Chronic Large Bowel Diarrhoea Research Articles

Faecal microbiome transplantation improves clinical signs of chronic idiopathic large bowel diarrhoea in working dogs.

Chronic diarrhoea is a common clinical sign in dogs with chronic enteropathy, and psyllium husk has been shown to improve clinical signs in affected dogs. The aim of this study was to investigate whether faecal microbiome transplant has a similar effect in alleviating clinical signs in dogs with chronic large bowel diarrhoea. Thirty large-breed working dogs with chronic large bowel diarrhoea were divided into a psyllium group (PG) and a faecal microbiome transplant group (FMTG). To the PG, 16g/day of psyllium husk was administered for 30 days. The FMTG received faecal microbiome transplantation (FMT) once via enema. A daily log of faecal characteristics was kept, and the dogs' canine inflammatory bowel disease index (CIBDAI) and body condition scores (BCS) were determined. A Wilcoxon-Mann-Whitney test was used to compare group results. In addition, the Kaplan-Meier test was used to evaluate the occurrence rate of 1 day or more of diarrhoea and 2 days or more of diarrhoea by day 30. The sample had a mean age of 3.9±2.1 years and a bodyweight of 25.3±6.8kg. The FMTG showed a more rapid onset of CIBDAI improvement but no difference in other measures. At 30 days, the FMTG showed a greater improvement in bodyweight and BCS, but no differences were observed in faecal scores, defaecation frequency and time of appearance of episodes of diarrhoea. Time played a significant positive role in the results observed across both groups (p < 0.05). This study did not compare the microbiomes of the dogs before and after treatment, so the role of specific types of bacteria cannot be determined. Psyllium husk and FMT had similar effects in improving clinical signs of chronic large bowel diarrhoea.

A prospective multicenter study of the efficacy of a fiber-supplemented dietary intervention in dogs with chronic large bowel diarrhea

BackgroundChronic large bowel diarrhea is common in dogs and can have a significant impact on their overall health and well being. We evaluated the safety and efficacy of a therapeutic food with select dietary plant fibers known to contain antioxidant and polyphenol compounds on clinical signs in dogs with chronic diarrhea.MethodsA prospective clinical study was conducted in 31 adult dogs currently experiencing chronic diarrhea from private veterinary practices in the United States. Enrolled dogs were switched to a complete and balanced dry therapeutic food containing whole grains and polyphenol-containing fiber sources for 56 days. Veterinarians evaluated changes from baseline in overall clinical signs, recurrence of clinical signs, and stool parameters at Days 2, 3, 4, 28, and 56. Dog owners evaluated stool consistency daily and nausea/vomiting, quality of life (QoL), and stooling behaviors at Days 1, 14, 28, and 56. Statistical analysis was performed using a mixed-effects model with Day as a fixed-effect.ResultsAssessments of overall clinical response and stool parameters indicated that diarrhea improved significantly within 1 day of initiating the therapeutic food. Veterinarians reported that 68% of dogs had complete resolution of their clinical signs by Day 56 and the remaining 32% experienced improvement (P < 0.05), with no cases of recurrence. Veterinarians also reported improvement in stool consistency (P < 0.001) and reductions of blood and mucus in stool (P < 0.001). Significant improvements in nausea/vomiting, stooling behaviors, and quality of life (QoL) were reported by dog owners after 28 days and were sustained through day 56 (P < 0.05). The therapeutic food was safe and well tolerated.ConclusionsIn dogs with chronic large bowel diarrhea, the therapeutic food rapidly improved stool consistency, resolved clinical signs, and improved stooling behaviors and QoL. Therapeutic foods supplemented with fiber sources rich in antioxidant and anti-inflammatory compounds contribute to rapid resolution of chronic diarrhea without recurrence and may contribute to long term health.

