Gilles Fecteau

Gilles Fecteau
Université de Montréal | UdeM · Department of Clinical Sciences

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231
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Publications

Publications (231)
Article
Full-text available
Mycobacterium avium subsp. paratuberculosis (MAP) is the causal agent of paratuberculosis, a chronic, contagious, and incurable enteric disease of ruminants. An in-house IS900 PCR assay validated for MAP detection in sheep has been shown to have a higher sensitivity than a commercial PCR and fecal culture. We have now compared the performance of th...
Chapter
The efferent and afferent effects of the vagus nerve on the developing brain have remained enigmatic. Here we review the evidence of such effects on microglial plasticity in the sheep model of human fetal development, one of the most recognized and deployed models of human fetal physiology. We show that vagotomy alters microglial phenotype and that...
Chapter
Background: Vagus nerve stimulation (VNS) reduced inflammation induced by lipopolysaccharide (LPS) in an adult rat sepsis model. A multi-dimensional heart rate variability (HRV) index reliably tracked the inflammatory profile in near-term sheep fetuses. The effects of VNS on neonates are not known. First, in a neonatal piglet model of sepsis, we pr...
Article
When a streak canal injury occurs, there may be subtle or no external signs of damage. The first sign a producer notices is it takes longer for the injured quarter to empty or milk flow is im­paired during milking. Given that a dairy cow with 4 efficiently functioning teats is essential to dairy production systems, an economically feasible procedur...
Article
Full-text available
Simple Summary Abomasal lesions are considered to be an important health issue in cattle, especially in milk-fed (or white) veal calves. Using a reliable scoring system to describe abomasal lesions can help in determining the possible risk factors in order to prevent this problem. The aim of this study was to determine the inter-rater reliability o...
Article
Full-text available
This study evaluated the associations between estimated distance from farms' locations to auction markets, and health indicators of surplus dairy calves sold during summer 2019 and winter 2020 in Québec, Canada. A total of 3,610 animals from 1,331 different farms were used in this cross-sectional cohort study. Geographic coordinates (latitude and l...
Article
Full-text available
Objective: To evaluate the association between serum phosphorus concentration and the outcome of postpartum downer cows. Animals: Postpartum downer dairy cows presented over a 22-year period. Procedures: In this cross-sectional study (1994 to 2016), medical records of all postpartum downer cows presented to a referral large animal hospital wer...
Preprint
Full-text available
The efferent and afferent effects of the vagus nerve on the developing brain have remained enigmatic. Here we review the evidence of such effects on microglial plasticity in the sheep model of human fetal development, one of the most recognized and deployed models of human fetal physiology. We show that vagotomy alters microglial phenotype and that...
Article
Full-text available
The use of recycled manure solids (RMS) as bedding for dairy cows has become more popular over the last decade. Once producers own the RMS producing equipment, they are not restricted in the amount of bedding they can use in stalls, due to its large availability and low production costs. Thus, they are usually able to provide a soft lying area for...
Article
Full-text available
Background: Hemodilution of the cerebrospinal fluid (CSF) could confound interpretation of results. Accurately predicting total nucleated cells count (TNCC) and total protein concentration (TPC) attributable to hemodilution is difficult. Objective: To determine the effects of hemodilution on TPC and TNCC in bovine CSF. Methods: Retrospective r...
Article
Enzyme-Linked Immunosorbent Assay (ELISA) test is commonly used for detection of antibodies to Salmonella Dublin in individual bovine milk samples. However, little is known about its accuracy when used on bulk tank milk for determining herd-level S. Dublin status and when evaluated without assuming a perfect reference test. The objectives of this s...
Preprint
Aim Chronically instrumented non-anesthetized fetal sheep (CINAFS) have been the mainstay model of human fetal development for 60 years. As a large “two for one” animal model, with instrumentation of the ewe and her fetus, the model poses challenges to implement de novo and to maintain overtime at the highest standards of operating procedures to en...
Article
Full-text available
Calves born on Eastern Canadian dairy farms that are not kept in the herds are traditionally sold through auction markets and are raised for meat purposes such as veal calves. Since February 2020, a new Canadian federal regulation has forbidden calves <9 d old to be sold through auction markets. However, in the absence of a real-time birth registry...
Preprint
Full-text available
The contribution of the vagus nerve to inflammation and glucosensing in the fetus is not understood. We hypothesized that vagotomy (Vx) will result in hyperglycemia and this will be enhanced during systemic and organ-specific inflammation. Efferent vagus nerve stimulation (VNS) should reverse this phenotype. Near-term fetal sheep (n=57) were surgic...
