Ian K Barker

Ian K Barker
University of Guelph | UOGuelph · Department of Pathobiology

DVM MSc (Guelph) PhD (Melb)

About

184
Publications
42,783
Reads
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6,823
Citations
Citations since 2016
4 Research Items
2191 Citations
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20162017201820192020202120220100200300
20162017201820192020202120220100200300
Additional affiliations
July 1993 - August 2010
Ontario Veterinary College, University of Guelph
Position
  • Professor
Description
  • Research, diagnostic work, and DVM and Graduate teaching in Veterinary Anatomic Pathology, Comparative Pathology, Wildlife Diseases/Zoonoses, Zoological Medicine
September 1992 - January 2012
Ontario Veterinary College, University of Guelph
Position
  • Director
Description
  • Ontario/Nunavut Region, Canadian Cooperative Wildlife Health Centre: Directed wildlife disease surveillance activity; liaised with provincial and federal government agencies with respect to prevention, detection, and management of wildlife diseases, including those shared with domestic animals, and wildlife zoonoses.
January 1988 - February 1988
Institute of Medical and Veterinary Science
Position
  • Honourary Associate
Description
  • Study Leave
Education
September 1970 - December 1974
Faculty of Veterinary Science, University of Melbourne
Field of study
  • Veterinary Parasitology
June 1968 - June 1970
Ontario Veterinary College, University of Guelph
Field of study
  • Veterinary Parasitology
September 1963 - May 1968
Ontario Veterinary College, University of Guelph
Field of study
  • Veterinary Medicine

Publications

Publications (184)
Article
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The combination of fentanyl and midazolam is commonly used as a sedative in humans. The objective of this study was to evaluate the sedative properties and physiological effects of fentanyl-midazolam and fentanyl-midazolam-ketamine compared with medetomidine-ketamine given intramuscularly in Japanese macaques ( Macaca fuscata). In a randomized cros...
Article
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Surveillance of West Nile virus (WNv) in Ontario has included passive reporting of human cases and testing of trapped mosquitoes and dead birds found by the public. The dead bird surveillance programme was limited to testing within a public health unit (PHU) until a small number of birds test positive. These dead corvid and mosquito surveillance pr...
Article
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In 2001–2002, Great Black-backed Gull (Larus marinus) eggs from Lake Ontario had significantly higher concentrations of organochlorine contaminants than Herring Gull (L. argentatus) eggs. This study investigated whether higher contaminants in Great Black-backed Gulls affected immunocompetence, packed cell volume (PCV) and body condition in chicks,...
Article
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Blacklegged ticks (Ixodes scapularis) are vectors for several important human diseases, including Lyme disease, human granulocytic anaplasmosis (HGA), and human babesiosis, caused by Borrelia burgdorferi, Anaplasma phagocytophilum, and Babesia microti, respectively. The continued northward range expansion of blacklegged ticks and associated pathoge...
Article
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Background: Many species of frogs secrete cutaneous antimicrobial peptides that are capable of killing Batrachochytrium dendrobatidis. Some of these species are nonetheless susceptible to chytridiomycosis, suggesting that host factors causing dysregulation of this innate immune response may be important in pathogenesis. Since stresses, such as fro...
Article
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Background The Loggerhead Shrike, Eastern subspecies (Lanius ludovicianus ssp.) (LOSH) is a predatory songbird native to Eastern North America. It is estimated that there are fewer than 55 breeding pairs of this subspecies in North America. Captive breeding plays a critical role in preventing the extirpation of this subspecies from its Canadian ran...
Article
The captive breeding program for the endangered Puerto Rican crested toad (Peltophryne [Bufo] lemur) has been hampered by an undiagnosed condition called “Brown Skin Disease” (BSD). Toads develop widespread skin darkening, skin thickening and abnormal shedding and eventually succumb to a chronic loss of viability. This project evaluated the marine...
Article
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The endangered Puerto Rican crested toad (Peltophryne [Bufo] lemur) has been held and bred in zoos for release into protected areas in Puerto Rico since 1982. In 2004, several cases of a novel syndrome of skin changes in toads were noticed at the Toronto Zoo. A total of 21 toads were found to have similar lesions and the condition has been seen in...
