Histologic characterization of the major duodenal papilla and association with concurrent biliary, pancreatic, and intestinal pathology in cats.

Conjoining of the major pancreatic duct and common bile duct at the major duodenal papilla (MDP) is suspected to predispose cats to the clinical syndrome of "triaditis." However, microanatomy of the MDP or presence of lesions at the MDP has not been assessed in cats with or without triaditis. The aims of this study were to characterize feline MDP histomorphology and to identify associations between MDP anatomy/disease and the presence of biliary, pancreatic, or intestinal inflammation or neoplasia. Histologic assessment was prospectively performed on the MDP, duodenum, jejunum, ileum, liver, and pancreas from 124 client-owned cats undergoing postmortem examination. The majority of cats (104/124, 84%) had a complex ductular network at the MDP, with no distinction between pancreatic and common bile ducts. Lymphoid aggregates at the MDP were common (63/124, 51%). Inflammation of the MDP (MDPitis) was present in 35 of 124 cats (28%) and was often concurrent with cholangitis, pancreatitis, or enteritis (32/35, 91%), but was only associated with enteritis (19/35, 54%, P < .05). Triaditis was less common (19/124, 15%), but was associated with both conjoined MDP anatomy (19/19, 100%, P < .05) and MDPitis (12/19, 63%, P < .05). Neoplasia was present in 37 of 124 cats (29%), with lymphoma (28/37, 78%) predominating. Enteropathy-associated T-cell lymphoma type 2 (EATL2) was most common (n = 16/37, 43%) and was associated with triaditis and MDPitis (P < .05). These findings suggest that anatomy, immune activation, and/or inflammation of the MDP may play a role in the pathogenesis of triaditis. Further studies are needed to elucidate the relationships between triaditis, MDPitis, and EATL2.

Microbiome analysis of bile from apparently healthy cats and cats with suspected hepatobiliary disease.

BACKGROUND: Bacterial infection of bile is a common cause of hepatobiliary disease in cats. Whether bile harbors a core microbiota in health or in cases of suspected hepatobiliary disease in cats is unknown. OBJECTIVES: Establish if gallbladder bile in apparently healthy cats harbors a core microbiota composed of bacterial taxa common to many individuals. Compare results of bile cytology, bile culture, and 16S rRNA gene amplicon sequencing in apparently healthy cats and cats with suspected hepatobiliary disease. ANIMALS: Forty-three client-owned cats with suspected hepatobiliary disease and 17 control cats. METHODS: Bile was collected by ultrasound guided cholecystocentesis (cats with suspected hepatobiliary disease) or laparotomy after euthanasia (controls). Bile samples underwent cytologic examination, aerobic and anaerobic culture, and DNA was extracted for 16S rRNA gene amplification and sequencing. RESULTS: Microbiome sequencing did not identify a core microbiota in control cats or cats having bile sampled because of clinical suspicion for hepatobiliary disease. Microbiome profiles from control cats were indistinguishable from profiles obtained from sampling instruments and reagents that were not exposed to bile (technical controls). Bacterial taxa that could not be explained by contamination or off-target amplification were identified only in samples from cats with bactibilia and positive bile culture results for Escherichia coli. In several E. coli positive samples, microbiome sequencing also identified a small number of potentially co-infecting bacterial genera not identified by culture. CONCLUSIONS AND CLINICAL IMPORTANCE: Cat bile does not harbor a core microbiota. Uncultured bacteria may contribute to pathogenesis of hepatobiliary disease in cats with bile E. coli infection.

Gallbladder microbiota in healthy dogs and dogs with mucocele formation.

