Photo by Diane Dehart

Lacie, a Labrador retriever mix, was healthy until she developed a fatal kidney disease that her veterinarian suspects was caused by eating chicken jerky treats.

Ever since Dr. Robin Hubbard had to euthanize Lacie, a vibrant Labrador retriever mix who developed kidney failure in April after eating chicken jerky, spreading the word about possible risks of the dog treats has become something of a crusade for the veterinarian.

Hubbard talks about it with her clients at Rustburg Veterinary Clinic in Virginia. She submitted a report to the U.S. Food and Drug Administration (FDA). She contacted a VIN News Service reporter, wrote a letter to the editor of her local newspaper and plans to reach out to the companies that make chicken jerky for dogs.

“These treats are everywhere,” Hubbard said. “They are in the grocery store, Sam’s Club, PetSmart, so people think, ‘They’re OK. They must be. They’re all over the place.’ ”

In fact, whether chicken jerky treats for dogs are OK is a long-running mystery. The FDA began in 2006 to receive complaints that chicken jerky treats made in China apparently were making dogs sick. Six years later, the agency has been unable to identify a contaminant and cannot say definitively whether the treats are safe or causing illness and death.

Meanwhile, the number of complaints is skyrocketing, surpassing 600 in the first 5-1/2 months of this year alone. The agency has received about 1,300 complaints total since 2006, according to Laura Alvey, a spokeswoman for the FDA Center for Veterinary Medicine.

Reported signs of illness, which tend to occur within hours or days of feeding the products, include decreased appetite; lethargy; vomiting; diarrhea, sometimes with blood; increased water consumption; and increased urination.

It’s unclear whether the problem is worsening or merely better recognized. Alvey noted that reports tend to surge following media attention or other publicity. The greatest spike to date came in March, with more than 400 complaints logged in the wake of news reports on MSNBC.com and other media outlets, Alvey said.

A smaller number of cases have occurred in Canada, as well. The Canadian Veterinary Medical Association has received reports of 35 cases since June 5, 2011, according to the association’s communications manager Tanya Frye.

Australia experienced an outbreak in 2007 and 2008 and has seen “a few sporadic cases” since then, according to Dr. Linda Fleeman, a veterinarian there who tried during the outbreak to identify the cause.

In the United States, the clamor for answers has intensified. In February, two Ohio lawmakers — U.S. Sen. Sherrod Brown and Congressman Dennis Kucinich — sent letters to the FDA pressing their concerns, including questioning whether the public was sufficiently informed and requesting details of the agency's investigation.

In a letter to Brown dated March 9, FDA Assistant Commissioner for Budget Patrick O. McGarey responded that the agency tested more than 170 samples of chicken jerky products between 2007 and 2011, and had complete results for another 80 samples tested during the first weeks of 2012.

McGarey said the samples tested negative for drugs, poisons and toxins, including several mycotoxins. A subset of samples tested additionally for heavy metals, melamine, formaldehyde, tetracycline breakdown products and/or maleic acid also were negative, he said.

He added: “Propylene glycol was found at low levels in about half of the samples where laboratories tested for this substance, but the levels were considered to be nontoxic. Propylene glycol is an allowed feed ingredient in pet foods.”

In sum, he said: “To date, scientists have not been able to determine a definitive cause for the reported illnesses.”

Brown called the response inadequate and sent a second letter. In a reply dated April 5, McGarey stated that the agency had posted a questions-and-answers document on its website to provide more information to pet owners.

In addition, McGarey said, the agency was continuing an intensified investigation, including stepping up surveillance of shipments of chicken jerky treats from China and scheduling inspections of five Chinese production facilities known to produce chicken jerky imported to the United States. He said the inspections began on March 28.

Findings have not been released. Alvey, in response to questions from the VIN News Service about the inspections, said: “We are limited in the information we can make public, as the investigation is active and ongoing.”

