Dr. Cristin Kelley Publishes Research Recommending Sedation of Wild Birds in Decontamination Process

Non Sedated birds are struggling and fighting against handlers—kicking, flapping their wings, biting, vocalizing—this is all consistent with the birds being stressed during that experience. Wild birds are naturally and rightfully fearful of humans, and the wash process requires close human contact, which is very stressful for the birds.

Dr. Cristin Kelley

While washing contaminated birds as the veterinarian for an oiled wildlife response program, Dr. Cristin Kelley, V12, (she/her), began to question the long- held practice of not sedating birds during a process acutely stressful for the animals. Kelley, currently an assistant clinical professor in the Department of Infectious Disease & Global Health at Cummings School of Veterinary Medicine at Tufts University, spearheaded a research study to investigate the use of sedation during the decontamination process and see what effect, if any, sedation would have on survivability. Her recently published paper should instigate changes to the protocols for washing birds.

Her research paper, titled “Comparison of Manual Restraint With and Without Sedation on Outcomes for Wild Birds Undergoing Decontamination,” was published in the Journal of Avian Medicine and Surgery this past July.

With the support of fellow colleagues at two rehabilitation organizations in California and Delaware, Kelley launched the study. Together they collected highly detailed data while washing 89 birds of 25 different species over a 12- month time period. “We used all the birds we washed as data points during that year,” she says.

Kelley joined Cummings School faculty two years ago in Tufts Wildlife Clinic and draws on years of experience treating wild birds. Her interest in avian medicine was sparked on a field trip identifying birds in the wild for an ornithology class as an undergraduate at the University of Illinois at Urbana-Champaign, an experience she says set her on a new path. She spent the following summer as a field assistant for a study monitoring songbird nests to assess the impact of growing numbers of brown-headed cowbirds on songbird populations.  

After completing her Bachelor of Science degree in ecology, ethology, and evolution, Kelley worked as a veterinary technician over the next eight years at the Dane County Humane Society and later the International Crane Foundation in Wisconsin. She then earned her D.V.M. at Cummings School and completed a small animal rotating internship at Angell Animal Medical Center in Boston and a wildlife medicine internship at Tufts Wildlife Clinic, experiences that solidified her interest in wildlife medicine.

After Cummings School, Kelley came on as the staff veterinarian for both the wild bird rehabilitation program and the oiled wildlife response program at Tri-State Bird Rescue & Research in Newark, Delaware.

Over her eight years at Tri-State, Kelley observed how stressful the cleaning process was for birds. Though never formally studied, it’s long been thought that sedation would hinder survival rates. Veterinarians rarely used sedation during the wash process based on that belief.

“Non Sedated birds are struggling and fighting against handlers—kicking, flapping their wings, biting, vocalizing—this is all consistent with the birds being stressed during that experience,” says Kelley. “Wild birds are naturally and rightfully fearful of humans, and the wash process requires close human contact, which is very stressful for the birds.”

Specifically, sedation was considered a potential risk for hypothermia and thought to delay or reduce preening in the drying pen, which is important for a quick return to adequate waterproofing.

“We were not seeing that on the ground,” says Kelley. She explains that though the idea was widely accepted in the oiled wildlife response community that sedation during the wash process would be detrimental, no studies had been published on the topic. Counter to the accepted protocols, Kelley believed sedation would be in the birds’ best interest.

She connected with Dr. Rebecca Duerr, a veterinarian at the International Bird Rescue (IBR) in San Pedro, California.

“We were both washing a fair amount of birds, and both had this idea that there is value in sedation,” says Kelley. “We were not seeing negative side effects of sedation: reducing the amount of preening in the drying pen, reducing release rates, or causing hypothermia. We needed to do the study to see if sedation was actually causing a problem for these birds. She and I had the impetus to investigate further what our predecessors told us.”

Though Kelley has contributed to published research studies on whooping crane health parameters while at the International Crane Foundation, this would be her first study as the principal investigator. She began the study in 2020 and spent a year collecting data at Tri-State, and colleagues at both IBR rehabilitation centers. It was a large undertaking, particularly standardizing the data between the two organizations.