Chapter
Clinical case presentations detail unique and clinically relevant anatomical features about the ruminant head and neck, including the ear, sinuses, teeth, and central nervous system. One case on dehorning describes this distinctive anatomical feature of ruminants.
Article
The objectives of this retrospective analysis were to: 1) estimate the diagnostic sensitivity (Se) and specificity (Sp) of bacterial culture of environmental samples for determining Mycobacterium avium subsp. paratuberculosis (MAP) infection status in Québec dairies, using a Bayesian Latent Class Model (BLCM); and 2) determine the association betwe...
Article
Full-text available
Background Downer cow syndrome, a common problem in dairy cattle, represents a diagnostic and therapeutic challenge for the attending veterinarian. Identifying prognostic indicators and assessing the odds of survival may improve the accuracy of the clinician's prognosis at the time of diagnosis. Objective To describe a population of downer dairy c...
Article
Background: The chronically instrumented pregnant sheep has been used as a model of human fetal development and responses to pathophysiologic stimuli. This is due to the unique amenability of the unanesthetized fetal sheep to the surgical placement and maintenance of catheters and electrodes, allowing repetitive blood sampling, substance injection,...
Article
Full-text available
Background The best test between thoracic ultrasonography (TUS) and thoracic radiography (TR) or the best combination of tests (series or parallel) to detect active infectious bronchopneumonia (BP) in hospitalized dairy calves remains unknown. Hypothesis/Objectives To estimate performances of TUS and TR to detect active BP in hospitalized dairy ca...
Article
Bovine respiratory disease complex (BRD) is a worldwide multifactorial infectious disease. Antimicrobials are commonly used for treating BRD because bacteria are often involved. The clinical diagnosis of BRD is a challenge, especially in adult dairy cows, where information on this syndrome is scant. Having a definition based on consistent and relia...
Article
Dairy calves not kept for replacement are sold at young age in Québec auction markets for white and grain-fed veal calf production. The province of Québec produces 80% of the Canadian veal meat, but little information is available on the factors associated with the calves' price per crude weight (Can$/kg; Can$1 = US$0.78 at time of writing). The ch...
Article
Inadequate transfer of passive immunity (TPI) is associated with increased risk for calfhood disease and increased risk of mortality and morbidity. Accurately diagnosing calves and herds with inadequate TPI is of primary importance and brix (BRIX) or classical refractometer (REF) devices are more practical for this purpose than measuring the serum...
Article
Paratuberculosis is an incurable disease caused by Mycobacterium avium spp. paratuberculosis (MAP). Variability in the definition of a true infection could explain the lack of consensus in published results on host genetic susceptibility to MAP. The objective of this study was to identify quantitative trait loci (QTL) for susceptibility to paratube...
Conference Paper
Full-text available
Introduzione: In medicina bovina gli ascessi retroperitoneali sono stati riportati solo aneddoticamente e sono stati considerati come conseguenza di infezioni profonde del sito chirurgico, legate a laparotomie del fianco. L'obbiettivo del nostro studio è stato quello di descrivere l'anamnesi, i segni clinici, i reperti clinico patologici, il tratta...
Conference Paper
Full-text available
Le Québec produit 80% des veaux lourds au Canada. Les élevages de veaux lourds présentent: un taux de mortalité de 8-10% et un taux de morbidité jusqu'à 60%. L'objectif de l'étude était l'évaluation des caractéristiques et de la santé des veaux vendus lors de la vente aux encans. Deux visites aux encans de Saint-Hyacinthe et de Saint Isidore ont ét...
Article
Infectious bronchopneumonia is a lower respiratory tract disease with major economic consequences in dairy calves. Thoracic radiography (TR) and thoracic ultrasonography (TUS) are two imaging diagnostic procedures available in bovine medicine for identifying thoracic lesions. However, no study has investigated whether one of these tests is superior...
Preprint
Full-text available
Background The chronically instrumented pregnant sheep has been used as a model of human fetal development and responses to pathophysiologic stimuli. This is due to the unique amenability of the unanesthetized fetal sheep to the surgical placement and maintenance of catheters and electrodes, allowing repetitive blood sampling, substance injection,...
Research
Full-text available
Little is known about the vagus nerve activity in near-term fetuses. The chronically instrumented unanesthetized fetal sheep model is used to study human fetal physiology, because it permits chronic instrumentation with catheters and electrodes, which allow repetitive blood sampling, substance injection and recording of bioelectrical activity. We d...
