1-15 Lexington Rd, Underwood, QLD, AU, 4119
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Subcutaneous Ureteral Bypass Catheter
Understanding ureteral obstructions in cats
In healthy cats, urine is produced in the kidneys, passes through the renal pelvis and flows down the ureter to the bladder. Ureteral obstructions occur when a blockage in the ureter prevents this flow, which can severely damage the kidneys.
The most common cause is kidney stones, accounting for 80% of obstructions, while other causes include blood clots, infections, scarring (ureteral strictures), and rarely, ureteral cancer. Ureteral obstructions can be partial or complete and may affect one or both kidneys, with complete obstructions leading to fatal kidney failure within 48-72 hours if left untreated.
Symptoms & diagnosis
Symptoms vary depending on the severity of the obstruction. Cats with partial obstructions or normal function in the other kidney may show few signs, while more severe cases can cause vomiting, lethargy, weight loss and difficulty urinating.
Stones can also increase the risk of chronic urinary tract infections. Diagnosing ureteral obstructions typically involves an ultrasound to identify changes like enlarged kidneys, dilated ureters and visible stones. X-rays or CT scans may also be used to confirm the diagnosis.
Treatment
Many ureteral obstructions ultimately require surgery. While medical management using intravenous fluids, muscle relaxants and anti-inflammatories can be attempted, it’s only effective in 7.7-15% of cases. If untreated, kidney function continues to deteriorate, leading to permanent damage. Many cats either aren’t candidates or don’t respond to medical treatment, making surgery necessary.
Surgical stone removal is challenging due to the small feline ureter size. Scar tissue commonly forms within the ureter that causes another obstruction after surgery is completed. The preferred treatment is Subcutaneous Ureteral Bypass (SUB), which bypasses the obstruction by directing urine from the kidney to the bladder via a catheter.
This advanced procedure is typically not available at regular veterinary clinics, so your cat will need to come to our specialised facility for the surgery and ongoing care.
SUBs are permanent prosthetic ureters placed into the kidney using fluoroscopy. We have used these devices to save the lives of many cats since they have become available.
The catheter is inserted into the renal pelvis, which is enlarged due to the obstruction, and connected to a metal port under the skin. A second catheter connects the port to the bladder, allowing urine to bypass the obstructed ureter and flow normally from the kidney to the bladder.
One study of 134 cats showed a 94% survival rate to discharge, though complications like catheter blockage, leakage, or kinking occurred in some cases. Long-term outcomes depend on kidney function three months post-surgery.
Regular veterinary care is essential for cats with SUBs to prevent blockages or infections, requiring routine flushing every few months. This life-saving procedure has proven highly successful, and our team has had positive experiences using it.
“A subcutaneous ureteral bypass device allows urine to flow around the obstruction.”
Frequently Asked Questions
What is a Subcutaneous Ureteral Bypass (SUB) catheter for cats?
A Subcutaneous Ureteral Bypass (SUB) catheter is a surgical device used to treat ureteral obstructions in cats. We place a catheter that redirects urine from the kidney directly to the bladder, bypassing the blocked ureter. This allows urine to flow normally again and helps protect kidney function.
What causes ureteral obstructions in cats?
The most common cause of ureteral obstruction is kidney stones, which account for about 80% of cases. Other causes can include blood clots, infections, ureteral scarring and, rarely, ureteral cancer. These blockages prevent urine from flowing from the kidney to the bladder and can lead to serious kidney damage.
What symptoms might my cat show with a ureteral obstruction?
Symptoms can vary depending on how severe the obstruction is. Some cats show very few signs if the obstruction is partial or the other kidney is functioning normally. More severe cases may cause vomiting, lethargy, weight loss or difficulty urinating.
How do you diagnose ureteral obstructions in cats?
We typically use ultrasound to look for changes such as enlarged kidneys, dilated ureters or visible stones. In some cases, we may also recommend X rays or CT scans to confirm the diagnosis. These tests help us determine the location and severity of the obstruction.
Why might my cat need a SUB procedure instead of medical treatment?
Medical management using intravenous fluids, muscle relaxants and anti-inflammatories may be attempted, but it is only effective in a small number of cases. Many cats either do not respond or are not suitable candidates for this approach. In these situations, we may recommend a SUB procedure to bypass the obstruction and restore urine flow.
Patient Stories
Our commitment to feline health is best seen in the stories of the cats we’ve had the privilege of treating. These journeys highlight the dedication, expertise and compassion that drive us.
Each patient faced unique challenges, and it was our honour to offer high-quality care and help them regain strength and happiness. We value the deep bonds with cats and their owners, knowing the difference we make in their lives.
Kitty, a lymphoma survivor
We first met Kitty after she was referred to CSS for the evaluation of a large intestinal mass
Poppi finds her feet again
Following surgery to remove a hairball obstruction, Poppi was referred to us at CSS as she had not bounced back as expected
Rusty and his ongoing chronic rhinitis journey
Lifelong nasal issues, including persistent discharge and breathing noise, have been a bit of a thorn in Rusty’s side.
Lando’s long game with cryptococcus
Lando was referred to CSS because he had a swelling under his jaw that wouldn’t go away.
Popeye coughs up the culprit
Ares is a handsome young Maine Coon who was referred to CSS after presenting at AES with sudden lameness in his back leg.