To date studies have not investigated the culture-independent microbiome of bile from dogs, a species where aseptic collection of bile under ultrasound guidance is somewhat routine. Despite frequent collection of bile for culture-based diagnosis of bacterial cholecystitis, it is unknown whether bile from healthy dogs harbors uncultivable bacteria or a core microbiota. The answer to this question is critical to understanding the pathogenesis of biliary infection and as a baseline to exploration of other biliary diseases in dogs where uncultivable bacteria could play a pathogenic role. A pressing example of such a disease would be gallbladder mucocele formation in dogs. This prevalent and deadly condition is characterized by excessive secretion of abnormal mucus by the gallbladder epithelium that can eventually lead to rupture of the gallbladder or obstruction of bile flow. The cause of mucocele formation is unknown as is whether uncultivable, and therefore unrecognized, bacteria play any systematic role in pathogenesis. In this study we applied next-generation 16S rRNA gene sequencing to identify the culture-negative bacterial community of gallbladder bile from healthy dogs and gallbladder mucus from dogs with mucocele formation. Integral to our study was the use of 2 separate DNA isolations on each sample using different extraction methods and sequencing of negative control samples enabling recognition and curation of contaminating sequences. Microbiota findings were validated by simultaneous culture-based identification, cytological examination of bile, and fluorescence in-situ hybridization (FISH) performed on gallbladder mucosa. Using culture-dependent, cytological, FISH, and 16S rRNA sequencing approaches, results of our study do not support existence of a core microbiome in the bile of healthy dogs or gallbladder mucus from dogs with mucocele formation. Our findings further document how contaminating sequences can significantly contribute to the results of sequencing analysis when performed on samples with low bacterial biomass.

Randomized placebo-controlled trial of feline-origin Enterococcus hirae probiotic effects on preventative health and fecal microbiota composition of fostered shelter kittens.

Introduction: Diarrhea is the second most common cause of mortality in shelter kittens. Studies examining prevention strategies in this population are lacking. Probiotics are of particular interest but studies in cats are largely limited to healthy adults or those with induced disease. Only one study in domestic cats describes the use of host-derived bacteria as a probiotic. We previously identified Enterococcus hirae as a dominant species colonizing the small intestinal mucosa in healthy shelter kittens. Oral administration of a probiotic formulation of kitten-origin E. hirae (strain 1002-2) mitigated the increase in intestinal permeability and fecal water loss resulting from experimental enteropathogenic E. coli infection in purpose-bred kittens. Based on these findings, we hypothesized that administration of kitten-origin E. hirae to weaned fostered shelter kittens could provide a measurable preventative health benefit. Methods: We conducted a randomized, placebo-controlled, blinded clinical trial to determine the impact of a freeze-dried E. hirae probiotic on body weight gain, incidence of diarrhea, carriage of potential diarrheal pathogens, and composition of the intestinal microbiota in weaned fostered shelter kittens. Results: One-hundred thirty kittens completed the study. Fifty-eight kittens received the probiotic and 72 received the placebo. There were no significant differences in age, weight upon initiation of the study, number of days in the study, average daily gain in body weight, or weight at completion of the study. Kittens treated with E. hirae were 3.4 times less likely to develop diarrhea compared to kittens treated with placebo (odds ratio = 0.294, 95% CI 0.109-0.792, p = 0.022). A significant impact of E. hirae was not observed on the presence or abundance of 30 different bacterial, viral, protozoal, fungal, algal, and parasitic agents in feces examined by qPCR. With exception to a decrease in Megamonas, administration of the E. hirae probiotic did not alter the predominant bacterial phyla present in feces based on 16S rRNA gene amplicon sequencing. Discussion: Decreased incidence of diarrhea associated with preventative administration of E. hirae to foster kittens supports a rationale for use of E. hirae for disease prevention in this young population at high risk for intestinal disease though additional studies are warranted.

Dysbiosis of fecal microbiota in cats with naturally occurring and experimentally induced Tritrichomonas foetus infection.

The protozoal pathogen Tritrichomonas foetus infects the colon of domestic cats and is a major cause of chronic colitis and diarrhea. Treatment failure is common, but antibiotics may improve clinical signs in a subset of cats, leading researchers to question involvement of the colonic microbiota in disease pathogenesis. Studies performed in women with venereal Trichomonas vaginalis infections have revealed that dysbiosis of host microbiota contributes to pathogenicity with similar findings also found in mice with intestinal Tritrichomonas musculis The aim of this study was to characterize differences in the fecal microbiota of cats with and without naturally occurring T. foetus infection and in a group of kittens prior to and after experimentally induced infection. Archived fecal DNA from cats undergoing testing for T. foetus infection (n = 89) and experimentally infected kittens (n = 4; at pre-, 2 weeks, and 9 weeks post-infection) were analyzed by sequencing of 16S rRNA genes. Amongst the naturally infected population, the genera Megamonas and Helicobacter were significantly increased in prevalence and abundance in cats testing positive for T. foetus infection. In the group of four experimentally infected kittens, fecal samples post-infection had significantly lower abundance of genus Dialister and Megamonas and greater abundance of the class Betaproteobacteria and family Succinivibrionaceae. We hypothesize that T. foetus promotes dysbiosis by competition for fermentable substrates used by these bacteria and that metabolic byproducts may contribute to the pathogenesis of colonic inflammation and diarrhea. Future studies are warranted for the measurement of fecal concentrations of microbial and protozoal metabolites in cats with T. foetus infection for the identification of potential therapeutic targets.