Article
OBJECTIVE To describe the clinical and clinicopathologic characteristics, treatment, and outcome for cattle that developed a retroperitoneal abscess (RA) following paralumbar fossa laparotomy (PFL). ANIMALS 32 Holstein cows with RA. PROCEDURES The record database of a veterinary teaching hospital was searched to identify cattle that were treated fo...
Article
Full-text available
Background: Abomasitis is a syndrome affecting young milk-fed calves. The current veterinary literature describes mainly its necropsy findings. Objectives: To describe the clinical presentation, complementary tests, treatments, and case-fatality rate of calves with a clinical diagnosis of abomasitis and to identify potential factors associated w...
Preprint
Full-text available
In adults, vagus nerve stimulation (VNS) reduces inflammation. In neonates, the effects of VNS are not known. An electrocardiogram (ECG)-derived heart rate variability (HRV) index reliably tracks the inflammatory response induced by low-dose lipopolysaccharide (LPS) in near-term sheep fetuses. We evaluated the VNS effect on the systemic inflammator...
Article
Dairy calves are at risk of being stressed when transported during the first week of life. A new Canadian federal rule will forbid transportation of calves younger than 9 d old to auction market. However, in the absence of reliable information to determine birth date, other indirect methods would be of interest. This study aimed to determine the pr...
Article
Paratuberculosis is a worldwide infectious disease caused by Mycobacterium avium ssp. paratuberculosis (MAP). Various ruminant species can be affected by the disease, and the diagnosis of the disease is challenging in the absence of a gold standard test. The aim of this systematic review protocol is to determine the accuracy of the direct and indir...
Article
The detection of lung lesions in dairy calves is commonly achieved using thoracic ultrasonography (TUS) and radiography (TR). However, it remains unclear from the literature if one diagnostic procedure is superior to another. The main objective of this study was therefore to evaluate the sensitivity (Se) and specificity (Sp) of TUS and TR to detect...
Article
Mycobacterium avium subspecies paratuberculosis (Map) is the etiological agent of paratuberculosis of domestic and wild ruminants. Map strains are segregated into 2 main groups or strain types referred to as sheep (S) type and cattle (C) type. Few small ruminant Map strains have been genetically characterized to date. The present study was undertak...
Article
Full-text available
Paratuberculosis, a chronic disease affecting ruminant livestock, is caused by Mycobacterium avium subsp. paratuberculosis (MAP). It has direct and indirect economic costs, impacts animal welfare and arouses public health concerns. In a survey of 48 countries we found paratuberculosis to be very common in livestock. In about half the countries more...
Article
Objective: Fetal heart rate variability (fHRV) is an important indicator of health and disease, yet its physiological origins, neural contributions, in particular, are not well understood. We aimed to develop novel experimental and data analytical approaches to identify fHRV measures reflecting the vagus nerve contributions to fHRV. Approach: In...
Article
Full-text available
Neuroinflammation in utero may result in lifelong neurological disabilities. Astrocytes play a pivotal role in this process, but the mechanisms are poorly understood. No early postnatal treatment strategies exist to enhance neuroprotective potential of astrocytes. We hypothesized that agonism on α7 nicotinic acetylcholine receptor (α7nAChR) in feta...
Article
Full-text available
Background Characterization of the clinical signs, response to treatment and prognosis can be useful information for decision‐making when evaluating cattle with pharyngeal trauma. Objective To describe the signalment, history, clinicopathologic, endoscopic, ultrasonographic, radiographic, and postmortem findings as well as treatments and outcomes...
Article
Objective To report the clinical presentation, treatment, and outcome of cattle undergoing surgical extraction of apically infected cheek teeth (CT). Study design Short case series. Animals Nine adult cattle. Methods Medical records were searched for cattle having a diagnosis of apical infection of CT that were treated with surgical extraction b...
Preprint
Full-text available
Heart rate variability (HRV) is an important indicator of health and disease, yet its physiological origins are poorly understood. The exact neural contributions to HRV are not well understood. In near-term fetal sheep, we aimed to identify fetal HRV measures reflecting the vagus nerve contributions to HRV. Fetal HRV was recorded during surgery and...
Article
Full-text available
Lameness is a severe welfare problem in cattle and has a detrimental effect on longevity, productivity, and reproductive performance. This study aimed to describe the frequency and distribution of foot lesions in cattle using hoof trimming records over a period of 6 years in the Province of Antioquia (Colombia). The data collection instrument enabl...
