Additional diagnoses of Echinococcus multilocularis in eastern chipmunks (Tamias striatus) from southern Ontario - results from ongoing surveillance for E. multilocularis in intermediate hosts in Ontario, Canada.

Echinococcus multilocularis, a cestode with zoonotic potential, is now known to have a high prevalence in wild canid definitive hosts of southern Ontario. The distribution of E. multilocularis across this region in red foxes (Vulpes vulpes) and coyotes (Canis latrans) is widespread yet heterogenous. In contrast, confirmed diagnoses of E. multilocularis in wild free-ranging intermediate hosts within Ontario are currently limited to a single eastern chipmunk (Tamias striatus). These findings prompted ongoing surveillance efforts in intermediate host species, primarily rodents. Our report describes the results of passive surveillance through wildlife carcass submissions to the Canadian Wildlife Health Cooperative (CWHC) and targeted active sampling of small mammal species from 2018 to 2023; a second and third eastern chipmunk were found to be infected with E. multilocularis. However, these were the only occurrences from surveillance efforts which collectively totaled 510 rodents and other small mammals. Continued surveillance for E. multilocularis in intermediate hosts is of high importance in light of the recent emergence of this parasite in Ontario.

Local outbreak of spontaneous pneumothorax secondary to paragonimosis in southwestern Ontario dogs.

Three dogs were diagnosed with spontaneous pneumothorax and referred to the Ontario Veterinary College Health Sciences Centre for management. The 3 dogs were diagnosed with secondary spontaneous pneumothorax due to paragonimosis. The diagnosis was made by visualization of adult trematodes during surgical exploration with histopathological confirmation in 1 dog, and detection of trematode eggs via fecal sedimentation in the other 2 dogs. Two of the dogs developed unusual additional lesions, including hemoabdomen, muscle abscess, and abdominal adhesions. These were suspected to be secondary to aberrant fluke larval migration. All 3 dogs lived within a relatively small geographical area of Ontario and were hospitalized between December 2021 and March 2022. Each dog survived to discharge with surgical or medical management of the pneumothorax and treatment with a prolonged course of fenbendazole. Key clinical message: Paragonimosis should be considered as a differential diagnosis for canine spontaneous pneumothorax in areas where Paragonimus kellicotti is, or may be, endemic, or in dogs that have travelled to endemic areas - particularly if the patient has a history of cough or potential exposure to freshwater crayfish. Routine anthelmintic treatment does not prevent infection and standard fecal floatation methods may not detect the eggs. Therefore, diagnostic testing should include a fecal sedimentation test and thoracic radiographs to screen for P. kellicotti.

Éclosion locale de pneumothorax spontané secondaire à la paragonimose chez des chiens du sud-ouest de l'Ontario. Trois chiens ont reçu un diagnostic de pneumothorax spontané et ont été référés au Ontario Veterinary College Health Sciences Centre pour prise en charge. Les 3 chiens ont été diagnostiqués avec un pneumothorax spontané secondaire dû à la paragonimose. Le diagnostic a été posé par la visualisation des trématodes adultes lors de l'exploration chirurgicale avec confirmation histopathologique chez 1 chien, et la détection des oeufs de trématodes par sédimentation fécale chez les 2 autres chiens. Deux des chiens ont développé des lésions supplémentaires inhabituelles, notamment un hémoabdomen, un abcès musculaire et des adhérences abdominales. Ces lésions étaient soupçonnées d'être secondaires à une migration larvaire aberrante de la douve. Les 3 chiens vivaient dans une zone géographique relativement restreinte de l'Ontario et ont été hospitalisés entre décembre 2021 et mars 2022. Chaque chien a survécu jusqu'à sa sortie avec une prise en charge chirurgicale ou médicale du pneumothorax et un traitement avec un traitement prolongé au fenbendazole.Message clinique clé :La paragonimose doit être considérée comme un diagnostic différentiel du pneumothorax spontané canin dans les zones où Paragonimus kellicotti est, ou peut être, endémique, ou chez les chiens qui ont voyagé dans des zones endémiques ­ en particulier si le patient a des antécédents de toux ou une exposition potentielle aux écrevisses d'eau douce. Le traitement vermifuge de routine n'empêche pas l'infection et les méthodes de flottaison fécale standard peuvent ne pas détecter les oeufs. Par conséquent, les tests de diagnostic doivent inclure un test de sédimentation fécale et des radiographies thoraciques pour dépister P. kellicotti.(Traduit par Dr Serge Messier).

