Effect of tylosin on dogs with suspected tylosin-responsive diarrhea: a placebo-controlled, randomized, double-blinded, prospective clinical trial

Oral Fecal Microbiota Transplantation in Dogs with Tylosin-Responsive Enteropathy-A Proof-of-Concept Study

A clinical trial was conducted to evaluate the effect of fecal microbiota transplantation (FMT) on the canine chronic enteropathy clinical activity index (CCECAI), fecal consistency, and microbiome of dogs with tylosin-responsive enteropathy (TRE). The trial consisted of four phases: (1) screening with discontinuation of tylosin for 4 weeks, (2) inclusion with re-introduction of tylosin for 3-7 days, (3) treatment with FMT/placebo for 4 weeks, and (4) post-treatment with follow-up for 4 weeks after treatment cessation. The study found that the treatment efficacy of FMT (71.4%) was slightly higher than that of placebo (50%), but this difference was not statistically significant due to underpowering. The most abundant bacterial species detected in the fecal microbiomes of dogs with TRE before FMT or placebo treatment were Blautia hansenii, Ruminococcus gnavus, Escherichia coli, Clostridium dakarense, Clostridium perfringens, Bacteroides vulgatus, and Faecalimonas umbilicata. After FMT, the microbiomes exhibited increases in Clostridium dakarense, Clostridium paraputrificum, and Butyricicoccus pullicaecorum. The microbiome alpha diversity of TRE dogs was lower when on tylosin treatment compared to healthy dogs, but it increased after treatment in both the FMT and placebo groups. Comparisons with the stool donor showed that, on average, 30.4% of donor strains were engrafted in FMT recipients, with the most common strains being several Blautia sp., Ruminococcus gnavus, unclassified Lachnoclostridium, Collinsella intestinalis, and Fournierella massiliensis.

Updating the Classification of Chronic Inflammatory Enteropathies in Dogs

Chronic inflammatory enteropathies (CIEs) in dogs are currently classified based on response to sequential treatment trials into food-responsive (FREs); antibiotic-responsive (AREs); immunosuppressant-responsive (IREs); and non-responsive enteropathies (NREs). Recent studies have reported that a proportion of NRE dogs ultimately respond to further dietary trials and are subsequently misclassified. The FRE subset among CIEs is therefore probably underestimated. Moreover, alterations in the gut microbiota composition and function (dysbiosis) have been shown to be involved in CIE pathogenesis in recent research on dogs. Metronidazole and other antibiotics that have been used for decades for dogs with AREs have been demonstrated to result in increased antimicrobial resistance and deleterious effects on the gut microbiota. As a consequence, the clinical approach to CIEs has evolved in recent years toward the gradual abandonment of the use of antibiotics and their replacement by other treatments with the aim of restoring a diverse and functional gut microbiota. We propose here to refine the classification of canine CIEs by replacing the AREs category with a microbiota-related modulation-responsive enteropathies (MrMREs) category.

The Use of Diets in the Diagnosis and Treatment of Common Gastrointestinal Diseases in Dogs and Cats

The nutritional health of dogs and cats is important to pet owners around the world. Nutrition is inextricably linked to the health of the gastrointestinal system and vice versa. Gastrointestinal signs, such as vomiting, diarrhea, anorexia, or weight loss, are one of the most common reasons that dog and cat owners make non-routine appointments with veterinarians. Those patients are evaluated systematically to identify and/or rule out the causes of the symptoms. Some causes of chronic diarrhea are within the gastrointestinal tract while others are secondary to pathogenic factors outside the digestive system. Some useful biomarkers of chronic intestinal disease (enteropathy) exist in serum and feces. After determination that the clinical signs are due to primary gastrointestinal disease and that there is no parasitism, specific diets are used for at least two weeks. There are several types of diets for pets with chronic enteropathies. There are limited ingredient diets and hydrolyzed protein diets with reduced levels of allergens. There are also highly digestible and fiber-enhanced diets. Some diets contain probiotics and/or prebiotics. If symptoms do not improve and the patient is stable, a diet from a different class may be tried. For chronic enteropathies, the prognosis is generally good for symptom resolution or at least improvement. However, if interventions with novel diets do not ameliorate the symptoms of chronic enteropathy, then antibiotic, anti-inflammatory, or immunosuppressant therapy or further, more invasive diagnostics such as taking an intestinal biopsy, may be indicated. Pancreatitis is a common gastrointestinal disease in dogs and cats and patients may present with mild to severe disease. Many patients with mild to moderate disease can be successfully treated with early supportive care, including feeding a low-fat diet. A novel pharmaceutical, fuzapladib (Panoquell-CA1) looks very promising for treating more severe forms of acute pancreatitis in dogs. Maintenance on a low-fat diet may prevent pancreatitis in at-risk dogs. Future advances in medicine will allow pet owners and veterinarians to use dietary management to maximize the health of their dogs and cats.