Microbiome function underpins the efficacy of a fiber-supplemented dietary intervention in dogs with chronic large bowel diarrhea

BackgroundChronic large bowel diarrhea is a common occurrence in pet dogs. While nutritional intervention is considered the primary therapy, the metabolic and gut microfloral effects of fiber and polyphenol-enriched therapeutic foods are poorly understood.MethodsThis prospective clinical study enrolled 31 adult dogs from private veterinary practices with chronic, active large bowel diarrhea. Enrolled dogs received a complete and balanced dry therapeutic food containing a proprietary fiber bundle for 56 days. Metagenomic and metabolomic profiling were performed on fecal samples at Days 1, 2, 3, 14, 28, and 56; metabolomic analysis was conducted on serum samples taken at Days 1, 2, 3, 28, and 56.ResultsThe dietary intervention improved clinical signs and had a clear effect on the gut microfloral metabolic output of canines with chronic diarrhea, shifting gut metabolism from a predominantly proteolytic to saccharolytic fermentative state. Microbial metabolism of tryptophan to beneficial indole postbiotics and the conversion of plant-derived phenolics into bioavailable postbiotics were observed. The intervention altered the endocannabinoid, polyunsaturated fatty acid, and sphingolipid profiles, suggesting a modulation in gastrointestinal inflammation. Changes in membrane phospholipid and collagen signatures were indicative of improved gut function and possible alleviation of the pathophysiology related to chronic diarrhea.ConclusionsIn dogs with chronic diarrhea, feeding specific dietary fibers increased gut saccharolysis and bioavailable phenolic and indole-related compounds, while suppressing putrefaction. These changes were associated with improved markers of gut inflammation and stool quality.

Comparison Study of Four Extraction Methods Combined with PCR and LAMP for Feline Tritrichomonas foetus Detection in Fecal Samples.

Feline trichomonosis occurs worldwide, with gastrointestinal symptoms such as chronic large-bowel diarrhea and abdominal pain. The inclusion of molecular methods in diagnostic and epidemiological studies has necessitated an effective method for extracting DNA from feces. We tested four extraction commercial kits: ZR Fecal DNA MiniPrep (50 preps) (Zymo Research, Irvine, CA, USA), QIAamp® DNA Stool Mini Kit (Qiagen Inc., Valencia, CA, USA), UltraClean Fecal DNA Kit (50 preps) (MO BIO, San Diego, CA, USA), and Sherlock AX/100 isolations (A&A Biotechnology, Gdynia, Poland). We assessed the sensitivity of detection of Tritrichomonas foetus in spiked fecal samples for the four kits combined with two molecular assays: PCR and LAMP. The extraction efficacy was quantified using defined aliquots of fecal samples spiked with 5 μL of suspensions containing serial dilutions of trophozoites (0.1; 1; 10; 100; 1000; 10,000), with six replicates for each concentration. In our study, we proved that the ZR Fecal DNA MiniPrep (50 preps) kit combined with LAMP and PCR had the highest efficiency among all the compared methods for the detection of feline T. foetus from fecal samples.

Effect of Tritrichomonas foetus, Tf-31 (a cattle isolate) and Tff6 (a feline isolate) on TLR signaling pathway in cervical epithelial cells.

Abstract Bovine trichomonosis is caused by Tritrichomonas foetus, which is widely prevalent in 33 US states, and is a reportable disease due to potential huge economic losses to cattle industry. T. foetus also causes chronic large-bowel diarrhoea in cats, complicated not only by its chronicity but for its difficulty to treat, with few registered or effective products available. T. foetus persistently colonize the lower genital tract of bulls but usually do not cause either major clinical signs or inflammation while vaginal inflammation is a common disease of the dairy cows’ reproductive tract. Mechanisms of immune response to this pathogen are poorly studied. This study for the first time, reports the effect of T. foetus; Tf-31-cattle isolate and Tff6-cat isolate, on activation of toll-like receptors (TLRs) and inflammatory response in vaginal epithelial cells. The expression levels of serial effectors related to the TLRs-MyD88/NF-κB signaling pathway (TLR2, TLR4, MyD88, NF-κB, IL-1β, IL-6, TNF-α, and IL-10) were measured with real-time polymerase chain reaction (RT-PCR), ELISA, and Western blot analyses. Of the 6 cell-membrane TLRs tested, TLR2 and TLR4 were activated by cells, as noted by increased mRNA expression levels of TLR2 and TLR4 in both Tf31 and Tff6 treated cervical epithelial cells relative to control cells. ELISA assays showed up-regulation on IL-10, both in Tf-31 and Tff6 treated epithelial cells. Treatment with inhibitors of MyD88 signaling pathway abolished the upregulation of downstream cytokines. These data indicate that T. foetus isolates activate TLR-MyD88 signaling pathway to induce innate immune response. However, further detailed in vitro and in vivo studies are required to confirm these findings. Supported by Biology department

