Copper oxide wire particles effective against gastrointestinal nematodes in adult alpacas during a randomized clinical trial.

OBJECTIVE: To determine whether copper oxide wire particles (COWP) administered as an oral bolus effectively decrease fecal gastrointestinal nematode (GIN) egg counts in adult alpacas. ANIMALS: 57 adult alpacas. PROCEDURES: A double-blind clinical trial was performed during the months of April through August 2019. Adult alpacas enrolled in the trial were administered 2 g of COWP or a placebo control capsule PO on day 0 and day 45. On day 0 and at 15-day intervals, fecal samples were collected, and Modified McMaster fecal egg counts (FEC) were performed as well as physical examinations, including FAMACHA scoring and body condition scoring (BCS). Hematocrits were measured in 30-day intervals (days 0, 30, 60, and 90). Results were compared across groups. RESULTS: A significant decrease in mean FEC was observed in the COWP-treated group over time, compared with the placebo group. Mean BCS, FAMACHA score, and Hct did not differ significantly between groups. No clinical evidence of copper toxicosis was observed. CLINICAL RELEVANCE: Oral administration of COWP was determined to be a safe and effective method of reducing GIN FEC in adult alpacas.

Emergency Subglottic Airway Training and Assessment of Skills Retention of Attending Anesthesiologists With Simulation Mastery-Based Learning.

BACKGROUND: Although included within the American Society of Anesthesiologists difficult airway algorithm, the use of "invasive airway access" is rarely needed clinically. In conjunction with highly associated morbidity and liability risks, it is a challenge for the average anesthesiologist to develop and maintain competency. The advancement of high-fidelity simulators allows for practice of rarely encountered clinical scenarios, specifically those requiring invasive subglottic airway techniques. METHODS: Sixty board-certified academic anesthesiologists were enrolled and trained in dyads in a simulation-based, mastery-based learning (MBL) course directed at 2 emergency airway subglottic techniques: transtracheal jet ventilation (TTJV) and bougie cricothyrotomy (BC). Performance metrics included: pretest, posttest, specific skill step error tracking, and 15-month period retest. All were pretested and trained once on the Melker cricothyrotomy (MC) kit. All pretest assessment, training, posttesting, and 15-month retesting were performed by a single expert clinical and educational airway management faculty member. RESULTS: Initial testing showed a success rate of 14.8% for TTJV, 19.7% for BC, and 25% for MC. After mastery-based practice, all anesthesiologists achieved successful invasive airway placement with TTJV, BC, and MC. Repeated performance of each skill improved speed with zero safety breaches. BC was noted to be the fastest performed technique. Fifteen months later, retesting showed that 80.4% and 82.6% performed successful airway securement for TTJV and BC, respectively. For safety, average placement time and costs, MC was discarded after initial training results. CONCLUSIONS: We discovered that only ~20% of practicing anesthesiologists were able to successfully place an invasive airway in a simulated life or death clinical setting. Using mobile simulation (training performed in department conference room) during a 2.5-hour session using mastery-based training pedagogy, we increased our success rate of invasive airway placement to 100%, while also increasing the successful speed to ventilation (TTJV, 32 seconds average; BC, 29 seconds average). Finally, we determined that there was a 15-month 80% retention rate of the airway skills learned, indicating that skills last at least a year before retraining is required using this training methodology.

Rapid Discovery and Detection of Haemaphysalis longicornis through the Use of Passive Surveillance and Collaboration: Building a State Tick-Surveillance Network.

Between March 2019 and February 2020, Asian long-horned ticks (Haemaphysalis longicornis Neumann, 1901) were discovered and collected for the first time in one middle and seven eastern Tennessee counties, facilitated by a newly developed passive and collaborative tick-surveillance network. Network collaborators included federal, state, county, university, and private resource personnel working with companion animals, livestock, and wildlife. Specimens were collected primarily from dogs and cattle, with initial detections of female adult stage ticks by stakeholders associated with parasitology positions (e.g., entomologists and veterinary parasitologists). Initial county tick detections were confirmed with morphological and molecular identifications, and then screened for the presence of animal-associated pathogens (Anaplasma marginale, Babesia species, Ehrlichia species, and Theileria orientalis), for which all tests were negative. Herein, we describe the identification and confirmation of these tick specimens as well as other results of the surveillance collaboration.

