The U.S. Food and Drug Administration has received 153 complaints during the past 16 months about illness in dogs that have eaten chicken jerky treats and continues to take reports “at a steady clip,” an agency spokeswoman said Friday.

The FDA in mid-December posted on its Web site cautionary notes to dog owners about jerky treats, following the Dec. 9 voluntary recall by the Australian company KraMar of its chicken breast strip treats.

Since the fall of 2007, veterinarians in both countries have seen symptoms in dogs that mimic the kidney disease Fanconi after the dogs ate chicken snacks. In Fanconi syndrome, which usually is inherited, the kidneys do not properly resorb electrolytes and nutrients to the body. Glucose “spills” into the urine, while blood-glucose levels are normal or even low.

Reports of Fanconi-like disease in the United States initially led to some voluntary product recalls but the culprit has not been identified. Likewise, KraMar in Australia has emphasized that it has no scientific evidence that its products are the cause of the illnesses.

Laura Alvey, a spokeswoman for the FDA’s Center for Veterinary Medicine, said Friday in an e-mail response to questions:

“The FDA is actively investigating the matter and conducting analysis for multiple different chemical and microbiological contaminants. We have tested numerous samples of chicken jerky products for possible contaminants including melamine. The complaints received have been on various chicken jerky products but to date we have not detected any contaminants and therefore have not issued a recall or implicated any products. We are continuing to test and will notify the public if we find evidence of any contaminants.”

Alvey said the agency has logged 153 complaints since September 2007. She could not say specifically at what rate new cases continue to be reported.

Although the FDA saw fit to issue a fresh caution in December, the continuing problem in this country has drawn little attention. A spokesman for the American Veterinary Medical Association told the VIN News Service in December that U.S. cases seemed to have “flamed out” in 2008.

Dr. Sharon Gwaltney-Brant, vice president and medical director of the American Society for the Prevention of Cruelty to Animals’ Animal Poison Control Center in Urbana, Ill., said the center received fewer than a dozen calls in total about jerky treats in 2007 and 2008 combined. That’s out of 136,000 and 146,000 cases of suspected and actual poisonings in each year, respectively.

Of the 10 or 11 calls the center received, some were only inquiries; others involved animals that had eaten jerky treats but did not show symptoms, she said. In only one case was there a report of glucosuria, or glucose in the urine.

Gwaltney said Dr. Stephen Sundlof, director of the FDA’s Center for Food Safety and Applied Nutrition, and former director of the agency’s Center for Veterinary Medicine, told participants of a meeting at the University of Illinois in September that pet owners should be careful not to overfeed their dogs with the treats.

“It sounds like maybe they’re giving them the whole bag of Oreos,” is how Gwaltney took it.

In its cautionary statement to pet owners, the FDA advises: “Do not substitute chicken jerky products for a balanced diet. The products are intended to be used occasionally and in small quantities. Owners of small dogs must be especially careful to limit the amount of these products.”

But when asked whether the cases tend to involve animals that were given an overabundance of treats, FDA spokeswoman Alvey responded, “We can’t speculate on what might be causing the reported illnesses.”

One commonality between the suspect jerky treats in the United States and those produced by KraMar in Australia is that they were manufactured in China. Consumers are especially wary of that source in the aftermath of a massive contamination with melamine of pet food by Chinese suppliers in 2007.

However, Gwaltney said, the Chinese origins of suspected chicken treats may not be much of a clue. Paraphrasing Sundlof, she said, “We can blame China, but maybe that’s just because most treats are made in China.”