Evidence of self-resolution of feline trichomonosis in a pair of single household cats due to ronidazole-resistant Tritrichomonas foetus

Tritrichomonas foetus causes chronic large-bowel diarrhoea in cats, complicated not only by its chronicity but for its difficulty to treat, with few registered or effective products available, subsequently resulting in ronidazole frequently used off-label. The extent of T. foetus resistance to ronidazole is unknown. To demonstrate in vitro resistance of feline T. foetus to ronidazole and the self-resolution of the infection, we isolated novel T. foetus “feline” genotype strains from two cats in 2017 from the same household and monitored these cats over a three-year period. Axenic cultures of T. foetus from the cats were tested for in vitro resistance to metronidazole and ronidazole using anaerobic and aerobic culture assays. The minimum lethal concentration for the novel strains after incubation in aerobic conditions for 48 h were 50–100 μg/ml and 6.25–12.50 μg/ml for metronidazole and ronidazole, respectively. For susceptible T. foetus strains, the minimum lethal concentrations ranged from 1.56–12.50 μg/ml for metronidazole, and 0.39–3.13 μg/ml for ronidazole. The self-resolution of the infection was assessed using repeat diagnostic qPCR and culture. Whilst positive in 2018, the cat samples are no longer returning positive qPCR results in 2020 and 2021, indicating self-resolution over this period. This study demonstrated resistance to ronidazole for the first time in Australian cats and infection self-resolution without antimicrobial intervention is demonstrated. This study provides clinicians with the evidence to reduce the use of off-label ronidazole, and advice on the resolution timeframe for cats in single households.

The use of soluble fibre for the management of chronic idiopathic large-bowel diarrhoea in police working dogs

BackgroundChronic intermittent or persistent diarrhoea is a common condition in dogs and may be a reflex of gastrointestinal or non-gastrointestinal disorders. Besides diarrhoea, many athletes experience other gastrointestinal symptoms. Dietary fiber can help normalize colonic motility and transit time, support normal gastrointestinal microflora growth and provide fuel for colonocytes. This study aimed to evaluate dietary supplementation effectiveness with psyllium husk in police working dogs with chronic large-bowel diarrhoea. Twenty-two animals were selected. Concurrent conditions were ruled out through complete blood count and serum biochemistry. Fecal Clostridium and Salmonella were also screened. A soluble fiber, psyllium husk, was added to the diet at the dose of 4 tablespoons/day for 1 month. A daily log of fecal characteristics (type, frequency, and color) was maintained during the supplementation month and for an additional month, without supplementation.ResultsResponse to treatment was classified as “very good” in 50% of animals, “good” in 40% of animals, and “poor” in 10% of cases. During the month of psyllium husk supplementation, defecation frequency decreased from 3.5 to 2.9 times a day, with 90% of animals showing consistent stools regularly and registering a mean increase of 2 kg in body weight. Beneficial effects were still observed during the second month, without psyllium husk supplementation.ConclusionPsyllium husk can be useful in the management of chronic large-bowel diarrhoea in working dogs, which exhibited lower defecation frequency, improved stool consistency, and gained weight. Effects were felt beyond the supplementation period. Alternative approaches for non-responsive cases need to be evaluated.