Manufacturers whose chicken jerky has been implicated in illness in American dogs are under pressure to pull their products but have resisted thus far. An online petition seeking a ban on all chicken jerky treats made in China has drawn more than 14,000 signatures.

Nestle Purina PetCare makes two brands among several that reportedly have been implicated by name in the complaints: Waggin’ Train and Canyon Creek Ranch. In a Q&A on its Waggin’ Train website, the company says it has not issued a voluntary recall because:

“Waggin' Train products are safe to feed as directed, and millions of dogs continue to enjoy them as a wholesome treat. The FDA has clearly stated that after extensive testing, scientists have been unable to determine a definitive cause for the reported illnesses. According to the FDA, samples collected from all over the United States have been tested for a wide variety of substances and no contaminant has been found. In addition, FDA continues to emphasize that many of the reported illnesses may be the result of causes other than eating chicken jerky.”

In April, Nestle Purina sent a letter to about 20,000 veterinarians nationwide asking them to share “accurate, fact-based information” to counter what it called “inaccurate and misleading information about chicken jerky treats for dogs ... circulating in the social media, online and in traditional media reports.”

Among the facts it offered: “Waggin’ Train chicken jerky treats are safe to feed as directed. To date, there has not been a recall of Waggin’ Train products, and consumers may continue to feed with confidence.”

Dr. Sherrie Hartke, owner of Willis Animal Hospital in Texas, said the letter struck her as “well-written corporate spin.”

Hartke has seen two cases of illness associated with chicken jerky. Her thought is: “Why feed these treats when so many others are available and not associated with health problems?”

Many veterinarians express the same sentiment.

Frustrated that potentially harmful chicken jerky treats remain on the market, Dr. Tony Buffington, the veterinary nutritionist at the Ohio State University Veterinary Medical Center, created this poster to display in the hospital for companion animals.

Dr. Tony Buffington, the Ohio State University Veterinary Medical Center’s veterinary nutritionist, created a poster to display in the hospital for companion animals to warn clients of the potential risk of feeding their pets chicken jerky. The poster reads in part:

“Until a cause or explanation can be found, we urge our clients not to purchase or feed chicken jerky products to your pets. There are many other ways to express your love for your pet; play, petting, teaching tricks ... contain all the love without the calories or the risks associated with these snacks.”

Buffington explained by email that when he was asked to speak to local press on the subject, he reviewed the issue to refresh his knowledge and was surprised to find the treats still available for sale. “While it seems incredible to me that anyone would continue to sell them with so many other snacks on the market, I thought that the least I could do was to warn our clients,” he said.

Hubbard, the veterinarian in Virginia, was struck deeply by the experience of trying to save the life of a dog that had been perfectly fine before eating the treats.

Remembering Lacie, a 5-year-old snowy white Lab mix who wagged her tail happily even when visiting the clinic for treatment, Hubbard said, “She was just a spectacular dog. ... I had to look at this lovely dog and euthanize her because of kidney failure. So it’s very personal.”

Lacie’s owner, Diane “Dee” Dehart, picked up the Waggin’ Train brand of chicken jerky at a grocery store in April. She’d never tried that treat before and knew nothing of the ongoing concerns about chicken jerky dog snacks made in China. She just thought her three pets might like it.

They did, Lacie most of all. Dehart remembered giving her “at least four to five good-sized pieces” at a time. The other two dogs, both male Lab mixes, also got some, but “I had a tendency to give her a little more,” Dehart said. “She was my little girl.”

About three days after buying the treat, Dehart, perusing news online during a lunch break, came across an article about the potential dangers of chicken jerky. That looks like the same stuff I have! she thought in alarm. At home, she confirmed it was the same product and immediately threw it away.

A few weeks later, Dehart noticed Lacie had lost weight. Wondering but not immediately worried, she waited a bit, watching Lacie closely. The dog was not obviously ill, but then Dehart noticed she ate grass and drank water more than usual. That’s when Dehart realized Lacie wasn’t well.

