A comprehensive analysis of gut and skin microbiota in canine atopic dermatitis in Shiba Inu dogs.

BACKGROUND: Like its human counterpart, canine atopic dermatitis (cAD) is a chronic relapsing condition; thus, most cAD-affected dogs will require lifelong treatment to maintain an acceptable quality of life. A potential intervention is modulation of the composition of gut microbiota, and in fact, probiotic treatment has been proposed and tried in human atopic dermatitis (AD) patients. Since dogs are currently receiving intensive medical care, this will be the same option for dogs, while evidence of gut dysbiosis in cAD is still missing, although skin microbial profiling in cAD has been conducted in several studies. Therefore, we conducted a comprehensive analysis of both gut and skin microbiota in cAD in one specific cAD-predisposed breed, Shiba Inu. Additionally, we evaluated the impact of commonly used medical management on cAD (Janus kinase; JAK inhibitor, oclacitinib) on the gut and skin microbiota. Furthermore, we genotyped the Shiba Inu dogs according to the mitochondrial DNA haplogroup and assessed its association with the composition of the gut microbiota. RESULTS: Staphylococcus was the most predominant bacterial genus observed in the skin; Escherichia/Shigella and Clostridium sensu stricto were highly abundant in the gut of cAD-affected dogs. In the gut microbiota, Fusobacteria and Megamonas were highly abundant in healthy dogs but significantly reduced in cAD-affected dogs. The abundance of these bacterial taxa was positively correlated with the effect of the treatment and state of the disease. Oclacitinib treatment on cAD-affected dogs shifted the composition of microbiota towards that in healthy dogs, and the latter brought it much closer to healthy microbiota, particularly in the gut. Additionally, even within the same dog breed, the mtDNA haplogroup varied, and there was an association between the mtDNA haplogroup and microbial composition in the gut and skin. CONCLUSIONS: Dysbiosis of both the skin and the gut was observed in cAD in Shiba Inu dogs. Our findings provide a basis for the potential treatment of cAD by manipulating the gut microbiota as well as the skin microbiota. Video Abstract.

Age-related analysis of the gut microbiome in a purebred dog colony.

Dogs are model animals that can be used to study the gut microbiome. Although the gut microbiome is assumed to be closely related to aging, information pertaining to this relationship in dogs is limited. Here, we examined the association between the canine gut microbiome and age via a bacterial 16S rRNA gene amplicon sequence analysis in a colony of 43 Japanese purebred Shiba Inu dogs. We found that microbial diversity tended to decrease with aging. A differential abundance analysis showed an association of a single specific microbe with aging. The age-related coabundance network analysis showed that two microbial network modules were positively and negatively associated with aging, respectively. These results suggest that the dog gut microbiome is likely to vary with aging.

A double-blind, placebo-controlled evaluation of orally administered heat-killed Enterococcus faecalis FK-23 preparation in atopic dogs.

BACKGROUND: Gastrointestinal microbiome modulation is reported to be an effective therapy to reduce the clinical signs of canine atopic dermatitis (cAD). The killed strain of Enterococcus faecalis FK-23 has been shown to reduce allergic responses in mice and people. HYPOTHESIS/OBJECTIVE: The aim of this multicentre, double-blinded, placebo-controlled study was to evaluate the safety and efficacy of an orally administered heat-killed E. faecalis FK-23 preparation (FK-23p) for the control of cAD. ANIMALS: Thirty-nine client-owned dogs with clinical signs of nonseasonal cAD were enrolled by 10 veterinarians at 15 hospitals. METHODS AND MATERIALS: Dogs were randomized to either FK-23p at a dose of ≥100 mg/kg/day or placebo. Owner-assessed pruritus Visual Analog Scale (pVAS), clinician-assessed Canine Atopic Dermatitis Extent and Severity Index, 4th iteration (CADESI-4) and daily medication scoring (DMS) were evaluated on days 0, 28, 56 and 84. Owners and clinicians were interviewed about the overall response to treatment (RTT), after the study. RESULTS: The CADESI-4 significantly decreased in the FK-23p group compared to the placebo group, by Day 84 (P = 0.035; Wilcoxon-Mann-Whitney U-test). There was no significant difference in pVAS and DMS between the groups. Owners and clinicians reported significantly better RTT in the FK-23p group than the placebo group (P = 0.043 and 0.002, respectively; Wilcoxon-Mann-Whitney U-test). There were no adverse events associated with FK-23p. CONCLUSIONS AND CLINICAL IMPORTANCE: Oral administration of FK-23p provided a small, but measurable benefit when used as an adjunct treatment, in reducing clinical signs of atopic dogs.

First identification of a single amino acid change in the spike protein region of feline coronavirus detected from a coronavirus-associated cutaneous nodule in a cat.