Article
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In the Thousand Islands region of eastern Ontario, Canada, Lyme disease is emerging as a serious health risk. The factors that influence Lyme disease risk, as measured by the number of blacklegged tick (Ixodes scapularis) vectors infected with Borrelia burgdorferi, are complex and vary across eastern North America. Despite study sites in the Thousa...
Article
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Errors in citations and notes were introduced by the editors
Article
An adult dog that lived in central British Columbia was examined because of a history of lethargy and vomiting. Histology, immunohistochemistry, and polymerase chain reaction (PCR) examination of a hepatic mass confirmed the presence of an alveolar hydatid cyst, the first description of Echinococcus multilocularis in British Columbia. We provide re...
Conference Paper
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Conference Paper
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Conference Paper
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Article
McLelland, D.J., Barker, I.K., Crawshaw, G., Hinds, L.A., Spilsbury, L., Johnson, R. Single-dose pharmacokinetics of oxytetracycline and penicillin G in tammar wallabies (Macropus eugenii). J. vet. Pharmacol. Therap. 34, 160–167. The pharmacokinetics of oxytetracycline and penicillin G was investigated in tammar wallabies (Macropus eugenii). Groups...
Article
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To assess the impacts of different types of human activity on the development of resistant bacteria in the feces of wild small mammals, we compared the prevalences and patterns of antimicrobial resistance and resistance genes in generic Escherichia coli and Salmonella enterica isolates from fecal samples collected from wild small mammals living in...
Article
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Avian influenza virus (AIV) was studied in ring-billed gulls (Larus delawarensis) in one breeding colony on Lake Erie in 2000, and two on Lake Ontario in both 2000 and 2004. Antibodies to H13 AIV were detected in 92% of adults in 2000 and 82% in 2004. Antibody prevalence in 3-wk-old chicks was 5%-30% (overall 15%) in 2000 and 21% and 76% (overall 4...
Article
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A polar bear (Ursus maritimus) housed at the Toronto Zoo presented with acute-onset, nonambulatory paraparesis. Physical examination 24 hr after onset was otherwise unremarkable, spinal radiographs looked normal, and blood tests indicated mild dehydration. With continued deterioration in its general condition, euthanasia was elected a day later. Ne...
Article
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A sarcomatoid carcinoma was diagnosed in the lung of a 10-year-old captive Egyptian fruit bat (Rousettus aegyptiacus). Both carcinomatous and sarcomatous cytologic phenotypes were identified histologically. Cells of both types stained positive for pancytokeratin and S-100. Stromal cells stained positively for muscle actin. No staining for vimentin...
Article
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Background Lyme disease is the commonest vector-borne zoonosis in the temperate world, and an emerging infectious disease in Canada due to expansion of the geographic range of the tick vector Ixodes scapularis. Studies suggest that climate change will accelerate Lyme disease emergence by enhancing climatic suitability for I. scapularis. Risk maps w...
Article
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During the spring in 2005 and 2006, 39,095 northward-migrating land birds were captured at 12 bird observatories in eastern Canada to investigate the role of migratory birds in northward range expansion of Lyme borreliosis, human granulocytic anaplasmosis, and their tick vector, Ixodes scapularis. The prevalence of birds carrying I. scapularis tick...
Article
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Deferiprone is a bidentate oral iron chelator used for the treatment of iron overload in people. The purpose of this study was to determine the pharmacokinetic disposition of deferiprone in the domestic pigeon (Columba livia) and to compare the results with a previous study in the white leghorn chicken. Deferiprone (DFP) was administered orally as...
Article
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Deferiprone is a bidentate oral iron chelator used for the treatment of transfusional iron overload in people. The purpose of this study was to determine the pharmacokinetic disposition of deferiprone in the white leghorn chicken as a potential model upon which to base therapeutic regimens for the treatment of iron storage disease (hemochromatosis)...
Article
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Fitness of tick-borne pathogens may be determined by the degree to which their infection dynamics in vertebrate hosts permits transmission cycles if infective and uninfected tick stages are active at different times of the year. To investigate this hypothesis we developed a simulation model that integrates the transmission pattern imposed by season...
Article
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The West Nile virus (WNv) became a veterinary public health concern in southern Ontario in 2001 and has continued to threaten public health. Wild bird mortality has been shown to be an indicator for tracking the geographic distribution of the WNv. The purpose of this study was to investigate the latent risk distribution of WNv disease among dead bi...
