KRT5 in-frame deletion in a family of German Shepherd dogs with split paw pad disease resembling localized epidermolysis bullosa simplex in human patients.

Split paw pad disease is a scarcely defined phenotype characterized by skin lesions on the paw pads of dogs. We studied a family of German Shepherd dogs, in which four dogs developed intermittent paw pad lesions and lameness. The paw pads of two of the affected dogs were biopsied and demonstrated cleft formation in the stratum spinosum and stratum corneum, the outermost layers of the epidermis. Whole genome sequencing data from an affected dog revealed a private heterozygous 18 bp in frame deletion in the KRT5 gene. The deletion NM_001346035.1:c.988_1005del or NP_001332964.1:p.(Asn330_Asp335del) is predicted to lead to a loss of six amino acids in the L12 linker domain of the encoded keratin 5. KRT5 variants in human patients lead to various subtypes of epidermolysis bullosa simplex (EBS). Localized EBS is the mildest of the KRT5-related human diseases and may be caused by variants affecting the L12 linker domain of keratin 5. We therefore think that the detected KRT5 deletion in dogs represents a candidate causal variant for the observed skin lesions in dogs. However, while the clinical phenotype of KRT5-mutant dogs of this study closely resembles human patients with localized EBS, there are differences in the histopathology. EBS is defined by cleft formation within the basal layer of the epidermis while the cleft formation in the dogs described herein occurred in the outermost layers, a hallmark of split paw pad disease. Our study provides a basis for further studies into the exact relation of split paw pad disease and EBS.

A placebo-controlled, double-blind study evaluating the effect of orally administered polyunsaturated fatty acids on the oclacitinib dose for atopic dogs.

BACKGROUND: Supplementation of polyunsaturated fatty acids (PUFA) enables dose reduction of prednisolone and ciclosporin in canine atopic dermatitis (cAD). OBJECTIVE: To determine if oral administration of PUFA reduces the dose of oclacitinib in cAD. ANIMALS: Twenty-two client-owned dogs with cAD receiving oclacitinib. MATERIALS AND METHODS: Dogs received a fish oil product (PUFA) or paraffin oil (placebo) for 16 weeks. Owners adjusted the oclacitinib dose according to daily pruritus assessments. On Day (D)0, D56 and D112, Canine Atopic Dermatitis Extent and Severity Index, fourth iteration (CADESI-04), pruritus Visual Analog Scale (PVAS), quality-of-life score (QoL), Global Assessment (GA), quality-of-coat (QoC) and adverse events were recorded. RESULTS: Mean daily oclacitinib dose was significantly reduced in the PUFA group from 0.51 ± 0.20 mg/kg/24 h (D0) to 0.19 ± 0.14 mg/kg/24 h (D85-112; p < 0.00001) and not in the placebo group (D0: 0.70 ± 0.33 mg/kg/24 h; D85-112: 0.53 ± 0.35 mg/kg/24 h, p = 0.5422). CADESI-04 did not change over time or differ between groups. PVAS was significantly lower in the PUFA group (2.8 ± 1.5) compared to placebo (4.2 ± 1.6) at D112 (p = 0.0375). QoL and QoC improved only in the PUFA group (QoL: D0: 20 ± 7, D112: 12 ± 5, p = 0.0057; QoC: D0: 0 ± 0.5, D112: 1 ± 0.5, p = 0.0410). GA on D112 was higher in the PUFA group (p = 0.008). No adverse events were observed. CONCLUSION: Oral supplementation of PUFA allowed dose reduction of oclacitinib and improved PVAS, QoL, QoC and GA. The use of PUFA is recommended and was safe in the atopic study dogs receiving oclacitinib.

Is "milk crust" a transient form of golden retriever ichthyosis?

