Susan Knowles
Biography
Susan Knowles is a Wildlife Veterinary Pathologist at the National Wildlife Health Center. She earned a Doctorate of Veterinary Medicine from the Virginia-Maryland Regional College of Veterinary Medicine and completed a residency in veterinary pathology and earned a Doctorate in Veterinary Pathology from the University of Georgia. She is a Diplomate of the American College of Veterinary Pathologists. She joined the Center in 2013 and her interests include wildlife, aquatic, invertebrate and toxicologic pathology, and pathogen discovery. Before joining the Center, she gained a variety of experience in and around her native Maryland, performing research on shortnose sturgeon, serving as a Veterinary Officer in the United States Public Health Service stationed at the National Institutes of Health, and working as a Natural Resources Biologist for the Maryland Department of Natural Resources where she was a member of the Fish and Wildlife Health Program and served as the Marine Mammal and Sea Turtle Stranding Coordinator for the state.
Education
- Ph.D. Veterinary Pathology, University of Georgia, 2013
- D.V.M., Virginia-Maryland Regional College of Veterinary Medicine, 2006
- B.S. Biology, Bucknell University, 1995
Professional Experience
- 2013 – Present Wildlife Veterinary Pathologist, U.S. Geological Survey, National Wildlife Health Center, Madison, WI
- 2006 – 2013 Resident of Anatomic and Aquatic Pathology and Graduate Assistant, Department of Veterinary Pathology, University of Georgia, Athens, GA
- 2003 – 2003 Veterinary Officer, Junior COSTEP, United States Public Health Service, Rockville, MD stationed at NIH, Diagnostic and Research Services Branch, Veterinary Pathology, Bethesda, MD
- 1996 – 2002 Natural Resources Biologist, Maryland Marine Mammal & Sea Turtle Stranding Coordinator, Fish and Wildlife Health Program, Maryland Department of Natural Resources, Cooperative Oxford Laboratory, Oxford, MD
- 1995 – 1996 Histology Technician, Maryland Department of Natural Resources, Cooperative Oxford Laboratory, Oxford, MD
Affiliations
Diplomate American College of Veterinary Pathologists
Science and Products
Native Freshwater Mussel Health
Native freshwater mussels are a keystone species and are considered both ecosystem engineers, improving habitat for other species, and indicator species important in assessing the health of the ecosystem.
Employment Opportunities
The USGS National Wildlife Health Center offers employment, externship, and volunteer opportunities in the field of wildlife health.
Necropsy & Pathology
The Necropsy and Pathology services are performed by board-certified veterinary pathologists and necropsy technical staff whose principal role is to determine the cause of death for animals submitted to the USGS National Wildlife Health Center.
Experimental challenge of a North American bat species, big brown bat (Eptesicus fuscus), with SARS-CoV-2
The recently emerged novel coronavirus, SARS‐CoV‐2, is phylogenetically related to bat coronaviruses (CoVs), specifically SARS‐related CoVs from the Eurasian bat family Rhinolophidae. As this human pandemic virus has spread across the world, the potential impacts of SARS‐CoV‐2 on native North American bat populations are unknown, as is the ability...
Hall, Jeffrey S.; Knowles, Susan; Nashold, Sean; Ip, Hon S.; Leon, Ariel Elizabeth; Rocke, Tonie E.; Keller, Saskia Annatina; Carossino, Mariano; Balasuriya, Udeni B.R.; Hofmeister, Erik K.Environmental contamination and unusual snake mortality in an urban national wildlife refuge
The National Wildlife Refuge (NWR) System protects ~150 million acres of land and water in the United States and provides habitat for >2,000 native vertebrates species. Although legally protected, wildlife populations within these refuges can be threatened by anthropogenic activities. The lack of knowledge about such threats has the potential...