Article
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The occurrence of chronic wasting disease (CWD) at the Toronto Zoo was investigated retrospectively, based on an examination of management, animal health, and postmortem records, and immunohistochemical studies. Records of animal movements, clinical signs, and postmortem findings were examined for all cervids 1973-2003. All available samples of fix...
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Since 1999, large-scale mortalities of fish-eating birds have been observed on the Great Lakes, and more specifically on Lake Erie. Type E botulism has been established as the primary cause of death. The mechanism of type E botulism exposure in fish-eating birds is unclear. Given that these birds are thought to eat live fish exclusively, it seems l...
Article
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In a 4-mo study (June 2004-September 2004), round gobies (Neogobius melanostomas) were dosed orally every 72 hr for up to 21 days with Clostridium botulinum neurotoxin type E (BoNT/E) at one of four doses: 0, 50, 250, and 500 mouse lethal doses (MLD). Fish were observed for changes in pigmentation and behavior for the duration of the experiment. Mo...
Article
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Passive surveillance for the occurrence of the tick Ixodes scapularis Say (1821) and their infection with the Lyme borreliosis spirochaetes Borrelia burgdorferi s.l. has taken place in Canada since early 1990. Ticks have been submitted from members of the public, veterinarians, and medical practitioners to provincial, federal, and university labora...
Article
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Rainbow trout (Oncorhynchus mykiss), round gobies (Neogobius melanostomas), yellow walleye (Stizostedion vitreum), and yellow perch (Perca flavescens) were given Clostridium botulinum neurotoxin type E (BoNT/E) at four doses (0, 800, 1500, and 4000 mouse lethal doses). BoNT/E was sought in the fish tissues at death or at the conclusion of the exper...
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Thirty-eight cases of renal tubular cell neoplasms were diagnosed in 184 captive, adult (>1-year-old), black-footed ferrets (Mustela nigripes) examined from 1985 to 1996. This prevalence (20.7%) is one of the highest reported for this neoplasm in a population of animals. These tumors rarely metastasized (1/38), and usually were incidental postmorte...
Article
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In southeastern Canada, most populations of Ixodes scapularis Say, the Lyme disease vector, occur in Carolinian forests. Climate change projections suggest a northward range expansion of I. scapularis this century, but it is unclear whether more northerly habitats are suitable for I. scapularis survival. In this study, we assessed the suitability o...
Article
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This study describes the macroscopic and microscopic lesions and the viral antigen distribution in 82 owls (Family: Strigidae) of 11 North American and one Eurasian species that died following natural West Nile virus infection. The range of lesions seen was greater than that previously reported for owls, and involved more organs. Two patterns of an...
Article
We used an Ixodes scapularis population model to investigate potential northward spread of the tick associated with climate change. Annual degree-days >0 °C limits for I. scapularis establishment, obtained from tick population model simulations, were mapped using temperatures projected for the 2020s, 2050s and 2080s by two Global Climate Models (th...
Article
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Partial sequences of a novel papillomavirus were amplified from a cutaneous lesion biopsy of a raccoon (Procyon lotor), by using PCR with degenerate papillomavirus-specific primers. The Procyon lotor papillomavirus type 1 (PlPV-1) DNA was amplified with long template PCR in two overlapping fragments, together encompassing the entire genome, and the...
Article
A dynamic population model of Ixodes scapularis, the vector of a number of tick-borne zoonoses in North America, was developed to simulate effects of temperature on tick survival and seasonality. Tick development rates were modelled as temperature-dependent time delays, calculated using mean monthly normal temperature data from specific meteorologi...
Article
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From July to September 2002, an outbreak of West Nile virus (WNV) caused a high number of deaths in captive owls at the Owl Foundation, Vineland, Ontario, Canada. Peak death rates occurred in mid-August, and the epidemiologic curve resembled that of corvids in the surrounding Niagara region. The outbreak occurred in the midst of a louse fly (Icosta...
Article
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We evaluated a rapid antigen-capture assay (VecTest) for detection of West Nile virus in oropharyngeal and cloacal swabs, collected at necropsy from owls (N = 93) and raptors (N = 27). Sensitivity was 93.5%-95.2% for northern owl species but <42.9% for all other species. Specificity was 100% for owls and 85.7% for raptors.
