Salter CE, O’Donnell K, Sutton DA, Marancik DP, Knowles S, Clauss TM, Berliner AL, Camus AC: Dermatitis and systemic mycosis in a group of lined seahorses Hippocampus erectus associated with a marine-adapted pathogen within the Fusarium solani species complex. Dis Aquat Org 101(1):23-31, 2012.
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
Date published: December 2, 2019
Status: Active 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.
Contacts: Susan Knowles
Date published: February 9, 2018
Status: Active Employment Opportunities
The USGS National Wildlife Health Center offers employment, externship, and volunteer opportunities in the field of wildlife health.
Contacts: Katie Richgels, Susan Knowles
Attribution: National Wildlife Health Center
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.
Year Published: 2021
Mussel mass mortality and the microbiome: Evidence for shifts in the bacterial microbiome of a declining freshwater bivalve
Freshwater mussels (Unionida) are suffering mass mortality events worldwide, but the causes remain enigmatic. Here, we describe an analysis of bacterial loads, community structure, and inferred metabolic pathways in the hemolymph of pheasantshells (Actinonaias pectorosa) from the Clinch River, USA, during a multi-year mass mortality event....
Richard, Jordan; Campbell, Lewis J.; Leis, Eric; Agbalog, Rose; Dunn, Christopher D.; Waller, Diane L.; Knowles, Susan; Putnam, Joel G.; Goldberg, TonyAttribution: Upper Midwest Environmental Sciences Center, Ecosystems
Year Published: 2021
Pathology of Lagovirus europaeus GI.2/RHDV2/b (rabbit hemorrhagic disease virus 2) in native North American lagomorphs
Rabbit hemorrhagic disease, a notifiable foreign animal disease in the US, was reported for the first time in wild native North American lagomorphs in April 2020 in the southwestern US. Affected species included the desert cottontail (Sylvilagus audubonii), mountain cottontail (Sylvilagus nuttallii), black-tailed jackrabbit (Lepus californicus),...
Lankton, Julia S.; Knowles, Susan; Keller, Saskia; Shearn-Bochsler, Valerie I.; Ip, Hon S.Attribution: National Wildlife Health Center, Ecosystems
Year Published: 2021
Domoic acid and saxitoxin in seabirds in the United States between 2007 and 2018
As harmful algal blooms (HABs) increase in magnitude and duration worldwide, they are becoming an expanding threat to marine wildlife. Over the past decade, blooms of algae that produce the neurotoxins domoic acid (DA) and saxitoxin (STX) and documented concurrent seabird mortality events have increased bicoastally in the United States. We...
Gibble, Corinne; Kudela, Raphael; Knowles, Susan; Bodenstein, Barbara; Lefebvre, KathiAttribution: National Wildlife Health Center, Ecosystems
Year Published: 2021
Investigation of algal toxins in a multispecies seabird die-off in the Bering and Chukchi seas
Between 2014 and 2017, widespread seabird mortality events were documented annually in the Bering and Chukchi seas, concurrent with dramatic reductions of sea ice, warmer than average ocean temperatures, and rapid shifts in marine ecosystems. Among other changes in the marine environment, harmful algal blooms (HABs) that produce the neurotoxins...
Van Hemert, Caroline R.; Dusek, Robert J.; Smith, Matthew M.; Kaler, Robert; Sheffield, Gay; Divine, Lauren M.; Kuletz, Kathy J.; Knowles, Susan; Lankton, Julia S.; Hardison, D. Ransom; Litaker, R. Wayne; Jones, Timothy; Burgess, Hillary K.; Parrish, Julia K.
Year Published: 2021
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.Attribution: National Wildlife Health Center, Ecosystems
Year Published: 2020
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, DarrellAttribution: National Wildlife Health Center, Ecosystems
Year Published: 2020
Mass 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, Tony
Year Published: 2020
Canine 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, SusanAttribution: National Wildlife Health Center, Ecosystems
Year Published: 2019
Leptospirosis 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.Attribution: National Wildlife Health Center, Ecosystems
Year Published: 2019
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.
Year Published: 2019
Pathology in practice: Knemidocoptiasis in a pine grosbeak (Pinicola enucleator)
No abstract available.
Knowles, Susan; Swan, Jennifer L.; Roderick, Constance; Cole, Rebecca A.
Year Published: 2019
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.Pre-USGS Publications
Page-Karjian A, Knowles S, Howerth E, Berliner A, Clauss T, Hyatt M, Camus A: Pathology in practice. J Am Vet Med Assoc 241(9):1159-1161, 2012.
Knowles S, Blas-Machado U, Butler AM, Gomez-Ibañez SE, Lowder MQ, Fayrer-Hosken RA: Ameloblastic fibro-odontoma associated with a retained molar in an Oldenburg mare. J Vet Diagn Invest 22:987-990, 2010.
Knowles S, Uhl EW, Blas-Machado U, Butler AM: Intrapericardial ectopic thyroid carcinoma in a cat. J Vet Diagn Invest 22:1010-1013, 2010.
Brown YK, Knowles S, Fiorello CV, Camus MS, Howerth EW: Pathology in practice. Morphologic diagnosis: Uterine adenocarcinoma with metastasis to the lungs, diaphragm, spleen, mesentery, and cecum. J Am Vet Med Assoc 237:1257-1259, 2010.
Knowles S, Hrubec TC, Smith SA, Bakal RS: Hematology and plasma chemistry reference intervals for cultured shortnose sturgeon (Acipenser brevirostrum). Vet Clin Pathol 35:434-440, 2006.
Blanchard TW, Santiago NT, Lipscomb TP, Garber RL, McFee WE, Knowles S: Two novel alphaherpesviruses associated with fatal disseminated infections in Atlantic bottlenose dolphins. J Wild Dis 37:297-305, 2001.
Marine sea turtle strandings in Maryland, 1991 to 1995
Evans JJ, Norden A, Cresswell F, Insley K, and Knowles S: Marine sea turtle strandings in Maryland, 1991 to 1995. The Maryland Naturalist 41:23-34, 1997.
Date published: October 1, 2021
Pathology Case of the Month - Red Crossbills and American Goldfinches
Case History: In July, approximately 45 red crossbills (Loxia curvirostra) and American goldfinches (Spinus tristis) exhibited lethargy and were later found dead around bird feeders at several houses in a neighborhood in Montana, U.S.A.
Attribution: National Wildlife Health Center
Date published: June 1, 2021
Pathology Case of the Month - Raccoon
Case History: An adult male 4.04-kg raccoon (Procyon lotor) was found dead near a campground in Arizona, US. Three raccoons and a gray fox (Urocyon cinereoargenteus) were observed panting, staggering with glazed eyes, seizing and exhibiting no fear of humans.
Attribution: National Wildlife Health Center
Date published: March 1, 2021
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.
Attribution: National Wildlife Health Center
Date published: November 1, 2020
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...
Attribution: National Wildlife Health Center
Date published: October 1, 2020
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.
Attribution: National Wildlife Health Center
Date published: April 30, 2020
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.
Attribution: National Wildlife Health Center
Date published: March 31, 2020
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.
Attribution: National Wildlife Health Center
Date published: August 30, 2019
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...
Attribution: National Wildlife Health Center
Date published: July 29, 2019
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.
Attribution: National Wildlife Health Center