BACKGROUND: A recessive inherited form of lamellar ichthyosis is well recognized in golden retrievers. In this breed, young puppies demonstrate a self-limiting scaling disorder which is commonly recognized by breeders, who use the term "milk crust" to describe this syndrome. HYPOTHESIS/OBJECTIVES: To determine whether "milk crust" is a new keratinization disorder or a self-limiting form of golden retriever ichthyosis. ANIMALS: A total of 179 golden retriever dogs (21 dams and 158 puppies) were examined. METHODS: Dermatological examination and assessment of the patatin-like phospholipase-1 (PNPLA1) genotype by PCR testing of buccal mucosal swabs. Skin biopsies from one affected puppy were evaluated for histopathological abnormalities. RESULTS: Forty-five of 158 (28%) puppies exhibited scaling at 8 weeks of age; 113 of 158 (72%) were dermatologically normal. Of 144 analysed samples, 40 of 144 (28%) puppies demonstrated a homozygous mutation of the PNPLA1 genotype [of which, 36 of 40 (90%) had signs of scaling], 77 of 144 (53%) demonstrated a heterozygous mutation and 27 of 144 (19%) were a normal wild-type. In six of 17 (35%) dams, a homozygous mutation of the PNPLA1 genotype was found, eight of 17 (47%) demonstrated a heterozygous mutation and three of 17 (18%) were normal wild-type. Dams with a homozygous mutation were clinically unaffected. A 1 year follow-up revealed that 23 of 28 (82%) puppies affected with this syndrome failed to develop typical signs of ichthyosis. In five of 28 (18%) dogs there was persistence of mild scaling. CONCLUSIONS AND CLINICAL IMPORTANCE: We hypothesize that the clinical syndrome termed "milk crust" could represent a transient form of golden retriever ichthyosis. Remission is not fully linked to PNPLA1 genotype, suggesting that unknown factors may contribute to the clinical disease.

[Intradermal and serologic testing for insect bite hypersensitivity in a Dahomey-Ox]. / Intradermaler und serologischer Allergietest zur Abklärung einer Insektenstich-Hypersensitivität bei einem Dahomey-Ochsen.

This case report describes an eosinophilic dermatitis on the prepuce of a Dahomey-Ox caused by an insect bite hypersensitivity against Culicoides spp. To the best of the authors' knowledge, this is the first report describing intradermal allergy and serological testing in cattle.

Nonuraemic nonfatal idiopathic calciphylaxis in a kitten.

BACKGROUND: Calciphylaxis is a rare cutaneous disorder, characterized by vascular calcification and progressive skin necrosis, not yet described in cats. It is scarcely reported in animals, mostly due to iatrogenic or uraemic disturbances of the calcium-phosphate balance. In human patients, it is most commonly seen with end-stage renal disease, but several nonuraemic disorders, including inherited dysfunctions of tissue calcification inhibitors, have also been described. HYPOTHESIS/OBJECTIVES: To describe a case of nonuraemic calciphylaxis in a cat. ANIMALS: A 10-week-old male domestic short hair kitten was presented with hyperacute skin lesions. Initial dermatological signs were characterized by sharp demarcated erosions and ulcerations on the face, including the nasal planum and lips. Cutaneous lesions rapidly progressed into thick crusts with ulcerations, involving parts of the face and pinna as well as abdominal skin. METHODS: Complete blood count, serum chemistry profile, urinalysis, parathyroid hormone measurement and histopathological examination of skin biopsies. RESULTS: Histopathology from newly developed abdominal skin lesions revealed severe epidermal necrosis and calcification, multifocal pannicular calcification and calcified subcutaneous vessels, supporting a diagnosis of calciphylaxis. Treatment consisted of systemic and topical antimicrobials, analgesics, pentoxifylline, Lantharenol(®) , sodium thiosulfate and vitamin K. After initiation of therapy, no further progression was noticed; all medications could be discontinued eventually, and no relapse was seen in the following 2 years. CONCLUSIONS AND CLINICAL IMPORTANCE: Calciphylaxis should be considered as a differential diagnosis for ulcerative cutaneous disorders in young cats. More information on this disease is needed to elucidate the pathomechanism.

Extensive fatal Pyoderma gangrenosum in a dog after drug exposure.

A 4-year-old, spayed female mixed breed dog was presented with large crater-like, well-demarcated, erosive and ulcerative necrotic lesions of the skin, elevated body temperature and lethargy, that began 14 days after vaccination and treatment with fluralaner and milbemycin/praziquantel. Cytology revealed severe pyogranulomatous inflammation with moderate numbers of extracellular microorganisms. Histopathologic examination showed severe multifocal pyogranulomatous dermatitis and panniculitis with severe dermal edema and severe neutrophilic exocytosis with band-like infiltration of the lower portion of the epidermis consistent with pyoderma gangrenosum. Despite intensive immunosuppressive and antimicrobial therapy and intensive inpatient care, the dog was euthanized 16 days after admission due to complications with clinical signs of sepsis, acute dyspnea and thoracic effusion.

Identification of an ADAMTS2 frameshift variant in a cat family with Ehlers-Danlos syndrome.

