalmatians have defective hepatic transport of uric acid, resulting in decreased production of allantoin and increased urinary excretion of uric acid.
PSS can I also lead to urate calculi
What drug can be used to reduce the chance of recurrence of urate calculi in dalmatians? What if a PSS is present?
Allopurinol
Correct PSS
What dog breeds are predisposed to silicate calculi?
German shepherds and English Sheepdogs
What is the most sensitive method for finding urethral and urinary bladder stones (even better than ultrasound)
“Double-contrast cystography/urethrography is probably the most sensitive method for finding stones (even better than ultrasound).”
Excerpt From
Small Animal Surgery E-Book
Theresa Welch Fossum DVM, MS, PhD, Dipl ACVS
https://books.apple.com/us/book/small-animal-surgery-e-book/id1367916984
This material may be protected by copyright.
What is considered the best method to avoid recurrence of urethral obstruction in dalmatians diagnosed with urate calculi?
“Cystotomy plus scrotal urethrostomy (p. 689) may be the most effective treatment in preventing recurrence of clinical signs in Dalmatians with urate calculi. Recurrence is common when a cystotomy alone is performed.”
Excerpt From
Small Animal Surgery E-Book
Theresa Welch Fossum DVM, MS, PhD, Dipl ACVS
https://books.apple.com/us/book/small-animal-surgery-e-book/id1367916984
This material may be protected by copyright.
What dog breeds are predisposed to developing cystine urinary stones?  What drug can be used to attempt medical dissolution? What precautions must be taken if this drug used to be used after surgical removal of calculi?
Dachshunds, basset hounds, English bulldogs and others
D-penicillamine;  “Penicillamine may inhibit wound healing and should not be initiated earlier than 2 weeks after surgery. ”
Excerpt From
Small Animal Surgery E-Book
Theresa Welch Fossum DVM, MS, PhD, Dipl ACVS
https://books.apple.com/us/book/small-animal-surgery-e-book/id1367916984
This material may be protected by copyright.
What is the reported failure to remove all stones after cystotomy?
20% (Grant, DC et al, JAVMA 2010)
Urethral prolapse can be treated via urethropexy or surgical ressection of the prolapsed urethra (or both). What’s the prognosis with and without surgical therapy? Whats the reported recurrence and hemorrage rates after surgical treatment? what can be done to decrease this chance?
“Without surgery, the prolapse will not spontaneously resolve. A 2014 study found a recurrence rate of 57%; the likelihood of recurrence was reduced when postoperative sedation was used (e.g., acepromazine or butorphanol).14 Postoperative hemorrhage occurred in 39% of dogs; hemorrhage was less common when a simple continuous pattern was used instead of a simple interrupted.”
Excerpt From
Small Animal Surgery E-Book
Theresa Welch Fossum DVM, MS, PhD, Dipl ACVS
https://books.apple.com/us/book/small-animal-surgery-e-book/id1367916984
This material may be protected by copyright.
Rhabdomyosarcomas are rare urinary tract tumors of dogs. What is their biological behavior?
“Rhabdomyosarcomas are uncommon, highly malignant tumors of striated muscle that may develop from pluripotent stem cells of the primitive urogenital ridge; they are remnants of the Müllerian or Wolffian ducts.”
Excerpt From
Small Animal Surgery E-Book
Theresa Welch Fossum DVM, MS, PhD, Dipl ACVS
https://books.apple.com/us/book/small-animal-surgery-e-book/id1367916984
This material may be protected by copyright.
What is the biological behavior of TCC in dogs?
“Most bladder tumors are malignant, and metastasis to the medial iliac lymph nodes and lungs is common. Local extension to the ureters and/or the urethra is also common.”
Excerpt From
Small Animal Surgery E-Book
Theresa Welch Fossum DVM, MS, PhD, Dipl ACVS
https://books.apple.com/us/book/small-animal-surgery-e-book/id1367916984
This material may be protected by copyright.
TCC are the most common malignant neoplasia of the urinary bladder of dogs and cats. List 5 other malignant and two benign tumors also occasionally observed.
