Myosin heavy-chain myopathy in 2 American quarter horses.

A 1.5-year-old American quarter horse gelding (case 1) and an 11-month-old American quarter horse filly (case 2) were presented for acute onset pelvic lameness and lethargy. Case 1 had nasal discharge, while case 2 developed rapid muscle atrophy. Both horses had elevated serum creatine kinase activity. The horses showed similar polyphasic histiocytic and lymphoplasmacytic myositis with necrosis, mineralization, and regeneration. Additionally, case 1 had Streptococcus equi subsp. equi-induced suppurative retropharyngeal lymphadenitis with renal purpura hemorrhagica and myoglobinuric nephropathy. A focal pulmonary abscess caused by Actinobacillus equuli was found in case 2. Genetic testing revealed case 1 as heterozygous and case 2 as homozygous for the E321G MYH1 variant, supporting the diagnosis of myosin heavy-chain myopathy, with concomitant bacterial disease as potential triggers.

Neurologic and cutaneous infection by Clostridium piliforme in a kitten with systemic Tyzzer disease.

Tyzzer disease (TD) is a highly fatal condition of animals caused by Clostridium piliforme and characterized pathologically by enteritis, hepatitis, myocarditis, and occasionally encephalitis. Cutaneous lesions have been reported only rarely in animals with TD, and infection of the nervous system has not been described in cats, to our knowledge. We describe here neurologic and cutaneous infection by C. piliforme in a shelter kitten with systemic manifestations of TD and coinfection with feline panleukopenia virus. Systemic lesions included necrotizing typhlocolitis, hepatitis, myocarditis, and myeloencephalitis. The cutaneous lesions consisted of intraepidermal pustular dermatitis and folliculitis, with necrosis of keratinocytes and ulceration. Clostridial bacilli were identified within the cytoplasm of keratinocytes by fluorescence in situ hybridization, and a PCR assay was positive for C. piliforme. C. piliforme can infect keratinocytes leading to cutaneous lesions in cats with the location suggesting direct contact with contaminated feces as a route of infection.

Detection of invasive Escherichia coli in dogs with granulomatous colitis using immunohistochemistry.

Granulomatous colitis in dogs can be associated with infection of the colonic mucosa by invasive strains of Escherichia coli. To date, fluorescence in situ hybridization (FISH) is the gold-standard method to assess intramucosal and intracellular bacterial invasion. However, FISH requires expensive fluorescence microscopy equipment and is therefore not widely available. We investigated the use of immunohistochemistry (IHC) as an alternative method to detect invasive E. coli in dogs with granulomatous colitis. Archived paraffin-embedded blocks were selected from 26 dogs with colitis, in which FISH had been performed by an outside laboratory. Using a polyclonal antibody, IHC for E. coli was performed on sections cut from the same blocks, and the presence of invasive E. coli was recorded. All 11 specimens in which FISH had detected E. coli were also positive on IHC, with strong immunolabeling in the cytoplasm of macrophages and extracellularly in the lamina propria; all 15 specimens that were negative for invasive bacteria on FISH were also negative on IHC. We found that IHC is a sensitive technique for the detection of invasive E. coli in dogs with granulomatous colitis.

Immunohistochemical Expression of Oxidative Stress and Apoptosis Markers in Archived Liver Specimens from Dogs with Chronic Hepatitis.

Chronic hepatitis (CH) in dogs is histologically characterized by an inflammatory infiltration of the liver accompanied by hepatocellular apoptosis or necrosis, varying degrees of fibrosis and regeneration. Oxidative stress has been suggested to play a role in the pathogenesis of various liver diseases, including CH. This study assessed the immunohistochemical expression of markers of oxidative stress (4-hydroxynonenal [4-HNE] and malondialdehyde [MDA]) and apoptosis (active caspase-3 [casp-3]) in 35 surplus archived formalin-fixed paraffin-embedded liver biopsies from 25 dogs with CH and 10 control dogs that had no significant hepatic changes. Correlations between immunohistochemical markers and necroinflammatory, fibrosis and histological copper scores, and hepatic copper concentrations were also determined. There were no significant differences in 4-HNE expression between the two groups. Control dogs had lower hepatic MDA scores than dogs with CH. MDA scores were positively correlated with copper scores as well as hepatic copper concentrations. There was no significant difference in casp-3-positive hepatocytes between groups. However, a positive correlation between casp-3 immunoreactivity and copper scores, as well as hepatic copper concentrations, was identified. Necroinflammatory and fibrosis scores were positively correlated with immunoreactivity for MDA and casp-3. MDA and casp-3 are expressed in canine liver and both markers are correlated with necroinflammatory scores, fibrosis scores and hepatic copper accumulation. Our results suggest the utility of immunolabelling for MDA and casp-3 for assessment of hepatic oxidative stress and apoptosis, respectively, in dogs with CH.