Proteinuria in dogs with gallbladder mucocele formation: A retrospective case control study.

BACKGROUND: Proteinuria is an independent risk factor for morbidity and mortality in dogs. An association between proteinuria and gallbladder mucocele formation in dogs is unknown. OBJECTIVE: Determine if gallbladder mucocele formation or clinicopathologic comorbidities are associated with proteinuria. ANIMALS: Twenty-five dogs with mucocele formation and 25 breed and age-matched control dogs from a prior study. METHODS: Retrospective case control study. Proteinuria defined by calculated urine dipstick protein concentration (mg/mL) to urine specific gravity (USG) ratio. Clinicopathologic findings, postcosyntropin cortisol concentration, thyroid function profile, and illness severity score were recorded. RESULTS: Median urine dipstick protein concentration to USG ratio and number of dogs having a ratio ≥1.5 were significantly higher for dogs with mucocele formation compared to control dogs. Proteinuria was not significantly associated with CBC or serum biochemistry profile abnormalities but increased in relation to severity of illness. CONCLUSIONS AND CLINICAL IMPORTANCE: Gallbladder mucocele formation is significantly associated with proteinuria in dogs. Diagnosis and treatment of proteinuria in dogs with mucocele formation might minimize long term kidney morbidity in these patients.

Comparative Genomics of Atypical Enteropathogenic Escherichia coli from Kittens and Children Identifies Bacterial Factors Associated with Virulence in Kittens.

Typical enteropathogenic Escherichia coli (tEPEC) is a leading cause of diarrhea and associated death in children worldwide. Atypical EPEC (aEPEC) lacks the plasmid encoding bundle-forming pili and is considered less virulent, but the molecular mechanism of virulence is poorly understood. We recently identified kittens as a host for aEPEC where intestinal epithelial colonization was associated with diarrheal disease and death. The purposes of this study were to (i) determine the genomic similarity between kitten aEPEC and human aEPEC isolates and (ii) identify genotypic or phenotypic traits associated with virulence in kitten aEPEC. We observed no differences between kitten and human aEPEC in core genome content or gene cluster sequence identities, and no distinguishing genomic content was observed between aEPEC isolates from kittens with nonclinical colonization (NC) versus those with lethal infection (LI). Variation in adherence patterns and ability to aggregate actin in cultured cells mirrored descriptions of human aEPEC. The aEPEC isolated from kittens with LI were significantly more motile than isolates from kittens with NC. Kittens may serve as a reservoir for aEPEC that is indistinguishable from human aEPEC isolates and may provide a needed comparative animal model for the study of aEPEC pathogenesis. Motility seems to be an important factor in pathogenesis of LI associated with aEPEC in kittens.

Association of fecal sample collection technique and treatment history with Tritrichomonas foetus polymerase chain reaction test results in 1717 cats.

BACKGROUND: Fecal polymerase chain reaction (PCR) testing for Tritrichomonas foetus is considered the most sensitive means for diagnosis of infection but results could be influenced by fecal collection technique and prior use of antimicrobial drugs. OBJECTIVES: To establish any association between fecal collection technique or treatment history and results of fecal PCR testing for T. foetus. ANIMALS: Fecal samples from 1717 cats submitted by veterinarians between January 2012 and December 2017. METHODS: This study used a retrospective analysis. T. foetus PCR test results from 1808 fecal samples submitted for diagnostic testing were examined for their association with method of fecal collection and prior antimicrobial treatments. Data were collected from sample submission form. RESULTS: Positive T. foetus PCR test results were obtained for 274 (16%) cats. Fecal samples collected via fecal loop had increased probability of positive PCR test results (odds ratio [OR] 2.04, 95% confidence interval [CI] 1.31-3.17, P = .002) compared to samples collected by colonic flush. There was no association between PCR test results and treatment history, treatment type, or prior treatment with ronidazole. After an initial positive PCR test, 4/19 (21%; 95% CI 2.7%-39.4%) cats treated with ronidazole had a second positive test result. CONCLUSIONS AND CLINICAL IMPORTANCE: Results of this study support that fecal samples collected by loop might be better for PCR diagnosis of T. foetus infection. Lack of association of ronidazole with PCR test results and a 21% all-potential-causes failure rate of ronidazole in cats with preconfirmed infection are important limitations to use of this drug.

