I have a 17 month old Malinois, Heidi who to be honest has never really been a big eater. She  often eats a meal and then picks at the next 3 or 4. She used to be fed Bakers as my Lab was but when we got our new puppy she was on CSJ so I changed them all to it. About 8 weeks ago Heidi was weighed and was 20.9kg (quite low then I thought) but we noticed about 2 weeks ago that when you stroked her you could feel her spine. I took her to be weighed and she was 19.8kg. I didn't book her in to see the vet as she hates going anyway and I knew he would say she was losing weight because she isn't eating. I have since brought about 5 different sorts of food, some she wont touch, others she has eaten a little of (James Wellbeloved and Royal Canin) but she still only eats a few mouth fulls and then walks off. I know people always say that a dog will eat it when they are hungr enough but she really wont! She is a very active dog and gets walked for at least 1 and a half hours a day off lead and does agility training so it isn't that she isn't exercised enough. I know the heat probably hasn't helped over the past few days but i'm quite stuck now. Some advice is greatly needed and I am going to make her an appointment with the vet for next week.

Nothing better than raw green tripe and terrier meal...

switching food will a fussy dog make! so be careful with that.

i vote tripe as well, a good dose of it in her dinner and she should go nutty for it :)

We have a 5yr old leonberger bitch who has always been fussy about her food.  Our old dog indy who died recently would eat ANYTHING and until he popped!  Why does big dog not go crazy for food too?  She is always lean (which is better than overweight admittedly), but she is fussy and will sometimes eat a bit and walk away.  or dinner time comes and she will just go away and sit down. 
I tried the 'eat it or don't eat at all' thing and it worked for a while - but she seems to go off a regular meal.  We had been feeding her BARF (either chicken wings/legs or beef mince), but is really fussy about bones.  She just doesn't seem to have an appetite and makes the food a game.  She will also whine for food and then if she's given it she often doesn't want it.  (I want to point out I don't give her food if she asks for it - this is just my mother! bad habits!).

Are some dogs just always fussy eaters?

we have a new pup (jack spaniel) and would liek to start her on barf too and don't want her copying the big dog behaviours (from what we can see, she's not going to be fussy about her food).

does sound like you are swapping and changing food quite often.
could be fussy dog training owner?
how many days do you wait before swapping food, and key, how long do you leave the food bowl down each time?

I too have a very fussy dog (toy poodle) so I can sympathise with you, I have tried various foods in the 4 or so years I have had him and now stick to natures menu the tins not the pouches as he prefers the tins and also Royal canin mini sensible dry food. I have a younger poodle who is related to my other poodle who is much easier to feed and has been changed onto different foods when I tried them on Mr Fussy, so I don't think changing the food has made the older dog any more fussy, as he has been like it since he was a puppy.

I think a vet appointment is a good idea to see if there are any problems underlying her poor appetite.  If you can easily feel her spine she is too light.

Ages ago I had a very fussy GSD.  She might eat for three days and then eat nothing the fourth day.    Then I got a Yorkie pup.  I fed both in the same room, near each other ... after the GSD realized the Yorkie would happily consume the GSD's food she never missed a meal.   The GSD was never an enthusiastic eater and didn't even mind if another dog stuck their heads in her food bowl as she was eating (with me dragging them out ASAP); but she always did eat.

I am not one of those people that believe that switching foods causes dogs to be picky eaters.  In fact, I actually think it helps keep them interested.   Just find two or three things that she likes and switch around adding them to her dry food, if that's what you are continuing to feed.

Also - buy the performance or other premium options for the dry food, the higher the kalorie content the better for an underweight dog.

Ive one been on the same food day 1 eats like its going out of fashion. Spaniel really odd not fussy just does not eat a lot. I did try a few foods but they upset his tummy so he has science plan biscuit with a half sachet of a wet food, 9 times out of 10 he will leave half and Jake finishes it. That carries on for about 4 days then he scoffs the lot and back to picking. He's about the right weight not fat, not really thin, plenty of energy so i have stopped worrying! One thing he will always do is mug babies for biscuits, very, very gentle but a born thief!

Thanks for all the advice, she has been to the vets and has had a series of blood tests as she may have hypothyroidism, just waiting for the results. On the plus side she has eaten every meal for the past 9 days. Royal Canin and Tuna of all things! It seems to be working though, she has put on 0.5kgs and looks much healthier.

> she has been to the vets and has had a series of blood tests as she may have hypothyroidism

I have a rottie with hypothyroidism and she was ravenous all the time and despite very small meals she was gaining weight at a ridiculous rate, underactive thyroid would generally make her overweight not underweight, she is also quite young for this condition too, she could have hyperthyroidism which is the opposite and would make her very hyper and lose weight?  Though this condition is not common in dogs, more in cats.

Whatever the cause i hope they get to the bottom of it for you and she improves soon. :)