Novel molecular diagnostic (PCR) diagnosis and outcome of intestinal Echinococcus multilocularis in a dog from western Canada.

OBJECTIVE: To describe the novel PCR diagnosis and outcome of intestinal Echinococcus multilocularis in a dog. ANIMAL: A 13-month-old female intact dog with naturally occurring intestinal E multilocularis. CLINICAL PRESENTATION, PROGRESSION, AND PROCEDURES: The 13-month-old dog initially presented with a reduced appetite and weight loss and then developed hematochezia. The clinical history included a lack of endoparasite preventive care (fecal testing, deworming), exposure to coyotes, fox, sheep, and rodents and the dog had intermittently been fed a raw food diet. Physical examination revealed a thin dog, with a 2/9 body condition score, that was otherwise clinically unremarkable. A fecal sample was submitted for screening for gastrointestinal parasites as part of an infectious disease assessment. The fecal PCR test reported detection of E multilocularis. This result was sequenced as the European haplotype E3/E4. Centrifugal flotation (same sample) did not detect taeniid eggs. TREATMENT AND OUTCOME: The dog was treated with metronidazole, maropitant, and milbemycin oxime/praziquantel. Clinical improvement was noted within 48 hours. No DNA of E multilocularis was detected in a fecal sample collected approximately 10 days after treatment. The dog's owner was advised to provide monthly deworming (praziquantel) for all dogs on the property and to contact their human health-care provider due to potential zoonotic exposure risk. CLINICAL RELEVANCE: Increasing detection of E multilocularis is occurring in dogs in Canada and the US. Alveolar echinococcosis can cause severe disease in dogs and humans. Fecal PCR detection and surveillance may alert practitioners to canine intestinal cases and allow dogs to serve as sentinels for human exposure risk.

Factors associated with Giardia infection in dogs in southern Ontario, Canada.

Information concerning risk factors associated with Giardia infection in dogs in southern Ontario, Canada, is currently lacking. This study therefore aimed to identify risk factors for Giardia infection in dogs that visit off-leash dog parks in southern Ontario. From May-November 2018, fecal samples were collected from 466 dogs in 12 off-leash dog parks in the Niagara and Hamilton regions of Ontario. A survey that asked questions pertaining to travel history (i.e., area of residence, locations and regions visited in the previous 6 months), basic medical history (i.e., spay/neuter status, veterinary visits, use of deworming medication), consumption of a raw diet, and the physical (i.e., age, sex, breed) and behavioral characteristics (i.e., off-leash activities, hunting activities) of each dog sampled was administered to the respective owner. All fecal samples were examined with the Giardia plate ELISA (IDEXX Laboratories) for parasite antigen. Multivariable logistic regression analyses were conducted on the survey data to investigate putative risk factors for Giardia infection. Overall, 11.8% (95% CI: 9.2-15.1%) of samples tested positive for Giardia antigen. Results from the multivariable logistic regression analyses identified an interaction between dog age and spay/neuter status that was significantly associated with Giardia infection. The odds of infection were greater in intact as compared to neutered adult dogs (OR: 3.6, 95% CI: 1.7-7.9, p = 0.001), and in neutered juvenile dogs as compared to neutered adults (OR: 5.2, 95% CI: 2.2-12.2, p < 0.001). The results provide veterinarians with evidence-based information for identifying dogs at greatest risk of Giardia infection in southern Ontario.

Identifying hepatic genes regulating the ovine response to gastrointestinal nematodes using RNA-Sequencing.

