Cassy may be facing the prospect of surgery and it has her caretaker Wanda a bit worried.  Actually I think “very worried” is a more accurate description.  Wanda has been caring for Cassy for nine years and she requires more than an average amount of care.  Cassy has diabetes mellitus and congestive heart failure both of which require daily treatment but most recently she has developed another problem.  Cassy has bladder stones. 

Bladder stones are a fairly common occurrence in our canine companions.  They also occur in cats but less commonly so and for that matter we see them in tortoises and iguanas as well.  In dogs, bladder stones are most often composed of either struvite or calcium oxalate crystals.  These two compounds differ as to the urine acidity within which they exist.  Calcium oxalate stones like a more acid urine, struvites prefer a more alkaline urine.  I bring this up because struvite stones can sometimes be dissolved using a special diet that helps to create a more acid urine.  This is especially important in a dog such as Cassy where other treatments for bladder stones might put her at a high risk for complications. 

For Cassy, the risk of complications with treatment must be weighed against the risk of the bladder stones themselves.  Bladder stones can obstruct the urethra which is a medical emergency.  They also can be responsible for recurrent and/or chronic urinary tract infections especially with struvite stones.

The most common treatment for bladder stones is a surgical procedure called a cystotomy.  This involves opening up the bladder and physically extracting the stones.  Before surgery, a urinalysis and blood panel are performed to help make sure the patient is ready for surgery and specifically with the urinalysis, to try to ascertain what type of stones might be in the bladder.  Sometimes the crystals making up the stones will show up on a urinalysis and beyond that, with struvite stones specifically, there is usually a bacterial infection associated.  There are cases of bladder stones where crystals do not show up in the urine.

Again, in Cassy’s case, we would like to try to avoid surgery because of her other medical conditions.  With diabetes, the potential for surgical complications including decreased healing potential and infection are higher.  Congestive heart failure also is an added risk but depending on the degree, surgery can still be an option.

As I mentioned, if we are able to determine Cassy’s bladder stones are struvite, we can opt for attempting dissolution with a special diet.  If we can not determine the stone makeup or we find they are calcium oxalate, another course of action needs to be taken.

One procedure I have used with great success in some of these cases is a procedure called cystoscopy.  This procedure does require anesthesia but no surgery.  Specifically for her, her heart should be evaluated thoroughly before the anesthetic in order to tailor the anesthetic to her heart condition.  Any added risk beyond that is unlikely.  Cystoscopy involves using a special scope to visualize the stones in the bladder and using instruments passed through channels in the sheath of the scope, we can pull the stones out of the bladder.  This only works however if the stones are not too big and only with female dogs as the scope is not flexible.  The female’s urethra is straight whereas a male’s is curved and will not allow the passing of the scope. 

Hopefully for Cassy, her stones can be dissolved but if not cystoscopy may be a good option.  If neither is feasible surgery needs to be considered paying extreme attention to her other underlying medical conditions.