Effect of chronic and acute enterotoxigenic E. coli challenge on growth performance, intestinal inflammation, microbiome, and metabolome of weaned piglets.

Post-weaning enteropathies in swine caused by pathogenic E. coli, such as post-weaning diarrhea (PWD) or edema disease (ED), remain a significant problem for the swine industry. Reduction in the use of antibiotics over concerns of antibiotic resistance and public health concerns, necessitate the evaluation of effective antibiotic alternatives to prevent significant loss of livestock and/or reductions in swine growth performance. For this purpose, an appropriate piglet model of pathogenic E. coli enteropathy is required. In this study, we attempted to induce clinical signs of post-weaning disease in a piglet model using a one-time acute or lower daily chronic dose of a pathogenic E. coli strain containing genes for both heat stable and labile toxins, as well as Shiga toxin. The induced disease state was monitored by determining fecal shedding and colonization of the challenge strain, animal growth performance, cytokine levels, fecal calprotectin, histology, fecal metabolomics, and fecal microbiome shifts. The most informative analyses were colonization and shedding of the pathogen, serum cytokines, metabolomics, and targeted metagenomics to determine dysbiosis. Histopathological changes of the gastrointestinal (GI) tract and tight junction leakage as measured by fecal calprotectin concentrations were not observed. Chronic dosing was similar to the acute regimen suggesting that a high dose of pathogen, as used in many studies, may not be necessary. The piglet disease model presented here can be used to evaluate alternative PWD treatment options.

Immunophenotype of the inflammatory response in the central and enteric nervous systems of cockatiels (Nymphicus hollandicus) experimentally infected with parrot bornavirus 2.

Proventricular dilatation disease is a lethal disease of psittacine birds. In this study, we characterized the local cellular immune response in the brain, proventriculus, and small intestine of 27 cockatiels (Nymphicus hollandicus) experimentally infected with parrot bornavirus 2 (PaBV-2). Perivascular cuffs in the brain were composed of CD3+ T-lymphocytes and Iba1+ macrophages/microglia in most cockatiels (n = 26). In the ganglia of the proventriculus, CD3+ T-lymphocytes (n = 17) and Iba1+ macrophages (n = 13) prevailed. The ganglia of the small intestine had a more homogeneous distribution of these leukocytes, including PAX5+ B-lymphocytes (n = 9), CD3+ T-lymphocytes (n = 8), and Iba1+ macrophages (n = 8). Our results indicate that perivascular cuffs in the brain and the inflammatory infiltrate in the proventriculus of PaBV-2-infected cockatiels is predominately composed of T-lymphocytes, while the inflammatory infiltrates in the ganglia of the small intestine are characterized by a mixed infiltrate composed of T-lymphocytes, B-lymphocytes, and macrophages.

Shapes of pathology / As formas da patologia

The shape is one of the key features of a lesion and a pathologist must be able to identify and interpret these forms in the context of any gross and microscopic changes. One of the principles of adult learning is to engage the learner with previously understood information. If, when presenting material that is new, a connection with something the student already has familiarity with, the learning process is accelerated. As the learners are already familiar with shapes they have encountered throughout their pre-pathology learning, these can be used to hasten the incorporation and understanding of lesions. This paper describes various shapes that are used in describing lesions in veterinary pathology.(AU)