Histological Evaluation of Patients with Chronic Nonbloody Large Bowel Diarrhea and Normal Colonoscopy

ABSTRACT Introduction: Chronic diarrhea is defined as the passage of soft or watery stool more than three times per day with or without blood and/or mucous or the passage of stool of more than 200 g per day and lasts for more than 4 weeks. Studies exploring the causes of chronic diarrhea in the developing countries are scarce and might not be generalizable from one setting to another. Aim: The aim of the study is to study the colonic and terminal ileal macroscopic and mucosal histopathological findings in chronic large bowel diarrhea patients. Methods: Eighty-six patients with chronic large bowel diarrhea were included after negative HIV status, stool analysis, and stool culture. A full-length colonoscopy with terminal ileoscopy was done. When the colon was within normal limits, randomly four biopsies each were taken from terminal ileum, ascending colon, transverse colon, and rectosigmoid region, respectively. Results: In a total of 86 patients, most of the patients (48%) were in the age group of 41–60 years. Females predominated in the present study in the ratio of 3:2. Ileal intubation was possible in all (100%) cases. Histology is normal in 35 patients. Fifty-one patients had histological changes of which 22 were diagnostic for specific disease which altered the treatment. Among 22 patients, 21 (95.4%) had histological changes in ascending colon and only 9 (40.9%) had changes in biopsy from rectosigmoid. In our study, definite diagnostic histology was obtained in 25.5% of cases. Conclusion: The yield of colonoscopy and biopsy in chronic large bowel diarrhea is moderate. Colonoscopy and biopsy have higher diagnostic yield than sigmoidoscopic biopsies.

Favourable long-term outcome of granulomatous colitis involving two Escherichia coli strains with multiple antimicrobial resistances in a French bulldog in Germany

A two-year-old female French bulldog was presented for chronic large bowel diarrhoea. The dog had been suspected to have granulomatous colitis, but no improvement was noted with enrofloxacin treatment. Diagnosis...

Co-infection by Tritrichomonas foetus and Pentatrichomonas hominis in asymptomatic cats

Abstract: Tritrichomonas foetus, a parasite well known for its significance as a venereally transmitted pathogen in cattle, has been identified as a cause of chronic large bowel diarrhea in domestic cats in many countries of the world. In Brazil, several studies on the diagnosis of bovine trichomoniasis have been performed, but until now, no study was made regarding feline trichomoniasis. Thus, this is the first study to report the occurrence of T. foetus and Pentatrichomonas hominis in cats using morphological and molecular analysis. Feces from 77 cats were examined, four of which (5.2%) were positive for the presence of parabasalids. Morphological analysis of stained smears revealed piriform trophozoites showing the three anterior flagella, elongated nucleus and axostyle ending abruptly in fillet, characteristic of T. foetus. In scanning and transmission electron microscopy, identification characters similar to those previously reported for T. foetus were observed. The cultures containing trophozoites were submitted for molecular analysis, which resulted positive for T. foetus DNA using specific primers (TFR3 and TFR4), and all samples were positive and subjected to sequencing in which they showed 99.7-100% similarity with another isolate sequencing of T. foetus (JX960422). Although no trophozoite with consistent morphology of P. hominis has been visualized in the samples, differential diagnosis was performed using specific primers for P. hominis (TH3 and TH5) amplicon. In three of the four samples (3.89%) sequencing revealed 100% similarity when compared with another sequence of P. hominis deposited in Genbank (KC623939). Therefore, the present study revealed through the diagnostic techniques employed the simultaneous infection by T. foetus and P. hominis in the feces of cats. However, it was necessary to use more than one technique for the diagnosis of the co-infection. These results demonstrate the importance of a correct diagnosis to allow an appropriate treatment by the veterinarian.

