Animal & Veterinary
Interview with Dr. Renate Reimschuessel
By Dr. Carmela Stamper, Contributing Writer/Editor, Communications
Dr. Renate Reimschuessel, in the Office of Research (OR) at FDA’s CVM, is an expert on melamine. She is also an expert in aquaculture and directs OR’s state-of-the-art aquaculture facility. In an interview with Dr. Carmela Stamper of FDA Veterinarian, Dr. Reimschuessel talks about her interest in aquatic animal medicine, her path to CVM, her research on melamine, and what her future at CVM holds.
1. Renate, you have been involved with some important issues during your career at CVM. Had you originally considered a career as a federal veterinarian?
No. I originally wanted to be a practicing veterinarian, with an exotic animal focus, perhaps at a zoo or aquarium. After I graduated from veterinary school, my husband was still working on his Ph.D. in Shakespearean literature at the University of Pennsylvania. I needed to stay near Philadelphia to support him. He had moved to Philadelphia so I could go to veterinary school. It was my turn to support his career.
So, I went into small animal practice in Langhorne, PA. I helped expand the practice to include exotic animals. We started seeing birds, reptiles, and other exotic animals as patients.
2. During your studies at the University of Pennsylvania’s School of Veterinary Medicine, you participated in two non-traditional externships: one in exotic animal medicine at the Philadelphia Zoo, and the other in marine animal science through the Aquavet program at the Woods Hole Oceanographic Institute in Massachusetts. After you graduated in 1981, you worked at the Langhorne, PA practice for five years. While in private practice, were you still considering a career with zoo animals or marine animals?
Yes. I was especially interested in aquatic animals, both fish and marine mammals. I was aware, however, that opportunities to work with dolphins, seals, and other marine mammals are rare.
3. When you moved to the Washington, DC area, you enrolled in a Ph.D. program in fish pathology at the medical school at University of Maryland, Baltimore (UMB). What prompted you to leave private practice to focus on fish diseases?
After graduating with his Ph.D., my husband got a job teaching at Goucher College [in Baltimore, MD]. We decided to move to Baltimore and agreed that I would pursue my goal of working more with aquatic animals. I looked at programs in the area and saw that a laboratory at UMB was handling fish pathology for the National Aquarium in Baltimore. The lab was also doing studies in the Chesapeake Bay to see if fish could be used as possible indicators of the Bay’s environmental decline. So I joined the lab faculty at UMB to increase my knowledge of aquatic animal diseases and how aquatic animals respond to chemical pollutants.
My investigation into a fish kill in Frederick County, MD led to my Ph.D. thesis topic at UMB. From my follow-up work on that fish kill, I concluded that fish, unlike mammals, can make new nephrons in their kidneys after being exposed to toxic chemicals.
Nephrons are microscopic structures in the kidneys that filter blood and make urine.
After getting my Ph.D., I stayed on as a member of UMB’s faculty, wearing three “hats”: teaching pathology and related subjects to medical, veterinary, and graduate students; doing aquatic animal research; and conducting diagnostic pathology for aquariums throughout the country.
|Diagnostic pathology for aquariums involves identifying the disease causing a fish, or group of fish, to be sick.|
4. As part of your aquatic animal research “hat” at UMB, you set up the university’s aquatic animal research program. The program focused on using fish to study the environment and as test models for human diseases. In 1999, CVM recruited you to create OR’s Aquaculture Research Program. Did CVM’s interest in aquaculture surprise you? What makes this research facility different from the one you created at UMB?
While doing my research at UMB, I was aware that veterinarians needed more drugs to treat fish diseases, both in pet medicine and in large-scale aquaculture. I attended meetings held by CVM, so CVM’s interest in aquaculture was not a surprise at all. While a faculty member at UMB, I worked with CVM when I became the United States advisor for a CVM employee who was working on a degree through the University of Stirling [in Scotland], but needed to do his research in the States. Copper is used to treat parasites in fish, and his research focused on its effects in tilapia.