Perceptions and attitudes of Small Animal Internal Medicine specialists toward the publication requirement for board certification.

BACKGROUND: The publication requirement for board certification in Small Animal Internal Medicine (SAIM) by the ACVIM is controversial. OBJECTIVES: Directly and indirectly evaluate the perceptions SAIM Diplomates have on the publication requirement. A secondary objective was to compare the frequency with which publications submitted for credentialing purposes (CredPubs) were cited compared to control articles. SUBJECTS: One thousand two hundred forty-one SAIM Diplomates were sent an electronic survey. METHODS: A electronic survey was sent to all SAIM Diplomates. Practice websites were evaluated for reference to publication or research. An electronic database was searched to identify the number of times a subset of CredPubs were cited was compared to control articles. RESULTS: Five hundred six individuals responded. The majority of respondents (n = 428, 85.25%) stated the requirement should be retained either with no changes (n = 186, 37.05%) or with clarifications or modifications (n = 242, 48.21%). A minority of respondents (n = 74, 14.7%) felt it should be eliminated. "Understanding the scientific process" was the most commonly selected reason (n = 467, 92.48%) for the publication requirement. All websites that mentioned research or publication did so using a positive sentiment. With regard to relative citation rates; 17% of CredPubs were in the lower quartile, 59.1% of CredPubs were in the interquartile range, and 23.5% were in the upper quartile compared to control articles. CONCLUSIONS AND CLINICAL IMPORTANCE: A majority of SAIM Diplomates favored the retention of the publication requirement in some form. CredPubs were cited at rates similar to control articles.

Interventions and observations associated with survival of orphaned shelter kittens undergoing treatment for diarrhea.

OBJECTIVES: The objective of this study was to identify significant associations between treatment interventions and survival of orphaned shelter kittens with diarrhea. METHODS: Orphaned kittens admitted to a large open-intake municipal animal shelter and entering a volunteer foster care provider network between April 2016 and July 2017 were studied. Individual orphaned kittens for which the care provider sought examination by shelter veterinarians because of clinical signs of diarrhea were included. Treatments administered were recorded and their association with kitten survival to adoption or transfer to a rescue partner was statistically examined. RESULTS: A total of 1718 orphaned kittens were fostered, among which 220 kittens (12.8%) from 118 different litters were presented for evaluation of diarrhea. A total of 172 (78.2%) kittens underwent treatment for their diarrhea, among which 153 (89.0%) survived to adoption or transfer to a rescue partner and 19 (11.0%) died or were humanely euthanized. Kittens with diarrhea that were ⩾4 weeks of age were 24.8 times more likely to survive (95% confidence interval [CI] 6.8-89.8; P <0.0001). While controlling for age, kittens that received a vitamin and mineral supplement were 12.8 times more likely to survive (95% CI 3.1-52.5; P = 0.0004) than kittens with diarrhea that did not receive the supplement. Treatment with subcutaneous fluids, penicillin G, tube feeding, a probiotic containing Enterococcus faecium SF68, ponazuril or metronidazole did not statistically significantly increase the survival of kittens with diarrhea. CONCLUSIONS AND RELEVANCE: Age ⩾4 weeks and treatment of diarrhea with a vitamin and mineral supplement favorably improves survival of orphaned kittens to adoption. Application of these findings are likely to improve the health and welfare of this population and contribute to a refinement in use of shelter resources.

The effect of enterococci on feline Tritrichomonas foetus infection in vitro.