Gastrointestinal nematode (GIN) infections are considered the most important disease of grazing sheep and due to increasing anthelmintic resistance, chemical control alone is inadequate. Resistance to Gastrointestinal nematode infection is a heritable trait, and through natural selection many sheep breeds have higher resistance. Studying the transcriptome from GIN-exposed and GIN-unexposed sheep using RNA-Sequencing technology can provide measurements of transcript levels associated with the host response to Gastrointestinal nematode infection, and these transcripts may harbor genetic markers that can be used in selective breeding programs to enhance disease resistance. The objective of this study was to compare liver transcriptomes of sheep naturally exposed to Gastrointestinal nematode s, with either high or low parasite burdens, to GIN-unexposed control sheep in order to identify key regulator genes and biological processes associated with Gastrointestinal nematode infection. Differential gene expression analysis revealed no significant differentially expressed genes (DEG) between sheep with a high or low parasite burden (p-value ≤0.01; False Discovery Rate (FDR) ≤ 0.05; and Fold-Change (FC) of > ±2). However, when compared to the control group, low parasite burden sheep showed 146 differentially expressed genes (64 upregulated and 82 downregulated in the low parasite burden group relative to the control), and high parasite burden sheep showed 159 differentially expressed genes (57 upregulated and 102 downregulated in the low parasite burden group relative to the control) (p-value ≤0.01; FDR ≤0.05; and FC of > ±2). Among these two lists of significant differentially expressed genes, 86 differentially expressed genes (34 upregulated, 52 downregulated in the parasited group relative to the control) were found in common between the two parasite burden groups compared to the control (GIN-unexposed sheep). Functional analysis of these significant 86 differentially expressed genes found upregulated genes involved in immune response and downregulated genes involved in lipid metabolism. Results of this study offer insight into the liver transcriptome during natural Gastrointestinal nematode exposure that helps provide a better understanding of the key regulator genes involved in Gastrointestinal nematode infection in sheep.

Assessing the spatial and temporal patterns and risk factors for acquisition of Ixodes spp. by companion animals across Canada.

Climatic and land use changes have contributed to substantial changes in the abundance, distribution, and activity patterns of ticks in Canada, which have led to an increased risk of tick bites and tick-borne pathogen exposure for companion animals. The objectives of this study were to describe current spatial and temporal patterns of Ixodes spp. on companion animals in Canada and explore the association between tick bites and dog and cat demographic factors. Ticks were collected for one year (April 2019 - March 2020) from 94 veterinary clinics. Included with each submission was a short questionnaire containing owner-reported information on travel history, date of removal and suspected location of tick acquisition, and animal-specific demographic factors. Ticks were identified morphologically using a stereomicroscope, standard keys, and through PCR analyses. Mixed effect multivariable logistic regression models were built to explore the association between an Ixodes scapularis bite and animal demographic factors; veterinary clinic was included as a random effect. Approximately 2300 submissions were received from clinics across Canada, totalling 4425 ticks. The most common Ixodes spp. was I. scapularis (n = 2168), followed by Ixodes pacificus (n = 172) and Ixodes cookei (n = 155). Ixodes scapularis were well distributed in regions across central and eastern Canada. Ixodes cookei was found in eastern Canada, with the greatest numbers from Quebec and New Brunswick. Ixodes pacificus submissions were restricted to British Columbia. Across eastern Canada, dogs of the herding, mixed breed (large and small), sporting, working, terrier, and toy breed groups, and spayed cats were all found to have higher odds of acquiring I. scapularis, compared to other tick species. For the dog model, significant interactions were found between predictor variables age and sex. Regional information on tick distribution, seasonality, and risk factors for acquisition contribute to evidence-based veterinary practices for tick and tick-borne disease control in Canada.

Vector-borne and other pathogens of potential relevance disseminated by relocated cats.

Large populations of unowned cats constitute an animal welfare, ecological, societal and public health issue worldwide. Their relocation and homing are currently carried out in many parts of the world with the intention of relieving suffering and social problems, while contributing to ethical and humane population control in these cat populations. An understanding of an individual cat's lifestyle and disease status by veterinary team professionals and those working with cat charities can help to prevent severe cat stress and the spread of feline pathogens, especially vector-borne pathogens, which can be overlooked in cats. In this article, we discuss the issue of relocation and homing of unowned cats from a global perspective. We also review zoonotic and non-zoonotic infectious agents of cats and give a list of practical recommendations for veterinary team professionals dealing with homing cats. Finally, we present a consensus statement consolidated at the 15th Symposium of the Companion Vector-Borne Diseases (CVBD) World Forum in 2020, ultimately to help veterinary team professionals understand the problem and the role they have in helping to prevent and manage vector-borne and other pathogens in relocated cats.