Effects of antimicrobials on the gastrointestinal microbiota of dogs and cats

Among several environmental factors, exposure to antimicrobials has been in the spotlight as a cause of profound and long-term disturbance of the intestinal microbiota. Antimicrobial-induced dysbiosis is a general term and includes decreases in microbial richness and diversity, loss of beneficial bacterial groups, blooms of intestinal pathogens and alterations in the metabolic functions and end-products of the microbiota. Mounting evidence from human and experimental animal studies suggest an association between antimicrobial-induced dysbiosis and susceptibility to gastrointestinal, metabolic, endocrine, immune and neuropsychiatric diseases. These associations are commonly stronger after early life exposure to antimicrobials, a period during which maturation of the microbiota and immune system take place in parallel. In addition, these associations commonly become stronger as the number of antimicrobial courses increases. The repeatability of these findings among different studies as well as the presence of a dose-dependent relationship between antimicrobial exposure and disease development collectively require careful consideration of the need for antimicrobial use. There are limited studies are available in dogs and cats regarding the long-term effects of antimicrobials on the microbiota and subsequent susceptibility to diseases. This review discusses the effects of antimicrobials on the gastrointestinal microbiota and the most important associations between antimicrobial-induced dysbiosis and diseases in humans, dogs, and cats.

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

Background

Chronic 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.

Methods

A 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.

Results

Assessments 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.

Conclusions

In 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.

Supplementary Information

The online version contains supplementary material available at 10.1186/s12917-022-03302-8.

Chronic Enteropathy in Dogs-Epidemiologic Aspects and Clinical Characteristics of Dogs Presenting at Two Swedish Animal Hospitals

Information about prevalence and breed predisposition of canine chronic enteropathy (CE) is limited. The aim of this retrospective study was to investigate period prevalence, breed disposition, clinical features, diagnostic results, and treatment response of CE in dogs presenting at two Swedish animal hospitals during 2013−2018. A medical record search was performed to identify CE dogs including those with ≥3 visits because of gastrointestinal disease and/or that had undergone gastroduodenoscopy/colonoscopy during 2013−2018. Dog characteristics, case history, physical examination, laboratory variables, therapeutic protocol, and treatment response were recorded. Inclusion criteria for CE were met by 814 dogs. Period prevalence of CE was 1.1% of total number of dogs. Breeds with the highest relative risk included Norwegian Lundehund, West Highland White Terrier, and Miniature Poodle. Median age at presentation was 3.8 (IQR 1.8−6.8) years. French Bulldogs and Miniature Schnauzers presented at a younger age (<2.5 years) compared to other breeds (p < 0.05). In a subset of dogs, serum hypoalbuminemia (116/662, 17.5%), hypocobalaminemia (98/647, 15.1%), and increased C-reactive protein (CRP) concentrations (145/267, 54.3%) were diagnosed. Treatment outcome was classified in 72.9% of dogs and characterized as immunosuppressant-responsive (55.2%), food-responsive (11.4%), non-responsive (5.2%), and antibiotic-responsive (1.1%). Non-responsive dogs were more likely to present with anemia hypoproteinemia/albuminemia, increased CRP, and ascites (p < 0.05). In conclusion, the prevalence of dogs with CE at Swedish hospitals agreed with earlier reports, but risk breeds differed slightly and, compared to other breeds, a younger age of CE onset was found in two breeds. The largest proportion of dogs was immunosuppressant-responsive and the smallest antibiotic-responsive.

