Characterization of the plasma proteome from healthy adult dogs.

Introduction: Bloodwork is a widely used diagnostic tool in veterinary medicine, as diagnosis and therapeutic interventions often rely on blood biomarkers. However, biomarkers available in veterinary medicine often lack sensitivity or specificity. Mass spectrometry-based proteomics technology has been extensively used in the analysis of biological fluids. It offers excellent potential for a more comprehensive characterization of the plasma proteome in veterinary medicine. Methods: In this study, we aimed to identify and quantify plasma proteins in a cohort of healthy dogs and compare two techniques for depleting high-abundance plasma proteins to enable the detection of lower-abundance proteins via label-free quantification liquid chromatography-mass spectrometry. We utilized surplus lithium-heparin plasma from 30 healthy dogs, subdivided into five groups of pooled plasma from 6 randomly selected individuals each. Firstly, we used a commercial kit to deplete high-abundance plasma proteins. Secondly, we employed an in-house method to remove albumin using Blue-Sepharose. Results and discussion: Among all the samples, some of the most abundant proteins identified were apolipoprotein A and B, albumin, alpha-2-macroglobulin, fibrinogen beta chain, fibronectin, complement C3, serotransferrin, and coagulation factor V. However, neither of the depletion techniques achieved significant depletion of highly abundant proteins. Despite this limitation, we could detect and quantify many clinically relevant proteins. Determining the healthy canine proteome is a crucial first step in establishing a reference proteome for canine plasma. After enrichment, this reference proteome can later be utilized to identify protein markers associated with different diseases, thereby contributing to the diagnosis and prognosis of various pathologies.

Plasma proteome signature of canine acute haemorrhagic diarrhoea syndrome (AHDS).

Acute haemorrhagic diarrhoea is a common complaint in dogs. In addition to causes like intestinal parasites, dietary indiscretion, intestinal foreign bodies, canine parvovirus infection, or hypoadrenocorticism, acute haemorrhagic diarrhoea syndrome (AHDS) is an important and sometimes life-threatening differential diagnosis. There is some evidence supporting the link between Clostridium perfringens toxins and AHDS. These toxins may be partially responsible for the epithelial cell injury, but the pathogenesis of AHDS is still not fully understood. Recent studies have suggested that severe damage to the intestinal mucosa and associated barrier dysfunction can trigger chronic gastrointestinal illnesses. Besides bloodwork and classical markers for AHDS such as protein loss and intestinal bacterial dysbiosis, we focused mainly on the plasma-proteome to identify systemic pathological alterations during this disease and searched for potential biomarkers to improve the diagnosis. To accomplish the goals, we used liquid chromatography-mass spectrometry. We compared the proteomic profiles of 20 dogs with AHDS to 20 age-, breed-, and sex-matched control dogs. All dogs were examined, and several blood work parameters were determined and compared, including plasma biochemistry and cell counts. We identified and quantified (relative quantification) 207 plasmatic proteins, from which dozens showed significantly altered levels in AHDS. Serpina3, Lipopolysaccharide-binding protein, several Ig-like domain-containing proteins, Glyceraldehyde-3-phosphate dehydrogenase and Serum amyloid A were more abundant in plasma from AHDS affected dogs. In contrast, other proteins such as Paraoxonase, Selenoprotein, Amine oxidases, and Apolipoprotein C-IV were significantly less abundant. Many of the identified and quantified proteins are known to be associated with inflammation. Other proteins like Serpina3 and RPLP1 have a relevant role in oncogenesis. Some proteins and their roles have not yet been described in dogs with diarrhoea. Our study opens new avenues that could contribute to the understanding of the aetiology and pathophysiology of AHDS.

Traces of Canine Inflammatory Bowel Disease Reflected by Intestinal Organoids.

Inflammatory bowel disease (IBD) is a chronic inflammatory condition that affects humans and several domestic animal species, including cats and dogs. In this study, we have analyzed duodenal organoids derived from canine IBD patients using quantitative proteomics. Our objective was to investigate whether these organoids show phenotypic traits of the disease compared with control organoids obtained from healthy donors. To this aim, IBD and control organoids were subjected to quantitative proteomics analysis via liquid chromatography-mass spectrometry. The obtained data revealed notable differences between the two groups. The IBD organoids exhibited several alterations at the levels of multiple proteins that are consistent with some known IBD alterations. The observed phenotype in the IBD organoids to some degree mirrors the corresponding intestinal condition, rendering them a compelling approach for investigating the disease and advancing drug exploration. Additionally, our study revealed similarities to some human IBD biomarkers, further emphasizing the translational and comparative value of dogs for future investigations related to the causes and treatment of IBD. Relevant proteins such as CALU, FLNA, MSN and HMGA2, which are related to intestinal diseases, were all upregulated in the IBD duodenal organoids. At the same time, other proteins such as intestinal keratins and the mucosal immunity PIGR were depleted in these IBD organoids. Based on these findings, we propose that these organoids could serve as a valuable tool for evaluating the efficacy of therapeutic interventions against canine IBD.