Prevalence of intestinal parasites in dogs in southern Ontario, Canada, based on fecal samples tested using sucrose double centrifugation and Fecal Dx® tests.

In southern Ontario, Canada, there is a lack of information concerning the prevalence of intestinal parasites in dogs. As such, this study aimed to characterize the prevalence of intestinal parasites in dogs visiting off-leash parks in the region using sucrose double centrifugation and Fecal Dx® tests. Additionally, data obtained via the sucrose double centrifugation method were used to evaluate the performance of the Fecal Dx® tests. Fecal samples were collected from 466 dogs aged ≥6 months from May to November 2018 (mean age = 3.7 years). Overall, eleven intestinal parasites were identified using sucrose double centrifugation. Roundworm eggs (Toxocara canis and Baylisascaris procyonis), hookworm eggs (Ancylostoma caninum and Uncinaria stenocephala), and whipworm eggs (Trichuris vulpis) were identified in 1.07% (95% confidence interval [CI] 0.38-2.56%), 5.79% (95% CI 3.85-8.31%), and 5.15% (95% CI 3.33-7.57) of samples, respectively. Using the Fecal Dx® tests, 1.07% (95% CI 0.38-2.56%), 4.29% (95% CI 2.64-6.55%), and 2.15% (95% CI 1.03-3.91) of the samples tested positive for roundworm, hookworm, and whipworm antigen, respectively. To assess the level of agreement between the Fecal Dx® tests and sucrose double centrifugation, three methods were used. Cohen's kappa indicated a fair-to-moderate level of agreement between Fecal Dx® tests and sucrose double centrifugation. In contrast, the prevalence-adjusted bias-adjusted kappa and Gwet's first-order agreement coefficient indicated almost perfect agreement between these tests, ranging from 0.87 to 0.99 among the parasites examined. This study provides valuable information on the prevalence of intestinal parasites in mature dogs in southern Ontario that will help guide parasite control recommendations for dogs in this region.

MORBIDITY AND MORTALITY IN ONTARIO RODENTS AND LAGOMORPHS: A 30-YEAR RETROSPECTIVE REVIEW.

Passive surveillance is an important component of wildlife health surveillance that allows for the identification of emerging pathogens as well as population-level threats. We investigated the most common causes of morbidity and mortality in rodents and lagomorphs submitted to the Canadian Wildlife Health Cooperative (CWHC) in Ontario and the Ontario Veterinary College (OVC) over a 30-yr period. A total of 836 cases representing 13 species of rodents and three species of lagomorph were submitted to the CWHC and the OVC wildlife pathology service. Infectious or inflammatory diagnoses were most common in our data set, followed by trauma and unknown diagnoses. The most frequently identified primary diagnosis was encephalitis with histological lesions consistent with neural larva migrans including the presence of inflammation and malacia of brain tissue and, in some cases, characteristic nematode larvae. Other infectious diagnoses were squirrel fibroma virus and Toxoplasma gondii infections. Knowledge of common pathogens observed in various species of rodents and lagomorphs can aid in triage and treatment decisions at veterinary clinics and wildlife rehabilitation centers, and guide sample collection and test requisition at post-mortem examination.

Investigation of the occurrence of Angiostrongylus vasorum in coyotes in southern Ontario, Canada.

In North America, the only endemic focus for Angiostrongylus vasorum (French heartworm) was historically thought to occur in the southeastern part of the island of Newfoundland. However, reports of A. vasorum infection in wild canids in West Virginia, USA, and Nova Scotia, Canada, suggest the introduction of the parasite to mainland North America. We screened for A. vasorum in coyotes from across southern Ontario. Additionally, we evaluated the performance of ELISAs for detection of circulating A. vasorum antigen (Ag-ELISA) and antibodies against A. vasorum (Ab-ELISA) designed for use in sera or blood of foxes for use with coyotes in this region. Autopsies were performed on 397 coyotes, and lung tissue extract prepared from each carcass was tested via both ELISAs. The sensitivity and specificity for both tests were estimated in the absence of a gold standard using a 2-test single population Bayesian model; sensitivity and specificity priors were based on the performance of the assays in foxes in Switzerland. Eight coyotes tested positive for A. vasorum antigen; no animal was antibody positive. The estimated sensitivity and specificity of the Ag-ELISA were 90.8% (95% credible interval [CrI]: 83.8-95.6%) and 95.5% (95% CrI: 93.4-97.2%), respectively. For the Ab-ELISA, the estimated sensitivity and specificity were 41.9% (95% CrI: 32.1-51.9%) and 98.0% (95% CrI: 96.3-99.0%), respectively. Based on these findings and negative postmortem data for the same animals, there is insufficient evidence to suggest the presence of A. vasorum in southern Ontario coyotes.