Comparative RNA-seq analysis of the Tritrichomonas foetus PIG30/1 isolate from pigs reveals close association with Tritrichomonas foetus BP-4 isolate ‘bovine genotype’

Tritrichomonas foetus was described as a commensal of the stomach, caecum and nasal cavity of pigs before it was recognised as the cause of reproductive tract disease of cattle. T. foetus also causes chronic large bowel diarrhoea in domestic cats. Multi-locus genotyping and comparative transcriptome analysis has previously revealed that T. foetus isolated from cat and cattle hosts are genetically distinct, referred to as the ‘feline genotype’ and ‘bovine genotype’, respectively. Conversely, multi-locus genotyping has grouped porcine T. foetus with the ‘bovine genotype’. To compare the extent of the similarity between porcine T. foetus and cattle ‘bovine genotype’ isolates, RNA-sequencing (RNA-seq) was used to produce the first cell-wide transcriptome library of porcine T. foetus PIG30/1. Comparative transcriptome analysis of the PIG30/1 with the published bovine (BP-4) and feline (G10/1) transcriptomes revealed that the porcine T. foetus shares a 4.7 fold greater number of orthologous genes with the bovine T. foetus than with the feline T. foetus. Comparing transcription of the virulence factors, cysteine proteases (CP) between the three isolates, the porcine T. foetus was found to preferentially transcribe CP8 like the ‘bovine genotype’ T. foetus, compared to thehigh transcription of CP7 seen for ‘feline genotype’ T. foetus. At the cell-wide transcriptome level, the porcine T. foetus isolate (PIG30/1) groups closer with the ‘bovine genotype’ T. foetus rather than the ‘feline genotype’ T. foetus.

Idiopathic eosinophilic colitis as a presenting feature of chronic large bowel diarrhea

Eosinophilic gastrointestinal disorder (EGID) is a spectrum of gastrointestinal disorders with eosinophilic infiltration of gut without any known cause for such tissue eosinophilia. Eosinophilic gastrointestinal disorders can be sub grouped as eosinophilic esophagitis, eosinophilic gastroenteritis, and eosinophilic colitis. The least frequent manifestation of EGIDs is eosinophilic colitis. We present a case of 51-year-old male patient who presented with chronic painless large bowel diarrhea with a rare diagnosis of eosinophilic colitis.

Comparative transcriptomics reveals striking similarities between the bovine and feline isolates of Tritrichomonas foetus: consequences for in silico drug-target identification.

BackgroundFew, if any, protozoan parasites are reported to exhibit extreme organ tropism like the flagellate Tritrichomonas foetus. In cattle, T. foetus infects the reproductive system causing abortion, whereas the infection in cats results in chronic large bowel diarrhoea. In the absence of a T. foetus genome, we utilized a de novo approach to assemble the transcriptome of the bovine and feline genotype to identify host-specific adaptations and virulence factors specific to each genotype. Furthermore, a subset of orthologs was used to characterize putative druggable targets and expose complications of in silico drug target mining in species with indefinite host-ranges.ResultsIllumina RNA-seq reads were assembled into two representative bovine and feline transcriptomes containing 42,363 and 36,559 contigs, respectively. Coding and non-coding regions of the genome libraries revealed striking similarities, with 24,620 shared homolog pairs reduced down to 7,547 coding orthologs between the two genotypes. The transcriptomes were near identical in functional category distribution; with no indication of selective pressure acting on orthologs despite differences in parasite origins/host. Orthologs formed a large proportion of highly expressed transcripts in both genotypes (bovine genotype: 76%, feline genotype: 56%). Mining the libraries for protease virulence factors revealed the cysteine proteases (CP) to be the most common. In total, 483 and 445 bovine and feline T. foetus transcripts were identified as putative proteases based on MEROPS database, with 9 hits to putative protease inhibitors. In bovine T. foetus, CP8 is the preferentially transcribed CP while in the feline genotype, transcription of CP7 showed higher abundance. In silico druggability analysis of the two genotypes revealed that when host sequences are taken into account, drug targets are genotype-specific.ConclusionGene discovery analysis based on RNA-seq data analysis revealed prominent similarities between the bovine and feline T. foetus, suggesting recent adaptation to their respective host/niche. T. foetus represents a unique case of a mammalian protozoan expanding its parasitic grasp across distantly related host lineages. Consequences of the host-range for in silico drug targeting are exposed here, demonstrating that targets of the parasite in one host are not necessarily ideal for the same parasite in another host.Electronic supplementary materialThe online version of this article (doi:10.1186/1471-2164-15-955) contains supplementary material, which is available to authorized users.

