Urinary Obstruction in Dogs

By: Christine New, DVM

TVMA Member
Dallas, Texas

Published January 2015

A pet with a urinary obstruction is unable to urinate normally. Urinary obstructions may be partial or complete, and the signs you may notice at home can range from subtle signs like taking longer than normal to urinate or urinating small amounts in several spots to severe signs such as collapse. Urinary obstruction can look similar to a urinary tract infection and can be difficult for pet owners to distinguish. If you feel your dog is not urinating normally, is in pain or crying out when urinating, a prompt veterinary exam is always needed!

How Does the Urinary System Work?

Just like in humans, your pet’s kidneys make urine and send the urine to the bladder via two tubes called ureters, which connect each kidney to the bladder. In a normal dog, urine is emptied from the bladder, leaving the body through a single tube called the urethra. The urethra starts at the bladder and provides the exit path out of the body. The most common areas for problems resulting in a urinary obstruction are the urinary bladder and the urethra, both in male and female dogs.

What are the Signs of Urinary Obstruction in Pets?

Signs of a urinary obstruction include crying when urinating, asking to go outside more frequently, posturing to urinate with no urine coming out, repeatedly posturing to urinate and only small amounts of urine are seen, bloody urine, vomiting, lethargy or lack of appetite. The composition of urine is waste products that are meant to be excreted from your pet’s body. If your pet is unable to urinate, these waste products can quickly reach toxic levels that can become dangerous or even life-threatening to your pet and will quickly make your pet ill.

What Causes Urinary Obstructions?

The most common causes of urinary obstructions in male and female dogs are bladder stones, urethral stones and cancer. Additionally, disease of the prostate gland can cause urinary obstruction in males only, as females do not have a prostate gland. Also, spinal cord injuries can render a pet unable to urinate.

Both male and female dogs are affected by urinary obstructions, although usually male dogs become more ill as they tend to form a complete obstruction. The reason male dogs are more seriously affected is because the urethra is longer in males than in females and narrows considerably as it approaches the penis. This is especially concerning when dealing with bladder and/or urethral stones. Stones are less likely to become lodged in a female urethra; the urethra in females is shorter and wider so a stone can more easily leave the body in the urine, although the process is still painful. In both sexes, almost all stones form in the bladder; large stones that are too small to leave the bladder through the urethra tend to remain in the bladder, resulting in pain, infection and potentially partial obstructions. Small stones or pieces of the larger stones can pass out of the bladder and become lodged in the urethra.

Tumors of the bladder and urethra also cause an obstruction when they grow large enough to stop the passage of urine. Signs seen are identical to what is seen with an obstruction caused by stones, and bloody urine is very common.

In male dogs, the urethra passes through the prostate gland, which forms a complete circle around the urethra. Enlargement of the prostate gland (prostamegaly) is extremely common in older dogs that have not been neutered. Prostamegaly also occurs in older neutered dogs but with less frequency and less severity. Severe prostamegaly closes off the urethra as it passes through the prostate, just after exiting the bladder, resulting most commonly in a partial urinary obstruction. Severe prostate enlargement can cause complete urinary obstruction. Prostamegaly can also be caused by a tumor of the prostate. Signs you may see at home are very similar to other causes of urinary obstruction. Some inflammatory prostate diseases can be treated by neutering an intact male.

How Does Your Veterinarian Diagnose and Treat Urinary Obstructions?

If your pet is unable to urinate, the urinary bladder will be very large and painful when examined by your veterinarian. Your veterinarian will complete X-rays to confirm a urinary obstruction and also to look for stones within the urinary bladder and urethra. Sometimes cancer can be seen on an X-ray, but typically an ultrasound exam is a better modality for identifying a tumor of the bladder or urethra. Your veterinarian will also collect a blood sample to test your pet’s electrolytes and kidney values. Specifically, the electrolyte potassium can become dangerously high if your pet cannot urinate; a very high potassium level can cause your pet’s heart to beat abnormally. Elevated kidney values may indicate kidney damage; whether the damage is permanent or transient can only be determined over the course of several days of treatment. The initial kidney values are almost always elevated with urinary obstruction, but unless your pet has pre-existing kidney disease or the obstruction was present for several days, the insult to the kidneys is usually transient and resolves within the first 48 hours of treatment. If your pet’s potassium level is high, additional treatment may be needed before your veterinarian can safely anesthetize your pet to relieve the obstruction. A urine sample will be analyzed for crystals, cancer cells, protein and infection.

In order to relive the urinary obstruction, a urinary catheter must be placed. To do this, your pet will be anesthetized briefly. A catheter will be inserted into the urethra and run all the way into the urinary bladder, sutured in place and secured to a collection bag that will hang outside of your pet’s hospital kennel. Your pet will now urinate out this catheter and into the bag. Typically, the urinary catheter is left in place for one to four days, meaning your pet will remain in the hospital during this time. Your pet will also be on IV fluids, pain medication and antibiotics. Bloodwork will be completed at least daily to monitor kidney values. Initially, blood testing may be needed to monitor electrolyte values every few hours until values are normal. As mentioned above, very high potassium values can be very dangerous, so your veterinarian will want to return the potassium level to a normal range as quickly as possible, and sometimes additional medications other than IV fluids may be indicated to achieve this.

