[Gpdd] [HEALTH] Details of urethral stone removal

[Ann Evans]

Our 4.5 year old sow Kinjaroo had a 16 mm long by 11 mm wide by 8 mm 
high stone in her urethra. The stone was 1.5 mm from the urethral 
opening. The female urethra is about 20 mm long and 2-3 mm in diameter 
(Cooper and Schiller).  On the 3rd of December Dr. Frank Bonsack DVM of 
Tampa Florida successfully removed the stone. Today she is totally 
normal. She was taking 10 mg of Rimadyl twice a day for pain for 2 days 
and 0.5ml of pediatric Bactrim twice a day to prevent infection for 7 
days. The following are the details of the surgery for those that are 
interested. Dr. Bonsack first spoke with Dr. Griffin of 
http://www.griffinexotics.com about a method he had pioneered using a 
catheter to remove urethral stones. However, Kinjaroo’s stone was too 
large to be removed by Dr. Griffin’s method. He then spoke with Vedra 
Stanley Spatcher of the Cambridge Cavy Trust (CCT) and Guinea Pig 
Hospital http://rodentology.co.uk/. She advised that he use a local 
anesthetic, insert obstetric lubricant into urethra via Jackson cat 
catheter, slide stone down to opening then using a number 11 blade make 
a slit at the opening of the urethra and remove stone. Vedra said there 
would be no need to suture the urethra because it will heal within a 
couple of days. She also advised to keep patient on clean towels or vet 
bed, give 10mg of Rimadyl twice daily for two days and give plenty to 
drink. I told Vedra that Kinjaroo is a very excitable cavy and I did not 
think that the surgery could be done under a local. Vedra then responded 
  “We use an anesthetic chamber and once they are under we take them out 
and use a nose cone to maintain, once you have cut through the skin you 
can reduce the concentration to about 2 or 2.5. Half hour prior to 
operating we give 0.2ml of Rimadyl. We never use Vetagesic or any form 
of injectable anesthetic. On completion of op turn off isoflurane flush 
patient with oxygen put dollop of Vick vapor rub on nose and guinea pig 
should be back in cage and eating/normal within 10 mins. PS empty mouth 
with 1 ml syringe prior to induction and if guinea pig has not been 
drinking well give 10ml of Hartman’s sub cut at shoulder prior to op.”
Kinjaroo was given 10 mg of Rimadyl post op per Vedra’s instructions. 
Dr. Bonsack did not have an anesthetic chamber so he put Kinjaroo three 
quarters of the way into a large anesthetic cone where she was breathing 
2.5% isoflurane. She calmed down quickly and that gave me the 
opportunity to take her out of the cone and using a 1 ml syringe remove 
any fluid from the back of her throat. I then made sure her tongue was 
extended as to not block her trachea and placed her on the pre-warmed 
operating cradle. Dr. Bonsack then put a nose cone on Kinjaroo, which 
was delivering 2.0% isoflurane and taped it to her body. After 
approximately 10minutes of receiving the isoflurane she moved her legs 
when Dr. Bonsack cleaned her skin with povidone iodine surgical scrub. I 
advised that at this point we should give her an injection of local 
anesthetic. He administered the local and then held the urethra open 
using tweezers and made a small incision using scissors. He then 
inserted the cat catheter along the sides of the stone and applied 
sterile mineral oil around the stone. He then gently pushed on the back 
of the stone closest to the bladder and it just slid out of the urethra 
entirely intact. Using vicryl suture thread he sewed the urethra in 
three places. He then turned off the isoflurane and flushed the nose 
cone with oxygen. Within 10 minutes Kinjaroo was completely awake and I 
applied Vick’s vapor rub to her nose. By 15 minutes she was in her 
cuddle cup eating cucumber, urinating and defecating normally. She has 
never shown any sings of pain. Her incision is almost completely healed 
5 days post op and she has not developed an infection.
Thank you to everyone who has given me advice, prayers and encouragement 
during this difficult situation. I am happy to answer any questions that 
you may have.
Cheers, Ann and the rescued Piggys of Piggyville Tampa Florida USA