A forma é uma das principais características de uma lesão. Um patologista deve ser capaz de identificar e interpretar essas formas no contexto de quaisquer alterações macroscópicas ou microscópicas. Um dos princípios da aprendizagem de adultos é envolver o aluno com informações previamente compreendidas. Se, ao apresentar um material novo, se estabelece uma conexão com algo que o aluno já conhece, o processo de aprendizagem torna-se mais rápido e eficiente. Como os alunos já estão familiarizados com as formas que encontraram ao longo de sua aprendizagem pré-patologia, elas podem ser usadas para acelerar a incorporação e a compreensão das lesões. Este artigo descreve várias formas que são usadas na descrição de lesões em patologia veterinária.(AU)

Shapes of pathology

ABSTRACT: The shape is one of the key features of a lesion and a pathologist must be able to identify and interpret these forms in the context of any gross and microscopic changes. One of the principles of adult learning is to engage the learner with previously understood information. If, when presenting material that is new, a connection with something the student already has familiarity with, the learning process is accelerated. As the learners are already familiar with shapes they have encountered throughout their pre-pathology learning, these can be used to hasten the incorporation and understanding of lesions. This paper describes various shapes that are used in describing lesions in veterinary pathology.

RESUMO: A forma é uma das principais características de uma lesão. Um patologista deve ser capaz de identificar e interpretar essas formas no contexto de quaisquer alterações macroscópicas ou microscópicas. Um dos princípios da aprendizagem de adultos é envolver o aluno com informações previamente compreendidas. Se, ao apresentar um material novo, se estabelece uma conexão com algo que o aluno já conhece, o processo de aprendizagem torna-se mais rápido e eficiente. Como os alunos já estão familiarizados com as formas que encontraram ao longo de sua aprendizagem pré-patologia, elas podem ser usadas para acelerar a incorporação e a compreensão das lesões. Este artigo descreve várias formas que são usadas na descrição de lesões em patologia veterinária.

Differentiation of lymphocytic-plasmacytic enteropathy and small cell lymphoma in cats using histology-guided mass spectrometry.

BACKGROUND: Differentiation of lymphocytic-plasmacytic enteropathy (LPE) from small cell lymphoma (SCL) in cats can be challenging. HYPOTHESIS/OBJECTIVE: Histology-guided mass spectrometry (HGMS) is a suitable method for the differentiation of LPE from SCL in cats. ANIMALS: Forty-one cats with LPE and 52 cats with SCL. METHODS: This is a retrospective clinicopathologic study. Duodenal tissue samples of 17 cats with LPE and 22 cats with SCL were subjected to HGMS, and the acquired data were used to develop a linear discriminate analysis (LDA) machine learning algorithm. The algorithm was subsequently validated using a separate set of 24 cats with LPE and 30 cats with SCL. Cases were classified as LPE or SCL based on a consensus by an expert panel consisting of 5-7 board-certified veterinary specialists. Histopathology, immunohistochemistry, and clonality testing were available for all cats. The panel consensus classification served as a reference for the calculation of test performance parameters. RESULTS: Relative sensitivity, specificity, and accuracy of HGMS were 86.7% (95% confidence interval [CI]: 74.5%-98.8%), 91.7% (95% CI: 80.6%-100%), and 88.9% (95% CI: 80.5%-97.3%), respectively. Comparatively, the clonality testing had a sensitivity, specificity, and accuracy of 85.7% (95% CI: 72.8%-98.7%), 33.3% (95% CI: 14.5%-52.2%), and 61.5% (95% CI: 48.3%-74.8%) relative to the panel decision. CONCLUSIONS AND CLINICAL IMPORTANCE: Histology-guided mass spectrometry was a reliable technique for the differentiation of LPE from SCL in duodenal formalin-fixed paraffin-embedded samples of cats and might have advantages over tests currently considered state of the art.

Bacterial Biogeography of the Colon in Dogs With Chronic Inflammatory Enteropathy.