Key Takeaways
A cat ureteral bypass catheter (SUB) is a surgical device used to bypass a blocked ureter and restore urine flow from the kidney to the bladder.
Ureteral blockages in cats can damage the kidneys and may become life-threatening if urine cannot drain properly.
The SUB device allows urine to flow around the obstruction and helps protect kidney function.
Cat Specialist Services Reviews 
on 
Tanya Bell
6 months ago
We transported our cat here from another animal hospital, as his condition was too complex for them. Our pet was given the highest quality of care, multiple investigations/procedures being able to be done at the one place a godsend. We were kept up to date frequently throughout his stay. All questions & options explained thoroughly. Being able to have private visits certainly helped us and our cat too. I would highly recommend Cat Specialist Services at Underwood. Amazing staff from reception, vet nurses, vets & specialists. Oh, and yes he is recovering wonderfully at home.
Melinda Cox
A month ago
So very happy we were asked to come here for advice for our NORBIT. He has had 2 x UTI blockages within weeks of each other since turning 6. Surgery seemed to be his only option and he didn’t feel it was very fair on him if we didn’t at least exhaust all other avenues first.
Dr Allison was very thorough in her tests and has let us know she would like to treat the cause of the problem. Great news.
It may lead to removal of crystals in his bladder if his diet doesn’t let him pass them naturally.
At least this surgery won’t be as severe at taking his penis off him – so as his fur parents – we are very happy with this.
We await further tests to see what’s in store for him.
NORBIT will now be a patient of the clinic as we are so far very happy with his treatment thus far.
Lesley Rosekrans
A month ago
Hi has only been a week since losing my beautiful Peaches but can’t thank Dr Cindy, Maree and Jackie enough for the tender care they gave her and they after care they gave me. I sincerely thank them and can’t recommend the Clinic highly enough they are such caring people. Peaches I’m happier times.
Madison McEwan
A month ago
I cannot thank the entire CSS team enough and especially Dr Cindy for the care they provided for our boy with a urinary blockage, and we will be taking both our cats here from now on. The clinic is exceptionally clean and calming compared to all other clinics we’ve been too, and all staff from the reception to the nurses/vets were so supportive during a stressful time. I knew from the first minute that I got to see him after he was transferred that he was in the best place, and that the staff genuinely care about their well-being and positive long term outcomes. We were given regular updates and full transparency, so much information including QR video codes on how to administer medications, along with print outs and emails about how to best help avoid future issues or recurrence. Our boy got to smooch on everyone and was beyond well looked after. Thank you again, you all made an incredibly stressful situation actually manageable and calming.
Astrid El Gamal
6 months ago
Dr Wan-Ju has been treating my baby since her first seizure in November 2025 and she has been fantastic.
Everybody at the clinic is so friendly and caring and I know my baby is in good hands.
Thank you team!
Deeba M
3 months ago
Dr Alison Jukes from CSS Underwood is an AMAZING feline physician. She is kind, professional, thorough and our cat is blessed to have her on his side. She even was able to save us money and invasiveness by being skilled to the level of doing ultrasound on two separate occasions without our cat needing to go under full sedation. Our other cat was recently seen by Dr Jukes as well, and she made sure our cat’s heart was ok. I also want to thank the lovely Jacqueline and Mairead from customer care. They are very kind each time I see them and call up. Sending thanks from our family, including Smokey and Floozy!
Judith Dionysius
A month ago
My whole experience with CSS was positive – from the first email I received giving lots of information regarding the process of radioactive iodine treatment to the expected costs, to checking my cat in for the treatment, boarding for 2 weeks after the treatment and picking her up to come home. They didn’t push for any tests that were not necessary.
Janelle Wieden
5 months ago
We never knew this service existed but we are very grateful we were referred to them. Our vet Cindy was really great, she made us feel at ease during a very stressful time. We got the sense straight away the Leo was in good hands. This service made us feel better knowing that they specialise is cats only. Would highly recommend their services
Georgia Carter
5 months ago
My Lani finished her I-131 treatment today and I am beyond impressed with the way she was looked after. I am by definition a neurotic pet owner and sending my fur child away for a week was seriously daunting.
I was given daily updates about how kitty was eating, toileting and behaving. This really put my mind at ease. Vets and vet nurses were so accomodating and allowed Lani to have her favourite foods from home prepared her favourite way.
Her vet was so thorough when explaining her treatment and condition to me.
The ladies at reception were so friendly and understanding.
I honestly cannot recommend this clinic enough and I am so thankful for the positive experience Lani and I have had.
Lauren Woodward
A year ago
My sweet ginger boy Louis was hospitalised at CSS for a Urinary Obstruction. Dr Cindy and all the reception staff were amazing and empathetic. I would often ring up with questions post procedure and Dr Cindy would make time to talk and explain things to me
Contacting Us
Pet Owners
If you would like to talk about treatment for your cat, call us on 1300 228 377 or fill in the form.
In an emergency, please contact your local vet.
Vets and Nurses
To refer a patient or book a telehealth consultation please call us on 1300 228 377, book through the portal or fill in the form. For advice calls, please see the guidelines here.
Monday-Friday: 8 am-6 pmSaturday/Sunday - Closed