We investigated 4 European domestic shorthair kittens with skin lesions consistent with the dermatosparaxis type of the Ehlers-Danlos syndrome, a connective tissue disorder. The kittens were sired by the same tomcat but were born by 3 different mothers. The kittens had easily torn skin resulting in nonhealing skin wounds. Both clinically and histologically, the skin showed thin epidermis in addition to inflammatory changes. Changes in collagen fibers were visible in electron micrographs. The complete genome of an affected kitten was sequenced. A one base pair duplication leading to a frameshift in the candidate gene ADAMTS2 was identified, p.(Ser235fs*3). All 4 affected cats carried the frameshift duplication in a homozygous state. Genotypes at this variant showed perfect cosegregation with the autosomal recessive Ehlers-Danlos syndrome phenotype in the available family. The mutant allele did not occur in 48 unrelated control cats. ADAMTS2 loss-of-function variants cause autosomal recessive forms of Ehlers-Danlos syndrome in humans, mice, dogs, cattle, and sheep. The available evidence from our investigation together with the functional knowledge on ADAMTS2 in other species allows to classify the identified ADAMTS2 variant as pathogenic and most likely causative variant for the observed Ehlers-Danlos syndrome.

Mycobacterium setense isolated from a cat with atypical mycobacterial panniculitis.

Atypical mycobacterial panniculitis was diagnosed in a cat. Mycobacterium setense was identified as causative agent by 16 S rRNA gene sequence analysis. This a gram-positive rod-shaped acid-fast bacterium belonging to Mycobacterium fortuitum group was never reported before in diseased animals. Resistance to doxycycline and clarithromycin was detected. During treatment with pradofloxacin, additional resistance to fluoroquinolones developed which was due to a mutation in the gyrase gene gyrA (S90W exchange). Despite of antimicrobial treatment for 33 months the patient did not fully recover. Species identification and susceptibility testing for choosing adequate antimicrobial treatment is recommended in cases of feline mycobacterial panniculitis.

Description and comparison of the skin and ear canal microbiota of non-allergic and allergic German shepherd dogs using next generation sequencing.

Atopic dermatitis is one of the most common skin diseases in dogs. Pathogenesis is complex and incompletely understood. Skin colonizing bacteria likely play an important role in the severity of this disease. Studying the canine skin microbiota using traditional microbiological methods has many limitations which can be overcome by molecular procedures. The aim of this study was to describe the bacterial microbiota of the skin and ear canals of healthy non-allergic and allergic German shepherd dogs (GSDs) without acute flare or concurrent skin infection and to compare both. Bacterial 16S rRNA gene amplicon sequence data revealed no differences of bacterial community patterns between the different body sites (axilla, front dorsal interdigital skin, groin, and ear canals) in non-allergic dogs. The microbiota at the different body sites of non-allergic GSDs showed no significant differences. Only for the samples obtained from the axilla the bacterial microbiota of allergic dogs was characterized by a lower species richness compared to that of non-allergic dogs and the bacterial community composition of the skin and ear canals of allergic dogs showed body site specific differences compared to non-allergic dogs. Actinobacteria was the most abundant phylum identified from the non-allergic dogs and Proteobacteria from allergic dogs. Macrococcus spp. were more abundant on non-allergic skin while Sphingomonas spp. were more abundant on the allergic skin. Forward step redundancy analysis of metadata indicated that the household the dogs came from had the strongest impact on the composition of the skin microbiome followed by sex, host health status and body site.

Update on therapy and prevention of canine leishmaniasis. / Aktuelle Kenntnisse zu Therapie und Prävention der kaninen Leishmaniose.

Canine leishmaniasis is an emerging infection with increasing importance because the main vector also exists in Germany and autochthonous infections have been described. In this article we present the latest information available regarding therapy and prevention of this disease. Allopurinol-resistant Leishmania infantum strains were isolated from dogs which experienced recurrent disease while being treated with allopurinol, highlighting the need for alternative treatment options. Differing results of long-term studies on the efficacy of miltefosine in combination with allopurinol in comparison to meglumine antimoniate and allopurinol can affect the selection of the treatment protocol. A high number of repellents with distinctive characteristics is available for the prevention of infection in dogs. In Europe, two vaccines are licensed for dogs which aim at reducing the risk of an active infection and the severity clinical disease.

Feline paraneoplastic alopecia associated with metastasising intestinal carcinoma.