Tritrichomonas foetus isolates from cats and cattle show minor genetic differences in unrelated loci ITS-2 and EF-1α

The protozoan parasite Tritrichomonas foetus is well known as an important causative agent of infertility and abortion in cattle (bovine trichomonosis). This World Organisation for Animal Health (O.I.E.) notifiable disease is thought to be under control in many countries including Switzerland. In recent studies, however, T. foetus has also been identified as an intestinal parasite that causes chronic large-bowel diarrhoea in cats. Since the feline isolates were considered indistinguishable from bovine isolates, the possibility and risk of parasite transmission from cats to cattle and vice versa has been intensively discussed in current literature. Therefore, we investigated if cat and cattle isolates are genetically distinct from each other or in fact represent identical genotypes. For this purpose, two independent genetic loci were selected that turned out to be well-suited for a PCR sequencing-based genotyping of trichomonad isolates: (i) previously published internal transcribed spacer region 2 (ITS-2) and (ii) a semi-conserved sequence stretch of the elongation factor-1 alpha (EF-1α) gene used for the first time in the present study. Respective comparative analyses revealed that both loci were sufficiently variable to allow unambiguous genetic discrimination between different trichomonad species. Comparison of both genetic loci confirmed that T. suis and T. mobilensis are phylogenetically very close to T. foetus. Moreover, these two genetic markers were suited to define host-specific genotypes of T. foetus. Both loci showed single base differences between cat and cattle isolates but showed full sequence identity within strains from either cat or cattle isolates. Furthermore, an additional PCR with a forward primer designed to specifically amplify the bovine sequence of EF-1α was able to discriminate bovine isolates of T. foetus from feline isolates and also from other trichomonads. The implications these minor genetic differences may have on the biological properties of the distinct isolates remain to be investigated.

First description of naturally acquired Tritrichomonas foetus infection in a Persian cattery in Spain

Tritrichomonas foetus has been identified as the causative agent of feline intestinal trichomonosis, characterized by clinical signs of chronic large bowel diarrhoea. This disease has been reported in cats from the USA, Europe and Australia. However, its epidemiology is still unclear. The aim of the present study was to describe T. foetus infection in a Persian cattery in Spain. T. foetus infection was sequentially diagnosed in 20 cats by direct faecal smear examined under the microscope, specific culture (In Pouch TF medium) and PCR. A standard coprological sedimentation method was also performed in order to screen for other intestinal parasites in all the cats included. In addition, sera were tested for IgG antibodies against Leishmania infantum, Toxoplasma gondii, and for the detection of feline immunodeficiency virus (FIV) and feline leukaemia virus (FeLV). Five out of 20 cats were positive for T. foetus (25%), two of them by microscopy, culture and PCR and three by culture and PCR. No association was found between T. foetus infection and age or sex. L. infantum and T. gondii seroprevalence rates were 15% and 10%, respectively. The prevalence of FeLV p27 antigen and of FIV antibodies in the study population was zero. Cystoisospora spp. oocysts were detected in one cat. These preliminary results show that the transmission of T. foetus infection in cluster conditions may occur between asymptomatic cats and young or immunocompromised animals.

Tritrichomonas foetusinfection in cats with diarrhoea in a rescue colony in Italy

Faecal samples from 74 cats with chronic large bowel diarrhoea that were living in a rescue colony in Italy, were submitted for assessment of Tritrichomonas foetus by direct microscopy of faecal smears (n=20) and T foetus-specific culture (n=74), with confirmation by polymerase chain reaction (n=1). Twenty-four of the cats (32%) were found to be infected with T foetus. The infected cats were predominantly over a year of age (67%) and were all neutered non-pedigree domestic cats.