Preprint
Full-text available
Neuroinflammation in utero may result in lifelong neurological disabilities. Astrocytes play a pivotal role, but the mechanisms are poorly understood. No early postnatal treatment strategies exist to enhance neuroprotective potential of astrocytes. We hypothesized that agonism on {\alpha}7 nicotinic acetylcholine receptor ({\alpha}7nAChR) in fetal...
Article
Paratuberculosis is a chronic infectious enteritis of ruminants caused by Mycobacterium avium subsp. paratuberculosis (MAP). In sheep, the antemortem detection of the infection is challenging given the slow progression of the disease and the lack of sensitive, specific, and cost-effective validated tests. We adapted an in-house real-time PCR (rtPCR...
Article
A 3-week-old female dairy calf was presented because of severe weakness and diarrhea. Physical examination and ultrasound findings lead to a tentative diagnosis of intestinal obstruction, although serum biochemistry suggested a primary renal disorder. Reassessment of ultrasound images allowed diagnosis of hydronephrosis that had been misdiagnosed p...
Article
Full-text available
Background: Threshold values for total nucleated cell count (TNCC) and protein concentration in cerebrospinal fluid (CSF) of downer dairy cows suggestive of a spinal cord lesion were recently published. Objectives: Determine short- and long-term survival of downer cows that underwent CSF analysis using the reported threshold values. Evaluate the...
Article
A latent class model fit within a Bayesian framework was used to estimate the sensitivity and specificity of individual fecal culture (IFC) in liquid medium (Para TB culture liquid medium and BACTEC MGIT 960 system) for the detection of Mycobacterium avium subsp. paratuberculosis (MAP) infections in Québec dairy cows. As a secondary objective, the...
Article
Objectives (1) To develop an evaluation grid to provide a systematic interpretation of calves' articular radiographs, (2) to describe radiographic lesions of septic arthritis in dairy calves less than 6 months of age, (3) to investigate potential associations between demographic data or synovial bacteriological culture results and radiographic lesi...
Article
Bovine respiratory disease complex is a major cause of illness in dairy calves. The diagnosis of active infection of the lower respiratory tract is challenging on daily basis in the absence of accurate clinical signs. Clinical scoring systems such as the Californian scoring system, are appealing but were developed without considering the imperfecti...
Chapter
The non-neuronal, immunological effects of the cholinergic signaling are exerted on the system’s scale of observation via the vagus nerve and on the cellular scale via α7 nicotinic acetylcholine receptor (nAChR) signaling in myeloid cells of the periphery or brain’s microglia and astrocytes. The developmental effects of such multi-scale signaling c...
Article
OBJECTIVE To describe clinical findings and diagnostic test results and identify potential prognostic indicators for calves with septic arthritis. DESIGN Retrospective case series. ANIMALS 64 calves with septic arthritis. PROCEDURES The medical record database for a veterinary teaching hospital was searched to identify calves ≤ 6 months old that we...
Article
Paratuberculosis is a chronic and contagious enteric disease of ruminants caused by Mycobacterium avium subsp. paratuberculosis (MAP). Control of paratuberculosis is justified given the associated economic losses and the potential role of MAP in Crohn’s disease in humans. Management practices that limit exposure of susceptible animals to MAP are mo...
Article
Objective: The utility of fetal heart rate (FHR) monitoring can only be achieved with an acquisition sampling rate that preserves the underlying physiological information on the millisecond time scale (1000 Hz rather than 4 Hz). For such acquisition, fetal ECG (fECG) is required, rather than the ultrasound to derive FHR. We tested one recently dev...
Data
Figure S1. Forest plot and summary receiver operating characteristic plot of studies reporting the accuracy of refractometry and Brix refractometry in the same calves for the diagnosis of inadequate transfer of passive immunity in calves. Figure S2. Forest plot and hierarchical receiver operating characteristic (HSROC) curve of studies reporting t...
Article
Full-text available
Background: Transfer of passive immunity in calves can be assessed by direct measurement of immunoglobulin G (IgG) by methods such as radial immunodiffusion (RID) or turbidimetric immunoassay (TIA). IgG can also be measured indirectly by methods such as serum refractometry (REF) or Brix refractometry (BRIX). Objectives: To determine the accuracy...
Article
Full-text available
Neuroinflammation in utero may result in life-long neurological disabilities. Microglia play a pivotal role, but the mechanisms are poorly understood. No early postnatal treatment strategies exist to enhance neuroprotective potential of microglia. We hypothesized that agonism on α7 nicotinic acetylcholine receptor (α7nAChR) in fetal microglia will...