Presentation, Clinical Pathology Abnormalities, and Identification of Gastrointestinal Parasites in Camels (Camelus bactrianus and Camelus dromedarius) Presenting to Two North American Veterinary Teaching Hospitals. A Retrospective Study: 1980-2020.

Old World Camelids (OWC) represent two species (Camelus bactrianus and Camelus dromedarius) with increasing numbers in North America. Gastrointestinal (GI) parasitism is a major cause of clinical disease in camelids and leads to significant economic impacts. Literature reporting on clinical parasitism of camels is localized to India, Africa, and the Middle East, with limited information available on OWCs in North America. Objectives of this study were to report on clinical presentation and diagnostic findings in Camelus bactrianus and Camelus dromedarius with GI parasitism and provide a comparative analysis between geographic regions. Medical records of OWCs presenting to two veterinary teaching hospitals (of the University of Tennessee and University of Wisconsin) were evaluated. Thirty-one camels including 11 Bactrians and six dromedaries (14 species not recorded) were included for the clinical component of this study, reporting on signalment, presenting complaint, and clinical pathology. Anorexia, weight loss, and diarrhea were the most common presenting complaint. Clinical pathology findings included eosinophilia, hypoproteinemia, and hyponatremia. For the second component of this study, a total of 77 fecal parasite examination results were evaluated for parasite identification and regional variation. Trichuris, Capillaria, Strongyloides, Nematodirus, Dictyocaulus, Moniezia, and protozoan parasites (Eimeria, Cryptosporidium, Giardia) were recorded. Strongyle-type eggs predominated, followed by Trichuris and Eimeria spp. There was a statistically significant variation in prevalence of coccidia between the two regions, with fecal examinations from Tennessee more likely to contain Eimeria (P = 0.0193). Clinicians treating camels in North America should recognize anorexia, weight loss, and diarrhea combined with clinical pathologic changes of hypoproteinemia, eosinophilia and hyponatremia as possible indications of GI parasitism. Clinicians should also consider the potential for regional variation to exist for GI parasites of camels in different areas of North America.

Train-the-trainer: Pilot trial for ebola virus disease simulation training.

Background: Highly infectious but rare diseases require rapid dissemination of safety critical skills to health-care workers (HCWs). Simulation is an effective method of education; however, it requires competent instructors. We evaluated the efficacy of an internet-delivered train-the-trainer course to prepare HCWs to care for patients with Ebola virus disease (EVD). Methods: Twenty-four individuals without prior EVD training were recruited and divided into two groups. Group A included nine trainees taught by three experienced trainers with previous EVD training. Group B included 15 trainees taught by five novice trainers without previous EVD training who completed the train-the-trainer course. We compared the efficacy of the train-the-trainer course by examining subject performance, measured by time to complete 13 tasks and the proportion of steps per task flagged for critical errors and risky and positive actions. Trainees' confidence in their ability to safely care for EVD patients was compared with a self-reported survey after training. Results: Overall trainees' confidence in ability to safely care for EVD patients did not differ by group. Participants trained by the novice trainers were statistically significantly faster at waste bagging (P = 0.002), lab specimen bagging (P = 0.004), spill clean-up (P = 0.01), and the body bagging (P = 0.008) scenarios compared to those trained by experienced trainers. There were no significant differences in the completion time in the remaining nine training tasks. Participants trained by novice and experienced trainers did not differ significantly with regard to the proportion of steps in a task flagged for critical errors, risky actions, or positive actions with the exception of the task "Man Down in Gown" (12.5% of steps graded by experienced trainers compared to 0 graded by novice trainers, P = 0.007). Discussion: The online train-the-trainer EVD course is effective at teaching novices to train HCWs in protective measures and can be accomplished swiftly.

Multiple drug resistance in the canine hookworm Ancylostoma caninum: an emerging threat?

