In situ hybridization to detect Escherichia coli in canine granulomatous colitis.

Canine granulomatous colitis (histiocytic ulcerative colitis) is an uncommon disease, predominantly of young French Bulldogs and Boxer dogs, that manifests from a dysregulated immune response, primarily to adherent-invasive Escherichia coli (AIEC). In conjunction with histopathology and periodic acid-Schiff staining, the diagnosis of granulomatous colitis currently relies on fluorescence in situ hybridization (ISH) or immunohistochemistry to identify and localize AIEC organisms within macrophages in the mucosa and/or submucosa. We investigated the utility of ISH for E. coli using formalin-fixed, paraffin-embedded specimens collected from 29 cases of suspected granulomatous colitis. Most confirmed cases of granulomatous colitis were in French Bulldogs (12 of 20; 60%) and Boxers (3 of 20; 15%), and the mean age was 25 ± 6 mo with no sex predilection. E. coli ISH signal localized bacterial genetic material within the mucosa in 20 of 29 (69%) cases, supporting the diagnosis. ISH signal was limited to the lumen in 8 of 29 (28%) cases, which did not support the identification of these organisms as AIEC. The remaining case had no hybridization signal, and the diagnosis of granulomatous colitis was not supported. Our results revealed that ISH is a quick and specific detection method that can effectively confirm the diagnosis of canine granulomatous colitis.

Adherent-invasive Escherichia coli associated with granulomatous colitis and extraintestinal dissemination in a Sphynx cat.

This case report describes a case of granulomatous colitis (GC) associated with adherent-invasive Escherichia coli (AIEC) with extension to cecum and ileum and dissemination to multiple lymph nodes, the spleen, and brain in a 10-year-old, male Sphynx cat. The cat had an episode of diarrhea 4 months prior to consultation due to sudden blindness. Signs rapidly progressed to ataxia, seizures, and death. Gross and histologic findings were consistent with granulomatous inflammation in all affected organs. In situ hybridization confirmed the presence of intracellular E. coli within enterocytes and infiltrating macrophages, and whole genome sequencing identified virulence traits commonly linked to AIEC strain. This is the first characterization of GC in a cat associated to AIEC resembling the metastatic form of Crohn's disease in humans and GC of dogs. Extraintestinal involvement might provide evidence of the ability of AIEC to promote granulomatous inflammation beyond the gut.

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.

Cytologic, histopathologic, and clinical features of granulomatous colitis in a French Bulldog.

A young French Bulldog was presented with clinical signs of chronic gastrointestinal disease, unresponsive to medical therapies. Parasite screenings and abdominal ultrasound failed to identify the etiology of the clinical signs. Cytologic evaluation of a rectal scraping sample diagnosed presumptive granulomatous colitis (GC) based on the presence of numerous macrophages with characteristic abundant, pink, granular cytoplasm, which showed an intense pink color when stained with periodic acid-Schiff. Tissue biopsy samples and Escherichia coli fluorescence in situ hybridization analysis confirmed the cytologic diagnosis. The cytologic, histopathologic, and clinical features and staining properties of GC in a French Bulldog are reported. Rectal scraping should be considered a part of the diagnostic evaluation in patients with suspected GC.

Correlation of cytology to histology in a case of canine granulomatous colitis in a Boxer dog.

A 2-year-old castrated male mixed breed dog presented to the North Carolina State Veterinary Teaching Hospital for chronic diarrhea with hematochezia and weight loss. Cytology performed on a rectal scraping revealed macrophages containing magenta, light pink, and variably blue granular inclusions, and phagocytosed material concerning for infectious organisms. Histopathology was consistent with granulomatous colitis and identified intra-histiocytic bacterial organisms, confirmed by fluorescent in situ hybridization (FISH)-tissue culture-confirmed Escherichia coli. Based on these findings, a diagnosis of granulomatous colitis was made. The patient was successfully treated with oral enrofloxacin, and near-complete remission of signs was achieved within 6 weeks. This report describes a case of granulomatous colitis in a mixed breed dog, and is the first published description of the cytologic features of this uncommon disease, offering a valuable cytologic-histologic correlation. In this case, the cytology was helpful in identifying features consistent with granulomatous colitis and prioritizing the differential diagnoses and diagnostic plan.

