Corinne Gurtner

Clinical and histological characterization of hair coat and glandular tissue of Chinese crested dogs

BACKGROUND Two varieties exist in the Chinese crested dog breed, namely hairless Chinese crested dogs presenting with hypotrichosis and dentition abnormalities, and the coated powderpuffs. Hairless Chinese crested dogs are obligate heterozygotes for a FOXI3 mutation, and this phenotype is classified as a form of canine ectodermal dysplasia. OBJECTIVES We provide a detailed histological description of hair follicles and their density for the three subphenotypes (true hairless, semi-coated and powderpuffs) of Chinese crested dogs. Apocrine and exocrine glands of the skin and other tissues were compared with findings reported from dogs with X-linked ectodermal dysplasia. ANIMALS Skin biopsies were collected from 22 Chinese crested dogs. Additionally, the glands of the skin and other tissues were examined from another two dogs available for postmortem examination. METHODS Skin biopsies and tissues were processed, stained and evaluated in a blinded fashion. RESULTS Hair follicular anomalies decreased with increasing number of hairs in the different phenotypes. The FOXI3 mutants had only simple primary hair follicles, whereas the nonmutant powderpuffs had compound follicles identical to other dog breeds. All Chinese crested dogs had an anagen-dominated hair cycle. Furthermore, apocrine glands in the skin and respiratory mucous glands of the mutant Chinese crested dogs were present and normal. CONCLUSIONS AND CLINICAL IMPORTANCE We have identified striking histopathological differences between the three subphenotypes of Chinese crested dogs. We clearly demonstrated distinct differences between the canine ectodermal dysplasia in Chinese crested dogs and dogs with X-linked ectodermal dysplasia.

A Missense Variant in KCNJ10 in Belgian Shepherd Dogs Affected by Spongy Degeneration with Cerebellar Ataxia (SDCA1).

Spongy degeneration with cerebellar ataxia (SDCA) is a severe neurodegenerative disease with monogenic autosomal recessive inheritance in Malinois dogs, one of the four varieties of the Belgian Shepherd breed. We performed a genetic investigation in six families and seven isolated cases of Malinois dogs with signs of cerebellar dysfunction. Linkage analysis revealed an unexpected genetic heterogeneity within the studied cases. The affected dogs from four families and one isolated case shared a ∼1.4 Mb common homozygous haplotype segment on chromosome 38. Whole genome sequence analysis of three affected and 140 control dogs revealed a missense variant in the KCNJ10 gene encoding a potassium channel (c.986T>C; p.Leu329Pro). Pathogenic variants in KCNJ10 were reported previously in humans, mice, and dogs with neurological phenotypes. Therefore, we consider KCNJ10:c.986T>C the most likely candidate causative variant for one subtype of SDCA in Malinois dogs, which we propose to term spongy degeneration with cerebellar ataxia 1 (SDCA1). However, our study also comprised samples from 12 Malinois dogs with cerebellar dysfunction which were not homozygous for this variant, suggesting a different genetic basis in these dogs. A retrospective detailed clinical and histopathological analysis revealed subtle neuropathological differences with respect to SDCA1-affected dogs. Thus, our study highlights the genetic and phenotypic complexity underlying cerebellar dysfunction in Malinois dogs and provides the basis for a genetic test to eradicate one specific neurodegenerative disease from the breeding population. These dogs represent an animal model for the human EAST syndrome.

Salmonella enterica subsp. diarizonae serotype 61:k:1,5,(7) associated with chronic proliferative rhinitis and high nasal colonization rates in a flock of Texel sheep in Switzerland

Salmonella (S.) enterica subspecies diarizonae (IIIb) serovar 61:(k):1,5,(7) (S. IIIb 61:(k):1,5,(7)) is considered to be host adapted to sheep and is found regularly in feces of healthy carriers and of sheep with salmonellosis. A few cases of chronic proliferative rhinitis (CPR) in sheep have been described as a new disease in association with S. IIIb 61:k:1,5,(7) in the USA, in Spain and now for the first time in Switzerland. Three animals of a flock of Texel sheep suffering from chronic nasal discharge and dyspnea with subsequent death were necropsied. The pathological lesions are consistent with a severe proliferation of the nasal mucosae of the turbinates in association with severe chronic inflammation. S. IIIb 61:(k):1,5,(7) was isolated from the lesions by direct bacteriological culture and the presence of Salmonella spp. was confirmed by immunohistochemistry. The affected flock was systematically tested after the first occurrence of the disease. Clinical examination of the flock revealed approx. 20% of the adult sheep to show nasal discharge, approx. 5% having severe dyspnea and approx. 5% having chronic intermittent diarrhea. Lambs (n=28) showed no clinical signs at all. High positivity of nasal mucosa (46%), but low prevalence in feces (6%) for S. IIIb 61:k:1,5,(7) was found. The results lead to the assumption of a direct animal to animal transmission by nasal discharge followed by a chronic disease leading to death after several months to years. Animals tested positive for S. IIIb 61:k:1,5,(7) were all >1year old. CPR represents a chronic disease in adult sheep posing a risk for spreading S. IIIb 61:k:1,5,(7) between flocks and with a zoonotic potential.