Terrell, Kimberly A.; Ballmann, Anne; Brown, Ashli; Childers, Christina; Knowles, Susan; Meredith, Ashley; Sparks, DarrellMass mortality in freshwater mussels (Actinonaias pectorosa) in the Clinch River, USA, linked to a novel densovirus
Freshwater mussels (order Unionida) are among the world’s most biodiverse but imperiled taxa. Recent unionid mass mortality events around the world threaten ecosystem services such as water filtration, nutrient cycling, habitat stabilization, and food web enhancement, but causes have remained elusive. To examine potential infectious causes of...
Richard, Jordon; Leis, Eric; Dunn, Christopher D.; Agbalog, Rose; Waller, Diane L.; Knowles, Susan; Putnam, Joel G.; Goldberg, TonyCanine distemper virus in the sea otter population (Enhydra lutris) in Washington State, USA
Before 2001, all serosurveys for morbilliviruses in sea otters (Enhydra lutris) in California, Washington, and Alaska, USA, documented a 0% seroprevalence. The first published serologic detections of morbillivirus in sea otters occurred in 2001–02 in live-captured Washington sea otters, with a documented 80% seroprevalence. We conducted a...
Thomas, Nancy; White, C. LeAnn; Saliki, Jeremiah; Schuler, Krysten L.; Lynch, Deanna; Nielsen, Ole; Dubey, J.P.; Knowles, SusanLeptospirosis in Northern Sea Otters (Enhydra lutris kenyoni) from Washington
We diagnosed leptospirosis in six northern sea otters (Enhydra lutris kenyoni) that stranded on beaches in Washington, US in 2002. Significant gross findings included cyanotic oral mucous membranes, renal swelling, congestion or pale streaks on the cut surface of the lobules, hematuria, dehydration, lymphadenopathy, pulmonary congestion and rarely...
Knowles, Susan; Lynch, Deanna; Thomas, Nancy J.Mortality of Tufted puffins (Fratercula cirrhata) and other alcids during an unusual mortality event in the eastern Bering Sea
Mass mortality events are increasing in frequency and magnitude, potentially linked with ongoing climate change. In October 2016 through January 2017, St. Paul Island situated at the shelf-edge of the Bering Sea, Alaska, experienced a mortality event of alcids (family: Alcidae), with over 350 carcasses recovered. Almost three-quarters of the...
Jones, Timothy; Divine, Laura M.; Renner, Heather; Knowles, Susan; Lefebvre, Kathi A.; Burgess, Hillary K.; Wright, Charlie; Parrish, Julia K.Pathology in practice: Knemidocoptiasis in a pine grosbeak (Pinicola enucleator)
No abstract available.
Knowles, Susan; Swan, Jennifer L.; Roderick, Constance; Cole, Rebecca A.Detection of Bisgaard taxon 40 in Rhinoceros Auklets (Cerorhinca monocerata) with pneumonia and septicemia from a mortality event in Washington, USA
We isolated Bisgaard taxon 40 from Rhinoceros Auklets (Cerorhinca monocerata) with pneumonia and septicemia from Washington, US, found dead in 2016. Previously isolated only from the respiratory tract of a gull (Laridae), little is known about its pathogenic potential and whether it acts as a primary or opportunistic pathogen.
Knowles, Susan; Bodenstein, Barbara; Berlowski-Zier, Brenda M.; Thomas, Susan M; Pearson, Scott F; Lorch, Jeffrey M.Lethal infection of wild raptors with highly pathogenic avian influenza H5N8 and H5N2 viruses in the USA, 2014–15
An outbreak of highly pathogenic avian influenza (HPAI) led to heavy losses of poultry in commercial farms in North America in 2014–15. Enhanced surveillance by virologists and pathologists at the US Geological Survey National Wildlife Health Center and its partners resulted in the identification of lethal infections with clade 2.3.4.4 subgroup...
Knowles, Susan; Shearn-Bochsler, Valerie I.; Ip, Hon S.Building a response network to investigate potential pathogens associated with unionid mortality events
Unexplained mortality events have confounded the mussel conservation community for over 30 years. While the effects of chemical pollutants and environmental factors have been examined, few investigations have focused on the identification of potential mussel pathogens. Consequently, very little is known regarding the impact that pathogens have on...
