I’ve a 12 month old Whippet she’s had Diarrhoea for about 4 weeks, no sickness or blood, she’s fine in her self apart from not eating much.
First visit to the vets she was given antibiotics, wormed and vitamin B12 injection and I went back with a poo sample, that came back clear so I took her back for blood tests and these came back her Folate was low, they suggested she needs a B12 injection every week for 4 weeks.
She had her first B12 last night, I was expecting a slight improvement today but there’s not.
I will see what she’s like tomorrow and if she’s the same I’m going to take more than 1 poo sample and insist on her having a scan, I asked for a scan on day one but the vet disagreed as she wasn’t sick or passing blood....

Have you kept her on a bland diet to settle her stomach? Chicken etc. If the tests don't show up anything my first course of action would be to look at the food you are using.

I agree with Goldmali, look at the food, I’ve had a few people who I know that had to change their dogs food ironically they were all on different types of Royal Canin like Goldmali said give her a bland diet of boiled chicken/Turkey and I would also add hills id prescription diet seeing as it’s bad and been going on for a while. She’ll also need a good probiotic, canikur pro paste or pro-kolin should help. Or you could use some good plain yogurt, onken bio yogurt is good but if she hasn’t had it then it may not be good to try her on it now whilst she’s still bad as some dogs don’t tolerate it. Hopefully it’s just a bad bout of diarrhoea, so many dogs have had dodgy tummies the last few weeks, 1 of mine included, not sure why? But because I gave her a probiotic and bland diet straight away it meant she was fine and back to normal within a week

The normal course would be starve for 24 hours and then bring them back using boiled rice, poached chicken and a little natural yogurt - if you can source goats yog., so much the better.   This normally sorts out uncomplicated tummy upsets.   However, it can be that Whippets do suffer with looseness on occasion - mine occasionally does.   Colitis.   I too would look at the maintenance food - I've found that a fish and potato diet helps digestion with those who have a sensitive digestive system.   And has your vet tested for Giardia, Coccidia and so on?   This can produce prolongued bad stools.

If you don't get answers, you are perfectly entitled to go for a second opinion.

Thanks for your replies, I should have said she’s been fed a good raw diet since she was a pup, for the last week I’ve gave her small amounts of tripe as it has all the good bacteria to help her stomach.

With tripe in these circumstances I would use lamb tripe as it's lower in fat than the more common beef .also if you join barf uk in fb they are a dedicated large raw feeding group and may be able to offer specific raw feeding advise.
Are u feeding a pre made or diy ? Amd has she been tested for pamcreatitis or coloitis? Also did  u make Any other changes just  before this started ?
A second option is also helpful

I would add Slippery Elm and pumpkin powder to her raw diet, along with FortFlora probiotics. 

If that didn't work, I would then do a 3 day course of Panacur (the giardia dosage).

Lambs tripe is far more smelly than cow & that is smelly enough!! Ours dont like lambs either. Whippets are not prone to stomach issues.

> Whippets are not prone to stomach issues.

I guess this depends on personal experience ....  certainly mine has a few bouts of unexplained runny stools over the years, as did those an old neighbour had.   Which is why I made that comment!

Most dogs will eat lambs tripe with relish however if they don't like it o would use cooked white fish or cooked chicken boneless of course . Often using something bland  and  Lower in fat can help if it's a temporary blip .otherwise u would need to look further of course..as for smelly yep i have some whole ones in my freezer but these days I hardly notice

Another one here wondering pancreatitis.  Totally fat free diet while she is being tested.  Then fat free afterwards if it's positive.

U usually have other signs at the very least signs if discomfort  with pancreatitis but worth doing  the test. If it did turn out to be that it is very easy to control on  fully raw diet