The intestinal microbiota is believed to play a role in the pathogenesis of inflammatory bowel disease in humans and chronic inflammatory enteropathy (CIE) in dogs. While most previous studies have described the gut microbiota using sequencing methods, it is fundamental to assess the spatial distribution of the bacteria for a better understanding of their relationship with the host. The microbiota in the colonic mucosa of 22 dogs with CIE and 11 control dogs was investigated using fluorescence in situ hybridization (FISH) with a universal eubacterial probe (EUB338) and specific probes for select bacterial groups. The number of total bacteria labeled with EUB338 probe was lower within the colonic crypts of dogs with CIE compared to controls. Helicobacter spp. and Akkermansia spp. were decreased on the colonic surface and in the crypts of dogs with CIE. Dogs with CIE had increased number of Escherichia coli/Shigella spp. on the colonic surface and within the crypts compared to control dogs. In conclusion, the bacterial microbiota in the colonic mucosa differed between dogs with and without CIE, with depletion of the crypt bacteria in dogs with CIE. The crypt bacterial species that was intimately associated with the host mucosa in control dogs was composed mainly of Helicobacter spp.

Comparison of 2 fixatives in the porcine colon for in situ microbiota studies.

Fixation is the first step towards preservation of tissues and can impact downstream histological applications. Historically, formalin has been the fixative of choice in both research and clinical settings due to cost, accessibility, and broad applicability. Here, we describe a method for collection of porcine colon, and compare the usage of Carnoy's solution (CS) to a 10% neutral buffered formalin (NBF) in tissue fixation. Consecutive colon samples were collected from 24 four-wk-old piglets and fixed in CS for 45 min or NBF for 24 h. We measured the thickness of the inner mucus layer using Alcian Blue stain and found thicker inner mucus layers in porcine colons fixed with CS as compared to NBF (P < 0.0001). Carnoy's solution-fixed colon exhibited greater bacterial cell counts than NBF-fixed colon (P < 0.0022) after labeling with an eubacterial probe in fluorescent in situ hybridization (FISH). No difference was observed between the mucosal height (P = 0.42) and number of goblet cells (P = 0.66) between the 2 fixatives. From this, we concluded CS is more suitable than NBF for the preservation of the mucus layer and the associated mucosal bacteria in the porcine colon without compromising on overall tissue morphology. This study provides a useful sampling and fixation methodology for histology studies in the porcine gastrointestinal tract, and may be beneficial to microbiota, pathology, and nutrition studies.

Enhanced protective efficacy of Borrelia burgdorferi BB0172 derived-peptide based vaccine to control Lyme disease.

Lyme disease (LD) accounts for over 70% of tick-borne disease reported in the United States. The disease in humans is characterized by skin rash, arthritis, cardiac and neurological signs. Vaccination is the most efficient preventive measure that could be taken to reduce the incidence of the LD worldwide; however, at present no vaccine is available. In this study, evaluation of the Borrelia burgdorferi BB0172-derived peptide (PepB) in conjugated formulations was investigated as a vaccine candidate in murine model of LD. In brief, PepB was conjugated to the Cross-Reacting Material 197 (CRM197) and to Tetanus Toxoid heavy chain (TTHc) molecules, and subsequently used to immunize C3H/HeN mice. Following the challenge with 105 spirochetes/mouse via subcutaneous inoculation, TTHc:PepB construct showed protection in 66% of the immunized animals. Hence, to further evaluate the efficacy of TTHc:PepB, immunized mice were challenged with B. burgdorferi using the tick model of infection. The outcome of this experiment revealed that serum from TTHc:PepB immunized mice was borrelicidal. After tick infection, bacterial burden was significantly reduced (over 70%) in vaccinated animals when compared with the control groups regardless of whether the mice were infested 8 or 12-weeks post-priming. Therefore, we conclude that PepB conjugated antigens can serve as an alternative to prevent LD; nevertheless, further studies will be needed to dissect the mechanisms by which anti-PepB IgG antibodies are able to kill B. burgdorferi in vitro and in vivo to further advance in the development of formulations and delivery alternative to generate a safe anti-LD vaccine.

Distribution of Viral Antigen and Inflammatory Lesions in the Central Nervous System of Cockatiels ( Nymphicus hollandicus) Experimentally Infected with Parrot Bornavirus 2.