CASE SUMMARY: A 32-month-old spayed female Singapura cat presented with a non-pruritic erythematous nodule on the upper lip. The cat also had multiple nodules in the liver but exhibited no other clinical signs consistent with classical feline infectious peritonitis (FIP), such as pleural effusion or ascites, uveitis or neurological symptoms. Histopathological and immunohistochemical analyses of the cutaneous nodule revealed pyogranulomatous dermatitis with intralesional macrophages laden with feline coronavirus (FCoV) antigen. Real-time reverse transcription (RT)-PCR of a cutaneous sample revealed a single nucleotide substitution in the spike protein gene of FCoV (mutation M1058L), which is consistent with an FCoV genotype commonly associated with FIP. The cat received a blood transfusion and supportive therapy, but the owner declined to continue the treatments owing to poor response. The cat was lost to follow-up 5 months after discharge. RELEVANCE AND NOVEL INFORMATION: This report describes a case of a coronavirus-associated cutaneous nodule in which the evidence of amino acid changes in the spike protein gene identified by RT-PCR were consistent with an FCoV genotype commonly seen in cases of FIP. To the best of our knowledge, this is the first report of a case of cutaneous disease associated with the mutated FCoV that was confirmed by molecular diagnostic testing.

Collagen-enriched serpiginous skin lesion in a cat resembling the linear form of localized scleroderma in humans.

Localized scleroderma (LS) is a sclerotic skin disorder rarely reported in the veterinary literature. We herein report the first case of a linear LS-like skin lesion in a cat. A 1-year-old castrated male Himalayan cat was presented with a 1-month history of an alopecic, indurated, serpiginous, branched skin lesion on the dorsal cervical to scapular area. The cat had no history of trauma, although a topical spot-on endectocide had been applied near the lesion. Histopathological examination revealed a focal area of hyperplastic dermal collagen with the absence of pilosebaceous units. The cutaneous lesion remained unchanged during a 2-year follow-up period. Clinical and histopathological similarities of this skin lesion with those of the linear form of LS in humans were considered.

A case of recovery from canine destructive cholangitis in a Miniature Dachshund.

A 7-year-old Miniature Dachshund presented with severe chronic jaundice and elevated liver enzymes. Destructive cholangitis was diagnosed according to histopathological findings of remarkable ductopenia with inflammatory infiltrates and fibrosis in the portal areas. Supportive therapy with prednisolone, high-dose ursodeoxycholic acid, human placental extract and antibiotics was tried, and the patient showed recovery of clinical signs 3 months after diagnosis. A second liver biopsy was performed about 1 year after initial diagnosis, and bile duct restoration was confirmed with continuous inflammation around portal areas and inside the lobules. Although we could not determine which treatment was effective in this case, destructive cholangitis in dogs may be recoverable with long-term supportive therapies.

Antifungal activity of itraconazole and voriconazole against clinical isolates obtained from animals with mycoses.

Animal mycosis, particularly deep mycosis, is one of the most challenging conditions encountered by veterinarians. Pathogens causing mycotic infections in animals include fungi such as Cryptococcus neoformans, Candida spp., and Aspergillus spp. The antifungal drugs used for the treatment of deep mycoses in animals as well as humans are polyenes and azoles. However, the sensitivity of clinical isolates obtained from animals toward these drugs has rarely been assayed. In this study, the antifungal activities of itraconazole and voriconazole against clinical isolates of C. neoformans, Candida spp., and A. fumigatus isolated from animals with mycoses were examined using the broth microdilution method performed according to the guidelines provided by the Clinical and Laboratory Standards Institute. The minimum inhibitory concentrations (MICs) of itraconazole toward the C. neoformans, Candida spp., and A. fumigatus isolates were 0.125 - 1, 0.125 - 2, and 0.25 - 2 microg/ml, respectively, and those of voriconazole were 0.0625 - 0.5, < or =0.0313 - 0.0625, and 0.0625 - 1 microg/ml, respectively. The results of the MIC analyses implied that the fungal isolates obtained from infected animals exhibit an equivalent degree of susceptibility to itraconazole and voriconazole, as is observed in the case of isolates obtained from humans. The appropriate antifungal therapeutic strategy for the treatment of mycoses in animals must be selected taking into consideration the host immune status and organ function as well as the in vitro sensitivity of the pathogens to antifungal drugs.

Prototheca zopfii genotypes isolated from cow barns and bovine mastitis in Japan.

This study is the first investigation on Japanese isolates of Prototheca zopfii from bovine mastitis and the cow-barn surroundings by molecular characterization to clarify routes of infection for bovine protothecal mastitis. We performed isolation of Prototheca from cow-barn surroundings (drinking water, sewage and feces) and milk samples from cases of bovine mastitis. Genotypes of the 32 isolates of P. zopfii from cow-barn surroundings and 67 isolates from mastitis were analyzed by genotype-specific PCR assays and restriction fragment length polymorphism (RFLP) assays. All mastitis isolates were identified as P. zopfii genotype 2. Conversely, 29 isolates from cow-barn surroundings were identified as P. zopfii genotypes 1 and 3 isolates as genotype 2, respectively. Given these results, both genotypes of P. zopfii could exist in cow-barn surroundings, but no sites were identified as frequent sources of P. zopfii genotype 2. P. zopfii isolates should thus be further explored with regard to genotype to clarify the reservoir of etiological agents in bovine Prototheca mastitis.