Evaluation of the prevalence of Echinococcus multilocularis in dogs that visit off-leash dog parks in southern Ontario, Canada.

Prior to 2012, Echinococcus multilocularis was not known to occur in any host in Ontario, Canada. However, since that year, five cases of alveolar echinococcosis have been diagnosed in dogs that resided at the western end of Lake Ontario. In addition, E. multilocularis has been shown to be a common infection in wild canids (i.e. coyotes and foxes) across southern Ontario with a high-risk infection cluster in the area surrounding the western shores of Lake Ontario and northern shores of Lake Erie. In regions endemic for E. multilocularis, dog ownership is considered a risk factor for human alveolar echinococcosis. A study was therefore carried out to determine the prevalence of E. multilocularis intestinal infections in dogs within the high-risk infection cluster. From May to November 2018, faecal samples were collected from 477 dogs aged ≥6 months that visited 12 off-leash dog parks in the Halton, Hamilton and Niagara public health units. Faecal samples were analysed via a magnetic capture probe DNA extraction and real-time PCR method for E. multilocularis DNA. Overall, 0% (97.5% CI: 0%-0.80%) of samples tested positive. This result informs preventive recommendations for E. multilocularis infections in dogs in this region.

Parasites and vector-borne diseases disseminated by rehomed dogs.

The Companion Vector-Borne Diseases (CVBD) World Forum is a working group of leading international experts who meet annually to evaluate current scientific findings and future trends concerning the distribution, pathogenesis, clinical presentation, diagnosis and prevention of vector-borne infections of dogs and cats. At the 14th Symposium of the CVBD World Forum in Trieste, Italy (March 25-28, 2019), we identified the need to (i) bring attention to the potential spread of parasites and vectors with relocated dogs, and (ii) provide advice to the veterinary profession regarding the importance of surveillance and treatment for parasites and vector-borne infections when rehoming dogs. This letter shares a consensus statement from the CVBD World Forum as well as a summary of the problem faced, including the role of veterinary professionals in parasite surveillance, causal issues, and the importance of interdisciplinary cooperation in addressing the problem. To limit opportunities for dissemination of parasites and vectors, whenever possible, underlying problems creating the need for dog rehoming should be addressed. However, when it is necessary to rehome dogs, this should ideally take place in the country and national region of origin. When geographically distant relocation occurs, veterinary professionals have a vital role to play in public education, vigilance for detection of exotic vectors and infections, and alerting the medical community to the risk(s) for pathogen spread. With appropriate veterinary intervention, dog welfare needs can be met without inadvertently allowing global spread of parasites and their vectors.

Laparoscopic ureteronephrectomy for the treatment of giant kidney worm infection in 2 dogs.

One male and one female dog were presented with giant kidney worm infection in the right kidney. Infection was identified through visualization of intra-renal Dioctophyme renale on abdominal ultrasound. Both dogs underwent right-sided laparoscopic ureteronephrectomy for treatment of the giant kidney worm infection. Additional adult worms were extirpated from the peritoneal cavity of both dogs. Both dogs recovered without complication from anesthesia and surgery and were discharged within 24 hours after surgery. Laparoscopic ureteronephrectomy has not previously been described for the treatment of giant kidney worm infection in North America.