Successful Treatment of 3 Dogs With Fluoroquinolone-Resistant Escherichia coli Associated Granulomatous Colitis.

Successful resolution of Escherichia coli associated granulomatous colitis (ECGC) is becoming a challenge due to the development of fluoroquinolone resistant E coli, which is associated with poor prognosis. Three dogs presented with signs of chronic colitis and were diagnosed with ECGC. All 3 were initially treated with enrofloxacin and trimethoprim-sulfamethoxazole, without clinical improvement. Despite the fact that culture and susceptibility testing results demonstrate resistance to fluoroquinolone and trimethoprim-sulfamethoxazole, the addition of amikacin fully resolved the clinical signs in all 3 cases. This case series describes the clinical presentation, diagnostic findings, and successful treatment of 3 dogs with fluoroquinolone-resistant ECGC. It suggests an alternative strategy for multidrug-resistance ECGC patients. Further investigations are required to confirm the efficacy of and to determine the molecular mechanisms underpinning the apparent success of aminoglycoside antibiotic combinations for treatment of ECGC.

[Granulomatous colitis in a French Bulldog puppy]. / Granulomatöse Kolitis bei einem Französische-Bulldogge-Welpen.

A 6-month-old French bulldog was presented due to chronic large intestinal diarrhea of 4 months duration. The diagnostic procedures initiated by the referring veterinarian had resulted in a tentative diagnosis of chronic enteropathy, however treatment consisting of elimination diet as well as antibiotic, anthelmintic, anti-inflammatory and immunosuppressive medication had been unsuccessful. By means of endoscopy and histological examination, pronounced erosions and ulcerations of the colonic mucosa were detected. Fluorescence in situ hybridization enabled the identification of invasive Escherichia coli within the colonic mucosa and colonic macrophages, allowing for the diagnosis of granulomatous colitis. The dog showed complete remission of clinical signs following 8 weeks of treatment with enrofloxacin. This case report describes the first successful treatment of granulomatous colitis with enrofloxacin in a French bulldog puppy in Germany and is intended to sensitize the reader to this disease in (young) dogs.

Clinical characteristics and long-term outcome of E. coli-associated granulomatous ileocolitis in dogs: five cases (2010-2014).

OBJECTIVES: To describe the clinical characteristics and long-term outcome of Escherichia coli-associated granulomatous ileocolitis in dogs. METHODS: Retrospective review of medical records from dogs with periodic acid-Schiff positive (PAS+) granulomatous ileocolitis and mucosally invasive E. coli in the ileum and colon. Initial bacterial colonisation was evaluated using fluorescence in situ hybridization (FISH) in all dogs and corroborated with colonic and/or ileal culture, when performed. RESULTS: Four boxer dogs and 1 French Bulldog with PAS+ granulomatous ileocolitis (GIC) were evaluated. All dogs had chronic diarrhoea refractory to empirical therapy. Ileocolonoscopy revealed mucosal haemorrhage and ulceration in the ileum (3/4) and colon (5/5). E. coli were visualised as clusters within the ileal and colonic mucosa. Complete (CR, 4/5) or partial (PR, 1/5) clinical response to fluoroquinolones was noted in all dogs within 30 days. CR was sustained in three of four dogs (median disease-free interval 40 months, range 16 to 60). Two dogs relapsed while receiving fluoroquinolones. Repeat biopsy isolated multidrug-resistant, mucosally invasive E. coli in the ileum (1/2) and colon (2/2). Targeted antimicrobial therapy was associated with long-term PR (78 months) in both dogs. CLINICAL SIGNIFICANCE: Concurrent E. coli-associated granulomatous inflammation in the ileum and colon did not impart a poor clinical outcome or lack of response to the conventional standard of care for granulomatous colitis in dogs that were aggressively diagnosed and treated. Clinical outcome was influenced by antimicrobial resistance, with response dependent upon antimicrobial therapy informed by susceptibility testing.

