Limited yield of diagnoses of intrahepatic infectious causes of canine granulomatous hepatitis from archival liver tissue

Fluorescent In Situ Hybridization for the Detection of Intracellular Bacteria in Companion Animals

FISH techniques have been applied for the visualization and identification of intracellular bacteria in companion animal species. Most frequently, these techniques have focused on the identification of adhesive-invasive Escherichia coli in gastrointestinal disease, although various other organisms have been identified in inflammatory or neoplastic gastrointestinal disease. Previous studies have investigated a potential role of Helicobacter spp. in inflammatory gastrointestinal and hepatic conditions. Other studies evaluating the role of infectious organisms in hepatopathies have received some attention with mixed results. FISH techniques using both eubacterial and species-specific probes have been applied in inflammatory cardiovascular, urinary, and cutaneous diseases to screen for intracellular bacteria. This review summarizes the results of these studies.

Characterization of clinical presentation, histological features, ultrasonographic findings, and survival in 29 dogs with granulomatous hepatitis

BACKGROUND

Granulomatous hepatitis (GH) is a form of chronic hepatitis (CH) in dogs for which limited information is published.

HYPOTHESIS

Describe the clinical presentation, clinical pathology, ultrasound, and hepatic histopathology findings and to report survival times in dogs with GH.

ANIMALS

Twenty-nine client-owned dogs with GH.

METHODS

Retrospective observational study. Pathology records were searched. Inclusion criteria included a histopathologic diagnosis of GH, absence of an identified etiology or evidence of extrahepatic granulomatous disease, and a medical record available for review. Clinical presentation, clinical pathologic findings, treatment protocols, and survival times were recorded. Available hepatic biopsy material was graded and scored, and ultrasound evaluations reviewed.

RESULTS

The median age was 7 years (range, 0.66-12 years). Nineteen breeds were represented. Decreased appetite (19/29), lethargy (16/29), and fever (13/29) were seen most commonly. All dogs had increased serum transaminase activities, whereas 21/29 and 12/24 had hyperbilirubinemia and neutrophilia, respectively. Ultrasonographic findings included hepatomegaly (12/22), nodular parenchymal lesions (9/22), and hyperechoic parenchymal bands (8/22). Histopathologic necroinflammatory scores were moderate to severe in 16/19 dogs, and fibrosis scores were mild in 14/19 dogs. Treatments varied and included antibiotics, immunosuppressive drugs, and hepatoprotectants. Overall median survival was 635 days (range, 1-2482 days).

CONCLUSION AND CLINICAL IMPORTANCE

Granulomatous hepatitis in dogs is associated with high histopathologic grade, fever, neutrophilia, and a high incidence of hepatomegaly and focal parenchymal lesions on ultrasound examination. Despite disease severity on presentation, dogs with GH can have a good outcome with prolonged survival.

ACVIM consensus statement on the diagnosis and treatment of chronic hepatitis in dogs

This consensus statement on chronic hepatitis (CH) in dogs is based on the expert opinion of 7 specialists with extensive experience in diagnosing, treating, and conducting clinical research in hepatology in dogs. It was generated from expert opinion and information gathered from searching of PubMed for manuscripts on CH, the Veterinary Information Network for abstracts and conference proceeding from annual meetings of the American College of Veterinary Medicine and the European College of Veterinary Medicine, and selected manuscripts from the human literature on CH. The panel recognizes that the diagnosis and treatment of CH in the dog is a complex process that requires integration of clinical presentation with clinical pathology, diagnostic imaging, and hepatic biopsy. Essential to this process is an index of suspicion for CH, knowledge of how to best collect tissue samples, access to a pathologist with experience in assessing hepatic histopathology, knowledge of reasonable medical interventions, and a strategy for monitoring treatment response and complications.

Hepatic leptospiral infections in dogs without obvious renal involvement

Background

Reports of chronic hepatitis in dogs caused by Leptospira spp. are confined to small case series. Fluorescence in situ hybridization (FISH) allows the identification of spirochetes in liver samples. Consequently, this technique may help elucidate the role of Leptospira spp. in cases of chronic hepatitis.

Objectives

To describe cases of hepatic leptospirosis in dogs diagnosed by FISH and subsequent polymerase chain reaction (PCR) speciation, with the absence of clinically relevant renal involvement.