Urétéro-néphrectomie laparoscopique pour le traitement d'une infection par le ver géant du rein chez deux chiens. Un chien mâle et un chien femelle furent présentés avec une infection par le ver géant du rein dans le rein droit. L'infection fut identifiée par visualisation de Dioctophyme renale intra-rénal par échographie abdominale. Les deux chiens furent soumis à une urétéro-néphrectomie laparoscopique pour le traitement de l'infection par le ver géant du rein. Des vers adultes additionnels furent retirés de la cavité péritonéale des deux chiens. Les deux chiens ont récupéré sans complication de l'anesthésie et de la chirurgie et ont obtenu leur congé en moins de 24 h après la chirurgie. L'urétéro-néphrectomie laparoscopique n'avait pas encore été décrite en Amérique du Nord pour le traitement de l'infection par le ver géant du rein.(Traduit par Dr Serge Messier).

Spatio-temporal clustering of Baylisascaris procyonis, a zoonotic parasite, in raccoons across different landscapes in southern Ontario.

Baylisascaris procyonis, the raccoon roundworm, is a parasite found throughout North America and parts of Europe. More than 150 species of mammals and birds including humans can develop neurological disease following infection with the larval stage of this parasite. To investigate whether B. procyonis infections in raccoons cluster in space, time, or space-time, we used data from 1353 Ontario raccoons submitted to the Canadian Wildlife Health Cooperative between 2013 and 2016. We identified a significant spatial cluster of increased infection prevalence in southern Ontario centered over a major metropolitan area, as well as a significant cluster of decreased infection prevalence in a primarily agricultural region in southwestern Ontario. Furthermore, we identified statistically significant temporal clusters in the fall in annual scans of data from 2014, 2015 and 2016. Examination of both Bernoulli and space-time permutation models for space-time analysis suggested that the purely spatial and temporal clusters were not explained by relatively short and spatially discrete events in space-time. The identified annual temporal clusters are consistent with previous research on the seasonality of B. procyonis infection in raccoons. Recognition of the spatial infection clusters will help identify potential geographic and anthropogenic factors associated with the occurrence of B. procyonis infection in raccoons. Given the zoonotic potential of this parasite, identification of a cluster of high infection prevalence in a major metropolitan area has implications for public education and risk management strategies.

Correlation of subclinical gastrointestinal nematode parasitism with growth and reproductive performance in ewe lambs in Ontario.

Infection with gastrointestinal nematode parasites (GINs) is an important cause of productivity loss on sheep farms in Ontario and worldwide. However, efforts to quantify the effect of GIN infection on growth have demonstrated mixed results. Furthermore, there has been limited investigation of their effect on reproductive performance. This study evaluated the effect of subclinical GIN parasitism on growth and reproductive performance of ewe lambs under Ontario grazing conditions. Rideau cross ewe lambs (n = 140) born in spring 2016 on a farm in central Ontario were followed for two years from before weaning through to November 2017, including their first lambing and lactation. These animals grazed from May to November of each year and were sampled every 6-8 weeks during both grazing seasons and once at mid-gestation in March 2017. At each sampling the ewe lambs were weighed, body condition scores assigned, fecal egg counts (FECs) performed, and pasture samples collected to assess number of infective GIN larvae. Study animals with a FEC of 500 eggs per gram or higher were selectively treated with anthelmintics to prevent morbidity and mortality. Fecal samples were cultured to determine infecting GIN species, and climate data were obtained from a weather station 26 km away from the farm. Precipitation levels and numbers of infective larvae on pasture were low during the first grazing season but were more typical of Ontario conditions in the second grazing season. The three most common GIN species were Haemonchus contortus, Teladorsagia circumcincta, and Trichostrongylus spp. General linear mixed models were generated for weight change over time, litter size at lambing, and weaning weights of offspring. Despite moderate peak GIN burdens in both grazing seasons, FEC was not significantly associated with weight change or litter size, apart from periparturient egg rise in study ewe lambs with larger litters (p = 0.05). Significant positive quadratic and negative linear associations were identified between late lactation FECs and offspring weaning weights; the association between FECs and weaning weights changed from negative to positive at a FEC of 361 eggs per gram. These results indicate that when GIN burdens are moderate as evidenced by fecal egg counts and infection is subclinical, there appears to be low to no impact on growth and reproductive performance in ewe lambs in the first 18 months of life. This suggests that when GIN parasitism is regularly monitored and controlled using targeted selective treatment, animal performance is minimally affected.