BACKGROUND: The canine hookworm, Ancylostoma caninum is the most prevalent and important intestinal nematode parasite of dogs in the USA. Hookworms are typically well controlled by treatment with all commonly used anthelmintics that are approved for this use in dogs. However, in the past few years, cases of recurrent/persistent canine hookworm infections appear to have dramatically increased, suggesting that anthelmintic resistance (AR) may have evolved in this parasite. These cases are highly overrepresented by greyhounds, but multiple other breeds are also represented. The aim of this study was to characterize several of these suspected resistant isolates using in vitro, genetic and clinical testing to determine if these cases represent true anthelmintic resistance in A. caninum. METHODS: Fecal samples containing hookworm eggs from three cases of persistent hookworm infections; one from a greyhound, one from a miniature schnauzer and one from a hound-mix, were received by our laboratory. These were then used to establish infections in laboratory dogs and to perform egg hatch assays (EHA) and larval development assays (LDA) for detecting resistance to benzimidazoles and macrocyclic lactones, respectively. Additional EHA and LDA were performed on eggs recovered from the laboratory-induced infections. Fecal egg count reduction tests were performed to detect resistance to pyrantel. Deep amplicon sequencing assays were developed to measure the frequency of non-synonymous single nucleotide polymorphisms (SNP) at codons 167, 198 and 200 of the A. caninum isotype-1 ß-tubulin gene. RESULTS: Resistance ratios for the three A. caninum isolates tested ranged from 6.0 to > 100 and 5.5 to 69.8 for the EHA and LDA, respectively. Following treatment with pyrantel, reduction in faecal egg counts was negative or 0%. Deep amplicon sequencing of the isotype-1 ß-tubulin gene identified a high frequency of resistance-associated SNPs at codon 167 in all three resistant isolates and in two additional clinical cases. CONCLUSIONS: These data conclusively demonstrate multiple anthelmintic resistance in multiple independent isolates of A. caninum, strongly suggesting that this is an emerging problem in the USA. Furthermore, evidence suggest that these resistant hookworms originate from racing greyhound farms and kennels, though additional research is needed to confirm this.

A Pilot Study of Simulation Training in Difficult Bag Mask Ventilation Using a Computerized Patient Simulator.

OBJECTIVE: Bag mask ventilation (BMV) is fundamental to airway management. Simulation is effective in airway management training, but its effectiveness for difficult BMV training is less clear. We evaluated the difference between type of training (simulation vs on patients) and the pass rate on a post-test on patients. DESIGN: A single center pilot study was performed with 32 medical students randomized to participate in difficult BMV training on simulators or patients. Pre- and post-training tests on the simulator and on patients were recorded. Surveys of trainee confidence level were collected. The primary goal was to estimate the difference between type of training (simulation vs on patients) and the pass rate on the post-test on patients with an improvement of 10% or more in passing rate considered as a meaningful improvement. Secondary outcomes included whether or not participants passed the simulator post-test, post-test on patient confidence, and pre- and post-test confidence. MEASUREMENTS AND MAIN RESULTS: Participants trained on the simulator had 13% higher passing rate on the post-test on patients compared to participants trained on patients (88% vs 75%). In addition, subjects that passed the simulator post-test had 11 times the odds of passing a post-test on patients relative to subjects that did not pass the simulator post-test (P = 0.023, odds ratio = 11.0, 95% confidence interval [CI] = 1.48-81.6). Post-training confidence levels were higher among those who passed the simulator pre-test and post-test and received simulator training. CONCLUSIONS: Simulation training for difficult BMV led to a higher passing rate on a post-test on patients compared to those trained on patients. This finding will need to be confirmed in larger randomized controlled trials. Successfully completing difficult BMV training on a simulator with a passing grade correlated with passing a test on difficult BMV on patients.

Eimeria gilruthi-associated abomasitis in a group of ewes.

Nine of 23 (39%) research ewes with severe diarrhea and weight loss had histologic lesions consistent with Eimeria gilruthi infection in their abomasa. Gross anatomic lesions included hundreds of opaque 1-mm nodules in abomasal mucosa that corresponded microscopically to 200-300 µm diameter organisms surrounded by areas of necrosis. Analysis of fecal samples from 4 ewes demonstrated oocysts from typical ovine Eimeria species, none of which were E. gilruthi. Two separate PCR reactions were performed on abomasal tissue from 4 sheep to amplify the 18S ribosomal DNA (rDNA) and internal transcribed spacer (ITS) region of the rDNA, respectively. The resultant 18S rDNA nucleotide sequences shared 99% homology with multiple Eimeria species in GenBank. The ITS region shared 77% homology with E. ellipsoidalis in GenBank. Further studies are needed to understand the life cycle and pathogenicity of E. gilruthi. Our results underscore the inclusion of E. gilruthi in the differential diagnosis of diarrhea and weight loss in sheep.