Article
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An outbreak of West Nile virus (WNV) infection occurred at a captive breeding facility for the endangered eastern loggerhead shrike (Lanius ludovicianus migrans) in August 2002. Within 10 d, five birds died; two were found dead, and the others died shortly after showing neurologic signs. West Nile virus was detected in all organs examined using imm...
Article
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Relationships between temperature and preoviposition, preeclosion, and premolt developmental periods for the tick Ixodes scapularis Say were investigated by holding field-collected ticks in the laboratory at temperatures of 0 to 32 degrees C at constant daylength. The duration of these developmental periods decreased significantly with increasing t...
Article
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An aged Barbary ape (Macaca sylvanus) at the Toronto Zoo became infected with naturally acquired West Nile virus encephalitis that caused neurologic signs, which, associated with other medical problems, led to euthanasia. The diagnosis was based on immunohistochemical assay of brain lesions, reverse transcriptase-polymerase chain reaction, and viru...
Article
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The clinical use of oral Fe chelators for the treatment of Fe-storage disease in birds requires evaluation. In this study, the efficacy of the Fe chelator deferiprone in reducing hepatic Fe stores, its effects on hematologic, biochemical, and plasma Fe parameters, and its potential toxicity during a 30-day treatment period were investigated in a co...
Article
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The utility of the VecTest antigen-capture assay to detect West Nile virus (WNV) in field-collected dead corvids was evaluated in Manitoba and Ontario, Canada, in 2001 and 2002. Swabs were taken from the oropharynx, cloaca, or both of 109 American Crows, 31 Blue Jays, 6 Common Ravens, and 4 Black-billed Magpies from Manitoba, and 255 American Crows...
Article
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A surveillance program has been in place since 2000 to detect the presence of West Nile virus (WNV) in Canada. Serological assays are most appropriate when monitoring for human disease and undertaking case investigations. Genomic amplification procedures are more commonly used for testing animal and mosquito specimens collected as part of ongoing s...
Article
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The epidemiology of neoplastic disease was studied retrospectively in the captive population of black-footed ferrets (Mustela nigripes). Postmortem reports were reviewed and archived tissues examined from 184 of the 227 adult (>1 yr old) black-footed ferrets that died from the beginning of the current captive propagation program in late 1985 to the...
Article
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A juvenile woodchuck (Marmota monax) with vestibular signs was found in Woodbridge, Ontario (Canada) and later euthanized. At necropsy there was marked distortion of the right side of the skull, where a large, fluctuant, subcutaneous mass extended under the zygomatic arch and caudally from the right eye towards the right ear. The mass was multilocu...
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The uterine tubes from 405 ewes, collected at an abattoir, were assessed grossly and microscopically for abnormalities that correlated with serological evidence of exposure to Chlamydophila abortus. Gross lesions were found in 41 ewes and 86 had microscopic lesions. Enzyme immunoassay (EIA) of serum was used as an indication of exposure of individu...
Article
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The safety and efficacy of a remotely delivered multivalent Pasteurella haemolytica supernatant vaccine (serotypes A2 and T10) were examined in captive Rocky, Mountain bighorn sheep (Ovis canadensis canadensis). Twenty bighorn sheep were grouped according to baseline leukotoxin neutralizing antibody titers (< or =2 or >2 log2(-1)) and vaccination h...
Article
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Eight 8-wk-old raccoon pups (Procyon lotor) with maternal canine distemper virus (CDV) neutralizing antibodies (NAb) and 24 8-wk-old seronegative pups were administered a commercial modified-live CDV vaccine (Galaxy, D, Solvay Animal Health, Inc., Kitchener, Ontario, Canada). All 24 seronegative raccoons had detectable serum CDV NAb titers 14 days...
Article
Ixodes scapularis Say populations were evaluated within 4 habitats on Long Point, Ontario, from 1990 to 1992 to ascertain whether differences in density of mouse populations within and among habitats were correlated with that of immature I. scapularis populations. I. scapularis immatures were rarely collected by dragging within the cottonwood dune...
Article
The impact of microclimate and density of hosts for adult ticks on the density of Ixodes scapularis Say was evaluated within 4 habitats on Long Point, Ontario, from 1989-1992. During the period from May to September, mean weekly vapor pressure deficits were greater within the oak savannah and cottonwood dune habitats than at the maple forest and wh...