Sunday, June 29, 2014

1393. VIDEO - Guidelines to treating pyometra


On June 16, 2014, a lady dog breeder phoned me as I was on the way to Changi Airport, going to Yangon."Do you remember Su Su?" she asked me. "The Miniature Schnauzer you did a Caesarean section in 2008."
"I cannot remember Su Su," I replied as she had . "What happened?"
"She was vomiting and my vet diagnosed pyometra after an X-ray. She told me that pyometra is a common problem and needed to be spayed. When I came back in 2 hours' time to take the dog home, she said that the dog had a "corrupted" bladder and needed to be put to sleep. For half an hour, she would walk in and out of her room refusing to stitch up the dog for me to bring to another vet."
"Did you consent to euthanasia?" I asked.
"Yes, but I had no choice."

I remembered Su Su now and here are her images after my Caesarean Section in 2008.

Six years have had passed by. Su Su was 9 years old when she was put to sleep on the operating table. What actually happened?  The breeder said that the vet had cut the bladder.
An accidentally incised or ruptured bladder could be repaired. Even if the uterus had ruptured spilling pus into the abdomen, there is still no need to euthanase the dog as the abdomen can be cleaned up.

The breeder wanted the truth and to sue for a premature death of her beloved dog.  What actually happened in a case of pyometra such that the vet insisted that the dog must be euthanased on the operating table? What actually happened to the bladder? 

It was with sadness that I left for Yangon to prepare for a talk in Yangon on "Guidelines For the Treatment of Pyometra."

Since it is hard to keep awake watching Power Point presentations, I have commissioned a "Be Kind To Pets' veterinary educational video which can be shared with more vets in You Tube. 

This is a "Be Kind To Pets" Veterinary Educational Video titled: 
GUIDELINES ON TREATMENT OF PYOMETRA CASES IN DOGS AND CATS written by Dr Sing Kong Yuen, BVMS (Glasgow), MRCVS. It is presented at the "Recent Advances in Veterinary Practice No.3. Myanmar Veterinary Association, July 5, 2014".

PYOMETRA is an infected uterus filled with pus. The uterine lining (endometrium) becomes cystic and hyperplastic due to the effects of oestrogen and progesterone. Bacteria from the vagina enters the cervix to invade the uterine lining leading to inflammation and pus formation. I will be discussing about closed pyometra, open pyometra and stump pyometra in dogs and cats.

If the cervix remains closed, the pus accumulates in large quantities inside the uterus (closed pyometra) as in the following 2 images.

If the cervix is open, the pus is discharged via the vagina (open pyometra). The uterus is not much distended as pus could flow freely out as in the respective images of the uterus of a dog in Singapore and a cat in Yangon.

If there are ovarian remnants after spay, the stump of the uterus may become infected and filled with pus. This medical condition is called Stump Pyometra. This occurs any time after ovariohysterectomy. A piece of the ovarian tissue or the whole ovary had been retained inside the abdomen. So the cat still caterwauls (cries loudly in heat) and the spayed dog still has heat periods!

In Singapore, almost all home cats are spayed to prevent them caterwauling (loud cries of heat). So pyometra in cats is uncommon.  However, many dog owners do not spay their dogs for reasons such as cruelty and therefore pyometra of older bitches is commonly encountered by all Singapore vets.

I rarely encounter stump pyometra in Singapore dogs in the past 30 years. The following image is one of such rare cases. 

I saw one case of a stump pyometra in a Yangon cat when I visited Dr Aung of the Royal Asia Veterinary Surgery and the two images of the cat, spayed by another vet using the flank approach is shown as follows:

SYNTHETIC PROGESTERONE INJECTIONS.  Yangon appears to have a higher incidence of pyometra in cats and dogs as they have been treated traditionally with the synthetic progesterone (Depo-M or Contracep)  IM every 3-4 months to suppress the heat cycle.

However, client education has led to more younger dog owners opting for ovariohysterectomy.