“I was afraid it was diabetes,” she recalled, adding wistfully: “I wish it had been. I’d have given her a shot every day.”

By the time Dr. Hubbard saw her on April 30, Lacie was in severe kidney failure. She was anuric — unable to urinate — her blood pressure was high, she had gastrointestinal ulcers and no appetite. Under her fluffy fur, she was bony, having dropped 10 of her usual 50 pounds. And Lacie had glucosuria — sugar in her urine, one of the hallmarks of Fanconi-like syndrome, the renal disease common to many of the cases involving consumption of chicken jerky.

Hubbard initially thought Lacie might have gotten into a chemical poison of some sort; antifreeze or transmission fluid, perhaps, but Dehart said she was very careful to keep all the dogs in a fenced yard with no access to toxicants. The veterinarian went down the list of possibilities. What about chicken jerky? she asked.

Yes, Dehart replied. Yes, she had chicken jerky.

Hubbard kept Lacie overnight, providing intensive fluid therapy and medications to help her urinate, protect her stomach and bring down her blood pressure. The following evening, Dehart took Lacie home, bringing her back in the morning for further treatment. But Lacie did not recover.

When Dehart realized the end was near, she took time off work to stay home with her pet. “She was just throwing up and throwing up,” Dehart said. “She hadn’t eaten anything. She just finally quit getting up.”

An animal lover who’s kept cats, dogs, mice and turtles over the course of her life, Dehart said most of her pets died of old age — never anything like this.

She’s struck by the irony of owners possibly causing their dogs harm by giving treats out of love. “You feel like you’ve done it to them,” she said.

Since Lacie’s death, Dehart has been looking at store shelves of chicken jerky with anger and frustration. “The Wal-Mart here, they’ve got a big display,” she said. “I want to knock them all off on the floor.”

She hasn’t done that, of course, but she did talk to the manager of the grocery store where she bought the treats. He was sympathetic and urged her to call the company’s customer service line to share her feelings. Because the store belongs to a national chain, he told her he was unable to make a unilateral decision to pull the treats. But Dehart said he told her, “If I see anybody going to buy them, I will say something.”

Hubbard said she, too, plans to urge the stores to stop selling chicken jerky. But her first priority was completing a report to the FDA on Lacie’s case, even as she wondered how much the report would count. She has helpful laboratory analyses but lacks other details.

“You’re supposed to be able to give them dates of when they ate the product. The (owner) is distraught, she doesn’t remember (exactly) when she gave it ...” Hubbard explained.

“Another thing is, the FDA says, ‘Well, you don’t have the product any more so this isn’t going to be a good case to report.’ The best ones they like for epidemiology, you’ve got the bag and the lot number and all the information on the bag, you have some of the product (they) can test, you’ve got an animal that’s now sick, and the lab work in is place,” Hubbard continued.

“It doesn’t happen like that in the real world,” she lamented. “It just doesn’t.”

FDA provides instructions online in how to report a problem with pet food. Agency spokeswoman Alvey acknowledged the information they seek is extensive. "In a perfect world, we'd love to get all of the (information requested) when a report is submitted but we know this isn't always possible," she said.

While the FDA investigation continues, at least one scientific paper has been published documenting the development of acquired Fanconi syndrome in four dogs exposed to chicken jerky treats in the United States. Appearing in the November/December 2011 edition of the Journal of the American Animal Hospital Association, the case report describes classic Fanconi syndrome in dogs as an inherited disease found in basenjis. (Fanconi syndrome occurs in people, as well.)

“Acquired Fanconi syndrome has been documented sparingly, with reports of only a few patients at a time,” the authors state.

The paper reports that documented causes of acquired Fanconi syndrome in dogs are leptospirosis infections; association with certain medications such as antibiotics and chemotherapy; copper storage hepatopathy, a liver condition; and exposure to chemical food additives.

Acquired Fanconi syndrome in humans has been traced to exposure to a variety of environmental toxicants, including cadmium, lead and mercury, and to certain medications; to the diseases amyloidosis and multiple myeloma; and to renal transplantations, the paper states.