Alveolar echinococcosis in a dog in the eastern United States.

An 8-y-old Labrador Retriever was presented to a small animal practice in northern Virginia with a history of recent lethargy. Physical examination findings were unremarkable. Ultrasound revealed several large hepatic masses and multiple smaller masses involving the pancreas. Cytologic findings on fine-needle aspirates of the hepatic masses included inflammation and necrosis with eosinophilic, membranous oval structures consistent with cestode infection. Histopathologic findings for biopsies of these masses included extensive necrosis, inflammation, and PAS-positive hyaline-like membranous material interpreted as metacestode cyst wall. A PCR product was generated from aspirate material using primers specific for Echinococcus multilocularis. Subsequent sequence data were 100% homologous to E. multilocularis NADH dehydrogenase subunit I gene sequences. The dog received daily oral albendazole (10 mg/kg) treatment, but its condition deteriorated, and the dog was euthanized. The dog, born in Mississippi, was brought as a puppy to Virginia with no other travel history. To our knowledge, alveolar echinococcosis has not been reported previously in a dog in the United States; E. multilocularis infection was apparently acquired in the mid-Atlantic region of the United States.

Correlation of salivary antibody to carbohydrate larval antigen (CarLA) with health and gastrointestinal nematode parasitism in sheep under Ontario grazing conditions.

Leveraging mucosal immunity is a promising method for controlling gastrointestinal nematode (GIN) parasitism in sheep. Salivary antibody to carbohydrate larval antigen (sCarLA), a heritable measure of immunity to third-stage GIN larvae (L3), has been successfully applied to genetic improvement programs in New Zealand. However, sCarLA levels wane in the absence of ongoing GIN exposure. New Zealand's temperate climate permits year-round exposure to L3, but cold winters in boreal regions such as Ontario, Canada interrupt exposure for five months or more. This study investigated associations between sCarLA levels, GIN parasitism, and indicators of overall health in sheep grazing under Ontario conditions. A commercial flock of 140 Rideau cross ewe lambs were followed from approximately 30 days of age in May 2016 until November 2017, including lambing and lactation in the spring of 2017. Every 6-8 weeks during the grazing season and at mid-gestation in March 2017, fecal egg counts were performed, blood collected to assess serum albumin, globulin, and hematocrit, and pasture samples obtained to confirm exposure to infective larvae. Measurements of sCarLA level were performed at the beginning, middle, and end of each grazing season, and at mid-gestation. Spearman's rank correlation coefficients were calculated to compare sCarLA levels over time, and general linear mixed models created to evaluate associations between sCarLA levels, GIN fecal egg count, hematocrit, serum albumin, and serum globulin. Levels of sCarLA followed a similar seasonal pattern to GIN fecal egg counts with a 6-8 week delay; much higher sCarLA levels were observed in the second grazing season. The proportion of the flock with detectable sCarLA (≥ 0.3 units/mL) was 68.3 % by the end of the first grazing season, declined over winter to 43.9 % at lambing, and approached 100 % after 3 months of grazing in the second grazing season. Correlations between sCarLA levels over time were consistently positive, of weak to moderate strength, and significant (p < 0.05). At all time points, sCarLA level was significantly (p < 0.001) and negatively associated with fecal egg counts. The flock displayed minimal variability in hematocrit, serum albumin, and serum globulin; none of which were significantly associated with sCarLA levels. These results suggest that sCarLA can be maintained over winter and is a useful measure of immunity to GINs in sheep under Ontario grazing conditions.

Evaluation of the SNAP® 4Dx® plus test for the detection of Dirofilaria immitis antigen and characterization of exposure to tick-borne pathogens in wild canids in southern Ontario.