Tritrichomonas foetus is a common cause of large bowel diarrhea in cats. Probiotics have been suggested to be effective for many intestinal pathogens; however, there are a lack of studies evaluating the effect of probiotics in T. foetus infection. In vitro studies were performed to evaluate the effect of a probiotic containing Enterococcus faecium (Efm) SF68 and a novel probiotic, Enterococcus hirae, on the inhibition of T. foetus growth, adhesion to, and cytotoxicity towards the intestinal epithelium. The effect of enterococci on T. foetus proliferation during co-culture was evaluated throughout log phase T. foetus growth. The previously validated in vitro co-culture model system using porcine intestinal epithelial cells (IPEC-J2) was used to evaluate the effect of enterococci on T. foetus adhesion and cytotoxicity towards intestinal epithelial cells. Cytotoxicity was assessed using fluorescent microscopy and spectrophotometry. Interactions of T. foetus, enterococci, and intestinal epithelial cells were assessed using scanning electron microscopy and immunofluorescence assays (IFA). Enterococcus-induced inhibition of T. foetus growth was demonstrated at concentrations as low as 104 enterococci colony forming units (CFU)/mL and was dependent, in part, on environmental pH and the presence of viable enterococci organisms. T. foetus adhesion, including with a ronidazole-resistant strain, was reduced with pretreatment of intestinal epithelial cells with enterococci but was not significantly affected when enterococci were introduced simultaneously or following T. foetus infection. Compared to Efm, E. hirae more effectively decreased T. foetus adhesion, suggesting its superior potential as a novel probiotic for T. foetus infection. There was no effect of enterococci treatment on T. foetus-induced intestinal epithelial cell cytotoxicity. Our results support further study into the investigation of a possible benefit of enterococci-containing probiotic treatment for prevention of T. foetus infection in at-risk uninfected cats.

Influence of the intestinal microbiota on disease susceptibility in kittens with experimentally-induced carriage of atypical enteropathogenic Escherichia coli.

Typical enteropathogenic E. coli (tEPEC) carries the highest hazard of death in children with diarrhea and atypical EPEC (aEPEC) was recently identified as significantly associated with diarrheal mortality in kittens. In both children and kittens there is a significant association between aEPEC burden and diarrheal disease, however the infection can be found in individuals with and without diarrhea. It remains unclear to what extent, under what conditions, or by what mechanisms aEPEC serves as a primary pathogen in individuals with diarrhea. It seems likely that a combination of host and bacterial factors enable aEPEC to cause disease in some individuals and not in others. The purpose of this study was to determine the impact of aEPEC on intestinal function and diarrhea in kittens following experimentally-induced carriage and the influence of a disrupted intestinal microbiota on disease susceptibility. Results of this study identify aEPEC as a potential pathogen in kittens. In the absence of disruption to the intestinal microbiota, kittens are resistant to clinical signs of aEPEC carriage but demonstrate significant occult changes in intestinal absorption and permeability. Antibiotic-induced disruption of the intestinal microbiota prior to infection increases subsequent intestinal water loss as determined by % fecal wet weight. Enrichment of the intestinal microbiota with a commensal member of the feline mucosa-associated microbiota, Enterococcus hirae, ameliorated the effects of aEPEC experimental infection on intestinal function and water loss. These observations begin to unravel the mechanisms by which aEPEC infection may be able to exploit susceptible hosts.

Interferon-λ3 Promotes Epithelial Defense and Barrier Function Against Cryptosporidium parvum Infection.

BACKGROUND & AIMS: The epithelial response is critical for intestinal defense against Cryptosporidium, but is poorly understood. To uncover the host strategy for defense against Cryptosporidium, we examined the transcriptional response of intestinal epithelial cells (IECs) to C parvum in experimentally infected piglets by microarray. Up-regulated genes were dominated by targets of interferon (IFN) and IFN-λ3 was up-regulated significantly in infected piglet mucosa. Although IFN-λ has been described as a mediator of epithelial defense against viral pathogens, there is limited knowledge of any role against nonviral pathogens. Accordingly, the aim of the study was to determine the significance of IFN-λ3 to epithelial defense and barrier function during C parvum infection. METHODS: The significance of C parvum-induced IFN-λ3 expression was determined using an immunoneutralization approach in neonatal C57BL/6 mice. The ability of the intestinal epithelium to up-regulate IFN-λ2/3 expression in response to C parvum infection and the influence of IFN-λ2/3 on epithelial defense against C parvum invasion, intracellular development, and loss of barrier function was examined using polarized monolayers of a nontransformed porcine-derived small intestinal epithelial cell line (IPEC-J2). Specifically, changes in barrier function were quantified by measurement of transepithelial electrical resistance and transepithelial flux studies. RESULTS: Immunoneutralization of IFN-λ2/3 in C parvum-infected neonatal mice resulted in a significantly increased parasite burden, fecal shedding, and villus blunting with crypt hyperplasia during peak infection. In vitro, C parvum was sufficient to induce autonomous IFN-λ3 and interferon-stimulated gene 15 expression by IECs. Priming of IECs with recombinant human IFN-λ3 promoted cellular defense against C parvum infection and abrogated C parvum-induced loss of barrier function by decreasing paracellular permeability to sodium. CONCLUSIONS: These studies identify IFN-λ3 as a key epithelial defense mechanism against C parvum infection.