CASE SUMMARY: A 10-year-old male neutered British Shorthair cat was presented with a 6 month history of lethargy, weight loss and alopecia. Clinical examination revealed widespread alopecia of the ventral abdomen and hindlimbs. The skin in these areas was smooth and shiny and hairs could be easily epilated. Spontaneous pruritus was observed. Cytological examination of superficial impression smears showed a severe Malassezia species dermatitis and pyoderma. Ectoparasites could not be detected and no sign of dermatophytosis was visible in trichograms and Wood's lamp analysis. Abdominal ultrasound found a focally thickened wall of the large intestine and multiple nodules in the liver. Fine-needle aspirates from lymph nodes, liver and altered colonic wall were consistent with an undifferentiated malignant neoplasia. The cat was euthanased at the owners' request, owing to potential neoplasia with metastatic spread. At necropsy a metastasising carcinoma of the colonic wall was found, as well as a paraneoplastic alopecia. RELEVANCE AND NOVEL INFORMATION: Feline paraneoplastic alopecia has been reported in association with pancreatic carcinoma, bile duct carcinoma and hepatocellular carcinoma, as well as with neuroendocrine pancreatic carcinoma and hepatosplenic plasma cell tumour. This is the first reported case of feline paraneoplastic alopecia associated with a colon carcinoma.

Case-control risk factor study of methicillin-resistant Staphylococcus pseudintermedius (MRSP) infection in dogs and cats in Germany.

Methicillin-resistant Staphylococcus pseudintermedius (MRSP) has emerged as a highly drug-resistant small animal veterinary pathogen. Although often isolated from outpatients in veterinary clinics, there is concern that MRSP follows a veterinary-hospital-associated epidemiology. This study's objective was to identify risk factors for MRSP infections in dogs and cats in Germany. Clinical isolates of MRSP cases (n=150) and methicillin-susceptible S. pseudintermedius (MSSP) controls (n=133) and their corresponding host signalment and medical data covering the six months prior to staphylococcal isolation were analysed by multivariable logistic regression. The identity of all MRSP isolates was confirmed through demonstration of S. intermedius-group specific nuc and mecA. In the final model, cats (compared to dogs, OR 18.5, 95% CI 1.8-188.0, P=0.01), animals that had been hospitalised (OR 104.4, 95% CI 21.3-511.6, P<0.001), or visited veterinary clinics more frequently (>10 visits OR 7.3, 95% CI 1.0-52.6, P=0.049) and those that had received topical ear medication (OR 5.1, 95% CI 1.8-14.9, P=0.003) or glucocorticoids (OR 22.5, 95% CI 7.0-72.6, P<0.001) were at higher risk of MRSP infection, whereas S. pseudintermedius isolates from ears were more likely to belong to the MSSP-group (OR 0.09, 95% CI 0.03-0.34, P<0.001). These results indicate an association of MRSP infection with veterinary clinic/hospital settings and possibly with chronic skin disease. There was an unexpected lack of association between MRSP and antimicrobial therapy; this requires further investigation but may indicate that MRSP is well adapted to canine skin with little need for selective pressure.

Intra- and interlaboratory variability of allergen-specific IgE levels in atopic dogs in three different laboratories using the Fc-epsilon receptor testing.

The IgE specific Fc-epsilon receptor test is widely used for serological evaluation of allergic canine patients. Aim of the study was to evaluate intra- and interlaboratory variability in three independent laboratories. Duplicate serum aliquots from 15 atopic dogs were submitted simultaneously to 3 laboratories (LA, LB, LC), which subsequently performed the test in a blinded fashion. LA and LC analysed sera for 35 allergens and expressed the results as optical density units (OD), while LB analysed 15 allergens and provided reaction grades (RG). Results were compared with three factorial ANOVA. Intralaboratory variability was evaluated by calculating the dispersion factor for data of LA and LC and standard deviation (SD) for LB. Correlation coefficients (r) were used to evaluate interlaboratory variability. Depending on the allergens, intralaboratory dispersion factor for LA and LC varied from 1.15 to 6.63 and 1.19 to 6.17, respectively. In LB the SD varied between 0 and 0.6 RG. Regarding interlaboratory variability, correlation of OD values between LA and LC was excellent (r>0.8, p<0.001) for 13 of 35 allergens. There was a significant difference in OD results for 9 allergens. The results were significantly correlated (r>0.8, p<0.001) for all except 3 allergens (Dermatophagoides pteronyssinus, mixed grasses, nettle). As far as negative/positive results were concerned, intralaboratory differences were 3.14% and interlaboratory differences were 4.76%.