FDA Progress Report on Ongoing Investigation into Jerky Pet Treats
What's new as of September 2014
Complaints continue to decrease
FDA is working with laboratories across the country to investigate causes
FDA continues to encourage the support of practicing veterinarians
FDA has provided advice for pet owners
What we need from pet owners
Why we usually don't test open bags of treats or food, and why JPT is the exception to the rule
Why the investigation is still ongoing
Where we go from here
As of September 30, 2014, FDA has received approximately 5,000 complaints of illness associated with consumption of chicken, duck, or sweet potato jerky treats, most of which involve products imported from China. The reports involve more than 5800 dogs, 25 cats, three people, and include more than 1,000 canine deaths.
These numbers include approximately 270 complaints received since FDA’s last update in May 2014. During the previous period (from the update in October 2013 to May 2014, FDA had received 1,800 complaints. FDA’s October 2013 update included novel outreach to veterinarians and pet owners in an effort to gain more clinical information about potential cases, resulting in a high response.
Although it is impossible to determine in every case whether the events reported were in fact caused by eating jerky pet treats, FDA continues to believe that there is an association between some of the reports and consumption of jerky pet treats. 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.
A hallmark of FDA’s jerky pet treat investigation has been the high prevalence of cases of acquired Fanconi syndrome (also called Fanconi-like syndrome or FLS), a rare kidney disease normally seen primarily in certain breeds as a hereditary condition. 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 FLS, 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 FLS usually drink and urinate much more than normal. 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 with appropriate veterinary treatment and removal of the pet jerky treats from the diet; however, a positive urine test for FLS can still be detected several weeks later.
Of the kidney and urinary cases, about 290 of the case reports, involving about 320 dogs, have reported FLS. These numbers do include newly reported cases since October 2013, but the majority are associated with previously suspected cases of FLS that have since been confirmed by the University of Pennsylvania’s PennGen testing method. 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 has also hosted Chinese scientists at our veterinary research facility to further our scientific cooperation.
What’s new as of September 2014
Response to Dear Veterinarian Letter: Following an October 2013 request for veterinarians to share case information with FDA, and the May 2014 update to our investigation, we received many well-documented case reports that have and continue to provide us with valuable information that is assisting in our ongoing investigation. Out of this effort, we have had the opportunity to perform necropsies (post-mortem examinations) on a total of 72 dogs.
The FDA performed necropsies on as many cases as possible in order to learn more about the cause of death, even when reported symptoms did not appear to be those commonly reported related to eating jerky pet treats. About 54 percent (39 dogs) were found to have died from identified causes such as widespread cancer, Cushing’s disease, mushroom toxicity, parvovirus enteritis, bacterial meningitis, abscess, pneumonia, cardiac lesions, infarcts, or internal bleeding secondary to trauma. In the remaining 33 dogs necropsy did not identify specific causes and jerky pet treats could not be ruled out as contributing to the deaths. Twenty-six of these dogs had indications of kidney disease and two dogs had gastrointestinal disease. Few of the necropsies (5 of 72) revealed indications of the FLS that has become the hallmark of the investigation, perhaps because some dogs diagnosed with FLS either improved or recovered with appropriate veterinary care and removal of the treats from the diet. Additionally, the necropsies of three of the dogs who tested positive for FLS revealed causes of death unrelated to jerky pet treats.
Although the majority of the dogs reported as testing positive for FLS survived, and their FLS seemed to resolve once the treats were no longer fed, it is important to note that most of these cases also received veterinary care, including hospitalization, intravenous fluids, etc., during the duration of their illness.
We continue to review case records; test treat samples from reported cases; screen tissue, blood, urinary and fecal samples; and communicate with the attending veterinarians and pet owners to thoroughly investigate select cases.
Partnership with CDC: Because the Centers for Disease Control and Prevention (CDC) is involved with public health issues that affect both human and animal health, FDA has requested their expertise in collaborating on a study of cases reported to the agency of sick dogs compared with “controls” (dogs who have not been ill). The goal of the study was to compare the foods eaten by the sick dogs (cases) to those eaten by the dogs that did not get sick (controls), in order to determine whether jerky pet treat exposure is associated with illness. Data collected during this investigation will allow federal investigators to better understand what is making pets sick. A manuscript of study results and analysis is currently being prepared for submission for publication in a peer-reviewed scientific journal and the data will be made public once published.
Investigators first identified about 100 cases of kidney illnesses in dogs reported to FDA since July 1, 2013 regardless of jerky pet treat exposure. The cases included dogs diagnosed with Fanconi or Fanconi-like illness, or dogs that were 5 years of age or younger and had kidney failure. Cases were selected solely on this case definition and not on what food they consumed. Investigators then identified approximately 3 control (not ill) dogs within a 100-mile radius of each sick dog. It took more than 12,000 phone calls to identify less than 300 controls. We then interviewed the owners of both the case and control dogs using a detailed questionnaire that included in-depth questions about the types of foods the dogs ate, as well as other factors that could lead to renal disease.