The American Association of Oral and Maxillofacial Surgeons Simulation Program.

Patient safety in dental anesthesia has been called into question in recent years. Simulation training has been proposed and developed as one possibility for increasing preparedness and training in cases of adverse events in dental anesthesia. This article presents an overview of the challenges of patient safety in dental anesthesia and how to address them with simulation training. The American Association of Oral and Maxillofacial Surgeons simulation program is unique in its potential to become a standardized, validated competency course with objective grading criteria, mastery-based cooperative learning model, and low facilitator-to-participant ratio, leading to a practical delivery cost structure.

Parasite prevalence survey in shelter cats in Citrus County, Florida.

Free-roaming cat population estimates within the United States currently range from 10 to 114million individual cats. Zoonotic parasites of free-roaming cats are public health concerns; therefore, it is important to investigate the parasite prevalence in these populations. Seventy-six fecal samples from shelter cats in Citrus County, FL were surveyed for parasites using the Sheather's sugar centrifugal flotation method. The objective was to determine the prevalence of patent gastrointestinal parasitism in the sampled shelter cats as a proxy for parasite prevalence in the free-roaming cat populations in the area. Parasites identified with zoonotic potential include Toxocara cati, Ancylostoma sp., Spirometra sp., Mesocestoides sp., Cryptosporidium sp., and Giardia sp. Both tapeworms detected can infect humans, but are not directly transmissible from cats to people. Other parasite diagnostic stages found included Aonchotheca putorii eggs, Cystoisospora felis and Cystoisospora rivolta oocysts, and Sarcocystis sp. sporocysts. The mites Lynxacarus radovskyi and Notoedres cati were detected in feces likely from ingestion while grooming.

Toxoplasma gondii: history and diagnostic test development.

Toxoplasma gondii is a protozoa that causes toxoplasmosis in people and other animals. It is considered one of the most common parasitic infections in the world due to its impressive range of hosts, widespread environmental contamination and the diverse means by which animals can be infected. Despite its ubiquity and numerous ongoing research efforts into both its basic biology and clinical management, many aspects of diagnosis and management of this disease are poorly understood. The range of diagnostic options that is available for veterinary diagnostic investigators are notably more limited than those available to medical diagnosticians, making accurate interpretation of each test result critical. The current review joins other reviews on the parasite with a particular emphasis on the history and continued development of diagnostic tests that are useful for veterinary diagnostic investigations. An understanding of the strengths and shortcomings of current diagnostic techniques will assist veterinary and public health officials in formulating effective treatment and control strategies in diverse animal populations.

Cooperative learning using simulation to achieve mastery of nasogastric tube insertion.

Traditionally, psychomotor skills training for nursing students involves didactic instruction followed by procedural review and practice with a task trainer, manikin, or classmates. This article describes a novel method of teaching psychomotor skills to associate degree and baccalaureate nursing students, Cooperative Learning Simulation Skills Training (CLSST), in the context of nasogastric tube insertion using a deliberate practice-to-mastery learning model. Student dyads served as operator and student learner. Automatic scoring was recorded in the debriefing log. Student pairs alternated roles until they achieved mastery, after which they were assessed individually. Median checklist scores of 100% were achieved by students in both programs after one practice session and through evaluation. Students and faculty provided positive feedback regarding this educational innovation. CLSST in a deliberate practice-to-mastery learning paradigm offers a novel way to teach psychomotor skills in nursing curricula and decreases the instructor-to-student ratio.

An approach to moderate sedation simulation training.

INTRODUCTION: Each year millions of patients undergo procedures that require moderate sedation. These patients are at risk of complications from oversedation that can progress to respiratory depression or even death. This article describes the creation of a simulation-based medical education course for nonanesthesiologists who use sedation in their specialty practice and preliminary data from our precourse and postcourse assessments. METHODS: Our course combined online and lecture-based didactics with simulation education to teach moderate sedation and basic emergency airway management to nonanesthesiologists. After online precourse materials were reviewed, participants attended an 8-hour simulation-based training course focused on the recognition of different levels of sedation, medication titration, sedation reversal, and airway support and rescue. To evaluate the course, precourse, and postcourse educational impacts, cognitive and simulation tests were administered. Participants completed a postcourse survey. RESULTS: To date, 45 physicians have participated in the course. We have cognitive performance data on 19 participants and survey data for 45 participants. Postcourse simulation tests results were improved compared with precourse tests. Our course was rated "better" or "much better" in comparison to courses using lecture-only format by 100% of the participants. CONCLUSIONS: A course using a combination of didactic and simulation education to teach moderate sedation is described. Our initial data demonstrated a significant increase in knowledge, skills, and clinical judgment. Future research efforts should focus on examining the validity and reliability of scenario scoring and the impact of training on clinical practice.