This video shares my experiences with the treatment of pyometra for the last 30 years and present relevant cases from my visit to see Dr Thein Tung Aung of the Royal Asia Veterinary Surgery in June 2014.

To perform a high standard of surgery, the vet must have a systematic approach to diagnosis and surgery. This process also keeps proper records of anaesthesia and surgery so that the vet can defend himself or herself in negligence litigation and investigation.

My guidelines for my associate vets performing pyometra are as summarised in the image under "SOP" (Standard Operating Procedures).


Basically, they should do the following: 

1. History of estrus. Do a thorough physical examination including weighing the dog, taking rectal temperature and checking for the recent onset of estrus, false pregnancy signs or mating history.


TIP. Always ask the owner when the vomiting intact female dog has the last estrus.  Pyometra occurs usually 1-12 weeks after estrus. I see many cases around 2 months after estrus. Pyometra may co-exist in pregnancy (20-24 days after ovulation) but it is rare. Many cases of vomiting in dogs have been mis-diagnosed as gastritits or gastro-enteritis.

1.2 Clinical signs - Vaginal discharge (serosanguinous or mucopurulent) is seen in open and stump pyometra. Polydipsia, polyuria and abdominal swelling may be present. Inspect for nipple discharge of false pregnancy.

TIP. A VOMITING DOG DOES NOT MEAN SHE HAS STOMACH ACHE. Many owners do not provide correct information saying that the vomiting dog has been fed a wrong type of food and had diarrhoea. Therefore a vet naturally mis-diagnose "gastritis or gastroenteritis".

TIP. A CASE OF CLOSED PYOMETRA MIS-DIAGNOSED AS GASTRO-ENTERITIS . In 2009, Vet 1 mis-diagnosed the closed pyometra as acute gastroenteritis in a Husky that lost a lot of weight. Medication did not stop the vomiting. The dog died on the operating table when I did an emergency spay. She was very ill and the owners had given me informed consent. Vet 1 did not advise blood test or radiography.


3. Uterine palpation. A large uterus may be palpated in a case of closed pyometra. Abdominal pain or discomfort (dog bites) may be present in a swollen abdomen.

TIP. Practise abdominal palpation in every dog or cat  and you will be able to feel swollen loops of uterine horns in the abdomen. The radiographs may confirm the uterine distensions.

4. Blood test. CBC/Biochemistry. Leucocytosis, neutrophilia and thrombocytopenia in closed pyometra cases. Anaemia. High serum BUN and creatinine will point to kidney damage.  

TIP. Blood test may not always show leucocytosis (increase in total white cell count)  in all cases of closed pyometra. It is a useful test to assess the chances of survival of the dog during and after surgery. The higher the white cell count, the lower the platelet count and the high serum urea and creatinine values mean that the dog is seriously ill and very unlikely to survive.

TIP. Always advise a blood test to screen the health of the dog and possible kidney damage to determine the anaesthetic risks and prognosis.

Some closed pyometra cases may have permanent kidney damage and will continue to vomit even after spay. I had one case of a Miniature Schnauzer whose owner’s father procrastinated surgery. The daughter was satisfied that the vomiting was due to kidney damage rather than from my surgery as I had interpreted the high serum BUN and urea to her from the blood test. 

Without this blood evidence, some owners blame the vomiting on the vet doing an incompetent spay.   

5. Imaging
5.1 Survey radiography may show large distended uterine horns or loops in closed pyometra in the above 15-year-old Maltese with the swollen abdomen. . Always take 2 views rather than just the lateral view as some vets may want to lower medical costs.

You can visualise the distended uterus in the X-ray (left) when you see the real uterus (right)

5.2 Ultrasonography shows the thickened uterine wall (cystic endometrial hyperplasia and intraluminal fluid (pus). Normal uterine wall cannot be detected by ultrasonography. Most vets prefer radiography.

