From an email I received (not sure how I got on Hill's mail list to vets,
though).  I just noticed this email as it went to my unmonitored email
account:

Dear Valued Partner,
 
April 18, 2007– Update: Hill’s products not affected by rice protein
concentrate recall.

On April 17 the FDA announced a further pet food recall associated with
melamine contaminant, reportedly from a supplier of rice protein
concentrate. No Hill’s products are affected by this recall.

While Hill’s uses rice protein concentrate in 4 of its products, we do
not use the supplier involved with the recall.

Hill’s has tested its ingredients and these tests show no melamine is
present in the rice protein concentrate that it uses.

Q. Do any Hill’s Pet Nutrition, Inc. products contain rice protein
concentrate?
A. Yes. Four Hill’s products contain rice protein concentrate; however,
none contain rice protein concentrate from the supplier associated with
this recent recall.

The four Hill’s products that contain rice protein concentrate AND ARE
NOT affected by recent recall announcements:

Prescription Diet ® z/d® Feline Dry
Prescription Diet ® k/d® Canine canned
Science Diet® Lamb Meal and Rice Recipe Puppy Large Breed
Prescription Diet® h/d® Canine Dry
Hill’s has tested its ingredients and these tests show no melamine is
present in the rice protein concentrate used in our products.

Q. How do you know Hill’s rice protein concentrate is safe?
A. Upon immediately learning about the presence of melamine in another
supplier’s rice protein concentrate, we tested our ingredients and have
confirmed that the rice protein concentrate ingredient from Hill’s
suppliers do not contain melamine.

Q. Where does Hill’s Pet Nutrition Inc. get its rice protein concentrate?
A. Hill’s uses two suppliers, neither of which are involved in this rice
protein concentrate recall.

Q. What is rice protein concentrate, and why is it used in pet food?
A. Rice protein concentrate is the product remaining after starch has
been washed away from rice. It is a commonly used protein ingredient in
various pet food products.