As of September 24, 2013, FDA has received approximately 3000 complaints of illness related to consumption of chicken, duck, or sweet potato jerky treats, most of which involve products imported from China. The reports involve more than 3600 dogs, 10 cats and include more than 580 deaths. FDA continues to investigate the cause of these illnesses in conjunction with our partners in the Veterinary Laboratory Investigation and Response Network (Vet-LIRN), a network of animal health laboratories affiliated with FDA.
The complaints FDA has received include adverse events involving different sizes, ages and breeds of dogs. About 60 percent of the reports are for gastrointestinal illness (with or without elevated liver enzymes) and about 30 percent relate to kidney or urinary signs. The remaining 10 percent of cases involve a variety of other signs, including convulsions, tremors, hives, and skin irritation.
Of the kidney and urinary cases, about 135 of the case reports have been for Fanconi syndrome, a specific kind of kidney disease. Part of the normal function of the kidney is to filter out waste while keeping in nutrients such as glucose, bicarbonate, and amino acids. In Fanconi syndrome, a part of the kidney called the proximal tubule doesn’t work properly, and these nutrients are lost into the urine instead of being reabsorbed.
Dogs with Fanconi Syndrome usually drink and urinate much more than normal. This can also be a sign of diabetes, but Fanconi dogs do not have the elevated blood sugar that is a hallmark of diabetes. They can also be lethargic and uninterested in eating. Some dogs may have all of these symptoms while others show only some of them. The symptoms may also be mild or severe. These dogs often improve when they are no longer being fed the treats; however, a positive urine test for Fanconi syndrome can still be detected several weeks later.
It is important to note that the reported illnesses are not limited to jerky treats made from chicken. We have received complaints about duck and sweet potato jerky treats and related products, such as jerky-wrapped rawhide treats. We know that the illnesses and deaths reported are mostly linked to jerky pet treats sourced from China. Pet owners should be aware, however, that manufacturers do not need to list the country of origin for each ingredient used in their products.
In trying to find the cause of the illnesses and deaths associated with jerky pet treats, we’ve worked with our colleagues in academia, industry, foreign governments and state labs. As part of the investigation, we have inspected production facilities in China and met with the General Administration of Quality Supervision, Inspection and Quarantine (AQSIQ), the Chinese regulatory agency responsible for pet food, to ensure that they are aware of U.S. requirements for pet food safety and to develop collaboration on sharing information to support FDA’s investigation. FDA also plans to host Chinese scientists at our veterinary research facility to further our scientific cooperation.
FDA has noticed a sharp drop in the number of complaints since several treat products were removed from the market in January 2013 following a study by the New York State Department of Agriculture and Marketing (NYSDAM) that revealed low levels of antibiotic residues in those products. Recalled products included several well-known brands believed to comprise the majority of the jerky pet treat market. FDA believes it unlikely that the reports of illness it has received are caused by the presence of antibiotic residues in jerky pet treat products. Rather, because the brands that were recalled represent a significant portion of the jerky pet treat market in the United States, FDA theorizes, therefore, that the drop off in complaints since January 2013 is the more likely the result of the general lack of availability jerky pet treat products.
Nonetheless, FDA is taking a closer look at the NYSDAM findings. When measurable levels of antibiotic drugs were found in the treats, they were consistently at very low levels—less than 0.0001% (< 1 part per million, or less than one inch in 16 miles). FDA scientists are currently working on a Health Hazard Evaluation (HHE) to more formally measure the potential for low levels of sulfaclozine, sulfaquinoxaline, other sulfonamide drugs, and sulfonamide pesticide residues in the diet over long periods of time to cause health problems in dogs and other animals. This process involves a review of the scientific literature, as well as any adverse event reports and consumer complaints sent to the FDA in connection with dogs and sulfonamide drugs, and may take many months to complete. In the meantime, our investigation continues to evaluate all potential causes for illness from the jerky pet treats.