“We didn’t know what was going to be interesting, so we collected everything we could think of,” says Kelley. “If we didn’t collect cloacal temperature data, for example, we wouldn’t have seen hypothermia affecting survivability. It was quite a data- collection feat. The goal of the study was not to change anything about the wash process aside from sedation. The washes themselves were business as usual, both of the institutions were washing a lot of birds.”

The birds were selected randomly for sedation during the wash process—50 birds were sedated, and 39 were not sedated. They gathered data on cloacal temperatures, the length of the wash process, the birds’ preening in the drying pen, and the birds’ dispositions, among other factors.

The biggest takeaway from the study was that there was no significant difference in the survivability of sedated and non sedated birds during the wash process, fully supporting her theory.

“There was no difference in release rates, no difference in disposition, no effect on survivability of birds sedated and non sedated,” says Kelley. Though not the intent of the study, they did have an additional statistically significant finding. “There is a point in the drying process where the birds are more likely to become hypothermic for both sedated and non sedated birds, which did lead to decreased survivability. There was some idea previously that sedation led to hypothermia in the drying process, but that was not found to be the case.”

The second finding led the researchers to recommend monitoring cloacal temperature throughout the drying process. They also determined that the length of wash did not impact survival, which was notable but not surprising to the investigators.

Kelley expressed the significance of the findings regarding birds’ well-being. “Reducing stress for birds during the wash process by using sedation drugs is beneficial for their psychological and physical health. If it can be done safely, and the birds can still be moved through the rehabilitation process and released, that benefits them.”

Not long after wrapping up the data collection portion of the study, Kelley decided she’d like to return to an academic setting where she could teach students while continuing to treat patients.

“I loved Tufts Wildlife Clinic so much that I came back,” she says. “Tufts is unique in having a wildlife clinic with the facilities to house so many species of animals through the entire rehabilitation process. That’s not always the case in wildlife clinics at veterinary institutions. I like to follow cases through their entire process prior to release. I get to do that here at Tufts Wildlife Clinic.”

The research study was published this past summer in the Journal of Avian Medicine and Surgery, a publication that captures her target audience, as washing birds is a clinical practice. The journal is published by the Association of Avian Veterinarians and features stories and research about both captive and wild birds. The study was authored by Dr. Kelley, Dr. Duerr, Dr. Terra, R. Kelly, Kylie Clatterbuck, Michelle C. Knapp, and Julie Skoglund.

The paper hypothesizes that sedation would not negatively impact survival and concludes: “Historical concerns that sedation would decrease survival or decrease preening in the drying pen were not supported by this study. We found no statistical differences in sedated versus non sedated birds for any of the data points studied, including survival, disposition, lengths of various portions of the wash process, temperatures at various points, preening in the drying pen, or time between wash and release.”

The paper notes that the decontamination process is long, typically more than 40 minutes, and describes the birds’ experience: “During the wash process, the bird’s body is heavily manipulated, wings extended, and the entire body and inside of the mouth are touched. Wild birds are not acclimated to humans, manual restraint, or excessive noise; thus, they exhibit signs of stress, such as struggling to escape, aggression toward handlers, respiratory distress, and vocalizing during the wash.”

The paper cites several other studies on the effect of stress on birds and survival rates, noting that reducing stress in patients improves medical outcomes. When sedated, birds struggle less during the wash process when sedated. A few non sedated birds in the study were injured while struggling against their handlers during the wash process.

According to the paper, “Sedation is known to reduce anxiety, fear, and stress for avian patients and fits with current trends in veterinary medicine to improve animal welfare. That, combined with the possibility of increased handling trauma in struggling non sedated patients, and our findings of no significant differences between sedated and non sedated birds leads the authors to recommend sedation for birds undergoing the wash process.”

Before the study was published, Drs. Kelley and Duerr fielded many inquiries from the oiled wildlife response community that were interested in their findings. They are happy to direct them to their paper now.

Going forward, Dr. Kelley would like to see changes in how wild birds experience the decontamination process and ensure that guidelines for the wash process are updated to recommend sedation. She believes that further research should evaluate drug dosage protocols that are more specific to species.

“I use Sedation during the wash process. I believe sedation will become more accepted—I hope this paper will continue to cause people to think about using sedation during the wash process,” says Kelley. “Publishing this paper is the first step in starting to think about those large protocols set out for oiled wildlife rehabilitation organizations.”