Page 174 - WSAVA2017
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An Urban Experience
WSVA7-0474
MULTIDISCIPLINARY CASE ROUNDS / INTERNAL MED
STOPPING THE LEAKY DOG. A CURE TO CANINE URINARY INCONTINENCE
S. Vaden1
1North Carolina State University, Department of Clinical Sciences, Raleigh, USA
Stopping the Leaky Dog: A Cure to Canine Incontinence
Shelly L. Vaden
North Carolina State University CVM, Raleigh, NC
It is estimated that 20% of dogs in the United States
will develop urinary incontinence. Urethral sphincter mechanism incompetence (USMI), ectopic ureters, paradoxical incontinence, destrusor hyperactivity, vestibulovaginal abnormalities and neurologic disorders are all causes of urinary incontinence in dogs. Signalment, historical information and the pattern of incontinence
can lead to an accurate diagnosis most of the time. In more complicated cases advanced imaging studies or cystourethroscopy or both may be needed to render
a diagnosis. Standard medical therapy can be used
to effectively treat 85-90% of dogs with USMI and
some dogs with ectopic ureters. Dogs with refractory incontinence can be very challenging to pet owners and veterinarians and require other forms of management.
The purpose of this presentation is to discuss advances in medical management of dogs with refractory incontinence.
Medical Management
Appropriate medical management depends upon the underlying cause of urinary incontinence. Alpha agonists and reproductive hormones are the most common agents used for the treatment of USMI, the most common form of urinary incontinence in mature female dogs. Reported success rates of the alpha agonist phenylpropanolamine (PPA) in female dogs with USMI have been as high as 90%. Some dogs may take as long as 4 weeks to demonstrate a complete response. Ephedrine and pseudoephedrine are alternative alpha agonists that can be used for the treatment of USMI, but have slightly lower success rates than PPA. These drugs should be avoided in dogs with cardiac disease or hypertension. Diethylstilbesterol (DES) has historically been the most common reproductive hormone used
in the management of USMI in female dogs and is reported to have a 60-80% success rate. Estriol is now commercially available and has similar response rates. Some female dogs that fail to become continent with PPA or DES will exhibit continence when the drugs are given as combination therapy. Gonadotropin releasing hormone analogues, such as leuprolide, buserelin, triptorelin or deslorelin, have also been be used to control incontinence with efficacy rates of 50-70%. They work by down-regulating LH secretion to restore continence and may be more effective when combined with PPA.
Male dogs with USMI have a lower and less predictable response rate to alpha agonists (<50%) but may respond to injections of testosterone cypionate given every 6-8 weeks. The low response rate in males might be due to the difficulty in differentiating detrusor weakness from urethral incompetence.
   Drug
  Dose
  Notes
   Phenylpropanolamine
0.5-1.5 mg/kg PO q12h
  Can be given every 8 hours but may increase tolerance
 Diethylstilbesterol
  1 mg PO q24h for 7 days then every 4-7 days
  Maintain with lowest effective dose
   Estriol
2 mg PO q24h for 14 days, then 1 mg q24h for 14 days, then 0.5 mg q24h
  Maintain with lowest effective dose
 Leuprolide
 5-10 mg SQ or IM
 Given to effect every 6-12 months
 Testosterone cypionate
  1-2 mg/kg IM q4-8 weeks
  Male dogs only
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Urethral Bulking Agents
Refractory USMI may be managed by submucosal injection of bulking agents in the proximal urethra during cystourethroscopy. Submucosal bulking creates a central filling volume that in turn increases the length of the muscle fibers and closure power of the urethral sphincter thereby increasing resistance to urine flow. Generally
the bulking agent is injected in 3-4 sites around the
circumference of the proximal urethra (just distal to the trigone) until the deposits close the urethral lumen, as seen through the cystoscope. Mild complications (e.g., dysuria) occur in up to 15% of dogs in the immediate post-procedural period. Success is usually apparent within 1-3 days.
Purified bovine collagen that has been cross-linked with glutaraldehyde is the bulking agent that has been used
 42ND WORLD SMALL ANIMAL VETERINARY ASSOCIATION CONGRESS AND FECAVA 23RD EUROCONGRESS
  





















































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