Neurotropism is a striking characteristic of bornaviruses, including parrot bornavirus 2 (PaBV-2). Our study evaluated the distribution of inflammatory foci and viral nucleoprotein (N) antigen in the brain and spinal cord of 27 cockatiels ( Nymphicus hollandicus) following experimental infection with PaBV-2 by injection into the pectoral muscle. Tissue samples were taken at 12 timepoints between 5 and 114 days post-inoculation (dpi). Each experimental group had approximately 3 cockatiels per group and usually 1 negative control. Immunolabeling was first observed within the ventral horns of the thoracic spinal cord at 20 dpi and in the brain (thalamic nuclei and hindbrain) at 25 dpi. Both inflammation and viral antigen were restricted to the central core of the brain until 40 dpi. The virus then spread quickly at 60 dpi to both gray and white matter of all analyzed sections of the central nervous system (CNS). Encephalitis was most severe in the thalamus and hindbrain, while myelitis was most prominent in the gray matter and equally distributed in the cervical, thoracic, and lumbosacral spinal cord. Our results demonstrate a caudal to rostral spread of virus in the CNS following experimental inoculation of PABV-2 into the pectoral muscle, with the presence of viral antigen and inflammatory lesions first in the spinal cord and progressing to the brain.

Distribution of bile acid receptor TGR5 in the gastrointestinal tract of dogs.

Takeda-G-protein-receptor-5 (TGR5) is a receptor for bile acids and its expression has been described in a variety of tissues and species. Characterization of TGR5 distribution and function has been investigated in drug discovery for the treatment of metabolic diseases in humans. Because dogs are one of the species used in biomedical research and share some similarities with human gastrointestinal diseases, the objective of this study was to characterize the distribution of TGR5 receptor in the canine species. This study characterizes the distribution of TGR5 receptor in the gastrointestinal tract, liver, gallbladder, and pancreas of 8 dogs. The distribution of TGR5 antigen and mRNA expression was investigated using immunohistochemistry and RNA in situ hybridization, respectively. TGR5 immunolabeling was located in the cell membrane or in the cell membrane and cytoplasm. TGR5 immunolabeling was broadly distributed in macrophages, endothelial cells, ganglion cells, and leiomyocytes throughout all the examined tissues. Epithelial cells from tongue, stomach to rectum, as well as from gallbladder, biliary and pancreatic ducts demonstrated TGR5 immunolabeling. In endocrine cells, TGR5 immunolabeling was observed in intestinal enteroendocrine cells and islets of Langerhans in the pancreas. The hepatocytes had a unique pattern of immunolabeling located on the canalicular surface of the cell membrane. TGR5 mRNA expression was located mainly in the nucleus and the only negative cells throughout all examined tissues were striated muscle from tongue and esophagus, muscularis mucosae, esophageal glands, and hepatic sinusoids. These findings indicate that the bile acid receptor TGR5 is ubiquitously distributed in the canine gastrointestinal tract.

Gross and histopathological pitfalls found in the examination of 3338 cattle brains submitted to the BSE surveillance program in Brazil / Ciladas macroscópicas e histopatológicas encontradas no exame de 3338 encéfalos de bovinos submetidos ao programa de vigilância da EEB no Brasil