Chronic enteropathy in dogs - retrospective case analysis and results of an owner survey

OBJECTIVE

Chronic gastrointestinal diseases in dogs are common and often require intensive diagnostic work-up and lifelong therapy. In this study, a survey of owners of affected dogs was conducted in parallel with a retrospective case analysis from the clinic's documentation system.

MATERIAL AND METHODS

The records of dogs with gastrointestinal symptomatology and exclusion of an extraintestinal cause, presented from January 2011 to October 2018, were acquired from the clinic's case system and analysed. Patient owners were interviewed using a questionnaire regarding diagnosis, treatment, course of the disease and improvement in the dog's quality of life as a result of treatment. To gain a better understanding of influencing factors for the different subtypes of chronic enteropathy, differentiation was made into feed-responsive (FRE), antibiotic-responsive (ARE), immunosuppressant-responsive (IRE), and nonresponsive enteropathy (NRE) according to the success of different therapeutic approaches.

RESULTS

Of 125 patient owners contacted, 81 participated in the study. The majority of the 81 dogs had FRE (45; 55.6 %), 11 (13.6 %) dogs had ARE, 23 (28.4 %) had IRE and 2 (2.5 %) had NRE. At the disease onset, dogs in the FRE and ARE groups were significantly younger than those in the IRE group. Interviews with dog owners showed that veterinary recommendations had not been consistently implemented, particularly in dogs in the FRE group. Successful treatment resulted in significant improvement in the quality of life in patients in all 3 groups according to owner assessment, with no differences between the groups.

CONCLUSION AND CLINICAL RELEVANCE

The majority of the contacted dog owners agreed to participate in the survey. A retrospective case analysis in combination with an owner survey is helpful to elicit the owners' assessment of their dog's treatment and disease course and to reveal starting points for improved owner compliance.

Physiological influence of tylosin tartrate overdose in vivo in rats

The aim of this study was to evaluate the physiological effects of tylosin in rats. Tylosin was administered orally to pubertal male and female rats at concentrations of 0.005, 0.2, 10 and 200 mg/kg b.w. for 6 weeks. The overall body and organ weights were recorded. Serum levels of immunoglobulins, haematological values, histopathological lesions in different organs, and gene expression profiles in pituitary glands were investigated. The mean platelet volume was increased, and the monocyte count was decreased significantly in both male and female rats treated with tylosin. Compared to the untreated control, alanine transaminase in both types of rats and total serum bilirubin in female rats were increased significantly with the administration of tylosin (200 mg/kg), however, lactate dehydrogenase in female rats was decreased. The levels of immunoglobulin M were reduced in both male and female rats but immunoglobulin G levels were significantly reduced only in female rats which were treated with tylosin. Cell proliferation- and adhesion-associated genes were expressed more but apoptosis gene expressions were decreased in the pituitary gland of tylosin-treated rats. In conclusion, this study revealed that the use of tylosin at therapeutic dosage is possibly not completely safe.

In Vitro Evaluation of the Effects of Tylosin on the Composition and Metabolism of Canine Fecal Microbiota

Simple Summary

The antibiotic-responsive enteropathy is a common canine chronic disorder for which tylosin represents an effective widely used therapeutic option, although its mechanism of action, beyond the well-known antibacterial activity, is still unclear. Given the beneficial role of prebiotic substrates for gut health, positive outcomes deriving from the association of tylosin with some prebiotic oligosaccharides might be supposed. The present study investigated in vitro the effects of tylosin, alone or supplemented with fructooligosaccharides, galactooligosaccharides, or xylooligosaccharides, on the composition and activity of the fecal microbiota of healthy dogs. It was partially confirmed that the antibacterial effect of tylosin, given the reduction of some microbial populations and metabolites, e.g., volatile fatty acids. Interestingly, the association of tylosin with prebiotics revealed counteracting effects on some undesirable changes exerted by tylosin, e.g., the reduction of bacteria generally considered beneficial such as lactobacilli and Clostridium cluster XIVa as well as volatile fatty acids, i.e., microbial fermentative end-products that are recognized as essential for enterocytes homeostasis.