Testing and Import Alert Implementation: Following testing performed by the New York State Department of Markets and Agriculture (NYSDAM) in 2012 that detected low levels of antibiotics in jerky pet treats, FDA undertook a project to adapt the NYSDAM method to the equipment in its own field laboratories for regulatory and enforcement purposes. This adaptation is now complete and the method is in use for testing both imported and domestic treats.
Since October 2013, FDA has tested 71 investigative jerky pet treat samples and identified 27 that tested positive for amantadine. FDA did not request a recall of these treats because they were sold a year or more ago. However, because of these findings, FDA has added testing for antiviral residues to its sampling assignment and implemented an Import Alert directing its field investigators to detain shipments of the particular products that tested positive. These products cannot enter the country unless the manufacturer or shipper can provide third-party documentation that the products don’t contain illegal antiviral and/or antibiotic residues.
Amantadine is an antiviral medication that is FDA-approved for use in humans. It has also been used in an extra-label manner (using an approved drug in a way that isn’t stated on the label) in dogs for pain control, but FDA prohibited its use in poultry in 2006.
Amantadine was first approved by FDA in 1966 for use in humans, and the approved uses include treatment of Parkinson’s disease and prevention or treatment of influenza A. The drug is no longer recommended for flu treatment because some strains of influenza virus are resistant to it.
FDA does not believe that amantadine contributed to the illnesses because the known side effects or adverse events associated with amantadine do not seem to correlate with the symptoms seen in the jerky pet treat-related cases. However, it should not be present in jerky pet treats. The agency has notified Chinese authorities that FDA considers the presence of amantadine in these products to be an adulterant. Chinese authorities have also assured us that they will perform additional screening and will follow up with jerky pet treat manufacturers. FDA has also notified the U.S. companies that market jerky pet treats found positive for amantadine of this finding.
Rates of complaints and product availability
FDA received approximately 1800 reports following its October 2013 update, Dear Veterinarian letter and outreach to pet owners. Although it is common for FDA to receive a large number of reports in response to increased publicity, the agency only received about 270 complaints following its May 2014 update.
FDA noticed a drop in the number of complaints after 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. Some of these brands returned to the market in February 2014 after formulation changes and FDA has received very few reports (primarily with gastrointestinal symptoms) associated with new product.After completing a Health Hazard Evaluation, 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. FDA scientists closely reviewed the NYSDAM findings and noted that when measurable levels of antibiotic drugs were found in the treats, they were consistently at very low levels—almost all were less than 0.0001% (< 1 part per million, or less than one inch in 16 miles). Our investigation continues to evaluate all potential causes for illness from the jerky pet treats, including antibiotics.
FDA is working with laboratories across the country to investigate causes
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 360 jerky treat samples relating to more than 165 consumer-related complaints, plus more than 240 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)
- Antivirals (amantadine, rimantadine, oseltamivir and others)
- 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 have completed 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. We continue to seek ways to detect and quantify the irradiation-specific markers 2-alkylcyclobutanones and 2-tetradecylcyclobutanones (2-ACB’s and 2-tDCB’s) in jerky pet treats in order to help determine the dose of irradiation that was used during production and to ensure that they were properly handled during the irradiation process. 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.
A summary of the tests that have been performed can be viewed here: Jerky Pet Treat Investigation Rationale and Results. A short overview of the testing performed since May 2014 is also available.
FDA continues to welcome the support of practicing veterinarians
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 October 2013, in an effort to expand the amount of information included in case reports, we reached 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 FLS by Vet-LIRN. This testing will allow FDA to get a better idea of how many of the suspected cases involve FLS, whether or not the pets display symptoms of kidney or urinary disease.
FDA has provided advice for pet owners
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.
What we need from pet owners
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.
Why we usually don’t test open bags of treats or food, and why JPT is the exception to the rule
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. FDA may not be able to use opened samples for microbiological cultures, because it is impossible to determine exactly when and how any bacteria entered the bag.
In our Jerky Pet Treat investigation, 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. We have also used these opened bags for measuring certain attributes that wouldn’t be affected by opening the bag, such as the nutritional or chemical composition of the treats or effects of irradiation on the treats.
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.
Why the investigation is still ongoing
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 or FLS 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 adequate post-mortem information in most cases. 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. We have had the opportunity to perform necropsies on some dogs in response to our Dear Veterinarian letter, and we are extremely grateful to the owners for their generosity in consenting to these procedures.
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.
Where we go from here
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.