This study stems from the findings during the gross and histopathological exam of 3,338 cattle brains as part of the bovine spongiform encephalopathy (BSE) active surveillance program of the Brazilian Ministry of Agriculture, Livestock, and Supply from 2001 to 2005. The work was carried out in the Veterinary Pathology Laboratory of the Federal University of Santa Maria which at the time (2001-2007) was the national reference laboratory for the diagnosis of BSE and other transmissible spongiform encephalopathies. Both gross and histopathological aspects are described. Several gross aspects were annotated: anatomic normal structures not commonly recognized (non-lesions), lesions of no clinical significance, postmortem changes and artifacts; all these can amount to important pitfalls that distract the pathologist during the routine gross examination of the central nervous system (CNS). Accordingly, equivalent pitfalls were described in the histological examination. Non-lesions observed were the pineal body, embryo remnants such as the external germinal layer of the cerebellum, subependymal plates, and clusters of neuroblasts in the basal ganglia; or circumventricular structures such as area postrema, subcomisural organ, and melanosis in the leptomeninges and vessel walls. Lesions with little or no clinical importance included age-related changes as lipofuscin, hemosiderin, mineralization and hyalinization of vessel walls within the brain and meninges. Corpora amylacea and corpora arenacea were detected respectively in astrocyte processes and the pineal body. Cytoplasmic neuronal vacuolization was observed in the red nucleus and habenular nucleus. Sarcocystis sp. without a correspondent inflammatory reaction was rarely observed. Included within findings with no clinical manifestation were axonal spheroids and perivascular mononuclear cuffings. Changes in the CNS due to killing, sampling and fixation methods can obscure or distract from the more critical lesions. The ones related to the process of killing included hemorrhages caused in cattle destroyed by a captive bolt. Artifacts related to sampling and handling of CNS tissue consisted of inclusion of bone sand in the neural tissue from sawing the calvarium; dark neurons produced by excessive handling of the brain, and micro-organisms that contaminated the tissues during sampling or histological processing. Postmortem autolytic or putrefactive changes observed included vacuolar changes in the myelin sheath, clear halos surrounding neurons and oligodendrocytes, clusters of putrefaction bacilli within vessels or dispersed throughout the brain tissue associated or not to clear halos. One interesting, and somewhat frequent, postmortem autolytic change found in the bovine brain was the partial dissolution of the granule cell layer (GCL) of the cerebellum, also referred to as conglutination of the GCL or as the French denomination "état glace". Due to the shortage of comprehensive publications in the subject, this review is intended to address the main pitfalls that can be observed in the brain of cattle hoping to help other pathologists avoiding misinterpret them.(AU)

Os resultados deste estudo foram obtidos pelo exame macroscópico e histopatológico de 3.338 cérebros de bovinos examinados durante o programa de vigilância ativa da encefalopatia espongiforme bovina (BSE) do Ministério da Agricultura, Pecuária e Abastecimento (MAPA), de 2001 a 2005. O trabalho foi realizado no Laboratório de Patologia Veterinária (LPV) da Universidade Federal de Santa Maria (UFSM) que, de 2001 a 2007, foi o laboratório nacional de referência para o diagnóstico da BSE e de outras encefalopatias espongiformes transmissíveis. Macroscopicamente, foram descritas estruturas anatômicas normais (não-lesões), mas que são, com frequência, interpretadas como lesões; lesões sem significado clínico; alterações pós-mortais e artefatos. Esses achados podem confundir e desviar a atenção do patologista durante o exame de rotina do sistema nervoso central (SNC). Da mesma forma, estruturas equivalentes foram descritas no exame histológico. As não-lesões observadas foram corpo pineal, remanescentes embrionários, como a camada germinativa externa do cerebelo, placas subependimárias e aglomerados de neuroblastos nos gânglios da base; ou estruturas circunventriculares, como área de postrema, órgão subcomissural e melanose em leptomeninges e paredes dos vasos. Lesões com pouca ou nenhuma importância relacionadas ao envelhecimento incluíram lipofuscina, hemossiderina, mineralização, hialinização das paredes dos vasos do encéfalo e das meninges. Corpora amylacea foram detectados em processos astrocíticos e corpora arenacea, no corpo pineal. Adicionalmente, foi observada vacuolização no citoplasma de neurônios do núcleo vermelho e do núcleo habenular. Sarcocystis sp. sem reação inflamatória correspondente foi raramente observado. Incluídos nos achados sem manifestação clínica estavam esferóides axonais e manguitos mononucleares perivasculares. Alterações no SNC causadas pelo método de abate, amostragem e fixação podem simular ou obscurecer lesões mais importantes. Aquelas relacionadas ao método de abate incluíram hemorragias causadas em bovinos dessensibilizados pelo dardo cativo ou por punção por faca da medula na articulação atlanto-occipital. Artefatos relacionados à amostragem e manuseio de tecido do SNC consistiram na inclusão de pó de osso no tecido neural em consequência do uso de serra para abrir a caixa craniana; neurônios escuros produzidos pelo manuseio excessivo do cérebro e micro-organismos que contaminaram os tecidos durante a amostragem ou processamento histológico. Alterações autolíticas pós-mortais ou de putrefação incluíram vacuolizações na bainha de mielina, halos claros em torno dos neurônios e oligodendrócitos, aglomerados de bacilos de putrefação dentro dos vasos ou dispersos em todo o tecido cerebral, relacionados ou não a halos claros. Uma alteração autolítica pós-mortal intrigante e relativamente frequente encontrada foi a dissolução parcial da camada de células granulares (CCG) do cerebelo, também referida como conglutinação da CCG ou "état glacé". Devido à escassez de publicações abrangentes neste assunto, esta revisão pretende abordar as principais ciladas que possam aparecer no cérebro de bovinos, na esperança de ajudar outros patologistas a evitar interpretá-las erroneamente.(AU)

Comparison of intestinal expression of the apical sodium-dependent bile acid transporter between dogs with and without chronic inflammatory enteropathy.