Abstract

The present study investigated the in vitro effects of tylosin (TYL), alone or associated with prebiotics (PRE), on selected canine fecal parameters. Eight treatments were set up: control diet with no addition of substrates; TYL; Fructooligosaccharides (FOS); Galactooligosaccharides (GOS); Xylooligosaccharides (XOS); TYL + FOS; TYL + GOS; TYL + XOS. The flasks (five for treatment), containing a canine fecal suspension (prepared with the feces of healthy adult dogs) and the residue of an in vitro digested dry dog food, were incubated in an anaerobic chamber at 39 °C. TYL and PRE were added at a concentration of 0.2 and 1 g/L, respectively. Samples were collected after 6 and 24 h for analyses. PRE decreased pH values, iso-butyrate, and iso-valerate throughout the incubation; increased lactobacilli, cadaverine, and, tendentiously, total volatile fatty acids after 6 h; increased n-butyrate, putrescine, spermidine, and reduced spermine and E. coli after 24 h. TYL resulted in lower total volatile fatty acids and lactobacilli and higher Clostridium cluster I after 6 h and higher pH values, spermidine, and E. coli throughout the study. When associated with TYL, PRE counteracted some undesirable effects of the antibiotic such as the decrease of lactobacilli and Clostridium cluster XIVa at both 6 and 24 h. In the present study, TYL exhibited inhibitory effects on canine fecal microbiota partially counteracted by PRE supplementation.

Chronic Enteropathy In Canines: Prevalence, Impact And Management Strategies

In this article, the studies about the prevalence of chronic enteropathy are reviewed as well as the information regarding short- and long-term prognosis for dogs treated with the three most common therapies; these include dietary modification, antibiotics, and immunosuppressants. Although the data available are limited, most studies support a good to excellent long-term response in dogs that have a successful food trial, whereas the response is poor with antibiotics or on-going treatment is required to retain remission. There is a risk of antimicrobial resistance developing with inappropriate use of antimicrobials such as in these situations. The published information highlights the need for alternative strategies to antibiotic treatment to manipulate the GI microbiome, and in the final part of this article studies on the use of probiotic for the treatment of chronic enteropathy are reviewed.

Long-term impact of tylosin on fecal microbiota and fecal bile acids of healthy dogs

Background

Tylosin is commonly prescribed to dogs with diarrhea. Orally administered antibiotics may alter the intestinal microbiota, which is responsible for crucial key bile acid (BA) biotransformation reactions.

Objectives

To prospectively evaluate the impact of tylosin administration on fecal microbiota and unconjugated bile acids (UBAs) over time.

Animals

Sixteen healthy adult dogs.

Methods

Prospective, randomized controlled clinical trial. Dogs were randomized to receive 20 mg/kg of tylosin or a placebo capsule PO q12h for 7 days while undergoing daily fecal scoring. Fecal samples were collected on days 0, 7, 21, and 63. The microbiota was assessed using quantitative PCR and 16S rRNA gene sequencing. Unconjugated BAs were assessed using gas chromatography‐mass spectrometry (GC‐MS).

Results

Fecal scores were unchanged during placebo and tylosin administration. In the placebo group, no significant changes were observed in fecal microbiota or UBA concentrations. Day 7 samples from tylosin‐exposed dogs exhibited decreased bacterial diversity (observed species, Chao1, Shannon, P < .001) characterized by decreases in anaerobes Fusobacteriaceae (linear discriminant analysis [LDA] score, 5.03) and Veillonellaceae (LDA score, 4.85). Primary UBA concentrations were increased at day 21 (median, [range]; 7.42, [0.67‐18.77] μg/kg; P = .04) and day 63 (3.49 [0‐28.43] μg/kg; P = .02) compared to day 0 (.14 [.03‐1.19] μg/kg) in dogs receiving tylosin. At day 63, bacterial taxa were not significantly different compared to day 0, but the extent of microbial recovery was individualized.