Escherichia coli-associated granulomatous colitis in dogs treated according to antimicrobial susceptibility profiling.

BACKGROUND: Eradication of intramucosal Escherichia coli correlates with remission of periodic acid-Schiff-positive E coli-associated granulomatous colitis (GC). Treatment failures attributed to multidrug resistant (MDR) bacteria necessitate alternative approaches. HYPOTHESIS/OBJECTIVES: Determine clinical outcome of E coli-associated GC in dogs treated based on antimicrobial susceptibility profiling and characterize E coli phylogeny and resistance mechanisms. ANIMALS: Twenty Boxers and 4 French Bulldogs with E coli-associated GC. METHODS: Culture, antimicrobial susceptibility profiling, and molecular characterization of E coli were performed and response to treatment was evaluated. RESULTS: Initial biopsy sample culture yielded fluoroquinolone-sensitive (FQ-S) E coli from 9/24 dogs and fluoroquinolone-resistant (FQ-R) E coli from 15/24. All but 1 FQ-R E coli were MDR with susceptibility to macrophage-penetrating antimicrobials restricted to carbapenems in 13/15 dogs. Of 22/24 treated based on susceptibility profiling, 8/9 FQ-S dogs had complete initial clinical response (CR) during fluoroquinolone (FQ) treatment, whereas 9/13 FQ-R dogs had complete or partial response (PR) during meropenem or doxycycline treatment. In 5/9 FQ-S and 12/13 FQ-R dogs with follow-up ≥3 months, CR was sustained in 5/5 FQ-S (median, 25 months; range, 4-46) whereas 6/12 FQ-R had long-term CR (median, 59 months; range 15-102), 4/12 PR (median, 19 months; range, 5-65), and 2/12 had no response (NR). Four dogs with long-term follow-up died within 4 years of diagnosis, including 2 euthanized for refractory colitis. Escherichia coli were genetically diverse. Fluoroquinolone resistance was associated with mutations in gyrA and parC, with plasmid-mediated resistance less common. CONCLUSIONS AND CLINICAL IMPORTANCE: Antimicrobial treatment guided by susceptibility profiling was associated with positive long-term outcomes in >80% of cases. Fluoroquinolone-resistance was widespread and not clonal. Further study is required to optimize treatment for dogs with MDR E coli-associated GC.

[Disseminated protothecosis with ulcerative granulomatous colitis in a Rhodesian Ridgeback from Germany]. / Ulzerative granulomatöse Kolitis durch Prototheca spp. bei einem Rhodesian Ridgeback in Deutschland.

A 10-month-old male Rhodesian Ridgeback was presented to the Clinic of Small Animal Medicine, LMU, Germany, with a 6-month history of chronic diarrhea and hematochezia. The dog lived in Germany and had never traveled abroad. Complete blood count and serum biochemistry performed by the referring veterinarian revealed neutrophilia, hyperkalemia, and hyponatremia, with a basal cortisol of 4.3 µg/dl, which excluded hypoadrenocorticism. Since antibiotic treatment had not resulted in any improvement, a 2 week course of prednisolone administration had been initiated, leading to a marked deterioration of intestinal signs and a significant weight loss of 6 kg. At the time of referral, the patient was markedly emaciated, dehydrated, hypovolemic and had a rectal temperature of 39.6 °C. Abdominal ultrasound showed a thickened and irregular colonic wall. On colonoscopy, an irregular colonic mucosa with ulcerations was observed. Histopathologic examination revealed an ulcerative granulomatous colitis, and on Periodic acid-Schiff reaction (PAS) numerous organisms consistent with Prototheca spp. were identified. Prototheca zopfii infection was confirmed by culture and MALDI-TOF MS. In order to test for an underlying immunodeficiency, immunoglobulin levels in serum were determined. IgM was decreased, while IgG and IgA levels were within the reference interval. Due to deterioration of general condition, grave prognosis and costs of a treatment trial, the patient was euthanized one week later, and necropsy was performed. Prototheca spp. were detected on histopathologic examination in the lymphnodes, however not in the eyes or the central nervous system. Protothecosis should be considered an differential diagnosis in dogs with chronic diarrhea and ulcerative granulomatous colitis even in dogs living in Germany. Histopathologic examination of colonic biopsies with special stains such as PAS is recommended in every dog with signs of chronic large bowel disease in order to avoid missing this rare infectious disease.