BACKGROUND: Intestinal absorption of bile acids is mediated by the apical sodium-dependent bile acid transporter (ASBT). Fecal bile acid dysmetabolism has been reported in dogs with chronic inflammatory enteropathy (CIE). OBJECTIVE: Characterization of ASBT distribution along the intestinal tract of control dogs and comparison to dogs with CIE. ANIMALS: Twenty-four dogs with CIE and 11 control dogs. METHODS: The ASBT mRNA and protein expression were assessed using RNA in situ hybridization and immunohistochemistry, respectively. The concentrations of fecal bile acids were measured by gas chromatography-mass spectrometry. The fecal microbiota dysbiosis index was assessed with a quantitative polymerase chain reaction panel. RESULTS: In control dogs, ASBT mRNA expression was observed in enterocytes in all analyzed intestinal segments, with highest expression in the ileum. The ASBT protein expression was restricted to enterocytes in the ileum, cecum, and colon. Dogs with CIE had significantly decreased expression of ASBT protein in the ileum (P = .001), which was negatively correlated with histopathological score (ρ = -0.40; Pcorr = .049). Additionally, dogs with CIE had a significantly increased percentage of primary bile acids in feces compared to controls (P = .04). The fecal dysbiosis index was significantly higher in dogs with CIE than in control dogs (P = .01). CONCLUSIONS AND CLINICAL IMPORTANCE: These findings indicate that ileal protein expression of ASBT is downregulated in dogs with CIE. This change may be linked to the inflammatory process, intestinal dysbiosis, and fecal bile acid dysmetabolism observed in these patients.

From nerves to brain to gastrointestinal tract: A time-based study of parrot bornavirus 2 (PaBV-2) pathogenesis in cockatiels (Nymphicus hollandicus).

Parrot bornaviruses (PaBVs) are the causative agents of proventricular dilatation disease, however key aspects of its pathogenesis, such as route of infection, viral spread and distribution, and target cells remain unclear. Our study aimed to track the viral spread and lesion development at 5, 10, 20, 25, 35, 40, 60, 80, 95 and 114 dpi using histopathology, immunohistochemistry, and RT-PCR. After intramuscular inoculation of parrot bornavirus 2 (PaBV-2) in the pectoral muscle of cockatiels, this virus was first detected in macrophages and lymphocytes in the inoculation site and adjacent nerves, then reached the brachial plexus, centripetally spread to the thoracic segment of the spinal cord, and subsequently invaded the other spinal segments and brain. After reaching the central nervous system (CNS), PaBV-2 centrifugally spread out the CNS to the ganglia in the gastrointestinal (GI) system, adrenal gland, heart, and kidneys. At late points of infection, PaBV-2 was not only detected in nerves and ganglia but widespread in the smooth muscle and/or scattered epithelial cells of tissues such as crop, intestines, proventriculus, kidneys, skin, and vessels. Despite the hallmark lesion of PaBVs infection being the dilation of the proventriculus, our results demonstrate PaBV-2 first targets the CNS, before migrating to peripheral tissues such as the GI system.