Conclusions and Clinical Importance

Tylosin causes fecal dysbiosis in healthy dogs with corresponding shifts in fecal UBAs. Changes did not uniformly resolve after discontinuation of tylosin.

Role of gut microbiota in dog and cat's health and diseases

Mammalian gastrointestinal tract is colonized by a large number of microorganisms, known as gut microbiota, that play a key role in the physiological and pathological states. In particular, the gastrointestinal tract of dogs and cats harbors a complex and highly biodiverse microbial ecosystem. Recent studies see it involved in a wide range of life processes, including energy needs, metabolism, immunological activity, and neuro-behavioral development. This review focuses on the role of the microbiota on the health of pets and will discuss changes that occur in the disease.

Comparison of the systemic phospholipid profile in dogs diagnosed with idiopathic inflammatory bowel disease or food-responsive diarrhea before and after treatment

BACKGROUND

Inflammatory bowel disease (IBD) and food-responsive diarrhea (FRD) are common chronic enteropathies in dogs, of which the exact pathogenesis has not been fully understood. In people dyslipidemia has been reported in patients with IBD, and potential therapeutic benefits of polyunsaturated fatty acids (PUFA) in the treatment of IBD have been investigated. Studies on the phospholipid profile in dogs with IBD and FRD are still lacking.

AIM

To investigate the systemic phospholipid profile of dogs with IBD or FRD and to evaluate possible differences in phospholipids before and after treatment.

METHODS

The phospholipids in whole blood and EDTA plasma of 32 dogs diagnosed with either IBD (n = 16) or FRD (n = 16) were analyzed by hydrophilic interaction liquid chromatography (HILIC) prior to and after initiation of treatment, which included an elimination diet enriched with PUFAs.

RESULTS

A clear separation of the phospholipids between whole blood and plasma was demonstrated on principal component analysis plots. In addition to the type of specimen, treatment and disease severity were the most significant factors determining the variance of the phospholipid profile. An increase in lysolipids was observed after treatment. The phosphatidylcholine (PC) species changed from PC 38:4 before treatment to mainly lysophosphatidylcholine 18:0 after treatment. Furthermore, several differences in the abundance of individual phospholipids were identified between dogs with IBD and dogs with FRD and between treatment statuses using random forest analysis.

CONCLUSION

Significant variances were identified in the phospholipid profiles of dogs with IBD and FRD. These were particularly determined by type of specimen used, disease severity and treatment status. After treatment, a shift of phospholipid species towards lysophosphatidylcholine 18:0 was observed. Future studies should further investigate the role of lipids in the pathophysiology of IBD and FRD as well as their potential therapeutic benefits.

Evaluation of a structured individualised protocol as a potential cost-effective diagnostic and therapeutic approach to chronic diarrhoea in the dog

Diagnostic investigation and management of chronic diarrhoea in dogs can be cost‐prohibitive to many owners. The objectives of this study were to evaluate evidence‐based, individualised diagnostic and therapeutic protocols for management of dogs with chronic diarrhoea, where financial constraints dictate a budget‐limited approach and where more expensive approaches are deferred until simple affordable protocols are unsuccessful. Twenty‐two client‐owned dogs with chronic (minimum 2 weeks duration) untreated small, large or mixed small/large bowel diarrhoea were enrolled in a budget‐limited step‐wise management protocol (maximum expenditure $300 over 6 weeks), with diagnostic testing and therapeutic trials managed in an individualised and evidence‐based fashion. Success was defined as complete resolution of diarrhoea for a minimum of 1 month. Dogs that failed to respond to a budget‐limited protocol were then enrolled for complete, referral‐level management. Four dogs exited the project early (one death due to caval syndrome, three lost to follow‐up). Thirteen out of the remaining 18 dogs had complete resolution of diarrhoea utilising a budget‐limited approach (success rate 72.2%, confidence intervals 46.5–90.3%) and five dogs were moved on to a referral‐level investigation, with complete resolution of diarrhoea in four out of five. Seventeen out of the 18 dogs therefore responded to a protocol based on a budget‐limited approach followed by extensive investigation only if needed, for an overall success rate of 94.4% (CI 72.7–99.9%). Comprehensive investigation of chronic diarrhoea can be deferred while simple affordable diagnostics and therapeutic trials are conducted in stable canine patients and, often, an extensive management approach will be unnecessary.