A SINE Insertion in ATP1B2 in Belgian Shepherd Dogs Affected by Spongy Degeneration with Cerebellar Ataxia (SDCA2)

Spongy degeneration with cerebellar ataxia (SDCA) is a genetically heterogeneous neurodegenerative disorder with autosomal recessive inheritance in Malinois dogs, one of the four varieties of the Belgian Shepherd breed. Using a combined linkage and homozygosity mapping approach we identified an ∼10.6 Mb critical interval on chromosome 5 in a Malinois family with four puppies affected by cerebellar dysfunction. Visual inspection of the 10.6 Mb interval in whole-genome sequencing data from one affected puppy revealed a 227 bp SINE insertion into the ATP1B2 gene encoding the β2 subunit of the Na+/K+-ATPase holoenzyme (ATP1B2:c.130_131insLT796559.1:g.50_276). The SINE insertion caused aberrant RNA splicing. Immunohistochemistry suggested a reduction of ATP1B2 protein expression in the central nervous system of affected puppies. Atp1b2 knockout mice had previously been reported to show clinical and neurohistopathological findings similar to the affected Malinois puppies. Therefore, we consider ATP1B2:c.130_131ins227 the most likely candidate causative variant for a second subtype of SDCA in Malinois dogs, which we propose to term spongy degeneration with cerebellar ataxia subtype 2 (SDCA2). Our study further elucidates the genetic and phenotypic complexity underlying cerebellar dysfunction in Malinois dogs and provides the basis for a genetic test to eradicate one specific neurodegenerative disease from the breeding population in Malinois and the other varieties of the Belgian Shepherd breed. ATP1B2 thus represents another candidate gene for human inherited cerebellar ataxias, and SDCA2-affected Malinois puppies may serve as a naturally occurring animal model for this disorder.

Bovine dilatative Kardiomyopathie: Altbekannt und dennoch gegenwärtig

INTRODUCTION Numerous cases of bovine dilatative cardiomyopathy (BDCMP) were registered in the nineteen-eighties, but the prevalence decreased steadily thanks to classical selection measures, i.e. excluding putative carrier animals from breeding. The cases described here show that the recessively inherited disease is still present in the Swiss cattle population. By use of a direct gene test developed a few years ago, a clinical tentative diagnosis can be confirmed. Since the end of the year 2016, carriers are officially labelled as such in Switzerland. Currently, about 2% of the insemination sires of the Holstein, Red Holstein and Swiss Fleckvieh breeds carry the causative mutation in the OPA3 gene. A combination of increased awareness of the disease and use of the gene test should allow for complete elimination of the disease from the Swiss cattle population.

Multicystic degeneration of the Cowper's gland in a Large White boar.

The present report describes a case of multicystic degeneration of the Cowpers gland in a 1.3-year-old purebred Large White intact boar with reduced fertility in Switzerland. Based on the case history, a general physical examination, an andrological investigation and a transrectal ultrasonography combined with a subsequent thorough pathological examination including histology a multicystic degeneration of the Cowpers gland were diagnosed. The case indicates that cystic degeneration of the bulbourethral gland should be contemplated in the differential diagnoses of andrological disorders even though it has not been described in pigs so far. While selecting breeding boars, a morphological check of the bulbourethral gland can be performed, since degeneration of the gland would potentially have an impact on future fertility.

Acute kidney injury in three dogs after ingestion of a descaling agent containing maleic acid

Maleic acid (MA) is a common component of descaling products and is widely used in daily life. Accidental ingestion in relevant amounts does not play a major role in human beings; however, it seems to be highly toxic for dogs. It has been commonly used experimentally to induce Fanconi syndrome in dogs or small rodents. Two dogs were presented for acute kidney injury (AKI) after accidental ingestion of a descaling agent containing MA at an estimated amount of 70 mg/kg each. The third dog involved was euthanased by the referring veterinarian, and postmortem pathological analysis revealed severe acute tubular necrosis consistent with toxic nephropathy. The other dogs received symptomatic therapy for AKI including treatment with haemodialysis and showed complete normalisation of serum creatinine at a follow-up after five months. Renal damage can be very severe, but seems to be at least partially reversible and an attempt to treatment is warranted.