1409. Update on calcium oxalate crystals and stones in dogs

TOA PAYOH VETS toapayohvets.com Date:   07 March, 2013     Focus: Small animals - dogs, cats, hamsters, guinea pigs & rabbits A Cavalier King Charles yelps when peeing   Dr Sing Kong Yuen, BVMS (Glasgow), MRCVS First written: 04 March, 2013 Date:   07 March, 2013   toapayohvets.com  Be Kind To Pets Veterinary Education Project 2010-0129 Monday, March 4, 2013 Calcium oxalate stones are radio-dense unlike urate stones which are radio-lucent (not visible in X-rays). Yesterday, I had a case of a Cavalier King Charles, female, 6 years passing smelly cloudy urine. She yelped occasionally when she peed. So I asked the owner to send me a sample of the urine. On March 2, 2013, she collected the urine in the clean pee tray and sent it to me. Urine analysis show pH=6.5 which is acidic and calcium oxalate crystals 2+. Bacteria was "occasional" and there was no blood in the urine. I advised X-rays which showed no stones but I could see radiodense cloudy urine inside the bladder, suggestive of calcium oxalate crystals which are radio-dense. I palpated the bladder confirming no big stones or bladder pain at that time. I turned the dog upside down on the examination table and discussed this case with Dr Daniel. I noted that she had unusually enlarged nipples as if the dog had given birth a few times. You can see the enlarged nipples on the lateral view of the X-ray below.  "She had never given birth," the lady owner in her late 30s said to me. White cloudy discharge appeared at the vulval area but the owner did not want to see it. "This could be pyometra," I said to Dr Daniel who disagreed. He thought it was just white turbid urine. The dog could be incontinent but the owner did not complain about incontinence or leaking urine. She said that the dog no longer came into heat although it usually happened around February. I palpated the abdomen. The dog did not experience any abdominal pain but I could few swollen uterine horns of around 2 cm in diameter.  6012. Yelped occasionally when peeing 6013. Calcium oxalate crystals, no stones seen on X-rays This dog lived in a house with a garden and sometimes the owner might miss the bleeding as the dog cleaned herself well by licking. This would account for her swollen vulval lips.    "So what to do now?" this was what the owner wants to know. She was a busy lady and all those technical information did not interest her.   "Put the dog on U/D diet for 3 months and don't feed any treats or food. Monitor the urine 4 weeks later to check for the presence of calcium oxalate crystals. Monitor amount of water being drunk daily." As to why the dog "yelped" occasionally when peeing, this was a mystery. This was the complaint. Not difficulty in urination or blood in the urine as in the 2009 case. My hypothesis was that the female stone had great difficulty passing out the calcium oxalate stones via her urethra. As she strained to pee out the stones, there was great pain and so she "yelped" during urination onto the grass. But the X-rays (2 views) showed no large stones and so I had no evidence. If stones were large, it would not be passed out as the diameter of the urethra in this female dog would be around 3-4 mm. But the stones were smaller and must have been urinated out. The owner ordered a packet of the dry U/D diet and drove home in a hurry as she was tired and although the children were grown up, she had lots of things to do. Monthly monitoring of urine every 4 weeks for the next 6 months and regular X-rays of the bladder and kidney are strongly advised but sadly, rarely do owners comply. Updates will be on this webpage: sinpets.com/links/20130305calcium_oxalate_crystals_king_charles_toapayohvets.htm Read a case of calcium oxalate stones in 2009. 2009 case: Calcium oxalate urethral obstruction in a Chihuahua Recurrence of Urate urolithiasis asiahomes.com/new1/20130221urate_stones_recurring_toapayohvets.htm   More info at: Dogs or Cats To make an appointment: e-mail judy@toapayohvets.com tel: +65 9668-6469, 6254-3326 Toa Payoh Vets Clinical Research

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