Granulomatous enteritis in rainbow trout (Oncorhynchus mykiss) associated with soya bean meal regardless of water dissolved oxygen level.

This study investigated morphological changes associated with soya bean meal-induced enteritis (SBMIE) in distal intestine (DI) of rainbow trout (Oncorhynchus mykiss) fed a soya bean meal (SBM)-based diet and exposed to normoxia or hypoxia created by optimal and low water flow rates, respectively. A 28-day adaption period was followed by a 42-day challenge period where 600 fish were subjected to dietary challenge and/or hypoxia. Twelve tanks each containing 50 juvenile trout were assigned randomly in triplicate to each treatment. Histopathological and immunohistochemical evaluation revealed pathological features that have not previously been described in association with SBMIE. Vacuolar degeneration of epithelial cells mainly at the base of mucosal folds, epithelial cysts, epithelial dysplasia, necrosis, shedding of necrotic cells, and granulomatous inflammation including infiltration of enlarged, sometimes finely vacuolated or "foamy" macrophages, multinucleated giant cells and increased proliferation of fibroblasts were observed. Acid-fast bacteria were not detected in enlarged macrophages; however, these cells contained AB-PAS- and sometimes cytokeratin-positive material, which was interpreted to be of epithelial/goblet cell origin. Hypoxia did not affect the morphological changes in DI. These results suggest that SBM was associated with a granulomatous form of enteritis in DI of rainbow trout regardless of water oxygen level.

Ulcerative and granulomatous enteritis associated with Molineus torulosus parasitism in neotropical primates / Enterite ulcerativa e granulomatosa com parasitismo de Molineus torulosus em primatas neotropicais

This paper reports eleven cases of ulcerative and granulomatous enteritis associated with Molineus torulosus parasitism in different species of neotropical primates of the Sapajus genus. All of the affected monkeys had been apprehended by the environmental police and were being treated in a rehabilitation center for wild animals. The clinical history was weight loss and debility. During the necropsy, several nodules were found on the duodenum and proximal jejunum wall, with ulcers on the adjacent intestinal mucosa, including the nodules in the pancreas of four monkeys. Histologically, eosinophilic granulomas were observed in the small intestine, associated with fibrosis, eggs and adult models of Trichostrongylidae, etiology consistent with Molineus torulosus. This study describes the first cases of parasitism in Sapajus flavius, a species previously considered extinct, but recently rediscovered, and presents the occurrence of M. torulosus in two other species, Sapajus libidinosus and Sapajus apella.(AU)

São relatados 11 casos de enterite ulcerativa e granulomatosa associada ao parasitismo por Molineus torulosus em diferentes espécies de primatas neotropicais do gênero Sapajus. Todos os macacos afetados haviam sido apreendidos pela polícia ambiental e estavam sendo tratados em um centro de reabilitação de animais silvestres. O histórico clínico era de emagrecimento e debilidade. Durante a necropsia, foram constatados diversos nódulos na parede do duodeno e jejuno proximal, com úlceras na mucosa intestinal adjacente, além de nódulos no pâncreas de quatro macacos. Histologicamente, observou-se no intestino delgado, granulomas eosinofílicos associados à fibrose, ovos e exemplares adultos de tricostrongilídeos, etiologia consistente com Molineus torulosus. O presente trabalho descreve os primeiros casos de parasitismo em Sapajus flavius, uma espécie antes considerada extinta e recentemente redescoberta, e relata a ocorrência de M. torulosus em outras duas espécies, Sapajus libidinosus e Sapajus apella.(AU)

Gut: An underestimated target organ for Aluminum.