To date, testing for contaminants in jerky pet treats has not revealed a cause for the illnesses. Since 2011, in concert with Vet-LIRN, we have collected approximately 250 jerky treat samples relating to more than 165 consumer-related complaints, plus more than 200 retail samples (unopened bags obtained from a store or shipment), and performed more than 1000 tests on these samples. We also ran more than 240 tests on historical samples (those received in 2007-2011).
While we do not subject every sample to the entire battery of testing, due to limited resources and in some cases a lack of enough material to test, we target our testing based on the product and the symptoms displayed by the pet. Testing may include one or more of the following analyses:
- Metals or Elements (such as arsenic, cadmium and lead, etc.)
- Markers of irradiation level (such as acyclobutanones).
- Antibiotics (including both approved and unapproved sulfanomides and tetracyclines)
- Mold and mycotoxins (toxins from mold)
- Nephrotoxins (such as aristolochic acid, maleic acid, paraquat, ethylene glycol, diethylene glycol, toxic hydrocarbons, melamine, and related triazines)
- Other chemicals and poisonous compounds (such as endotoxins).
Testing has also included measuring the nutritional composition of jerky pet treats to verify that they contain the ingredients listed on the label and do not contain ingredients that are not listed on the label.
Another area of investigation includes the effects of irradiation and its byproducts. We are currently performing preliminary testing of jerky using four different irradiation levels to determine if marker compounds can be identified in irradiated jerky to evaluate the dosage used. These studies are a collaborative effort between FDA, USDA, and a university partner.
We are also interested in collaborative efforts with veterinary hospitals to perform further study into the cases seen in the clinical setting to investigate the possibility of a genetic or other basis for gastrointestinal or renal symptoms.
You can see a summary of the tests that have been performed at Jerky Pet Treat Investigation Rationale and Results.
FDA has been investigating the root cause of these adverse events since 2007, and has issued several consumer updates advising pet owners about complaints associated with jerky treats, also noting that such treats are not essential for nutrition. Despite these warnings, we have continued to receive reports of illnesses in both dogs and cats.
In an effort to expand the amount of information included in case reports, we are reaching out to all licensed veterinarians through a “Dear Veterinarian” letter to, among other things, let them know in advance what specific types of information FDA would find it most useful to receive from them when they report cases of suspected jerky pet treat-related illness to the agency. This information includes:
- How long the owner has been feeding the treat
- What else the pet has been eating (all treats, human food, and pet food), including how much is given daily of all items
- Bloodwork values, especially for liver and kidney
- Urinalysis results
FDA also requests in the letter that veterinarians obtain a urine sample (10 ml if possible) from dogs or cats that may have illness associated with jerky pet treats and freeze it for testing for Fanconi Syndrome by Vet-LIRN. This testing will allow FDA to get a better idea of how many of the suspected cases involve Fanconi Syndrome, whether or not the pets display symptoms of kidney or urinary disease.
FDA uses its website to provide pet owners with periodic information about its ongoing investigation into jerky pet treats. Despite extensive media coverage highlighting the investigation, we continue to hear from pet owners who were unaware of the issue and have purchased and fed jerky treats to their pets. In response, FDA has developed a Fact Sheet for pet owners that can be made available at veterinary hospitals, pet supply stores, other stores selling pet food, and anywhere pet owners visit.
FDA continues to caution pet owners that jerky pet treats are not required for a balanced diet. The agency encourages pet owners to consult with their veterinarian both prior to feeding treats and if they notice signs of illness in their pets after feeding treats.
Furthermore, FDA asks pet owners to pay attention to sudden adverse symptoms, like vomiting, diarrhea, increased thirst, increased urination, or lethargy, and to seek veterinary care if these symptoms occur.