Molecular characterisation of the gut microflora of healthy and inflammatory bowel disease cats using fluorescence in situ hybridisation with special reference to Desulfovibrio spp.

Inflammatory bowel disease (IBD) is a common cause of chronic large bowel diarrhoea in cats. Although the aetiology of IBD is unknown, an immune-mediated response to a luminal antigen is thought to be involved. As knowledge concerning the colonic microflora of cats is limited and requires further investigation, the purpose of this study was to determine the presence of specific bacterial groups in normal and IBD cats, and the potential role they play in the health of the host. Total bacterial populations, Bacteroides spp., Bifidobacterium spp., Clostridium histolyticum subgp., Lactobacillus-Enterococcus subgp. and Desulfovibrio spp. were enumerated in 34 healthy cats and 11 IBD cats using fluorescence in situ hybridisation. The study is one of the first to show the presence of Desulfovibrio in cats. Total bacteria, Bifidobacterium spp. and Bacteroides spp. counts were all significantly higher in healthy cats when compared with IBD cats, whereas Desulfovibrio spp. (producers of toxic sulphides) numbers were found to be significantly higher in colitic cats. The information obtained from this study suggests that modulation of bacterial flora by increasing bifidobacteria and decreasing Desulfovibrio spp. may be beneficial to cats with IBD. Dietary intervention may be an important aspect of their treatment.

Antibiotic‐Responsive Histiocytic Ulcerative Colitis in 9 Dogs

Canine histiocytic ulcerative colitis (HUC) is characterized by colonic inflammation with predominantly periodic acid‐Schiff (PAS)‐positive macrophages. The inflammation results in colonic thickening, ulcerations, and distortion of normal glandular architecture. Resultant clinical signs consist of chronic large bowel diarrhea, tenesmus, and marked weight loss, and the disease frequently results in euthanasia. Conventional therapy consists of some combination of prednisone, azathioprine, sulfasalazine, and metronidazole. Nine dogs (8 Boxers and 1 English Bulldog) with histologic confirmation of HUC were treated with antibiotic therapy (either with enrofloxacin alone or in combination with metronidazole and amoxicillin). Clinical signs, physical examination findings, laboratory abnormalities, and the histologic severity of the disease were evaluated. Four of the 9 dogs had been treated previously with conventional therapy and had failed to respond favorably; then, these dogs were placed on antibiotic therapy (enrofloxacin, n = 1; enrofloxacin, metronidazole, and amoxicillin, n = 3) and had resolution of clinical signs within 3–12 days. Five dogs were treated solely with antibiotic therapy (enrofloxacin, n = 1; enrofloxacin and metronidazole, n = 1; enrofloxacin, metronidazole, and amoxicillin, n = 3), and clinical signs resolved in 2–7 days. Repeated biopsy specimens were obtained from 5 dogs after treatment, and all showed marked histologic improvement. The increase in body weight after treatment was statistically significant (P= .01). Three dogs currently are not on any treatment and have had resolution of clinical signs for up to 14 months. These observations suggest that an infectious agent responsive to antibiotics plays an integral role in the clinical manifestation of canine HUC, and they support the use of antibiotics in its treatment.

Erosive Colitis in Experimental Canine Leishmaniasis

Six 4 month-old beagles were inoculated with Leishmania infantum, three of them intraperitoneally (Group A) and the other three intravenously (Group B). The animals from Group A were killed at 109, 433 and 592 days after inoculation and animals from Group B 109, 171 and 334 days after inoculation. At 350 days (Group A) and 275 days (Group B) after inoculation, dogs started to develop a chronic large bowel diarrhoea. At necropsy a diffuse colonic and rectal wall thickening of gradually increasing severity was observed. Histological examination of the colon showed a diffuse inflammatory infiltration of the mucosa and submucosa by macrophages with amastigotes, lymphocytes, plasma cells and some neutrophils and eosinophils. The surface epithelium developed increasingly extensive degeneration, which caused the development of erosions on the mucosal surface. The crypts of Lieberkühn decreased in number and showed degeneration of the crypt epithelium.