Urinary Tract Diseases of Horses

Colt with neurological signs, abdominal distention, hypoNa, hypoCl, hyperK, and azotemia most likely has

ruptured bladder/uroabdomen

Post-renal azotemia differentials?

-Neonatal uroabdomen

-Obstructive urolihtiasis

-Bladder necrosis

what part of the bladder is most commonly ruptured with uroperitoneum?

dorsal apex

Evidence of uroperitoneum due to urethral rupture?

perineal/preputial edema

Evidence of uroperitoneum due to urachal rupture?

subcutaneous edema around umbilicus

Evidence of uroperitoneum due to ureteral rupture?

retroperitoneal fluid

What are the most common causes of uroperitoneum in foals?

Birth trauma

Congenital abnormalities

Sepsis

Dummy foals

Are colts or fillies more likely to develop uroperitoneum?

colts

1 multiple choice option

Clinical signs of uroperitoneum?

Abdominal distension

Colic

Tachypnea

Stranguria

Poliakuria

Lethargy

Anorexia

uroperitoneum dx?

Ultrasound

Abdominocentesis

Urinary cath

Contrast radiographs

lab findings consistent with uroperitoneum?

HypoNa

HypoCl

HyperK

Post-renal azotemia

Abdominocentesis fluid analysis results for uroperitoneum?

Peritoneal creatinine > 2x serum creatinine

uroperitoneum tx?

1. Stabilize electrolytes - address hyperkalemia!!

2. IV fluids

3. Antimicrobials

4. Abdominal drainage (abdominocentesis or urinary cath)

5. Surgical correction

Does calcium gluconate lower potassium?

no!

1 multiple choice option

Patent urachus in foals can occur secondary to

-sepsis

-systemic illness

-weakness

-prolonged recumbency

how is Patent urachus diagnosed?

physical exam - urine excreted via umbilicus

Patent urachus tx?

-Antimicrobials and wait for it to close

-Surgery if prolonged or associated infection develops

Most common signalment for urolithiasis?

Geldings ~10yo

List these in order from most common to least common

a. nephrolith

b. urethrolith

c. ureterolith

d. cystolith

dbac

3 multiple choice options

Common types of urolithiasis?

Calcium carbonate

Calcium phosphate

Clinical signs of cystoliths?

-Hematuria post-exercise

-Stranguria

-Incontinence

-Recurrent colic

Clinical signs of nephrolith/ureterolith?

Silent until bilateral obstructive disease and CKD

urolithiasis diagnosis?

Rectal palpation

Ultrasound

Cytoscopy

Urolithiasis tx in mares?

Removal via urethra

Urolithiasis tx in males?

Pararectal cystotomy

Perineal urethrostomy

Cystotomy

Laparascopic

Post surgical tx for urolithiasis?

-Bladder lavage

-Anti-inflammatories

-Antimicrobials

-Encourage water consumption

-Eliminate legumes

-Lower DCAD to lower urine PH

Urolithiasis prognosis following treatment?

41% recurrence within 1-32 months

How can you differentiate pigmenturia from hematuria?

Centrifuge urine - RBCs in sediment with hematuria

If hematuria is present throughout a urine stream, where might the problem be?

Kidney

Bladder

If hematuria is present only at the beginning of urination, where might the problem be?

distal urethra

If hematuria is present only at the end of urination, where might the problem be?

proximal urethra

Differential diagnoses for renal-related hematuria?

-NSAID toxitiy

-Idiopathic renal hematuria

-Renal adenocarcinoma

Differential diagnoses for bladder-related hematuria?

-Cystolith

-Neoplasia

-Equine idiopathic hemorrhagic cystitis

-Blister beetle toxicity

Differential diagnoses for urethra-related hematuria?

-Urethral tear

-Urethra/external genitalia neoplasia

-Habronemiasis

What can cause false hematuria?

Pyrocatechin + Snow/bedding/air

sudden onset, life-threatening/massive hematuria characterized by acute blood loss on physical exam with no systemic disease

Idiopathic Renal Hematuria

What should you rule out before diagnosing Idiopathic Renal Hematuria?

Renal adenocarcinoma

Coagulopathy

How is Idiopathic Renal Hematuria diagnosed?

-Rule out renal adenocarcinoma and coagulopathy

-endoscopy

-U/S

Idiopathic Renal Hematuria tx?

-Supportive care

-Unilateral nephrectomy (often bilateral though)

-Dexamethasone

-Euthanasia

Renal adenocarcinoma clinical signs?

-hematuria

-weight loss

-colic

-unilateral disease

-no azotemia

Renal adenocarcinoma tx?

nephrectomy

Is azotemia commonly seen with Idiopathic Renal Hematuria, Renal adenocarcinoma, both or neither?

neither

3 multiple choice options

Clinical signs of bladder neoplasia?

Hematuria

Pollakiuria

Stranguria

how is bladder neoplasia diagnosed?

Rectal palpation

Ultrasound

Cystoscopy

Biopsy

bladder neoplasia prognosis?

guarded

bladder neoplasia can be difficult to distinguish from equine idiopathic hemorrhagic cystitis without a ________

biopsy

Clinical signs of equine idiopathic hemorrhagic cystitis?