If you believe your pet has become ill from consuming a jerky pet treat, you can provide us with valuable information. In addition to your contact information, your pet’s symptoms, and medical records, the one piece of information we most often lack is the lot number of the jerky treat product. If we have the lot numbers, we can identify whether particular lots triggered more complaints, trace products back to specific manufacturing facilities, and identify lots for testing. While we still want to hear from you even without the lot number, this information can help our investigation immensely.
If you find it convenient to transfer pet food and treats to a secondary container to protect them from rodents, insects or spoilage, FDA recommends that you consider saving the original packaging. This will help ensure that you will still have access to the lot code if your pet becomes ill from consuming the product.
While working with your veterinarian to review your pet’s records, FDA and Vet-LIRN scientists might request specific testing to try to narrow down the cause of your pet’s illness. The costs of tests requested by the scientists will be covered by Vet-LIRN and FDA, but pet owners will not be reimbursed for any additional testing expenses they may incur.
Although it is always a difficult topic to consider, in the event of a pet death that appears to be related to the consumption of jerky pet treats, post-mortem testing of animal tissues, such as a necropsy (in human medicine, doctors call this procedure an autopsy) may also be helpful. While we want to do everything we can to prevent pets from becoming ill in the first place, having the chance to examine tissues may fill gaps in information that can help us pinpoint a cause for the reports of injury and death.
While FDA occasionally collects samples from consumers to test, open containers by their very nature make it difficult to identify exactly when any contamination occurred. As a general rule, the agency prefers to test unopened samples of the same lot number, because the chain of custody in these closed samples is usually well-documented.
In our Jerky Pet Treat investigation, however, we have collected treats from previously opened bags directly from owners for two reasons: to be sure we have samples from the same bag from which the affected pet was eating and to measure variability in the contents of the bags. It is not unusual for bags of jerky treats to contain strips from several different birds.
If you do not have any treats left from the bag, we still request that you hold onto the packaging because lot codes can provide valuable information about when and where the treat was made.
This investigation continues to be a challenging one for FDA. Complicating the investigation are some fundamental differences between investigations into illnesses in people versus those in pets.
In human illness outbreaks caused by foodborne bacteria or contaminates, FDA works in concert with the Centers for Disease Control and Prevention (CDC) and state boards of health, which collect and track cases of foodborne illness. Unfortunately, there is no equivalent for pets, which means that it is difficult to accurately evaluate the scope of an outbreak. For instance, FDA is unaware of any statistics on the rate of occurrence of Fanconi Syndrome in non-Basenji breed dogs. Without such a baseline, it’s hard to appreciate how unusual the findings of Fanconi syndrome might be.
In the Basenji, and some other breeds such as the Norwegian Elkhound, Fanconi Syndrome is usually a genetic condition that can be passed down from parents to offspring. Very little is known about the possible causes for non-genetically related (acquired) Fanconi Syndrome cases in dogs, but certain toxins, medications and infections have been linked to its development in dogs and people.
Another complicating factor in the investigation is the lack of post-mortem information. When a person dies unexpectedly, it is not unusual for a medical examiner to perform an autopsy to try to determine the cause of death. When a pet dies, it is much less likely that qualified veterinary pathologists will have the opportunity to examine the body. By the time FDA receives reports of deaths in pets, the body has often already been cremated or buried, eliminating the chance for scientists to gather more information about potential causes for the pet’s illness.
Finally, FDA does not have access to market data about food items for pets. FDA regulations do not require product registration for foods, whether they are intended for people or animals. Therefore, it is difficult to appreciate the scope of the jerky pet treat market and the different products available to consumers.
Since 2007, FDA’s Center for Veterinary Medicine (CVM) has dedicated increasingly more resources to pet food, and CVM continues to work diligently to find the cause for illnesses and deaths linked to jerky pet treats.
As veterinarians, animal scientists, and animal lovers ourselves, we strive to make sure that the products FDA’s Center for Veterinary Medicine regulates are safe, effective, and properly manufactured. We understand the love and devotion pets provide, and we are determined to find the answer to this mystery.