What and how much to feed my yorkies

Question
QUESTION: I have struggled to feed my 4 yorkies.  They are between the ages of 1 and 3 and weigh from 3.5 lbs to 6 lbs.  I was feeding Natures Variety Raw (1 medallion 65/cal -- 2 xs a day)and they were fat and starving.  I took the weight off them with Royal Canin Calorie Control.  I was told that they should not remain on the Calorie Control so I use Royal Canin Duck and potato reduced fat (prescription diet also).  I switched them slowly and they love the food but 2 of the 4 have diarrhea from it.  I've used tylan powder and it controls the diarrhea, but as soon as I stop the tylan, the diarrhea comes back.  They never had a problem on the raw food.  I have tried every food available and they put on weight immediately and now have diarrhea.  My question(s) is -- how many calories should a 3.5, 4, 5 and 6 lb yorkie have per day, and what is the best food for them?  Can I just use dry or should it be dry/canned?  Thanks for any help you can give me.

ANSWER: Hi Annette,

Sorry I missed this one, it appears to have gone unanswered.
calorie requirements for toy dogs can be tricky. If we go by the books, the calorie range for each dog is as follows;

3.5 lbs = 125 to 182
4 lbs =  140 - 200
5 lbs =  165 - 240
6 lbs = 190 - 250

Now these are the numbers and since dogs, like humans, have very individual systems and metabolisms, you may find the smallest one needs the top end of the range to maintain weight and the largest stays near the low end in order not to gain, thus not a lot of difference in actual intake. metabolism depends on multiple factors and these numbers should only be used as a guideline. But it can be useful to compare them against the actual amount you have been feeding.

I would suggest a home made diet for them, cooked or raw, but probably cooked going on what I know so far. Try another dogfood brand geared to small dogs, like the Acana small breed:
http://www.championpetfoods.com/acana/show-product.php?formulation=asb
if the one you're using doesn't work. How many times per day do you feed? Do they get a  lot of treats?

I would start with a premium food like Acana and the middle of the caloric range and be precise.Although your 2 medallions only amounted to 130 calories you might have been giving soem extras as well? Use only very low calorie treats and factor them into the daily calories, not more than 10%. And see what happens over a few weeks. I'd be interested to hear how they are doing. :)
All the best, Catherine

---------- FOLLOW-UP ----------

QUESTION: Hi Catherine -- I have done extensive research on dry foods for small breeds.  Acana was not one of them.  I did look into it briefly and see its about 400 cal/cup.  I was wondering why you chose that particular brand?  Do you think its a better food for small dogs then Innova or Canidae?  BTW, I tried Canidae platinum (330 cal/cup) and they were very overweight on that diet too!  I give them about 4 treats per day, each are 2 calories per treat.
Annette

Answer
I do think it's worth a try. What you would be getting here is higher levels and quality of protein with lower carbohydrate overall, and it *may* be the carb that keeps weight on your dogs. In a case like yours, if you really cannot do home cooked, continued experimentation with foods like Acana and EVO may be necessary, as well as having their thyroid tested (full panel sent to Jean Dodds, not the in-house standard vet test) and carefully watching calories.
All the best, Catherine