My Dog Is Peeing a Lot After Spay Surgery

Known scientifically as an ovariohysterectomy, spaying is a form of permanent sterilization in dogs. By removing both the uterus and ovaries, the dog is unable to become pregnant. In addition to the prevention of unwanted pregnancy, the dog's risk of serious diseases such as fatal uterine infections are eradicated or lowered drastically. Since they are no longer able to produce significant amounts of certain sex hormones, their temperament also tends to become more even.

While more invasive than castration in male dogs, spay surgery is considered a very safe procedure. It is recommended by veterinarians for almost all dogs. Exceptions are made only if the dogs have exemptions for breeding or if there is a preexisting health condition which can cause a risk to their health, among a few other considerations.

A dog may be urinate a little more immediately after spay surgery. This could be due to fluid intake during the procedure and the fact they have been unconscious for a short time. They may also experience acute stress due to being in a veterinary clinic, confusion after general anesthetic or discomfort after the procedure. This stress can lead to a temporary level of increased urination.

Complications of spay surgery are generally very uncommon, especially after the dog has recovered. Spay incontinence is equally uncommon, but it is possible. We explain the reasons why a dog pees more after spay surgery in the next sections.

The most common cause of incontinence after a spay in dogs is urethral sphincter mechanism incompetence (USMI). The reduction in estrogen levels after spaying negatively affects the function of the urethral sphincter, which can trigger an incontinence problem. Such incontinence is particularly common when at rest, so we may see the dog pees the bed after a spay.

Some studies suggest that large female dogs have a higher risk of developing USMI. There are also certain breeds that are believed to be particularly susceptible, such as the Boxer, Doberman, Irish Setter or Giant Schnauzer.

Treatment of urethral sphincter mechanism incompetence in dogs

90% of female dogs with urethral sphincter incompetence respond well to therapy with alpha-adrenergic agonists such as phenylpropanolamine. These drugs help to increase the tone of the internal urethral sphincter and prevent urine leakage. Alpha-adrenergic agonists can be used alone or in combination with other pharmacological treatments such as estriol, ephedrine or deslorelin acetate.

The drug of choice is usually Propalin for dogs, also known as Proin in the US market. Your veterinarian will be the one to prescribe the most appropriate drug for each dog's specific treatment needs. If medical treatment is not effective, surgical treatment may be used to return urinary sphincter function. These include intraurethral collagen injection, placement of hydraulic sphincters, colposuspension or placement of a transobturator vaginal tape^[1].

A urovaginal fistula is an abnormal communication between the urinary tract and the vagina, usually affecting the urethra or urinary bladder. Such a fistula allows the involuntary passage of urine into the vaginal canal. These fistulas may occur as a complication of spaying, appearing immediately after surgery as a result of adhesions between the vaginal vestibule and the ureter. This can be why the dog is peeing a lot after spaying.

Treatment of urovaginal fistula in dogs

In these cases of a urovaginal fistula after spay surgery urinary incontinence is common. It does not respond to conventional medical therapy. Treatment consists of surgical resolution of the fistula.

Similar to the above reason why a dog keeps peeing after spay surgery, a urethrorectal fistula consists of an abnormal communication between the urethra and the rectum, meaning the urinary and digestive systems are connected. It is often a result of a congenital problem, usually due to alterations in embryonic development.

Urethrorectal fistulas can also be acquired, either due to trauma affecting the pelvic region, injuries caused during surgery in the pelvic region or recurrent urethral catheterizations that end up injuring the urethra. Although very rare, it is a possible complication of spay surgery.

Treatment of urethrorectal fistula in dogs

In these cases, recurrent urinary incontinence with urine excretion through the anus often occurs. To resolve this, surgical closure of the fistula is required, using reconstructive techniques such as tissue flaps when necessary.

Discover why a spayed dog is bleeding from her vagina with our related guide.

The detrusor muscle is the smooth muscle that forms one of the layers of the bladder. When the bladder is filling with urine, the detrusor muscle is relaxed to allow the bladder walls to stretch and urine to be stored. For urination to occur, the detrusor muscle contracts to allow urine to be excreted to the outside.

When the detrusor muscle has a functional alteration it leads to detrusor instability. This is generally an issue with neurotransmitter signaling, rather than with physical alteration of the muscle itself. These neurotransmitter issues cause small spasms to occur in the bladder during the storage phase, resulting in part of the urine content to be excreted involuntarily.

Treatment of detrusor instability in dogs

To treat this problem, the primary cause must be controlled. When this cannot be corrected, mild sedatives and anticholinergic substances that act as smooth muscle relaxants can be used. These function by blocking neurotransmitter signals which relax the muscle. These include medications such as acepromazine maleate, flavoxate or oxybutynin.

When the bladder is overdistended, the bonds that hold the muscle fibers together break down. This can lead to weak, uncoordinated or absent contraction of the bladder's detrusor muscle, known as atony. When the detrusor muscle does not contract, urine builds up in the bladder until the pressure in the bladder exceeds the resistance of the urethra, at which point incontinence occurs.

Treatment of detrusor primary atony

In these cases of incontinence in spayed dogs, treatment consists of indwelling catheterization for 1-2 weeks to allow the bladder to empty and smooth muscle junctions to reestablish themselves. If muscle damage is not complete and partial contractions still occur, treatment with parasympathomimetic drugs (such as bethanechol) may be helpful to stimulate bladder contraction.

So far we have seen a number of non-neurogenic causes that can cause urinary incontinence in spayed female dogs. We also need to consider possible neurogenic causes that can trigger this disorder, including upper motor neuron and lower motor neuron lesions.

The etiology of these disorders is very varied, including herniated discs, fibrocartilaginous embolisms, vertebral trauma, spinal neoplasia and others. The treatment will depend on the specific cause that triggers the incontinence. This may include surgery to eliminate the primary cause, bladder emptying 3 times a day, alpha-adrenergic blockers if there is hypertonia of the urethral sphincter, anticholinergics if there is hyperreflexia of the detrusor muscle and others. As you can see, a visit to the veterinary center is crucial to provide a differential diagnosis.

We have shared the various reasons why a dog may be peeing a lot after spay surgery. Unless you have veterinary experience, it is unlikely you will have heard of many of these disorders. This is because complications from spay surgery such as prolonged incontinence are incredibly rare. If the veterinarian is experienced and qualified, the ovariohysterectomy is a safe and routine procedure.

The benefits of spaying which are provided both dog and guardian mean it is a procedure which is recommended by vets. The benefits to public health also mean it is a legal requirement in many jurisdictions. While complications are rare, it is important to look out for any possible warning signs after spaying a dog which could suggest an adverse reaction. Contact a veterinarian immediately if you observe any irregular symptoms.

This article is purely informative. AnimalWised does not have the authority to prescribe any veterinary treatment or create a diagnosis. We invite you to take your pet to the veterinarian if they are suffering from any condition or pain.

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