6. Correct Diagnosis. Pyometra - Closed or Open Pyometra?

6.1. Pyometra is a medical emergency requiring immediate surgery. Most owners do not want surgery as it is expensive. However, with evidence from the blood test and X-rays, most owners are convinced that the vet has got the correct diagnosis.

6.2  Informed consent for anaesthesia and surgery explaining the high risks involved esp. for old dogs. This is important as there have been litigation against Singapore surgeons who have not fully explained the risks of anaesthesia and surgery.

6.3  Client Education. An illustration may be needed to educate the client on what has happened to his dog and what the surgery is about.



He may not be able to relate the uterine distensions in the X-ray unless the vet does illustration as in this example. (PUT TWO IMAGES OF ILLUSTRATION + X-RAY NEXT TO ONE ANOTHER). 

6.4  Medical Costs. An estimated amount of medical costs must be given to the owner before the surgery. A pyometra surgery and anaesthesia in small breeds cost around $800 in Toa Payoh Vets in 2014. This excludes supportive therapy and in-patient nursing.


1. Immediate I/V fluid therapy, antibiotics and pain-killers for 1-2 days. I usually give Hartmann’s, dextrose and amino acids, baytril and spasmogesic IV. The dog is an in-patient.

8. PROPER RECORDING OF ANAESTHESIA & SURGERY are strong defences in cases of litigation. My vet assistant is required to record the drug dosages and times of anaesthesia and surgery. It also allows me to audit the surgical performance of my younger associate vets and to let them know that an excellent surgery comes from SPEED, ACCURACY AND COMPLETENESS.     

Sometimes I provide the information to clients who ask "how long it takes to spay her dog?" In this image, the time taken to spay a small breed with normal uterus is 19 minutes from first skin incision to skin stitched up.

8.1  I use 25-50% of the calculated dosage I/V for sedation/induction depending on the health of the dog. Then I intubate and maintain with isoflurane + o2 anaesthesia. If the dog is very weak and lethargic, I use entirely isoflurane + O2 anaesthesia and find this to be very effective and safe.

8.2 My calculated dosage is as follows: For a young 10-kg dog, Domitor + Ketamine IV = 0.4 ml + 0.5 ml respectively.

8.3  For very old (over 10 years) dogs and/or in poor health, I use only isoflurane + oxygen gas.

8.4  Clipping and cleaning to be done before sedation outside the operating room reduces anaesthetic time and risks.

8.5 Make a long incision carefully to get the swollen uterus out easily and without rupturing the friable parts, contaminating the abdomen with pus.

TIP. The full bladder may be just below the skin. If the vet is not careful, the bladder may be cut spilling urine into the peritoneum.

8.6  I use the 3-haemostat method to clamp and ligate. I release the middle of the 3 haemostats. Then I ligate on the clamped grooved area vacated by the middle of the 3 haemostats.

TIP. I see some vets use only 2 haemostats and do not ligate over the clamped area. So, the ligature slips leading to bleeding.  Some vets using this method ligate two the ovarian ligament in two areas instead of the usual one spot to prevent slippage.

For the uterine body, I usually ligate the clamped area of the middle of the 3 haemostats. In big breeds, I used the inverting continuous suture to close the stump and ligate the stump.

TIP. Be careful. Avoid contamination of the peritoneum with pus leaked from the uterus.  

8.7. Sutures - absorbable. For medium to large breed dogs, I use 2/0 braided absorbable sutures (Polysorb). For small breeds I use 3/0 sutures. My associate vet, Dr Daniel prefers the monofilament absorbable sutures (Monosyn). Usually the client does not need to return for stitch removal.

8.8  I use Anti-sedan IM to reverse and abolish the effects of Domitor sedation in cases where the dog is still not conscious after the surgery. The dog is usually awake within 5 minutes of the injection.

9. Post-op antibiotics & painkillers. One injection of baytril and tolfedine is given SC after the surgery.

10.  In-patient 3-7 days. The dog is hospitalised around 3 days to lower the medical costs. She goes home with antibiotics for another 10 days and an Elizabeth collar. Tolfedine pain-killers are given for the first 4 days.