Since World War II, several factors such as an impressive industrial growth, an enhanced environmental bioavailability and intensified food consumption have contributed to a significant amplification of human exposure to aluminum. Aluminum is particularly present in food, beverages, some drugs and airbone dust. In our food, aluminum is superimposed via additives and cooking utensils. Therefore, the tolerable intake of aluminum is exceeded for a significant part of the world population, especially in children who are more vulnerable to toxic effects of pollutants than adults. Faced with this oral aluminum influx, intestinal tract is an essential barrier, especially as 38% of ingested aluminum accumulates at the intestinal mucosa. Although still poorly documented to date, the impact of oral exposure to aluminum in conditions relevant to real human exposure appears to be deleterious for gut homeostasis. Aluminum ingestion affects the regulation of the permeability, the microflora and the immune function of intestine. Nowadays, several arguments are consistent with an involvement of aluminum as an environmental risk factor for inflammatory bowel diseases.

Enteritis granulomatosa en caninos: reporte de un caso / Granulomatous enteritis in dogs: case report

Se presenta el caso de una hembra canina de raza indefinida con síntomas de diarrea crónica a la que se le diagnosticó una enteritis granulomatosa crónica por medio de histopatología. Este estudio describe los hallazgos ecográficos observados. (AU)

Enteritis granulomatosa en caninos: reporte de un caso / Granulomatous enteritis in dogs: case report

Se presenta el caso de una hembra canina de raza indefinida con síntomas de diarrea crónica a la que se le diagnosticó una enteritis granulomatosa crónica por medio de histopatología. Este estudio describe los hallazgos ecográficos observados.

Histiocytic typhlocolitis in two colony Beagle dogs.

Two young female Beagle dogs in a laboratory colony with clinical signs of loose stools and fecal blood were confirmed to have histiocytic ulcerative colitis by histologic evaluation. This syndrome is well recognized in other dog breeds such as Boxers and related French Bulldogs, Mastiffs, Alaskan malamutes and Doberman Pinschers. Formalin-fixed paraffin sections of large intestine from one dog demonstrated the presence of Escherichia coli strain LF82 by immunohistochemistry and 16S ribosomal RNA gene sequencing. E coli strain LF82 has been implicated in the pathogenesis of Crohn's disease and similar bacteria have been cultured from cases of histiocytic ulcerative colitis in Boxer dogs. Spontaneous histiocytic ulcerative colitis must be differentiated from test article-related findings in nonclinical toxicity studies in Beagle dogs.

Association between granulomatous colitis in French Bulldogs and invasive Escherichia coli and response to fluoroquinolone antimicrobials.

BACKGROUND: French Bulldogs develop a form of granulomatous colitis (GC) with histopathological resemblance to GC of Boxer dogs (GCB). GCB is associated with mucosally invasive Escherichia coli whose eradication correlates with clinical remission. HYPOTHESIS/OBJECTIVES: To characterize the clinical and histopathological features, presence or absence of invasive colonic bacteria, and response to fluoroquinolones in French Bulldogs with GC. ANIMALS: A total of 6 French Bulldogs with a histological diagnosis of GC. METHODS: Retrospective study of medical records. Bacterial colonization was evaluated using 16S rRNA probes for eubacteria and E. coli. Biopsy specimens from 3 dogs were cultured for bacteria. Clinical response to fluoroquinolone antimicrobials was determined. RESULTS: All dogs were ≤1 year of age with hematochezia that was refractory to empirical therapy. Clinicopathologic and fecal analysis did not reveal abnormalities. Abdominal ultrasound revealed patchy thickening of the colon in 4/5 dogs and regional lymphadenopathy in 5/5. Colonoscopic abnormalities included irregularly thickened and ulcerated mucosa, hyperemia, and overt bleeding in 4/6 cases. Multifocal accumulations of PAS-positive macrophages and intramucosal E. coli were present in colonic biopsies of all 6 dogs. Administration of enrofloxacin (5/6) or marbofloxacin (1/6) at 4.4-10 mg/kg (median 10 mg/kg) PO q24h for 6-10 weeks was associated with clinical improvement within 5-14 days. All dogs remained in remission over a 3-30 month follow-up period. CONCLUSIONS: Granulomatous colitis in young French Bulldogs is associated with the presence of invasive E. coli and closely parallels GCB. Treatment with fluoroquinolone antimicrobials can induce lasting clinical remission.