Hematuria

Pollakiuria

Stranguria

No bacterial growth on urine culture

how is equine idiopathic hemorrhagic cystitis diagnosed?

Ultrasound

Cystoscopy

Biopsy

equine idiopathic hemorrhagic cystitis tx?

Abx

Anti-inflammatories

equine idiopathic hemorrhagic cystitis prognosis?

good

Clinical signs of cantharidin toxicity?

Hematuria of any mucosal surface (GI, oral, cystitis, nephrosis, myocarditis)

how is cantharidin toxicity diagnosed?

HypoCa

HypoMg

Azotemia

GI contents or urine

ID beetle in hay

cantharidin toxicity tx?

Fluid/electrolyte support

Analgesia

Charcoal

Biosponge

Most common types of urethra/external genitalia neoplasia?

Squamous cell carcinoma

Sarcoid

summer sore of the urethra/external genitalia known as a local hypersensitivity and characterized by sulfur granules

Habronemiasis

Habronemiasis tx?

Ivermectin

Steroids

Fly control

Clinical signs of urethral tear?

-Hematuria at the end of urination

-Bright red

-No pollakuria or dysuria

most common signalment for urethral tears?

quarterhorse gelding

how are urethral tears diagnosed?

Endoscopy

urethral tears tx?

-benign neglect

-corpus spongiosum incision

-buccal mucosal graft

urinary incontinence due to ? motor neuron disease is characterized by increased bladder tone, increase urethral resistance, and a firm bladder with paresis/paralysis of pelvic limbs

upper

1 multiple choice option

urinary incontinence due to ? motor neuron disease is characterized by decreased bladder tone, and a flaccid bladder with loss of anal/tail tone

lower

1 multiple choice option

Upper motor neuron urinary incontinence clinical signs?

-pollakiuria

-sporadic dribbling

Lower motor neuron urinary incontinence clinical signs?

-continuous dribbling

-cauda equine syndrome

What causes upper motor neuron urinary incontinence?

Spinal cord lesions

What causes lower motor neuron urinary incontinence?

-Trauma

-Polyneuritis equi

-EHV-1 myeloencephalitis

-Sorghum/sudan grass toxicity

condition characterized by loss of anal/tail tone, perineal analgesia, and hind limb weakness/ataxia

cauda equina syndrome

form of urinary incontinence that can be idiopathic or secondary to obstruction leading to accumulation of sabulous debris

myogenic bladder

myogenic bladder leads to ? cystitis

sabulous

sabulous cystitis tx?

Culture urine

Treat bacterial cystitis

Lavage bladder

Stimulate bladder emptying

Ectopic ureters are usually not clinical in males or females?

males

1 multiple choice option

Is bacterial cystitis common in horses?

no

1 multiple choice option

Clinical signs of bacterial cystitis?

Dysuria

Pollakiuria

Hematuria

how is bacterial cystitis diagnosed?

-Sediment with >10wbc/hpf

-Bacteriuria

->10,000cfu/mL midstream or catheterized

most common cause of bacterial cystitis?

gram negative enterobacteraceae

bacterial cystitis tx?

-Trimethoprim sulfonamide

-Penicillin

-Ceftiofur

-Diuresis

inflammation of the renal pelvis and the kidney

pyelonephritis

pyelonephritis can occur secondary to

-ectopic ureter

-bladder paralysis

-nephrolithiasis

-bacteremia

clinical signs of pyelonephritis?

Systemic illness with dysuria and hematuria

how is pyelonephritis diagnosed?

U/S

Cystoscopy

Culture

pyelonephritis tx?

Abx

Nephrectomy

Polyuria is defined as urine output greater than

50ml/kg/day

Polydipsia is defined as urine output greater than

100ml/kg/day

DDx for PU/PD?

Renal failure

Psychogenic polydipsia

Diabetes insipidus

PPID

Sepsis

Alpha 2 agonists

how is the cause of PU/PD diagnosed?

water deprivation test

how is psychogenic polydipsia diagnosed?

USG > 1.025 after water deprivation sufficient to produce 5% loss in body weight

diabetes insipidus caused by a loss of hypothalamus neurons and subsequent decrease in ADH that can occur secondary to encephalitis

neurogenic (central) diabetes insipidus

diabetes insipidus caused collecting ducts that are insensitive to ADH

nephrogenic diabetes insipidus

method to diagnose types of diabetes insipidus ?

Vasopressin concentration test

if specific gravity of urine following vasopressin administration AND H2O deprivation is greater than >1.020, what is your diagnosis?

Psychogenic polydipsia

2 multiple choice options

if specific gravity of urine following H2O deprivation is isosthenuric and greater than >1.020 after vasopressin administration, what is your diagnosis?

Neurogenic diabetes insipidus

2 multiple choice options

if specific gravity of urine is isosthenuric following H2O deprivation and vasopressin administration, what is your diagnosis?

Nephrogenic diabetes insipidus

2 multiple choice options

condition that can cause PU/PD characterized by impingement on hypothalamus and posterior pituitary resulting in excessive cortisol

PPID

what class of drugs can cause PU/PD in horses?

alpha 2 agonists