Narrative review of therapies for chronic enteropathies in dogs and cats

BACKGROUND

The optimal medical treatment for chronic enteropathy (CE) in dogs and cats is controversial. Sequential treatment using diet, antimicrobials, and immunosuppressive drugs is the most common strategy used by clinicians.

OBJECTIVES

To review the evidence for the effectiveness of dietary, drug, and alternative health interventions for inducing clinical remission in dogs and cats with CE.

ANIMALS

Retrospective study of dogs and cats with a diagnosis of chronic enteropathy.

METHODS

MEDLINE and Centre for Agriculture and Bioscience International (CABI) databases (1950 to March 2017) were searched for randomized controlled trials (RCTs), observational studies, and case series. The primary outcome was induction of clinical remission. All studies were evaluated using the quality of evidence grading guidelines (I-IV), which assign a score defining the strength and quality of the evidence.

RESULTS

Twenty-two studies (11 RCTs in dogs and 2 in cats and 9 cohort studies or case series) met the inclusion criteria for inducing remission of gastrointestinal (GI) signs. Of the 13 RCTs achieving grade I scores, 10 studies (totaling 218 dogs and 65 cats) compared single treatment: diet (n = 3), immunosuppressives (n = 3), antimicrobials (n = 2), anti-inflammatory drugs (n = 1), and probiotics (n = 1). Three case series (grade III) reported clinical remission using an elimination diet fed to 55 cats and use of enrofloxacin to induce remission in dogs with granulomatous colitis (2 studies totaling 16 dogs).

CONCLUSIONS AND CLINICAL IMPORTANCE

The current evidence for treatment of CE is much greater in dogs than in cats. There is sufficient strong evidence to recommend the use of therapeutic GI diets, glucocorticoids, enrofloxacin, or some combination of these in dogs with CE. Therapeutic GI diets and glucocorticoids are most useful in cats with CE.

S100A12 concentrations and myeloperoxidase activities are increased in the intestinal mucosa of dogs with chronic enteropathies

Background

Intestinal mucosal S100A12 and myeloperoxidase (MPO) are inflammatory biomarkers in humans with inflammatory bowel disease (IBD). However, these biomarkers have not been studied in the intestinal mucosa of dogs with chronic enteropathies (CE), even though dogs with CE have increased S100A12 concentrations in feces and serum. This study investigated mucosal S100A12 concentrations and MPO activities in both dogs with CE and healthy Beagles. ELISA (S100A12 concentrations) and spectrophotometric methods (MPO activity) were used. The associations of both biomarkers with canine IBD activity index (CIBDAI), histopathologic findings, clinical outcome, and serum albumin concentrations were also investigated. We studied intestinal mucosal samples originating from different intestinal regions of 40 dogs with CE and 18 healthy Beagle dogs (duodenum, ileum, colon, and cecum).

Results

Compared with healthy Beagles, mucosal S100A12 concentrations in dogs with CE were significantly higher in the duodenum (p < 0.0001) and colon (p = 0.0011), but not in the ileum (p = 0.2725) and cecum (p = 0.2194). Mucosal MPO activity of dogs with CE was significantly higher in the duodenum (p < 0.0001), ileum (p = 0.0083), colon (p < 0.0001), and cecum (p = 0.0474). Mucosal S100A12 concentrations in the duodenum were significantly higher if the inflammatory infiltrate consisted mainly of neutrophils (p = 0.0439) or macrophages (p = 0.037). Mucosal S100A12 concentrations also showed a significant association with the severity of total histopathological injury and epithelial injury in the colon (p < 0.05). Mucosal MPO activity showed a significant association (p < 0.05) with the severity of total histopathological injury, epithelial injury, and eosinophil infiltration in the duodenum. There was no significant association of both biomarkers with CIBDAI or clinical outcome.