Article
The acute abdomen is a term used to characterize an animal presented as an emergency, in a more or less severe critical state, and for which medical and possibly surgical treatment will be necessary. To succeed, the clinician should use a systematic approach, have an excellent knowledge of the bovine abdominal anatomy, and have a good understanding...
Article
A bovine practitioner should master abdominal exploratory surgery (laparotomy). Several gastrointestinal (GI) problems require surgical correction to save the animal's life and to keep it in production. This article reviews the surgical preparation, procedures, and the postoperative care of several conditions affecting the GI tract of cattle.
Article
Paratuberculosis is a chronic and contagious enteric disease of ruminants caused by Mycobacterium avium subsp. paratuberculosis (MAP). This disease of worldwide distribution is responsible for significant economic losses and the bacteria itself has been linked to human Crohn's disease. Paratuberculosis control programs focus on reducing MAP transmi...
Article
Full-text available
We developed an algorithm for high-quality, non-invasive maternal and fetal ECG (fECG) monitoring. We tested its ability to extract fECG from a single channel maternal thoracic ECG signal rather than the routine abdominal signal, and compare it with other algorithms. At 126dG, ECG was attached to near-term ewe and fetal shoulders, manubrium and xyp...
Article
Microbial overgrowth can interfere with Mycobacterium avium subsp. paratuberculosis (MAP) growth and detection. We estimated the percentage of positive samples by PCR performed on the incubated media of individual fecal samples classified as non-interpretable (NI) by bacteriologic culture of liquid media. A total of 262 liquid cultures declared NI...
Article
Full-text available
Background: Diagnosis of central nervous system (CNS) lesions in recumbent dairy cattle (RDC) is challenging because neurologic examination is limited and medical imaging often is challenging or unrewarding. Cerebrospinal fluid (CSF) analysis is useful in the diagnosis of CNS disorders in cattle. However, its utility in identifying spinal cord les...
Article
The objective of this study was to determine if precolostral blood samples are useful to detect apparent fetal infections with bovine viral diarrhea (BVD) and infectious bovine rhinotracheitis (IBR) viruses. A convenience sample of 317 sera from 50 Canadian herds was used in the study. Antibody level was measured using 2 commercial IBR and BVD ELIS...
Article
In this article, the neurologic examination of ruminants is reviewed. The proposed approach is simple, although thorough and methodical. The bovine veterinary practitioner should be able to efficiently assess the nervous system to rule out a primary neurologic disorder. Simple observations and procedures are suggested to allow evaluation of the ner...
Article
Full-text available
Background: The signalment, clinicopathologic, bacteriological, histopathological, ultrasonographic characteristics, and the treatment and outcomes of adult cattle with cholangiohepatitis are poorly defined. Animals: Thirteen Holstein cows with cholangiohepatitis. Methods: Retrospective study of medical records of cattle admitted to the CHUV a...
Preprint
Full-text available
Neuroinflammation in utero may result in life-long neurological disabilities. Microglia play a pivotal role, but the mechanisms are poorly understood. No early postnatal treatment strategies exist to enhance neuroprotective potential of microglia. We hypothesized that agonism on α7 nicotinic acetylcholine receptor (α7nAChR) in fetal microglia will...
Article
Background: The chronically instrumented fetal sheep is a widely used animal model to study fetal brain development in health and disease, but no methods exist yet to interrogate dedicated brain cell populations to identify their molecular and genomic phenotype. For example, the molecular mechanisms whereby microglia or astrocytes contribute to in...
Article
Full-text available
Culture of Mycobacterium avium subsp. paratuberculosis (MAP) is the definitive antemortem test method for paratuberculosis. Microbial overgrowth is a challenge for MAP culture, as it complicates, delays, and increases the cost of the process. Additionally, herd status determination is impeded when noninterpretable (NI) results are obtained. The per...
Article
Lameness is an important problem in cattle and is often associated with an important economic loss in beef and milk production. Because of the pain, it is becoming an important welfare issue and represents 1 of the major culling causes in dairy herds. The joint is the second most important cause of lameness after the digit. There is in an important...
Article
Full-text available
Vagus nerve stimulation (VNS) has been used since 1997 for treatment of drug-resistant epilepsy. More recently, an off-label use of VNS has been explored in animal models and clinical trials for treatment of a number of conditions involving the innate immune system. The underlying premise has been the notion of the cholinergic antiinflammatory path...