CVM’s research facility is different from the lab I constructed at UMB in two main ways. First, CVM’s facility is much larger and can hold market-sized fish, like the size you’d see in a grocery store, for example, hybrid striped bass, salmon, trout, catfish, tilapia, yellow perch, and large mouth bass. At UMB, we mostly used smaller fish species as test models, like goldfish, zebrafish, and medaka. But, we also did some studies with wild-caught fish from the Bay and its tributaries, like toadfish and mummichogs.
Second, at CVM’s facility, we can do studies using radioactive chemicals to track the amount and location of drugs through the fishes’ bodies. We use these studies to develop ways to test imported fish products for illegal drugs. Having the facilities to conduct these types of studies is very rare in aquatic animal research.
5. What are the areas of focus in your CVM aquaculture research? What types of studies does the OR aquaculture facility conduct?
My research focuses on two main areas – food protection and drug evaluation.
We [OR] have done studies to help develop methods to test fish for illegal drugs. We also conduct studies to help CVM make decisions about drugs that may be useful for treating fish.
We have conducted effectiveness studies with the U.S. Fish and Wildlife Service and the U.S. Geologic Survey on drugs that may be useful for treating fungal diseases in fish raised in U.S. hatcheries. We have developed test models in fish to study parasitic and bacterial diseases and the effectiveness of drugs to treat those diseases.
|An effectiveness study is done to prove that a drug consistently and uniformly does what it is supposed to do.|
We have worked with CLSI to find methods to test bacteria in and on fish to see if the bacteria are resistant to antibiotics. The tests help veterinarians choose the most appropriate drugs to treat fish diseases. The tests also help veterinarians monitor changes in the resistance patterns of fish-related bacteria in the environment.
|CLSI stands for Clinical Laboratory Standards Institute and is a group that creates global standards for medical laboratories.|
6. March 15, 2007, is an important date in FDA history. It’s the date that Menu Foods, a large pet food manufacturing company, announced a recall of various brands of canned and moist pet food. The recall occurred after several dogs and cats died from kidney failure after eating different brands of “cuts and gravy” pet food made by Menu Foods between December 3, 2006, and March 6, 2007.1 Scientists found that the food was contaminated with melamine.
The melamine recall is still fresh in the public’s mind. Pet owners are very concerned about the safety of their pets’ food.
Did you expect the melamine recall to grow so large? What other animal feeds were also contaminated?
No, I didn’t expect the recall to get so large so quickly. At first, scientists didn’t even know the cause of the toxicity. Once melamine was detected in the wheat gluten and it became clear that melamine was purposely added, I did expect the recall to balloon. I was worried about other products being contaminated, including human foods. Fortunately, I was not alone in my worry, and FDA immediately tested numerous other products for contamination. Hog, chicken, and fish feeds were also contaminated, and of course, the contamination of fish feeds was right up my research alley.
7. Because CVM regulates pet food, the Center was pulled in quickly to address the melamine problem. At first glance, your background as a fish pathologist and your expertise in aquaculture research don’t fit with melamine research and pet food. How did you become involved with the melamine recall?
I became involved when my office director at the time, Marleen Wekell, asked if I could help. She knew I had experience both in pathology and in investigating how kidneys respond to toxic compounds. So, I offered to help CVM’s Office of Surveillance & Compliance with reviewing pathology reports, interacting with veterinary pathologists, and researching the mechanism of toxicity.
My background in human pathology from UMB helped me recognize the similarity of the melamine crystals to the uric acid crystals found in people with gout. That started my search through the literature. Eventually, I came up with the hypothesis linking the kidney failure seen in the dogs and cats to a mechanism of crystal-induced kidney failure seen in people.
8. You have become a world expert on melamine and melamine-related toxicity in animals. You have also received many awards and nominations related to your melamine research. Two recent examples include your “Best Paper” award and your nomination for a Service to America medal.
