Hydronephrosis: A rare but serious complication of dog spay surgery

Hydronephrosis: A rare but serious complication of dog spay surgery

Health & Safety

Unless you are planning to breed from your dog and are prepared to wait until the time is right, do plenty of research, and undertake any relevant pre-breeding health tests first, the responsible choice for owners of female dogs is to have their dog spayed to prevent unwanted litters.

Spay surgery is one of the most common and routine procedures undertaken in veterinary clinics up and down the country, and any vet that has been practicing for a few years will likely have performed thousands of spay procedures, the vast majority of which are problem-free. However, a spay procedure for a female dog is still a major operation, which means that it comes with some risks and complications that can occur either during the surgery itself, or in recovery.

Complications from spay surgeries are very rare, but it is important to be vigilant to any signs of problems after a spay, and until your bitch is fully healed and back to normal. One potential complication of spaying that is thankfully rare but that is also acute and serious when it does occur is hydronephrosis – and by learning about the symptoms of hydronephrosis in dogs, you will be better able to monitor your dog after spaying and be alert to signs of problems.

In this article we will look at hydronephrosis in more detail, explaining why this complication might occur after a spay surgery, what it means, and how to recognise the symptoms. Read on to learn more.

What is hydronephrosis?

Hydronephrosis is a problem that affects the dog’s kidneys, and it may affect both of them or alternatively, just one. The word itself means “kidney dilation,” and hydronephrosis prevents urine from passing naturally out of the kidneys for elimination, making the affected kidney(s) swell up.

Hydronephrosis is not a specific health condition in and of itself, but rather a collection of symptoms that result from other issues affecting the dog’s kidneys and urinary tract.

Why does spay surgery raise the risk of hydronephrosis in dogs?

Spay surgery is not the only potential cause of hydronephrosis in dogs, and it can also be caused by a range of other things including kidney or bladder stone formation, urinary tract tumours, accidents or injuries, and blood clots within the circulatory system that block the kidneys themselves.

However, spay surgeries can cause accidental damage or occlusion of the ureter – the tubes that exit the kidneys to the bladder, allowing urine to pass through the bladder and exit the body. This complication is very rare after a spay procedure, but the risks increase the younger the dog is at the time of the surgery, as a delicate surgery of this type is more challenging on younger dogs as they are so much smaller. Very small dogs too, like the Chihuahua, also have slightly higher risks, again due to their small size.

The symptoms of hydronephrosis in dogs

When your dog has undergone her spay surgery, your vet will provide you with guidance and advice on how to care for her during her recovery, including letting you know some of the main warning signs to watch out for that can indicate a potential complication. However, post-spay advice won’t cover every potential eventuality, and so it is important to learn the basics of the symptoms of hydronephrosis in dogs after a spay, particularly if your bitch is very young or very small.

It bears repeating again that post-spay hydronephrosis is rare, but it is also acute and serious – and so if you spot any symptoms or have any other reason to be concerned about your bitch after her spay, contact your vet immediately.

Some of the symptoms of hydronephrosis in dogs to be aware of include a distended or enlarged lower stomach and abdomen, associated signs of pain or discomfort, and problems with urinating.

This may present as urinary incontinence, inappropriate toileting, or an inability to urinate entirely. If the problem is acute and already severe, your dog may also display more obvious symptoms of something being wrong, like loss of appetite, vomiting (particularly after eating) lethargy, exercise intolerance, and a desire to drink more water than normal.

Can hydronephrosis in dogs be treated?

Hydronephrosis is a serious problem that requires emergency treatment, and so you should ensure that you let your vet know as soon as possible if your dog develops any post-spay complications. How the condition is treated and resolved depends on the issue it is causing and how acute it is, but will generally mean that your bitch will need to be admitted to the veterinary clinic for further investigation and treatment.

This treatment will usually take the form of close monitoring, IV fluid therapy and if necessary, antibiotic medications to deal with any associated infection, and may also involve the need for a second surgery to explore the issue and correct it where possible.

Assuming that your dog’s treatment is successful, she should make a full recovery from both her spay surgery and the complication itself, and when fully healed, go on to live a perfectly normal, healthy life.



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