Depending on the cause of the obstruction, surgery may be needed once the kidney and electrolyte values are normal and your pet is stable. Bladder and urethral tumors may require surgery as do male dogs with stones in the urethra or bladder typically. Female dogs with stones may be candidates to diet dissolution. Some stones may be dissolved by a special prescription diets, but this process may take months and re-obstruction can occur. Ask your veterinarian if your pet is a candidate for prescription diets meant to dissolve and prevent recurrence of stones. If you have a male dog and prostatic disease is the cause of the urinary obstruction, your veterinarian will likely recommend your dog be neutered immediately to encourage the prostate to decrease in size.

Regardless of the cause, urinary obstruction is a serious condition, and veterinary care should not be delayed. If you feel your pet is not urinating normally, always contact your family veterinarian or local emergency clinic for an immediate exam.

Dr. Christine New practices veterinary medicine at the Hillside Veterinary Clinic in Dallas.

16 Responses

  1. […] the majority of cases, dogs suffer from Struvite stones, which are made up of magnesium ammonium phosphate hexahydrate crystals. This compound would […]

  2. […] the majority of cases, dogs suffer from Struvite stones, which are made up of magnesium ammonium phosphate hexahydrate crystals. This compound would […]

  3. […] Urinary Obstruction in Dogs | Causes, Signs, and Treatment TexVetPets – The most common causes of urinary obstructions in male and female dogs are. In male dogs, the urethra passes through the prostate gland, which forms a. […]

  4. […] Urinary Obstruction in Dogs | Causes, Signs, and Treatment TexVetPets – Urinary obstruction in dogs can be painful to your pet, so watch for these signs, find. and the signs you may notice at home can range from subtle signs like taking. In male dogs, the urethra passes through the prostate gland, which forms a. […]

  5. Robert Reynolds says:

    My dog currently had both knees replaced and he is still on medication, Rovira, gabapentin and trazodone. My dog stop urinating today it’s just dropping out is it safe to keep giving him his medication

  6. Monika saraf says:

    My 2 years old male dog stopped urinated today suddenly. Vomit once and not eating anything. He collapsed 2 times since morning. What should I do.. I am already calling a vet but I live in a very small village. There is not much facilities available.

  7. Glemna Clmons says:

    How long can a female dog go without peeing

  8. […] No matter the cause, not being able to properly urinate is a grave situation for your pet and should be taken very seriously. If you fear that your pet isn’t properly relieving themselves, always contact your preferred veterinarian or emergency vet for an exam right away. For more information about urinary obstructions, you can visit here, here, or here. […]

  9. Kathy Arch says:

    My 11 month border collie was neutered on Thursday. Unable to urinate. No stream just dribbles. Returned to vet Friday. Exam revealed a suture had caught his urethra. Suture removed. Urine flowing. Home with pain meds and antibiotics. Vet assures me there will be no issues and dog will be fine. Should I be concerned?

    • Meir says:

      Dear Vet. What does it mean when a male dog gives all his urine all at once? He used to mark territory etc. but now it’s like when he start he can not stop.
      Thanks so much

    • Tom Carroll says:

      This happens to my dog about once every 4-6 weeks. During her bouts, she struggles to pee, feels the need to pee about every five minutes, only very small amounts come out, and this is accompanied with vomiting. It usually lasts about 12 hours rhen stops. I have been to 3 different vets and nobody can figure her problem out. Looking for answers.

  10. Tom Carroll says:

    My female dog is 13, for over a year now she goes through cycles where she pants all day, has the constant urge to urinate, but struggles to get small amounts out. This usually lasts about 24 hours and is sometime accompanied by vomiting. Initially it was happening about every 6 weeks, but it has become more frequent. We have been to the vet multiple time and have had her on a special prescription diet for urinary stones, but our Vet has not been able to pin point the problem and the prescription diet has not helped. When this happens our dog is greatly distressed and I am typically kept up all night.. Any insight would be greatly appreciated.

  11. Dave says:

    Myb5 year golden has had the same problem for years. Every ten weeks +/- he dribbles to pee and vomits for about 2-4 Days. It awful and He def is in pain. In the past we were told it’s not stones but rather some type of nerve situations and he was put on gabapentin but to no avail. Now when this happens we give him tramadol for pain but I don’t think it helps since he still vomits up all his food and some yellow bile on occasion. It’s heart breaking and we simply don’t have the money to go exploring much further. We worry so much for him. Can anyone offer some explanation or tips? Thank you

  12. Veronica says:

    Dave, I would like to have answers too as our male dog has been having identical problems, except he does not vomit. He has bouts of this every six weeks or so where he cannot pee for 2 days. He started having these issues when he was 3 or 4 years old, but they would be further apart, like 6 months or so, but as he has got older these issues are more frequent, more like 6 weeks as I mentioned before. The vet did all kinds of tests but found no real answers. I am at my wits end as I hate to see him suffering like this. One thing that I have resorted to is expressing his bladder by hand. This seems to work. Google “expressing a dog’s bladder”. I wish there was a vet who could help more….

  13. Meyo says:

    Mi perrito no puede ordinar kiere aser pero no puede y le duele y no hace

  14. Laurence says:

    My walking buddy a 5y/o Rott, was diagnosed with bladder stine/and a stone blocking his uterus making him difficult to pee,. I brought him to Vet, and gave him some medications that may somehow may help him, and Doc.put a catheter on him, but the they can’t push thru the bladder as it blocked already as advised for immediate operation. Idont know what to do as i was out budget gor $650 operation. Today he’s not eating and struggling pee. This wouldn’t happened if his handler take care of him seriously while im overseas, his skinny when i saw him this vacation and im the one who personally takes care of him. I would like to ask a help/Charity for the operation of my walking buddy Drako. God Bless you all.

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