Population-level surveys for Dirofilaria immitis in wild canids typically rely on identification of the parasite at necropsy. More recently, some studies have employed the use of the SNAP® 4Dx® Plus test. However, since the assay was designed for use with domestic dogs it needs to be validated for use with wild canids for accurate interpretation of results. We therefore evaluated the performance of the SNAP® 4Dx® Plus test for detection of D. immitis in wild canids in southern Ontario. Overall, 199 wild canid carcasses were collected from across the region and assessed for the presence of D. immitis parasites at necropsy; ten were infected. Lung tissue extract (LE) and thoracic fluid filter paper extract (TFE) prepared from each wild canid were tested via the SNAP® 4Dx® Plus test, which simultaneously tests for the presence of D. immitis antigen and antibodies to Borrelia burgdorferi, Anaplasma spp., and Ehrlichia spp. The prevalence adjusted bias adjusted kappa (PABAK) and Gwet's first-order-agreement coefficient (AC1) were used to assess the level of agreement between sample pairs. The PABAK and AC1 between LF and TFE applied to the SNAP® 4Dx® Plus test and the necropsy-confirmed D. immitis status indicated a very high level of agreement for all sample pairs. Compared to necropsy-confirmed D. immitis status, the estimated sensitivity and specificity of the SNAP® 4Dx® Plus test for D. immitis antigen in LE was 80 % (95 % CI 44.4-97.5%) and 98.9 % (95 % CI 96.2-99.9%), respectively. For the TFE, the sensitivity was 70 % (95 % CI 34.8-93.3%) and the specificity was 97.9 % (95 % CI 94.7-99.4%). With respect to the tick-borne pathogen components, 1.5 % (3/199; 95 % CI 0.3-4.5%) of wild canids tested positive for B. burgdorferi antibody; 1.0 % (2/199; 95 % CI 0-3.8%) of LE samples were positive and 0.5 % (1/199; 95 % CI 0-3.1%) of TFE samples were positive. No samples tested positive for antibody to Anaplasma spp. (95 % CI 0-2.3%) or Ehrlichia spp. (95 % CI 0-2.3%). Collectively, the results suggest that the SNAP® 4Dx® Plus test may be a suitable test for use with LE and TFE for the detection of D. immitis antigen in wild canids from southern Ontario.

Factors associated with Echinococcus multilocularis infection in coyotes in southern Ontario.

Echinococcus multilocularis was recently reported in wild canids across southern Ontario, a newly recognized endemic area in Canada. In such areas, a comprehensive understanding of factors associated with infection in definitive hosts (wild canids) is critical for mitigating risk of transmission to humans. However, little is known about the transmission dynamics of the parasite in definitive hosts for this region. A study was therefore carried out to investigate the association of host-level (sex, body condition), environmental (southern Ontario region, land cover), temporal (season, hunting season, calendar year) and extraneous factors (submitter type) with E. multilocularis infection in coyotes in southern Ontario. Between November 2015 and March 2017, 416 coyotes were collected from across the region as part of a study that investigated the prevalence and distribution of the parasite in wild canids; approximately 24% of coyotes were positive for E. multilocularis. Associations between infection and factors of interest were assessed via a mixed-effects logistic regression model with a random intercept for submitter to account for clustering. Coyotes with poor body condition were at greater odds of E. multilocularis infection than those in good condition (odds ratio [OR] 2.14; 95% CI: 1.08-4.26; p = .030). A negative association was observed between infection in coyotes and the proportion of natural land in a coyote's estimated home range (OR: 0.67; 95% CI: 0.52-0.85; p = .001). Coyotes from the western region of southern Ontario had lower odds of infection compared to coyotes from the central region (OR: 0.26; 95% CI: 0.12-0.55; p < .001). These results can be used to help guide future public health prevention strategies for human alveolar echinococcosis.

Prevalence of Baylisascaris procyonis in raccoon latrines in southern Ontario, Canada.

Raccoon latrines represent sites of potential infection by the zoonotic parasite Baylisascaris procyonis for wildlife and humans. Our objective was to determine the prevalence of B. procyonis at raccoon latrine sites in southern Ontario. Thirty raccoon latrines were sampled between June - July 2018; multiple scats were collected and homogenized to form a representative sample of each latrine. To determine the presence or absence of B. procyonis eggs in each sample, we used the Cornell-Wisconsin centrifugal floatation technique. Twenty-three percent (7/30) of homogenized samples tested positive for B. procyonis. Eggs per gram of feces ranged from 1 to 388 (median = 1.28, IQR = 0.32-232.5). Baylisascaris procyonis positive latrines were found in conservation areas heavily used by people, which may represent a possible source of exposure for humans in these areas.