Conclusions

This study showed that both mucosal S100A12 concentrations and MPO activities are significantly increased in the duodenum and colon of dogs with CE; mucosal MPO was also increased in the ileum and cecum. Future research should focus on assessing the clinical utility of S100A12 and MPO as diagnostic markers in dogs with CE.

Role of the gastrointestinal microbiota in small animal health and disease

There is a large and emerging interest in the role of the gastrointestinal microbiota in health and disease. This paper serves to review the current knowledge and recommendations of the gastrointestinal microbiota in health and gastrointestinal disease. Further, this review evaluates the current literature and suggests guidelines for faecal microbial transplantation, a novel therapy for dysbiosis in veterinary medicine.

Atopic dermatitis and the intestinal microbiota in humans and dogs

The prevalence of human and canine allergic diseases is commonly perceived to be increasing. Suggested predisposing factors in people and dogs include increased allergen load, increased exposure to pollutants, reduced family size, reduced microbial load and less exposure to infection at a young age, increasingly urbanised environment, and changes in dietary habits. Genetic make‐up may provide a template for phenotypic predisposition which is strongly influenced by our diet and environment leading to constant regulation of gene expression. One way in which diet can alter gene expression is via its effects on the gut flora or microbiota, the collection of microbes residing in the gastrointestinal tract. The resident microbiota is important in maintaining structural and functional integrity of the gut and in immune system regulation. It is an important driver of host immunity, helps protect against invading enteropathogens, and provides nutritional benefits to the host. Disruption of the microbiota (dysbiosis) may lead to severe health problems, both in the gastrointestinal tract and extra‐intestinal organ systems. The precise mechanisms by which the intestinal microbiota exerts its effects are only beginning to be unravelled but research is demonstrating close links between gut microflora and many factors involved in the pathogenesis of atopic dermatitis (AD). AD and indeed any other ‘skin disease’, may be seen as a possible manifestation of a more systemic problem involving gut dysbiosis and increased intestinal permeability, which may occur even in the absence of gastrointestinal signs. Manipulation of the canine intestinal microbiota as a method for modifying atopy, may be attempted in many ways including avoidance of certain foods, supplementation with probiotics and prebiotics, optimising nutrient intake, minimising stress, antimicrobial therapy, correction and prevention of low stomach acid, and faecal microbiota transplantation (FMT).

Extrahepatic biliary duct obstruction as a result of involuntary transcavitary implantation of hair in a cat

Case summary

A 4-year-old male neutered domestic shorthair cat was referred for investigation of jaundice. The cat had a recent history of a skin laceration repair following trauma. Sequential serum biochemistry demonstrated increasing plasma bilirubin concentrations; abdominal ultrasonography revealed ongoing pancreatitis and apparent extrahepatic obstruction of the common bile duct. Exploratory laparotomy identified constriction of the common bile duct with foreign material (cat hair). The constricting band of hair was removed surgically; cholecystoduodenostomy was performed. Postsurgical quality of life is excellent with chronic treatment of tylosin, omeprazole and ursodeoxycholic acid.

Relevance and novel information

To our knowledge, this is the first reported case of extrahepatic biliary duct obstruction resulting from the intra-abdominal migration of a foreign body, in this case, hair shafts. The mechanism by which this occurred was likely a combination of physical constriction by the hair shafts and subsequent foreign body reaction surrounding this. This should be included in the differential diagnosis of a cat with jaundice.