11. Record post-op follow up on Day 3. I advise follow-up Day 3 after surgery to check on the surgical wound, medication, change of dressing and success of home nursing.

12. AMA (Against Medical Advice). Nowadays, I give the client a written record that he does not want blood tests, X-rays or procedures as advised by me. I have the written evidence in case of litigation or complaint. In computerized records, there is the allegation of falsifying evidence by deleting the earlier record, but vets using manual records need to keep proper records to protect their reputation.


Make a long incision to access the retained or remnant ovarian tissues located caudal to the kidney area. You need to exteriorise the intestines to locate the ovarian tissues.The remnant ovary is usually cystic and enclosing the sutures.

I observe that some vets incise the skin too far away from the umbilical scar. They do not wish to extend the incision since they wish to impress the client that they make the shortest skin incision. When they pull out the first ovary, they can ligate the ovarian ligament. However, the second ovary is much harder to hook out as the surgical hole is now filled with the uterine horn of the first ovary. As they pull a bit harder, the second ovary breaks and is lost into the abdomen!  The cat in heat has an ovarian ligament that is easily torn when pulled. So, the "spayed" cat caterwauls or the "spayed" dog continues vaginal bleeding during heat.

The two images show the distance between the umbilical scar and the beginning of my skin incision in spaying a young female Chow Chow with easy access to the two ovaries. This distance (XY) is around 2 cm.  This means that the ovaries are easily accessed and pulled out while I do not make a longer skin incision than necessary as some clients judge competence by incision length.   

TIP. Incise the skin around 2.5 cm from the umbilical scar and you will have no problem. Or extend the incision cranially by another 1 cm if you find that the ovary is hard to pull out.


1. PGF2alpha is an effective pregnancy terminating drug. It causes uterine contractions to expel the pus. In closed pyometra, the uterus may rupture. I have no experience with this treatment.

However, a senior vet in Singapore had one successful case. He did a laparotomy to view the swollen uterine horns. He passed catheters into the uterine horns to suck out the pus and pumped normal saline and antibiotics to irrigate the uterus. The Pekinese gave birth to one pup at the next cycle.  He strongly advised spay as it is much cheaper.  

In Singapore, the well educated and travelled client wants “cheap and good” surgery and has a choice of over 60 veterinary clinics to treat his dog or cat..

Sometimes the kind vet tries to reduce medical costs by not taking blood tests or doing only one view in radiography. No ultrasonography will be done. It is best to practise evidence-based medicine by taking blood test and X-rays in cases of vomiting unless the client does not want to pay for the tests. This should be recorded in the case sheet under AMA.

 Pyometra is a medical emergency and if the dog or cat dies on the operating table, all family members feel that the vet is incompetent. After all, he has not done blood tests or X-rays which other vets would have done.   


1. Hook. MVI 8491.  June 16, 2014. phone call from old dog breeder client.
   Use 00:00 - 04:04 narration by Dr Sing Kong Yuen and insert the 3 Miniature Schnauzers images in between.  


2.1 PRE-SURGERY  DAY 2.   MVI_1352  0:00 - 0:30  

2.2  SURGERY  DAY 2     MVI_1357    0:00 - 0.58   Surgery - Spay.  00:00 - 0:58  3-haemostat method to clamp and ligate6

                                                                  0.14 - 2:04   Gas mask by Dr Daniel. Speed, Accuracy and Completeness are factors to achieve an excellent surgical outcome

2.3  POST SURGERY. DAY 2.  MVI_1374. 
0:01 - 0:06   Completion of dog spay. Stitched up skin
1:38 - 1.49    Incise uterus to show it is full of yellow pus

2:05 - 2:25   Dog wakes up fast at last stitch as she was anaesthesized using only gas isoflurane + oxygen and no sedation.  Dog is fully recovered as at Day 4 after surgery. 

There is no time to screen this video of one of my recent cases of closed and open pyometra. It can be viewed at:

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