Intoxicação natural por Senecio brasiliensis em equinos / Natural poisoning by Senecio brasiliensis in horses

Intoxicações por plantas do gênero Senecio representam uma importante causa de morte em animais de produção, sendo Senecio brasiliensis a espécie mais envolvida nos casos de intoxicação espontânea. Nesse trabalho, são descritos os aspectos epidemiológicos, clínicos e anatomopatológicos de um surto de intoxicação natural por Senecio brasiliensis em equinos. Dois equinos, de um total de dezoito, foram afetados. Os casos ocorreram em uma propriedade rural no município de São Martinho da Serra, Rio Grande do Sul, Brasil. Grande quantidade de exemplares de Senecio brasiliensis em estágio de brotação foi encontrada na área onde os equinos estavam. Os animais eram da raça Crioula, sendo uma égua com quatro anos e um potro com cinco meses. A égua apresentou evolução aguda da doença com duração de três dias e o potro evolução crônica de dois meses. As principais manifestações clínicas observadas em ambos os equinos incluíam apatia, anorexia, emagrecimento, desidratação e sinais neurológicos. Além disso, havia moderado edema subcutâneo na região ventral do abdômen e marcada icterícia nas mucosas ocular, oral e vulvar da égua e palidez das mucosas no potro. Na avaliação bioquímica do potro, havia acentuado aumento da atividade sérica da gamaglutamil transferase (119 U/L), aumento da fosfatase alcalina (434 U/L) e hipoalbuminemia (2,1g/dL). No hemograma do mesmo, observou-se leve anemia normocítica e normocrômica (30% de hematócrito; VCM: 39,5 fL; HCM: 15,3pg). As alterações presentes em ambas as necropsias foram observadas principalmente no fígado, que estava difusamente aumentado de tamanho, escuro e firme. Na superfície de corte, observaram-se acentuação do padrão lobular e hemorragia. Histologicamente, no fígado dos equinos, havia graus variados de necrose coagulativa, hemorragia, fibrose, proliferação de ductos biliares, hepatomegalocitose e bilestase. Nas diferentes seções analisadas do encéfalo, havia alterações astrocitárias restritas à substância cinzenta, predominantemente, no córtex telencefálico. Os astrócitos degenerados eram similares aos astrócitos de Alzheimer tipo II. O diagnóstico da intoxicação nesses casos foi baseado na epidemiologia, no quadro clínico, nas lesões de necropsia e nos achados histopatológicos. Cabe ressaltar que a necrose de coagulação e a discreta fibrose e proliferação de ductos biliares observados na égua, constituiu uma apresentação subaguda da intoxicação, enquanto que a fibrose, mais predominante no potro, caracterizou uma hepatopatia crônica.(AU)

Poisoning due to plants of the genus Senecio is considered an important cause of death in livestock. Senecio brasiliensis is the most common species involved in spontaneous cases. This paper describes the epidemiological, clinical and pathological aspects of a natural outbreak of intoxication with Senecio brasiliensis affecting two out of eighteen horses in a farm. The cases occurred in the municipality of Sao Martinho da Serra, Rio Grande do Sul State, Southern Brazil. A large amount of Senecio brasiliensis in its sprouting stage was found in the fields where the horses used to be kept. A four-year-old, Crioulo mare and a five-month-old, male, Crioulo foal were affected. The clinical course was acute in the mare, comprising three days and chronic in the foal, lasting for two months. The main clinical signs in both animals included apathy, anorexia, weight loss, dehydration and neurological signs. Moreover, subcutaneous edema was noted in the ventral abdomen and the mucous membranes were icteric in the mare and pale in the foal. The serum biochemistry in the foal showed hypoalbuminemia (2.1g/dL), increased activity of the serum alkaline phosphatase (434 U/L) and gamma glutamyl transferase (119 U/L). In the hemogram, a mild normocytic normochromic anemia was noted in the foal (Hct: 30%; MCV: 39.5 fL; MCH: 15.3pg). Necropsy findings observed in both horses included an enlarged, dark red and firm liver with extensive areas of hemorrhage and enhanced lobular pattern on cut surface. Histologically, the liver showed variable degrees of fibrosis, coagulative necrosis, biliary ducts hyperplasia, megalocytosis and cholestasis. In the brain, the astrocytes in the cerebrum were degenerated and similar to Alzheimer type II astrocytes. The diagnosis in this outbreak was established based on the epidemiology, clinical picture, gross and histologic findings. It is noteworthy that the coagulative necrosis, minimal fibrosis, and biliary duct hyperplasia observed in the mare are characteristic of a subacute presentation. On the other hand, the fibrosis that was more prominent in the foal characterizes a chronic hepatopathy.(AU)