Granulomatous colitis of boxer dogs.

Granulomatous colitis (GC) is a rare, breed-specific inflammatory bowel disease of young Boxer dogs. GC has been refractory to treatment and associated with high mortality rates, but culture-independent molecular analysis has transformed therapy and prognosis by uncovering a correlation between GC and Escherichia coli invasion within colonic mucosal macrophages. GC-associated invasive E coli are similar to a newly identified E coli pathotype, "adherent and invasive E coli," that are increasingly associated with Crohn's disease in humans. Successful treatment of GC requires antimicrobials that are effective against E coli and penetrate intracellularly. Enrofloxacin is widely regarded as the antibiotic of choice.

Achados patológicos e imuno-histoquímicos em bovinos com doença granulomatosa sistêmica pelo consumo de Vicia villosa (Leg. Papilionoideae) no Rio Grande do Sul / Pathological and immunohistochemical findings in cattle affected by systemic granulomatous disease by consumption Vicia villosa (Leg. Papilionoideae) in Rio Grande do Sul

A doença granulomatosa sistêmica associada ao consumo de Vicia villosa (Leg. Papilionoideae) foi diagnosticada em 5 bovinos no período de 2005 a 2008. Os bovinos apresentavam alopecia, lesões crostosas na pele, prurido, febre, queda da produção leiteira, anorexia e emagrecimento. O curso clínico médio da doença foi de 2 semanas. Dos bovinos analisados três morreram e dois foram eutanasiados. As lesões macroscópicas de alopecia e crostas na pele eram localizadas principalmente na face e pescoço. Observava-se nódulos multifocais a coalescentes branco-acinzentados que infiltravam vários órgãos especialmente em linfonodos, rins e coração. As lesões microscópicas consistiam na infiltração de linfócitos, macrófagos, células epitelioides, células gigantes multinucleadas, eosinófilos e plasmócitos. Linfonodos, rins, adrenal, baço e fígado de todos os bovinos apresentaram infiltrado granulomatoso, porém de intensidade variável. Nos testes imuno-histoquímicos dos órgãos com infiltrado inflamatório, as principais células visualizadas foram os linfócitos T, seguidos de macrófagos/células epitelioides/células gigantes multi-nucleadas e os linfócitos B foram raramente detectados nos locais de inflamação granulomatosa. O número reduzido de células marcadas por Ki-67 nas lesões granulomatosas, tende a indicar que a proliferação celular não foi responsável pela hipercelularidade das lesões e que o recrutamento de macrófagos e linfócitos para o local da inflamação provavelmente tenha sido o responsável pelo acúmulo de células no infiltrado inflamatório.

The systemic granulomatous disease associated with consumption of Vicia villosa (Leg. Papilionoideae family) has been diagnosed in 5 cattle from 2005 to 2008. Affected cattle showed alopecia, crusted lesions on the skin, had itching, fever, decreased milk yield, anorexia and wasting. Average clinical course was 2 weeks. Three cattle died and two were euthanized in extremis. The main gross changes are alopecic and crusts in the skin, mainly on the face and neck. There also were multifocal to coalescent whitish nodules that infiltrated several organs, but especially lymph nodes, kidneys and hearth. Microscopic changes consisted of infiltration with lymphocytes, macrophages, epithelioid cells, giant multinucleated cells, eosinophils, and plasmocytes. Lymph nodes, kidneys, adrenal gland, spleen and liver from affected cattle showed varying degrees of granulomatous infiltration. Immunohistochemical procedures on samples from affected organs revealed that T-lymphocytes and macrophages/epithelioid cells/giant multinucleated cells were the main components of the inflammatory infiltrates, B-lymphocytes were only rarely seen within. The reduced numbers of cells marked by Ki-67 in the granulomatous lesions would indicate that cell proliferation was not responsible for the hypercellularity in the lesions and that rather the recruitment of macrophages and lymphocytes to the site inflammation probably accounted for the building up of the local cellular inflammatory infiltrate.

