Just a big long update on my lovely new pup.
She came home on 25th June. She was eating, although as you guys all rightly said, she still wouldn't eat her dry food unless they were drenched in the cheapest, shittiest tinned food with gravy I could find. Not the best, because as nellie says dals need low purine.
nellie Yep, definitely low purine for dals. No red meat, no game. She's my third dalmatian so we have a decent stock of low purine foods - OldGirlDog has been on fish4dogs white fish for a while as she's allergic to the Royal Canin dal-specific food, and BoyDog had kidney problems which at his autopsy a couple of months ago sob, I'm still very sad to lose my awesome boy were shown not to be hereditary so are suspected as being due to poor diet for a prolonged period - we got him at 9 years old. He ended up on a purely home-cooked diet to get the levels right, but then again he was utterly pampered towards the end.
So, back to YoungGirlDog, The first week was back to the vets on the Saturday, Tuesday and Thursday for more blood tests. They showed more reduction in platelets - normal is 175-500, and hers were 18 :( Her red blood cell count also continued dropping, as did her weight. She was 16.9kg when we got her, and her lowest was 14.5. Last visit last saturday she was up to 15.6kg so that's good.
The vet was bemused by it all, because she went from being a very sick dog, to being a typical 18 month old dalmatian - constantly bouncing, eating everything in sight, chewing everything. However her blood test results were showing that her bone marrow wasn't responding at all and they were concerned the erlichia has turned chronic and not just acute, and the vet was preparing me for blood transfusions etc if we didn't see improvement within a week as her levels were very worryingly low.
Anyway, she's now being treated for babesia as well as erlichia, and since then, both her platelets and red blood cells are now increasing. We'll know more tomorrow.
I've also managed to wean onto her dry food with a small tin of decent wet food - plain chicken Applaws the chicken and veg has green peas which are high purine so I'm happy with that as its the nearest to a decent ready-made wet food that suits the dietary requirements. Shame its almost 2 quid per 166g tin! 
Hence she's allowed one per meal maximum. No more crappy tins with ridiculously long ingredients lists.
So, fab news health-wise. She's back at the vets tomorrow for more tests and she looks to have gained weight - her spine isn't quite as prominent.
Bad news - she' battling OldGirl for top-dog. My poor OldGirl has a wonderful cut about an inch long on her bum from YoungGirl's claws which needed a couple of staples this week. They're now strictly separated when they can't be 100% supervised by two of us - that happened when DH was alone with them walking them both and the leads got tangled, they grizzled at each other, and he couldn't separate them before they started fighting. Hopefully she'll be able to be spayed soon which might help this situation, but her op had to be cancelled after we realised how ill she was.
Cupcakes Lets her her a few more kg on so we can have a proper before/after skinny/chunky comparison, and then I'll show her off properly! She's a sweety - unless you're called OldGirl. She's slightly taller than OldGirl who is 23.8kg and on the chubbier side, so we think about 22-23kg will be about the right weight for a taller, bigger framed girl. Only 7kg to gain before she's normal!