Investigation of adrenal and thyroid gland dysfunction in dogs with ultrasonographic diagnosis of gallbladder mucocele formation.

Gallbladder mucocele formation is an emerging disease in dogs characterized by increased secretion of condensed granules of gel-forming mucin by the gallbladder epithelium and formation of an abnormally thick mucus that can culminate in obstruction of the bile duct or rupture of the gallbladder. The disease is associated with a high morbidity and mortality and its pathogenesis is unknown. Affected dogs have a significantly increased likelihood of concurrent diagnosis of hyperadrenocorticism, hypothyroidism, and hyperlipidemia. Whether these endocrinopathies represent coincidental primary disease processes that exacerbate gallbladder mucocele formation in predisposed dogs or reflect a concurrent disruption of endocrine and lipid metabolism is unclear. In this study, we investigated a hypothesis that dogs with gallbladder mucocele formation would have a high prevalence of occult and atypical abnormalities in adrenal cortical and thyroid gland function that would suggest the presence of endocrine disruption and provide deeper insight into disease pathogenesis. We performed a case-control study of dogs with and without ultrasonographic diagnosis of gallbladder mucocele formation and profiled adrenal cortical function using a quantitative mass spectrometry-based assay of serum adrenal-origin steroids before and after administration of synthetic cosyntropin. We simultaneously profiled serum thyroid hormone concentrations and evaluated iodine sufficiency by measurement of urine iodine:creatinine ratios (UICR). The studies were complemented by histological examination of archival thyroid tissue and measurements of thyroid gland organic iodine from dogs with gallbladder mucocele formation and control dogs. Dogs with gallbladder mucocele formation demonstrated an exaggerated cortisol response to adrenal stimulation with cosyntropin. A prevalence of 10% of dogs with gallbladder mucocele formation met laboratory-based criteria for suspect or definitive diagnosis of hyperadrenocorticism. A significantly greater number of dogs with gallbladder mucocele formation had basal serum dehydroepiandrosterone (DHEAS) increases compared to control dogs. A high percentage of dogs with gallbladder mucocele formation (26%) met laboratory-based criteria for diagnosis of hypothyroidism, but lacked detection of anti-thyroglobulin antibodies. Dogs with gallbladder mucocele formation had significantly higher UICRs than control dogs. Examination of thyroid tissue from an unrelated group of dogs with gallbladder mucocele formation did not demonstrate histological evidence of thyroiditis or significant differences in content of organic iodine. These findings suggest that dogs with gallbladder mucocele formation have a greater capacity for cortisol synthesis and pinpoint DHEAS elevations as a potential clue to the underlying pathogenesis of the disease. A high prevalence of thyroid dysfunction with absent evidence for autoimmune thyroiditis suggest a disrupted thyroid hormone metabolism in dogs with gallbladder mucocele formation although an influence of non-thyroidal illness cannot be excluded. High UICR in dogs with gallbladder mucocele formation is of undetermined significance, but of interest for further study.

Qualitative metabolomics profiling of serum and bile from dogs with gallbladder mucocele formation.