The four case studies presented in the paper involve small-breed dogs that ate chicken jerky daily as a significant part of their diets. Their clinical signs included lethargy, vomiting, anorexia, diarrhea and altered thirst and urination. Through supportive care, including intravenous fluids, antibiotics, gastroprotectants and oral nutritional supplements, all survived. Three recovered completely, but one developed chronic kidney disease.

The dogs all were seen by Veterinary Specialists of South Florida, in Cooper City, Fla., where the paper’s lead author, Dr. Ashley Nichole Hooper, was a resident at the time. In an interview, Hooper recalled the practice seeing a rash of such cases in fall 2007 — approximately seven during an 8-week period. And she knew from reading message boards of the American Veterinary Medical Association that other practitioners were seeing similar cases.

Today, Hooper is surprised the cause of the syndrome remains a puzzle. So many reports, messages and bulletins circulated in veterinary circles at the time that she felt someone surely would crack the mystery soon.

“It’s hard for me to think it was already five years ago now,” she said.

Confounding the conundrum further is the fact that treats other than chicken jerky have been associated with symptoms of Fanconi syndrome. On a message board of the Veterinary Information Network (VIN), an online community for the profession, several practitioners recently posted about cases involving dogs that ate sweet potato and yam treats made in China. Colleagues urged them to report the cases to the FDA.

Many veterinarians suggest it would be wise to avoid all treats made in China until the mystery is solved.

Consumers have been highly wary of pet foods and ingredients produced in China ever since unscrupulous manufacturers in that country were discovered in 2007 to have deliberately spiked certain ingredients with melamine — an industrial chemical not approved for use in food — in an attempt to boost apparent protein levels.

The melamine contamination scandal sickened and killed tens of thousands of cats and dogs and led to the largest pet food recall in North American history.

The chicken-jerky issue has resulted in few recalls to date. In 2007, as complaints to the FDA about chicken jerky began to mount, Eight In One Inc. recalled its Dingo Chick’n Jerky, citing potential Salmonella contamination. However, Salmonella has not been identified as a culprit in other brands that have been the subject of complaints.

In 2008 in Australia and New Zealand, KraMar Pet Company Pty. Ltd. recalled its China-made Supa Naturals Chicken Breast Strips after learning that at least 15 dogs developed acquired renal tubulopathy, or Fanconi-like syndrome, a company spokeswoman said at the time.

The following year, Virbac pulled from the Australian market its VeggieDent doggie dental chews for the same reason. Quite unlike chicken jerky, VeggieDents contain no meat. Virbac said they were made in Vietnam of ingredients sourced in Vietnam.

The recall did not affect VeggieDents sold in Europe, Japan and the United States, where the chews had generated no complaints of illness. Virbac’s recall notice pointed out that those sold in Australia were irradiated as required by the Australian government but were not irradiated for other markets.

The Australian government in 2009 banned irradiation of cat food in response to studies linking ingestion of irradiated food to development of neurological problems in cats, including limb paralysis. Similar problems have not been identified in dogs, but the Royal Society for the Prevention of Cruelty to Animals in Australia advocates prohibiting irradiation of all pet foods because cats often have access to dog food and because “there may be as yet unidentified health effects on dogs following ingestion of irradiated dog food.”

At least two brands of chicken jerky implicated in illness in the United States — Waggin’ Train and Canyon Creek Ranch — are subject to irradiation, according to information on the brands’ websites. Jill Winte, a spokeswoman for Waggin' Train, said in an interview that the FDA-sanctioned practice is intended to make the products safer by killing pathogens.

Asked whether the FDA has examined the role of irradiation in its chicken jerky investigation, agency spokeswoman Alvey confirmed that it is doing so. “We are considering irradiation as one potential factor in the jerky problem,” she said.

Irradiated foods in the United States generally bear a symbol called a radura or are otherwise labeled as irradiated.