Sclerosing encapsulating peritonitis in cats: a two-case report and literature review.

Case series summary: Two castrated male domestic shorthair cats (aged 8 months [case 1] and 13 years [case 2]) were presented at the Small Animal Clinic of the Veterinary Medicine University of Vienna, Austria, both with acute vomiting and distended abdomen, as well as a history of chronic apathy, recurrent vomiting and diarrhoea. Both cats underwent invasive diagnostic procedures approximately 1 month before the diagnosis of sclerosing encapsulating peritonitis (SEP), namely an exploratory laparotomy and a bronchoscopy, respectively. Abdominal ultrasound revealed severely corrugated intestinal loops and, in case 2, the presence of peritoneal effusion. A thick and diffuse fibrous capsule around the intestine was detected and removed surgically, and biopsies were taken from the affected organs confirming the SEP. Case 1 recovered well, was discharged some days after surgery and was clinically unremarkable for the next 2 years. Case 2 showed unsatisfactory improvement directly after surgery and was euthanased a few days later, as the owner declined any further therapy. Relevance and novel information: SEP is a very rare condition of unclear origins in cats. Here we describe the clinical and diagnostic imaging features, surgical treatment, and outcome of SEP in two cats. The results indicate that prompt diagnosis and appropriate interventions may improve the outcome.

Gut microbiome signatures of Yorkshire Terrier enteropathy during disease and remission.

The role of the gut microbiome in developing Inflammatory Bowel Disease (IBD) in humans and dogs has received attention in recent years. Evidence suggests that IBD is associated with alterations in gut microbial composition, but further research is needed in veterinary medicine. The impact of IBD treatment on the gut microbiome needs to be better understood, especially in a breed-specific form of IBD in Yorkshire Terriers known as Yorkshire Terrier Enteropathy (YTE). This study aimed to investigate the difference in gut microbiome composition between YTE dogs during disease and remission and healthy Yorkshire Terriers. Our results showed a significant increase in specific taxa such as Clostridium sensu stricto 1, Escherichia-Shigella, and Streptococcus, and a decrease in Bacteroides, Prevotella, Alloprevotella, and Phascolarctobacterium in YTE dogs compared to healthy controls. No significant difference was found between the microbiome of dogs in remission and those with active disease, suggesting that the gut microbiome is affected beyond clinical recovery.

Bilateral cholesterol granulomas in the middle ear cavities of a cat with sinonasal disease successfully removed via video-otoscopy.

CASE DESCRIPTION: A 9-year-old spayed female Maine Coon cat was presented at the University of Veterinary Medicine Vienna for further investigation of chronic nonpruritic bilateral ear disease and unilateral Horner syndrome. CLINICAL FINDINGS: Physical examination and otoscopy findings included right sided Horner syndrome, a right head tilt of approximately 20° and a small pink nodule in the right and several smaller nodules in the left proximal horizontal external ear canal. Computed tomography and magnetic resonance imaging revealed soft tissue opacity material in both middle ear cavities, the caudal portion of the nasal cavity, the left nasopharyngeal meatus and the right frontal sinus. Via videootoscopy, 2 multilobular and several flat nodules were detected in the proximal right horizontal external ear canal and in the left tympanic bulla, respectively. Histopathological examination confirmed the diagnosis of cholesterol granulomas. TREATMENT AND OUTCOME: All otic cholesterol granulomas (CGs) were removed via video-otoscopy (VO), and topical treatment was initiated in addition to oral prednisolone. After the histopathological confirmation, negative microbial cultures from the middle ear cavities, and the remission of the symptoms by the first recheck, topical, and systemic treatment were discontinued. A follow-up 6 months later, did not reveal any recurrence of the CGs. CLINICAL RELEVANCE: To our knowledge, this is the first case of bilateral CGs diagnosed with a combination of CT, MRI, VO, and histopathology and removed minimal invasively via VO, without a need for ventral bulla osteotomy, which led to complete remission of all signs and no relapse until the follow up 6 months later.