“other malignant bladder tumors include squamous cell carcinoma, adenocarcinoma, fibrosarcoma, leiomyosarcoma, neurofibrosarcoma, rhabdomyosarcoma, and hemangiosarcoma. Fibroma, leiomyoma, hemangioma, rhabdomyoma, myxoma, and neurofibroma are benign bladder tumors. ”
Excerpt From
Small Animal Surgery E-Book
Theresa Welch Fossum DVM, MS, PhD, Dipl ACVS
https://books.apple.com/us/book/small-animal-surgery-e-book/id1367916984
This material may be protected by copyright.
What condition presents similar clinical signs (stranguria, hematuria, pollakiuria, vaginal discharge) to urethral neoplasia? How are they differentiated and how is this inflammatory condition treated?
“Proliferative urethritis and granulomatous inflammation of the urethra in female dogs may cause clinical signs similar to those of urethral neoplasia (e.g., stranguria, hematuria, pollakiuria, vaginal discharge, and/or urinary obstruction). Neoplasia and granulomatous inflammation may be differentiated by cytologic evaluation of urethral aspirates or surgical biopsies. The cause of granulomatous urethritis is unknown. Affected dogs may respond favorably to immunosuppressive therapy (e.g., prednisone or prednisone plus cyclophosphamide) plus antibiotics.”
Excerpt From
Small Animal Surgery E-Book
Theresa Welch Fossum DVM, MS, PhD, Dipl ACVS
https://books.apple.com/us/book/small-animal-surgery-e-book/id1367916984
This material may be protected by copyright.
Is there a gender or breed predisposition for urinary bladder neoplasia in dogs?
Female dogs and male cats are at a higher risk for bladder cancer
Shetland sheep dogs, beagles, collies and terriers, particularly Scottish terriers
What paraneoplastic syndrome may be seen in a dog with TCC?
“Lameness may be associated with hypertrophic osteopathy paraneoplastic syndrome in dogs with TCC”
Excerpt From
Small Animal Surgery E-Book
Theresa Welch Fossum DVM, MS, PhD, Dipl ACVS
https://books.apple.com/us/book/small-animal-surgery-e-book/id1367916984
This material may be protected by copyright.
Describe the technique for transurethral biopsy that can be used for the diagnosis of urinary bladder TCC
“Transurethral biopsy using a sterile urinary catheter is often diagnostic. First, insert a finger into the rectum. Then, advance the largest urinary catheter that easily passes through the urethra until the tip is digitally felt to advance just to the point where the thickening or mass is palpated. At that point, apply negative pressure. If urine is obtained, empty the bladder. After the bladder is emptied, or if negative pressure is present to begin with, establish 8 to 12 mL of negative pressure with a syringe that has 10 mL of sterile saline in it, while pulling the catheter tip back out through the thickened area. Once the catheter tip is clearly out of the affected area, remove the catheter from the urethra, place the tip in a clot tube, and blow the tissue fragments in the tip out by forcing saline out through the catheter. Examine the fluid, and retrieve tissue fragments and use them to make squash cytology preparations. In the case of female dogs with severe obstruction of the distal urethra, the most that may be possible is to insert a small, stiff polypropylene catheter a few millimeters into the urethra (which is as far as is possible[…]”
Excerpt From
Small Animal Surgery E-Book
Theresa Welch Fossum DVM, MS, PhD, Dipl ACVS
https://books.apple.com/us/book/small-animal-surgery-e-book/id1367916984
This material may be protected by copyright.
What precaution should always be taken immediately after the surgical excision of a bladder TCC (prior to closure)?
“Transplantation of TCC to the subcutaneous tissue of the surgical incision has been reported in dogs; therefore the same instruments used for biopsy or resection of a bladder tumor should not be used on other tissues.”
Excerpt From
Small Animal Surgery E-Book
Theresa Welch Fossum DVM, MS, PhD, Dipl ACVS
https://books.apple.com/us/book/small-animal-surgery-e-book/id1367916984
This material may be protected by copyright.