On November 18, 2009, you and your fellow colleagues at Procter and Gamble received the “Best Paper in Toxicological Sciences” award from the Board of Publications for the journal, Toxicological Sciences. The paper describes the steps involved in solving the melamine toxicity puzzle.2 Why do you think this paper is so important to toxicology?
The paper describes a study that Procter and Gamble conducted to conclusively prove that melamine was involved in forming the crystals seen in the kidneys of the sick dogs and cats. It’s important because it demonstrates a coming together of industry, academia, and government scientists during a crisis – working quietly but with open communication. The information shared by scientists in industry and academia with CVM, and CVM’s suggestions for the second part of Procter and Gamble’s study, were key to getting quick results and proving the hypothesis that it was melamine and cyanuric acid together creating the crystals, which caused the kidney failure seen in the pets.
9. Because of the prominent role you played in solving the melamine puzzle, and because of its significant animal and public health impact, in June 2009, the Partnership for Public Service nominated you for a Homeland Security Service to America Medal. According to the nomination criteria, nominees must “have demonstrated a significant accomplishment within his or her particular government field that was innovative and high impact, and met a critical need for the nation.”3 What were your thoughts upon receiving this nomination?
I was truly and deeply honored to even be considered for this award. To become a finalist was really – as my kids would say – AWESOME!
10. What public health issues are you currently working on? And, what issues would you like to study in the future?
Since 2007, I have continued to work on melamine-related issues, like determining the residue depletion of melamine in fish over time. We started that study because I was convinced that the pet food recall was just the tip of the iceberg – a needed wake-up call for FDA to watch for other economic fraud by companies or individuals using something cheaper instead of the ingredient the consumer expects to be in the food. Melamine had been intentionally added to poor quality wheat gluten to make it appear as if the pet food had a much higher protein content than it really did. I was worried that melamine contamination, or contamination with other triazines, would continue. If melamine or a similar triazine contaminant is found in animal feeds again, we need to know how long of a wash-out period is needed for the contaminant to drop to safe levels in the animal’s tissue. That way, we will know when it is safe for people to eat food made from animals that eat the contaminated feed.
Residue depletion is how long it takes for a substance to leave the body.Triazines are a class of compounds with a similar chemical shape. The class includes melamine and the herbicideatrazine.4
I also started a study to find out the lowest dose of the combined melamine-cyanuric acid that will cause crystals to form in fish kidneys. This information will help us adequately determine the health risks to people and animals if products are contaminated in the future.
On September 11, 2008, the media reported the widespread melamine contamination of infant formula in China. At that time, our fish studies on melamine residues took on added importance because we were the only folks who had these types of data, which were definitely needed for determining the human health risk. I participated in FDA’s melamine risk assessment process as well as in the December 2008 WHO expert meeting to review the toxicological aspects of melamine and cyanuric acid (http://www.who.int/foodsafety/fs_management/infosan_events/en/index.html).
I continue to work with NCTR and CFSAN scientists on melamine studies in mammals. So melamine has monopolized much of my research since 2007. Our aquaculture team, however, continues to conduct other non-melamine studies to support CVM’s animal and public health missions.
In the future, I am stepping into a new role to develop a program that will make communication between FDA and private and state veterinary diagnostic laboratories easier by coordinating facilities, equipment, and professional expertise. FDA’s new program will also work closely with FERN and its associated laboratories. With better coordination, we can respond more efficiently to feed contamination problems.
FERN stands for Food Emergency Response Network. The network integrates the nation's food-testing laboratories at local, state, and federal levels to respond to emergencies involving food contamination.
From dogs and cats to fish, Dr. Reimschuessel has led an interesting career. Stay tuned for more about her fascinating veterinary career at CVM!
2Dobson RLM, Motlagh S, Quijano M, et al. “Identification and Characterization of Toxicity of Contaminants in Pet Food Leading to an Outbreak of Renal Toxicity in Cats and Dogs.” 2008. Toxicological Sciences, 106: 251–262.