Prevalence of antibodies to Toxoplasma gondii in white-tailed deer (Odocoileus virginianus) in New York State, USA.

Sera collected from 299 white-tailed deer (Odocoileus virginianus) harvested in New York State by hunters in November 2010 were assayed for anti-Toxoplasma gondii IgG antibodies. White-tailed deer are a useful sentinel for risk of human and domestic animal exposure to Toxoplasma oocysts and pose a potential risk for infection to humans and other animals by ingestion of the meat. White-tailed deer share grazing space with domestic animals raised for meat and are likely to be exposed by horizontal transmission through oocyst consumption, similar to other grazing species of economic concern. Overall, 42.2% of samples were positive by enzyme-linked immunosorbent assay, indicating a true prevalence of 38.5%, with a significantly higher proportion of adult than immature deer antibody positive. No significant difference in prevalence was found between male and female deer nor was there a significant effect of local human population density on deer antibody prevalence. These results provide insight into the risk of environmental Toxoplasma exposure in New York State and support horizontal transmission through oocyst consumption as the most common mechanism of white-tailed deer infection.

Validation of simulated difficult bag-mask ventilation as a training and evaluation method for first-year internal medicine house staff.

INTRODUCTION: The past decade has witnessed the increased use of patient simulation in medical training as a method to teach complex bedside skills. Although effective bag-mask ventilation (BMV) is a critical part of airway management, the quality of training in this skill has been questioned. METHODS: First-year internal medicine house staff (novices) were used to evaluate a computerized patient simulator as a tool to teach difficult BMV. A novice group and an expert group (certified registered nurse anesthetists and anesthesiologists) were tested to validate the simulator's ability to distinguish between these 2 skill levels. RESULTS: The difference between the novice and expert groups in the ability to perform difficult BMV was statistically significant (P < 0.0001). Brief training for novices led to a 100% pass rate and competence as measured by the simulator. Simulation training was effective in increasing the ability to ventilate a simulated difficult-to-ventilate patient (P < 0.0001). CONCLUSIONS: This study suggests that this computerized patient simulator was validated as a simulation model for teaching difficult BMV and differentiating skill levels in BMV. Using the simulator with brief training on difficult BMV allowed new internal medicine house staff to successfully ventilate a simulated difficult patient.

Validation of a detailed scoring checklist for use during advanced cardiac life support certification.

INTRODUCTION: Defining valid, reliable, defensible, and generalizable standards for the evaluation of learner performance is a key issue in assessing both baseline competence and mastery in medical education. However, before setting these standards of performance, the reliability of the scores yielding from a grading tool must be assessed. Accordingly, the purpose of this study was to assess the reliability of scores generated from a set of grading checklists used by nonexpert raters during simulations of American Heart Association (AHA) Megacodes. METHODS: The reliability of scores generated from a detailed set of checklists, when used by 4 nonexpert raters, was tested by grading team leader performance in 8 Megacode scenarios. Videos of the scenarios were reviewed and rated by trained faculty facilitators and a group of nonexpert raters. The videos were reviewed "continuously" and "with pauses." The grading made by 2 content experts served as the reference standard, and 4 nonexpert raters were used to test the reliability of the checklists. RESULTS: Our results demonstrate that nonexpert raters are able to produce reliable grades when using the checklists under consideration, demonstrating excellent intrarater reliability and agreement with a reference standard. The results also demonstrate that nonexpert raters can be trained in the proper use of the checklist in a short amount of time, with no discernible learning curve thereafter. Finally, our results show that a single trained rater can achieve reliable scores of team leader performance during AHA Megacodes when using our checklist in a continuous mode because measures of agreement in total scoring were very strong [Lin's (Biometrics 1989;45:255-268) concordance correlation coefficient, 0.96; intraclass correlation coefficient, 0.97]. CONCLUSIONS: We have shown that our checklists can yield reliable scores, are appropriate for use by nonexpert raters, and are able to be used during continuous assessment of team leader performance during the review of a simulated Megacode. This checklist may be more appropriate for use by advanced cardiac life support instructors during Megacode assessments than the current tools provided by the AHA.