Leis, Eric; Waller, Diane L.; Knowles, Susan; Goldberg, Tony; Putnam, Joel G.; Richard, Jordan; Erickson, Sarah; Blevins, Emilie; Weinzinger, JesseAn update on Toxoplasma gondii infections in northern sea otters (Enhydra lutris kenyoni) from Washington State, USA
Toxoplasmosis in marine mammals is epidemiologically and clinically important. Toxoplasma gondii antibodies (by modified agglutination test, cut-off ≥1:25) were detected in serum of 65 of 70 (92.9%) northern sea otters (Enhydra lutris kenyoni) from Washington State, USA. Brains and/or muscles of 44 sea otters were bioassayed in mice (INF-γ knock-...
Verma, Shiv K.; Knowles, Susan; Cerqueira-Cezar, Camila K.; Kwok, Oliver C.; Jiang, Tiantian; Su, Chunlei; Dubey, Jitender P.Chlamydia psittaci in feral Rosy-faced Lovebirds (Agapornis roseicollis) and other backyard birds in Maricopa County, Arizona
In 2013, a mortality event of nonnative, feral Rosy-faced Lovebirds (Agapornis roseicollis) in residential backyards in Maricopa County, Arizona, US was attributed to infection with Chlamydia psittaci. In June 2014, additional mortality occurred in the same region. Accordingly, in August 2014 we sampled live lovebirds and sympatric bird...
Dusek, Robert J.; Justice-Allen, Anne; Bodenstein, Barbara; Knowles, Susan; Grear, Daniel A.; Adams, Laura; Levy, Craig; Yaglom, Haley D.; Shearn-Bochsler, Valerie I.; Ciembor, Paula; Gregory, Christopher R.; Pesti, Denise; Ritchie, Branson W.Pre-USGS Publications
Pathology Case of the Month - Big Brown Bat
Case History: An adult male big brown bat (Eptesicus fuscus) from Wisconsin, USA was submitted for necropsy. There were no reported clinical signs.
Pathology Case of the Month - Northern Pintail Duck
Case History: An adult male Northern Pintail Duck (Anas acuta) was found dead on a refuge in Arizona, US. Collectively at this location, 29 birds including Snow Geese (Chen caerulescens), Canada Geese (Branta canadensis), Mallard Ducks (Anas platyrhynchos), and Northern Pintail Ducks (Anas acuta) were found dead with no reported...
Pathology case of the month - Mountain Cottontail
Case History: In June 2020, one adult female, 950-g, mountain cottontail rabbit (Sylvilagus nuttallii) with bloody nasal discharge was found dead by a private landowner in Montana, U.S.A. and submitted frozen for cause of death determination. Two juvenile rabbits were found dead in proximity.
Pathology Case of the Month - Canada Goose and Bald Eagles
May's Pathology Case of the Month details the cases of a Canada Goose and two Bald Eagles.
Pathology Case of Month - Zebra Finch
Case History: An adult female 9.95-g Zebra Finch (Taeniopygia guttata) from a California aviary was found dead. It was noted to be thin several days prior to its death.
Pathology Case of the Month - Mourning Dove
Case History: An immature female 122-g Mourning Dove (Zenaida macroura) was found dead in a park in Arizona, US. An estimated 18 birds including Inca Doves (Columbina inca), Great-tailed Grackles (Quiscalus mexicanus), and Mourning Doves were found dead with no reported clinical signs. Zinc phosphide was applied to ground squirrel burrows the day...
Pathology Case of the Month - Ross's Goose
Case History: An adult male 1545-g Ross’s Goose (Chen rossii) was found dead on a refuge in Kansas, US. Collectively at this location, over 300 birds including Snow Geese (Chen caerulescens), Canada Geese (Branta canadensis) and Mallard Ducks (Anas platyrhynchos) were found dead with no reported clinical signs.