Mucocele formation is characterized by secretion of abnormally thick mucus by the gallbladder epithelium of dogs that may cause obstruction of the bile duct or rupture of the gallbladder. The disease is increasingly recognized and is associated with a high morbidity and mortality. The cause of gallbladder mucocele formation in dogs is unknown. There is a strong breed predisposition and affected dogs have a high incidence of concurrent endocrinopathy or hyperlipidemia. These observations suggest a significant influence of both genetic and metabolic factors on disease pathogenesis. In this study, we investigated a theory that mucocele formation is associated with a syndrome of metabolic disruption. We surmised that a global, untargeted metabolomics approach could provide unique insight into the systemic pathogenesis of gallbladder mucocele formation and identify specific compounds as candidate biomarkers or treatment targets. Moreover, concurrent examination of the serum and hepatic duct bile metabolome would enable the construction of mechanism-based theories or identification of specific compounds responsible for altered function of the gallbladder epithelium. Abnormalities observed in dogs with gallbladder mucocele formation, including a 33-fold decrease in serum adenosine 5'-monophosphate (AMP), lower quantities of precursors required for synthesis of energy transporting nucleotides, and increases in citric acid cycle intermediates, suggest excess metabolic energy and a carbon surplus. Altered quantities of compounds involved in protein translation and RNA turnover, together with accumulation of gamma-glutamylated and N-acetylated amino acids in serum suggest abnormal regulation of protein and amino acid metabolism. Increases in lathosterol and 7α-hydroxycholesterol suggest a primary increase in cholesterol synthesis and diversion to bile acid formation. A number of specific biomarker compounds were identified for their ability to distinguish between control dogs and those that formed a gallbladder mucocele. Particularly noteworthy was a significant decrease in quantity of biologically active compounds that stimulate biliary ductal fluid secretion including adenosine, cAMP, taurolithocholic acid, and taurocholic acid. These findings support the presence of significant metabolic disruption in dogs with mucocele formation. A targeted, quantitative analysis of the identified serum biomarkers is warranted to determine their utility for diagnosis of this disease. Finally, repletion of compounds whose biological activity normally promotes biliary ductal secretion should be examined for any therapeutic impact for resolution or prevention of mucocele formation.

Association of Atypical Enteropathogenic Escherichia coli with Diarrhea and Related Mortality in Kittens.

Diarrhea is responsible for the death of approximately 900,000 children per year worldwide. In children, typical enteropathogenic Escherichia coli (EPEC) is a common cause of diarrhea and is associated with a higher hazard of death. Typical EPEC infection is rare in animals and poorly reproduced in experimental animal models. In contrast, atypical EPEC (aEPEC) infection is common in both children and animals, but its role in diarrhea is uncertain. Mortality in kittens is often attributed to diarrhea, and we previously identified enteroadherent EPEC in the intestines of deceased kittens. The purpose of this study was to determine the prevalence and type of EPEC in kittens and whether infection was associated with diarrhea, diarrhea-related mortality, gastrointestinal pathology, or other risk factors. Kittens with and without diarrhea were obtained from two shelter facilities and determined to shed atypical EPEC at a culture-based prevalence of 18%. In contrast, quantitative PCR detected the presence of the gene for intimin (eae) in feces from 42% of kittens. aEPEC was isolated from kittens with and without diarrhea. However, kittens with diarrhea harbored significantly larger quantities of aEPEC than kittens without diarrhea. Kittens with aEPEC had a significantly greater severity of small intestinal and colonic lesions and were significantly more likely to have required subcutaneous fluid administration. These findings identify aEPEC to be prevalent in kittens and a significant primary or contributing cause of intestinal inflammation, diarrhea, dehydration, and associated mortality in kittens.

The conundrum of feline Trichomonosis.

Practical relevance: Trichomonosis of the large intestine of the cat was described as a cause of chronic diarrhea over 20 years ago. The trichomonad was identified as Tritrichomonas foetus, with a genotype that is distinct from venereal T foetus of cattle. Clinical challenges: Despite multiple means for diagnosis of the infection, including light microscopy, protozoal culture and PCR amplification using species-specific primers, tests with even greater sensitivity are needed. Feline trichomonosis is resistant to all commonly used antiprotozoal drugs. Ronidazole is currently the only drug demonstrated to be effective in eliminating the infection from cats; however, this drug has a narrow safety margin and clinical resistance is increasingly recognized. The more we learn about trichomonosis in cats, the more complicated and controversial the infection has become, ranging from what we should call the organism to whether we should even bother trying to treat it. Global importance: Feline trichomonosis is recognized to occur worldwide and is regarded as one of the most common infectious causes of colitis in the domestic cat. The infection is widespread in catteries and shelters; and, while remission of diarrhea may occur over time, persistence of the infection is common. Evidence base: This review provides a comprehensive examination of what is currently known about feline trichomonosis and pinpoints areas, based on the authors' opinion, where further research is needed.