Animals

Ten client‐owned dogs.

Methods

Retrospective case series from the University of Cambridge presented between 2013 and 2016 or cases consulted by telephone advice during this time period. Cases were selected based on histopathologically confirmed granulomatous hepatitis and leptospiral organisms identified by FISH and PCR speciation (Leptospira interrogans/kirschneri).

Results

All cases had increased liver enzyme activities, and FISH in combination with PCR speciation‐confirmed infection with L. interrogans/kirschneri. Four dogs underwent repeat liver biopsy, FISH and PCR speciation 4‐15 months after initial presentation and doxycycline treatment with 1 dog undergoing repeat sampling at necropsy. Three dogs that underwent repeat biopsy remained positive for L. interrogans/kirschneri infection. Six dogs were alive at the time of manuscript preparation and 4 dogs were euthanized as a result of progressive liver disease.

Conclusions and Clinical Importance

The presence of hepatic leptospiral organisms may be associated with chronic granulomatous hepatitis without clinical evidence of renal involvement. Further studies are necessary to elucidate the etiological role of these organisms in the disease.

Canine Hepatitis Associated with Intrahepatic Bacteria in Three Dogs

This case report describes the detection of intrahepatic bacteria in formalin-fixed paraffin-embedded histopathological sections from three dogs with neutrophilic, pyogranulomatous, or lymphoplasmacytic hepatitis and cholangiohepatitis. In each of these cases, eubacterial fluorescence in situ hybridization enabled colocalization of intrahepatic bacteria with neutrophilic and granulomatous inflammation in samples that were negative for bacteria when evaluated by routine hematoxylin and eosin histopathology augmented with histochemical stains. Positive responses to antimicrobial therapy were observed in of 2 out of 2 patients that were treated with antimicrobials. These findings suggest that eubacterial fluorescence in situ hybridization analysis of formalin-fixed paraffin-embedded histopathological sections is more sensitive than conventional histochemical stains for the diagnosis of bacteria-associated canine hepatitis.

Solitary Hepatic Eosinophilic Granuloma Accompanied by Eosinophilia Without Parasitosis: Report of a Case

A 43-year-old Japanese woman visited for a hepatic tumor incidentally found. We suspected eosinophilic granuloma of the liver (EGL) due to visceral larva migrans (VLM). However, neither past history nor medical interview indicated a risk of parasitosis. Blood testing revealed eosinophilia, serum examination showed normal results for immunoglobulin E, and enzyme-linked immunosorbent assay yielded negative for Toxocara and Anisakis. Gastric and colonic endoscopy revealed normal features. Several imagings showed central necrosis of the tumor. After informed consent, laparoscopic resection was performed. Histopathological examination showed EGL without parasites. No recurrence had occurred postoperatively. Most reports documented that EGL are caused by VLM. However, parasites are not always demonstrable on serum, histopathological, or immunochemical examinations. When acting as allergens to induce type I responses, microscopic agents other than parasites in the intestinal tract could induce eosinophilic inflammation in the liver. Accumulation of more cases should help clarify other pathogeneses for EGL.

High prevalence and genetic heterogeneity of rodent-borne Bartonella species on Heixiazi Island, China

We performed genetic analysis of Bartonella isolates from rodent populations from Heixiazi Island in northeast China. Animals were captured at four sites representing grassland and brushwood habitats in 2011 and examined for the prevalence and genetic diversity of Bartonella species, their relationship to their hosts, and geographic distribution. A high prevalence (57.7%) and a high diversity (14 unique genotypes which belonged to 8 clades) of Bartonella spp. were detected from 71 rodents comprising 5 species and 4 genera from 3 rodent families. Forty-one Bartonella isolates were recovered and identified, including B. taylorii, B. japonica, B. coopersplainsensis, B. grahamii, B. washoensis subsp. cynomysii, B. doshiae, and two novel Bartonella species, by sequencing of four genes (gltA, the 16S rRNA gene, ftsZ, and rpoB). The isolates of B. taylorii and B. grahamii were the most prevalent and exhibited genetic difference from isolates identified elsewhere. Several isolates clustered with strains from Japan and far-eastern Russia; strains isolated from the same host typically were found within the same cluster. Species descriptions are provided for Bartonella heixiaziensis sp. nov. and B. fuyuanensis sp. nov.