Chimeric protein A/G conjugate for detection of anti-Toxoplasma gondii immunoglobulin G in multiple animal species.

Serological testing for toxoplasmosis diagnosis remains the method of choice in human medicine due to the accessibility of the requisite sample, the difficulty in predicting the parasite's location in the host for direct detection, and the availability of established commercial methods. In veterinary medicine, although the first 2 conditions are unchanged, there is a need for commercially produced test methods that are validated for Toxoplasma gondii detection across the range of animal species that can serve as intermediate hosts. The development of such a serological method for animals would allow the diagnosis of toxoplasmosis in individual animals and a higher throughput method for population-level toxoplasmosis surveys. The incorporation of a non-species-specific chimeric protein A/G conjugate into an anti-Toxoplasma immunoglobulin G enzyme-linked immunosorbent assay is described. Serum from potential intermediate hosts was reevaluated using this method and compared with earlier testing using an established agglutination procedure. Very good agreement between the 2 tests was noted (κ = 0.81), establishing the method as a useful option for veterinary diagnostic testing.

Literature review: instructional design and pedagogy science in healthcare simulation.

This article is a review of the literature focused on simulation as an educational intervention in healthcare. The authors examined the literature based on four key levels: (1) the validity and reliability of the simulator, (2) the validity and reliability of the performance evaluation tool, (3) the study design, and (4) the translational impact. The authors found that the majority of research literature in healthcare simulation does not address the validity and reliability of the simulator or the performance evaluation tool. However, there are well-designed research studies that address the translation into clinical settings and have positive patient safety outcomes.

Modification of a commercial Toxoplasma gondii immunoglobulin G enzyme-linked immunosorbent assay for use in multiple animal species.

A challenge faced by veterinary diagnosticians in serologic analysis for exposure to pathogens is the need for a protein conjugate capable of antibody attachment in many animal species. The advent of protein conjugates that are less specific in nature allows diagnosis across many species with little or no modification of technique. Toxoplasma gondii is an organism of veterinary interest that has been demonstrated to infect a plethora of warm-blooded animals. However, the serologic tests available for simultaneous diagnosis in this broad range are limited in number. The current study examined the use of an immunoglobulin G enzyme-linked immunosorbent assay (ELISA) modified by the use of non-species-specific protein conjugates in domestic animal species commonly submitted to diagnostic laboratories for evaluation of Toxoplasma exposure status. Comparison with results from an established indirect hemagglutination technique revealed very good agreement between the 2 test methods. This modification of the ELISA provides a useful method for veterinary diagnosticians to perform rapid and accurate evaluation of multiple animal species for Toxoplasma exposure using a single test.

Efficacy of a doxycycline treatment regimen initiated during three different phases of experimental ehrlichiosis.

Doxycycline is the treatment of choice for canine monocytic ehrlichiosis (CME), a well-characterized disease and valuable model for tick-borne zoonoses. Conflicting reports of clearance of Ehrlichia canis after treatment with doxycycline suggested that the disease phase during which treatment is initiated influences outcomes of these treatments. The purpose of this study was to evaluate the efficacy of a 28-day doxycycline regimen for clearance of experimental E. canis infections from dogs treated during three phases of the disease. Ten dogs were inoculated with blood from E. canis carriers and treated with doxycycline during acute, subclinical, or chronic phases of CME. Daily rectal temperatures and semiweekly blood samples were monitored from each dog, and Rhipicephalus sanguineus ticks were acquisition fed on each dog for xenodiagnosis. Blood collected from dogs treated during acute or subclinical CME became PCR negative for E. canis as clinical parameters improved, but blood samples collected from dogs treated during chronic CME remained intermittently PCR positive. R. sanguineus ticks fed on dogs after doxycycline treatments became PCR positive for E. canis, regardless of when treatment was initiated. However, fewer ticks became PCR positive after feeding on two persistently infected dogs treated with doxycycline followed by rifampin, suggesting that antibiotic therapy can reduce tick acquisition of E. canis.