Cyniclomyces guttulatus Infection in Dogs: 19 Cases (2006-2013).

Cyniclomyces guttulatus, a gastrointestinal yeast of rabbits, is considered an uncommon, nonpathogenic, "pass through" organism and possible opportunistic pathogen in dogs that consume rabbit feces. This retrospective study aimed to characterize the presenting complaint, clinical findings, location of organisms, and final diagnosis of dogs in which yeast morphologically consistent with C. guttulatus were identified at a veterinary teaching hospital from 2006-2013. The prevalence of C. guttulatus infection in a general population of dogs from a regional animal shelter was also determined. Nineteen dogs were retrospectively identified as diagnosed with C. guttulatus infection. Among these, 79% presented with a chief complaint and/or clinical signs consistent with gastrointestinal tract disease. The most common clinical sign was chronic diarrhea. The majority of dogs had C. guttulatus identified cytologically within samples obtained from the gastrointestinal tract; however, four dogs had C. guttulatus identified in non-gastrointestinal tract samples, including a nasal biopsy (one dog) and urine (three dogs). C. guttulatus was not identified in any of 105 shelter dogs evaluated, suggesting low prevalence of C. guttulatus in our region. These findings suggest that additional studies to determine if C. guttulatus is a potential cause or consequence of gastrointestinal illness in dogs may be warranted.

Evaluation of associations among Coxiella burnetii and reproductive abnormalities in cats.

OBJECTIVES: Coxiella burnetii is an obligate intracellular bacterium that is found worldwide, is associated or suggested to be associated with reproductive abnormalities in a number of species including cats, and is the cause of Q fever in humans. In a previous study, C burnetii DNA was amplified from the uterine tissues of 8.5% of client-owned cats in the USA but reproductive history was unknown and histopathological examination was not performed. In this study, uterine tissues of 26 normal cats and 11 cats with histopathological evidence of uterine disease or other reproductive abnormalities were evaluated for the presence of C burnetii. METHODS: A PCR assay that amplifies the repetitive transposon-like region (Trans 1 and 2) and a PCR assay that amplifies the IS-1111-insertion sequence (IS-1111) were optimised and applied to the DNA extracts. The sensitivity threshold of both PCR assays was 12 pg/µl. Positive samples were evaluated for the presence of the organism using immunohistochemistry performed on paraffin-embedded tissue. RESULTS: Amplicons of the expected size developed in three samples (one from a cat with reproductive abnormalities) in the IS-1111 assay; however, there was not enough DNA for sequence analysis. Immunohistochemical analysis was used to further evaluate these three samples and was negative for C burnetii. While C burnetii could not be confirmed by sequence analysis or immunohistochemistry, the PCR positive prevalence rate (8.1%) was similar to that published previously. CONCLUSIONS AND RELEVANCE: Biosafety precautions should be taken when working with cats that are aborting or parturient. Further research should be performed to evaluate the role that C burnetii may play in reproductive abnormalities in cats.

Excess Secretion of Gel-Forming Mucins and Associated Innate Defense Proteins with Defective Mucin Un-Packaging Underpin Gallbladder Mucocele Formation in Dogs.

Mucosal protection of the gallbladder is vital yet we know very little about the mechanisms involved. In domestic dogs, an emergent syndrome referred to as gallbladder mucocele formation is characterized by excessive secretion of abnormal mucus that results in obstruction and rupture of the gallbladder. The cause of gallbladder mucocele formation is unknown. In these first mechanistic studies of this disease, we investigated normal and mucocele-forming dog gallbladders to determine the source, identity, biophysical properties, and protein associates of the culprit mucins with aim to identify causes for abnormal mucus behavior. We established that mucocele formation involves an adoptive excess secretion of gel forming mucins with abnormal properties by the gallbladder epithelium. The mucus is characterized by a disproportionally significant increase in Muc5ac relative to Muc5b, defective mucin un-packaging, and mucin-interacting innate defense proteins that are capable of dramatically altering the physical and functional properties of mucus. These findings provide an explanation for abnormal mucus behavior and based on similarity to mucus observed in the airways of people with cystic fibrosis, suggest that abnormal mechanisms for maintenance of gallbladder epithelial hydration may be an instigating factor for mucocele formation in dogs.