Enterite granulomatosa associada a larvas de ciatostomíneos em eqüinos no Rio Grande do Sul / Granulomatous enteritis associated with larval cyathostomiasis in horses in Rio Grande do Sul, Brazil

São descritos cinco casos de enterite granulomatosa associada a larvas de ciatostomíneos em eqüinos provenientes de três propriedades rurais do Rio Grande do Sul. Os casos ocorreram entre janeiro de 1999 e dezembro de 2007. A evolução clínica nos dois casos cujo seguimento clínico foi acompanhado foi de 10 e 14 dias. Os sinais clínicos apresentados por três eqüinos foram semelhantes e consistiam de diarréia (3/3), emagrecimento (2/3), pirexia (1/3), taquicardia (1/3) e taquipnéia (1/3). Os achados macroscópicos incluíram espessamento da parede do cólon maior e ceco por edema e ocorrência de numerosos pontos marrom-escuros com 1-4mm, levemente salientes, disseminados pela mucosa. A incisão desses pontos revelou pequenas larvas de nematódeos marrom-avermelhadas de 1-2mm. Numerosos parasitas, compatíveis morfologicamente com pequenos estrôngilos, foram observados na luz intestinal ou aderidos à mucosa do cólon maior e ceco. Histologicamente, na mucosa e submucosa do cólon maior e ceco, foram observados múltiplos granulomas constituídos por moderado ou acentuado infiltrado inflamatório, composto por macrófagos, macrófagos epitelióides e eosinófilos circundados por linfócitos e plasmócitos. No centro desses granulomas, observaram-se cortes transversais de parasitas com morfologia compatível com ciatostomíneos. Adicionalmente, havia edema e infiltrado inflamatório linfo-histioplasmocitário e eosinofílico, leve ou moderado na submucosa e mucosa do cólon maior e ceco; necrose e proliferação linfo-histiocítária em folículos linfóides na submucosa e hiperplasia de células caliciformes na mucosa. O diagnóstico de enterite granulomatosa associada a ciatostomíneos foi realizado com base nos achados epidemiológicos, clínicos e macroscópicos e confirmado pela histologia.

Five cases of granulomatous enteritis associated with cyathostomes are described in horses from three farms in Rio Grande do Sul, Brazil. The cases occurred from January 1999 to December 2007. The clinical course in two cases in which clinical follow-up was available was 10-14 days. Clinical signs presented by two horses were similar and included diarrhea (3/3), weight loss (2/3), pyrexia (1/3), tachycardia (1/3), and tachypnea (1/3). Gross changes consisted of thickening of the wall of large colon and cecum by edema and the occurrence of numerous 1-4mm, dark-tan, slightly raised multifocal pinpoints disseminated throughout the mucosa. Up on the incision of these pinpoints, brown-reddish, small (1-2mm) nematode larvae emerged. Large numbers of parasites with morphology compatible with small strongyles were observed in the lumina of large colon and cecum or adhered to the mucosae of these organs. Histologically, multiple granulomas were seen in the mucosa and submucosa of large colon and cecum. These granulomas consisted of moderate to severe inflammatory infiltrate of macrophages, epithelioid macrophages, and eosinophils surrounded by fewer lymphocytes and plasma cells. In the center of these granulomas, transversal cut sections of parasites with morphology compatible with cyathostomes larvae were observed. Additionally, there was edema and moderate to marked lymphohistioplasmacytic and eosinophilic inflammatory infiltrate throughout the mucosa and submucosa of the large colon and cecum; necrosis and lymphohistiocytic proliferation in the submucosal lymphoid follicles, with hyperplasia of goblet cells in the epithelial lining of these organs were also observed. The diagnosis of granulomatous enteritis associated with larval cyathostomiasis was made based on epidemiological, clinical, and gross findings which were confirmed by histopathology.