I know it's not the same but it might offer a gravy option for poor
little Houdini Petco carries a Eagle Pac canned cat food

Eagle Pack Super Premium Cat Food in Cans
13 oz. - Turkey & Barley - Case Of 12
SKU: 970930
Natural, holistic approach to pet nutrition in a canned diet.

It appears the company below still has some ProPlan left you might try
ordering some from them

<http://www.thehungrypuppy.com/merchant.mvc?Screen=CTGY
&Category_Code=proplan-dry-cat-food>

I also found a rather limited site that has pet food made from Turkey and
barley

http://www.backtobasicsnaturalfoods.com/pet.html#pet%20food

I had a dog who had severe allergies to corn and wheat-- I ended up
cooking for her -- It was more trouble but definitely worth it-- I'm sure
you could adapt most any "gravy" recipe to use Turkey instead of Chicken
and thicken it with barley meal instead of standard kibble-- you might
need to add some vitamins.. but..  I think it'd work out ..

My heart and thoughts remain with Houdini..  best wishes

Lisa

PS I gave Purina my 2 cents worth -- hope it helps

~A dog or cat may steal your heart but a ferret will steal your soul~
[Posted in FML issue 5271]