Hills s/d and c/d Food

[MissFoodie]

1 yr old male cat diagnosed with crystals despite grain free diet to date...
Has anyone mixed Hills sd and cd foods? Won’t eat wet sd food but will eat dry sd... and wet cd...
Also have sibling cat without crystals, apparently safe for him to eat cd food but not sd?
And what is the difference? Both contain L Methionine as active ingredient to acidify urine...?!!!!
TIA

After my cat had a blocked bladder and £800 vet bill I switched to Hills c/d dry food, on offer to his lordship all day with Felix senior sachets fed on demand. So far he’s had no further problems.

So they didn’t prescribe sd first to dissolve them and then cd full time?

My friends cat has sd one week and cd thee weeks, continuously....!

Apparently sibling cats are more likely to get crystals - had 2 sisters with it. They lived the rest of their lives on Hills (one still going) - vet doesn't seem bothered which version.

The other cat is fine and both have had grain free diets which contradicts the “meat only diet doesn’t cause crystals” theory...
hills do not recommend mixing cd and sd diets but he will only eat dry sd....
So do I continue to mix the two diets or do just cd and bypass sd?
Vet doesn’t know either so all in all very frustrating...!

You could either call hills for technical advice (or your vet could), or you could switch to Royal Canin equivalent- I find usually if cats won't eat one, they'll accept the other

S/d is the struvite dissolving food, if struvite crystals are found you should use s/d until a urine sample is clear of crystals.
C/d prevents recurrence of both struvite and cysteine crystals once they have been dissolved ( struvite) or removed (cysteine) surgically.
You do not need to feed both the wet and dried foods, you can just use one. S/d has 'restricted' nutrition and should only be used when necessary hence not for the non-affected cat. C/d has normal nutrition and comes in varieties that control weight ( vast majority of cats with crystals are overweight) and l-tryptophan to control stress.
Frankly this is basic management of urinary crystals in cats an incredibly common problem, plus hills have a free technical support line for vets so they are just not trying to give you the right info.

Complained to vet chain hq and got hospital vet to call me who confirmed what I thought which is that fine for him to eat sd dry and cd wet at same time then switch to both cd for maintenance.
Cd fine for other cat too, obv not the sd.
After 5 days on sd dry he did a small but definite pee last night so looks like its working!
And yes have cd wet and dry stress low cal foods arriving tomorrow so that will also help with weight and stress maintenance.