Oral tylosin administration is associated with an increase of faecal enterococci and lactic acid bacteria in dogs with tylosin-responsive diarrhoea

The term tylosin-responsive diarrhoea (TRD) is used for canine recurrent diarrhoea cases for which no underlying cause can be found after extensive diagnostic investigations, but which show a response to the antibiotic tylosin in a few days. The objective of this prospective, one-arm longitudinal trial was to assess the effects of oral tylosin administration on the faecal levels of potentially probiotic bacteria, such as Enterococcus spp. and lactic acid bacteria (LAB), in dogs with TRD. This trial included 14 client-owned suspected TRD dogs that were on tylosin treatment and had firm faeces. Treatment was then terminated and dogs were followed up for up to 2 months to determine the recurrence of diarrhoea. Once diarrhoea started, dogs received tylosin (orally, 25 mg/kg, once daily for 7 days). At the end of the treatment period, stools were firm again in 11 dogs (TRD dogs); three dogs continued having diarrhoea and were excluded from the study. Faecal samples were collected at all three time-points for culture of LAB and enterococci. In TRD dogs, the colony counts of Enterococcus spp. (P = 0.003), LAB (P = 0.037), tylosin-resistant Enterococcus spp. (P <0.001) and LAB (P <0.001) were significantly higher when the dogs were on tylosin treatment and had normal faecal consistency compared to when they had diarrhoea following discontinuation of tylosin. In conclusion, cessation of diarrhoea in TRD dogs with tylosin treatment could be mediated by selection of a specific lactic acid population, the Enterococcus spp., due to their potential probiotic properties.

Efficacy of two low-dose oral tylosin regimens in controlling the relapse of diarrhea in dogs with tylosin-responsive diarrhea: a prospective, single-blinded, two-arm parallel, clinical field trial

BACKGROUND

Despite its wide acceptance as a treatment for canine chronic enteropathies, the macrolide antibiotic tylosin lacks official oral dosage recommendations. Not even textbooks share consensus about the dose; daily recommendations vary from 25 to 80 mg/kg and dosing intervals from one to three times daily.

RESULTS

All eight dogs responded to the 5 mg/kg dose, and six of seven dogs responded to the 15 mg/kg dose. The mean fecal consistency scores at the 25 mg/kg tylosin dosage were no significantly different from scores at the 5 mg/kg or 15 mg/kg tylosin dosages (P=0.672, P=0.345).

CONCLUSIONS

Interestingly, 14/15 (93%) of the dogs responding to a dose of 25 mg/kg tylosin once daily for seven days also responded to the lower dosages at diarrhea relapse. The data indicate that a suitable dose of tylosin for treating diarrhea relapse in canine TRD could be as low as 5 mg/kg once daily for seven days.

Impact of diets with a high content of greaves-meal protein or carbohydrates on faecal characteristics, volatile fatty acids and faecal calprotectin concentrations in healthy dogs

Background

Research suggests that dietary composition influences gastrointestinal function and bacteria-derived metabolic products in the dog colon. We previously reported that dietary composition impacts upon the faecal microbiota of healthy dogs. This study aims at evaluating the dietary influences on bacteria-derived metabolic products associated with the changes in faecal microbiota that we had previously reported. We fed high-carbohydrate starch based (HCS), [crude protein: 194 g/kg, starch: 438 g/kg], high-protein greaves-meal (HPGM), [crude protein: 609 g/kg, starch: 54 g/kg] and dry commercial (DC), [crude protein: 264 g/kg, starch: 277 g/kg] diets, and studied their effects on the metabolism of the colonic microbiota and faecal calprotectin concentrations in five Beagle dogs, allocated according to the Graeco-Latin square design. Each dietary period lasted for three weeks and was crossed-over with washout periods. Food intake, body weight, and faecal consistency scores, dry matter, pH, ammonia, volatile fatty acids (VFAs), and faecal canine calprotectin concentrations were determined.

Results

Faecal ammonia concentrations decreased with the HCS diet. All dogs fed the HPGM diet developed diarrhoea, which led to differences in faecal consistency scores between the diets. Faecal pH was higher with the HPGM diet. Moreover, decreases in propionic and acetic acids coupled with increases in branched-chain fatty acids and valeric acid caused changes in faecal total VFAs in dogs on the HPGM diet. Faecal canine calprotectin concentration was higher with the HPGM diet and correlated positively with valeric acid concentration.

Conclusions

The HPGM diet led to diarrhoea in all dogs, and there were differences in faecal VFA profiles and faecal canine calprotectin concentrations.