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Hepatic fibrinogen storage disease (HFSD) was diagnosed in a 5‐month‐old Wagyu calf with a history of recurrent respiratory disease. It was characterized by lethargy, dehydration, acidemia, and increased liver enzyme activities. Histologically, disseminated hepatocytes were swollen and showed a single, sharply demarcated, faintly eosinophilic cytoplasmic inclusion with a ground‐glass appearance, with the nucleus in an eccentric position. Cytoplasmic inclusions did not stain with the periodic acid‐Schiff (PAS) reaction. Using a rabbit polyclonal antibody against fibrinogen, the cytoplasmic vacuoles in the hepatocytes stained intensely. Electron microscopy disclosed hepatocytes with membrane‐bound cytoplasmic inclusions filled with fine granular material interspersed with a few coarse‐grained electron‐dense granules. A trio whole‐genome sequencing approach identified a deleterious homozygous missense variant in DGKG (p.Thr721Ile). The allele frequency in 209 genotyped Wagyu was 7.2%. This is a report of a DGKG‐related recessive inherited disorder in cattle and adds DGKG to the list of candidate genes for HFSD in other species. [ABSTRACT FROM AUTHOR]

Background: A recessive form of MOCOS‐associated xanthinuria type II is described in Tyrolean grey cattle. A similar case was identified in a 5‐month‐old Brown Swiss calf with hoof overgrowth, rough coat, urine sediment, and pneumonia. Hypothesis/Objectives: To characterize the disease phenotype, to evaluate its genetic etiology, and to determine the prevalence of the deleterious allele in the Brown Swiss population. Animals: An affected calf, its parents, and 65 441 Swiss dairy cattle. Methods: The affected animal was clinically examined and necropsied. Microarray genotyping was used to determine the genotypes and to assess the frequency of the MOCOS allele in a Brown Swiss control cohort. Results: Ultrasonography revealed hyperechoic renal pyramids with multifocal distal shadowing and echogenic sediment in the urinary bladder. Necropsy revealed suppurative bronchopneumonia and urolithiasis. Histology revealed numerous nephroliths with multifocal chronic lymphohistiocytic interstitial infiltrates, fibrosis, tubular degeneration, chronic multifocal glomerulonephritis with sclerosis, and bilateral hydronephrosis. Dysplastic changes were observed in the corium of the claw and the cornea. Genetic testing identified the homozygous presence of a known MOCOS frameshift variant in the case. Both parents were heterozygous and the prevalence of carriers in genotyped Brown Swiss cattle was 1.4% (342/24337). Conclusions and Clinical Importance: The findings were consistent with the diagnosis of a recessive renal syndrome similar to xanthinuria type II described in Tyrolean grey cattle. The prevalence of the deleterious MOCOS allele is low in the Brown Swiss breed. However, mating of carriers should be avoided to prevent further losses. [ABSTRACT FROM AUTHOR]

Hemifacial microsomia (HFM) was diagnosed in a 9‐day‐old Romagnola calf. The condition was characterized by microtia of the left ear, anotia of the right ear, asymmetry of the face, and deafness. Magnetic resonance imaging revealed agenesis of the right pinna and both tympanic bullae, asymmetry of the temporal bones and temporomandibular joints, and right pontine meningocele. Brainstem auditory evoked responses confirmed the impaired auditory capacity. At gross post mortem examination, there was agenesis and hypoplasia of the right and the left external ear, respectively. No histological abnormalities were detected in the inner ears. A trio whole‐genome sequencing approach was carried out and identified a private homozygous missense variant in LAMB1 affecting a conserved residue (p.Arg668Cys). Genotyping of 221 Romagnola bulls revealed a carrier prevalence <2%. This represents a report of a LAMB1‐related autosomal recessive inherited disorder in domestic animals and adds LAMB1 to the candidate genes for HFM. [ABSTRACT FROM AUTHOR]

A 6‐day‐old Belgian Blue‐Holstein calf was referred because of a syndrome resembling epidermolysis bullosa simplex (EBS). The clinical phenotype included irregular and differently sized erosions and ulcerations spread over the body, in particular on the limbs and over bone prominences, as well as in the nasal planum and oral mucosa. Blisters were easily induced by rubbing the skin. The skin lesions displayed a clear dermal‐epidermal separation at the level of the basal cell layer. Post mortem examination revealed erosions in the pharynx, proximal esophagus, and rumen. Whole‐genome sequencing revealed a heterozygous disruptive in‐frame deletion variant in KRT5 (c.534_536delCAA). Genotyping of both parents confirmed the variant as de novo mutation. Clinicopathological and genetic findings were consistent with the diagnosis of KRT5‐related EBS providing the second example of a spontaneous mutation causing epidermolysis bullosa in cattle. [ABSTRACT FROM AUTHOR]