A Shanghai dealer has issued an emergency recall of a batch of Optima dry dog food with a production date between August and September last year.

Some dogs eating "Optima Puppy Lamb and Rice Dry Dog Food" have been poisoned by aflatoxin - a naturally occurring toxic chemical that comes from a fungus found on corn and other grains.

It can cause severe liver damage.

"Three dogs have been confirmed dead, and they all ate the batch of Optima food," said the Shanghai Naughty Family Pet Co, a pet clinic on Hongqiao Road. These dogs were fussy about their food, had diarrhea and vomited, all symptoms of aflatoxin exposure, staff said.

The clinic is now treating its fourth patient, a two-year-old Yorkshire who showed symptoms after eating Optima dog food.

"Yesterday he vomited four times," said a woman surnamed Tan, the dog's owner. "Before he got so severely sick, he ate very little, shivered or just lay on the floor."

Tan said she had bought the Optima dog food on November 18.

"I started to use the brand last March. My dog never showed anything wrong until he ate this bag," she said.

Since the end of November at least 20 dogs are believed to have died in Beijing, Shanghai, Nanjing and Hangzhou from liver complications. Some pets died within 10 days of showing symptoms.

An agent of Shanghai Yidi Pet Co Ltd, a Shanghai dealer of Optima food, admitted that a "severe quality problem" was found in the batch, and they were recalling the products.

Yidi said pet owners should return the contaminated food to be exchanged for other brands.

Yidi purchased the batch of Optima dog food from a Taiwan supplier, according to an agent who declined to be named.

An imported feedstuff registration list posted by China's Ministry of Agriculture shows that the Optima dog food's production enterprise is Australia-based Doane International Pet Products.

But Tan said her purchase order said the food was made in the United States. "American-made Optima is a very famous brand. That's part of the reason I chose it," Tan added.

(Shanghai Daily January 12, 2009)