Urolith help!

RE: Urolith help!

Anthony Todd — Fri, 26 Aug 2016 12:03:05 GMT

[quote user="villagevet"]

sg is a concern if routinely high - low purine wet diet?

[/quote]

+1. the advice i was given after 2 ureteral stones was "drink more water" [and I do] so wet food has got to be fundamental

RE: Urolith help!

Lindsey Edwards — Thu, 25 Aug 2016 17:10:03 GMT

sg is a concern if routinely high - low purine wet diet?

RE: Urolith help!

Andrew Kent — Wed, 24 Aug 2016 20:44:47 GMT

So the nidus is the important bit and suggests urate is likely the significant bit with secondary infection.

There is often a very poor association between crystalluria and uroliths which does add to the challenge of these cases sometimes!

Andy

RE: Urolith help!

Stephanie Wellings — Wed, 24 Aug 2016 10:39:42 GMT

Thanks! I was thinking the shunt is less likely because the BAST wasn't sky high and she's very healthy otherwise, recovered fine from anaesthesia etc. I'm not sure funds will allow for imaging :-( especially as the owners don't feel there's any issue with the dog at present.

There are no crystals in the urine any more (but I have had a bit of a spate of cases with no crystalluria who later turned out to have uroliths and needed surgery, so I am a bit hesitant to take the absence of crystalluria as an all clear!)

Nidus was 60% struvite 40% urate

stone 70% urate 30% struvite

surface 70% calcium phosphate carbonate 30% urate

RE: Urolith help!

Andrew Kent — Tue, 23 Aug 2016 19:35:10 GMT

Hi Steph,

In your analysis do you have information on what was the nidus and what was the stone? If not thats a good reason to use the Minnesota Urolith Center (via Hills) rather than other places as they give you that information when available.

Both struvite and calcium phosphate carbonate are related to urinary tract infection so, if we can keep the dog clear of infection, we should be able to reduce the chance of formation of these. That means considering if there are any predisposing causes of infection and frequent urinalysis/culture.

The urate component can be due to hepatic vascular abnormalities or due to genetic hyperuricosuria. As long as you are confident in your bile acid stim test then for me it largely excludes a true portosystemic shunt. A microvascular dysplasia is perhaps still possible but it would be uncommon for that to cause problems. If in any doubt another bile acid stim could be useful.

For hyperuricosuria dietary management is typically advised using a low purine diet.

As you say general tips include making the urine as dilute as possible to reduce saturation.

Some of these cases are tough and I always warn owners that dogs with a predisposition to stones often form more despite our best attempts at control.

Andy

RE: Urolith help!

Rob Loxley — Tue, 23 Aug 2016 19:22:48 GMT

Portosystemic shunt in a dog especially Schnauzer with urate urolith would be high on my list of suspicions. Struvite crystals and urolithiasis could just be due to secondary UTI. Would they go for further imaging to try and find a shunt, or ammonia measurement. Once the UTI is demonstrated to be resolved, are there still any crystals to worry about?