Evaluation of antimicrobial and non-steroidal anti-inflammatory treatments for BRD on health and welfare in fattening bulls: a cross-sectional study.

Our study aimed to evaluate the effect of different treatments for BRD on health and welfare in fattening bulls. A total of 264 bulls were enrolled. Welfare was assessed on day 2 (T0) and day 15 (T1) after arrival. A decrease in the welfare level was observed from T0 to T1. All bulls were inspected clinically at T0 and T1 revealing an increase of skin lesions and lameness in T1. In both periods, a high incidence of respiratory disease was observed. A prevalence of 79.55% and 95.45% of Mycoplasma bovis using RT-PCR and culture at T0 and T1 respectively was observed. Blood samples were collected for haematology at T0 and T1. At T0, 36 animals were individually treated for BRD with an antimicrobial (IT), 54 received a metaphylactic treatment with tulathromycin (M), 150 received a metaphylactic treatment with tulathromycin plus a second antimicrobial (M + IT) whereas 24 were considered healthy and therefore not treated (NT). Additionally, 128 were treated with a non-steroid anti-inflammatory (NSAID). Neutrophils of M + IT were significantly higher than groups NT and M and the lymphocytes of M + IT were significantly lower than that of IT. White blood cells, neutrophils and N/L ratio of animals treated with an NSAID was significantly higher than that not treated. Lung inspection of 172 bulls at the abattoir indicated that 92.43% presented at least one lung lesion. A statistically significant effect of the NSAID treatment on the lung lesions was observed. Our findings indicate that BRD was a major welfare and health concern and evidence the difficulties of antimicrobial treatment of M. bovis.

DYRK1B haploinsufficiency in a Holstein cattle with epilepsy.

In this study, epilepsy with focal seizures progressing to generalized seizures was diagnosed in a 6-month-old Holstein heifer. The seizures were characterized by a brief pre-ictal phase with depression and vocalization. During the ictal phase eyelid spasms, tongue contractions, nodding and abundant salivation were observed, rapidly followed by a convulsive phase with bilateral tonic, clonic or tonic-clonic activity and loss of consciousness. Finally, during the postictal phase the heifer was obtunded and disorientated, unable to perceive obstacles and hypermetric, and pressed its head against objects. In the inter-seizure phase, the heifer was clinically normal. Neuropathology revealed axonal degeneration in the brainstem and diffuse astrocytic hypertrophic gliosis. Whole genome sequencing of the affected heifer identified a private heterozygous splice-site variant in DYRK1B (NM_001081515.1: c.-101-1G>A), most likely resulting in haploinsufficiency owing to loss-of-function. This represents a report of a DYRK1B-associated disease in cattle and adds DYRK1B to the candidate genes for epilepsy.

First Report on Medical Treatment and Outcome of Burnt Cattle.

The management of livestock affected by fire often comes down to two options: euthanasia or slaughtering. However, the therapeutic approach can be attempted for high-value cattle. The aim of a primary assessment is to identify signs of smoke inhalation injuries, cardiovascular impairment and shock and to determine the severity and extent of burn injuries. Full-thickness burns covering 40% or more of the body are highly unfavorable prognostic factors and are usually fatal. Moreover, it can take several days for the burns to appear in their full extent, leaving the prognosis uncertain. In this case report, the clinical findings, treatment and outcome of two burnt Holstein heifers are described. Daily wound care required cleaning, the removal of eschars and the application of topical antibacterial agents for seven months in order to discharge one heifer. The topical use of honey with a solution of povidone-iodine proved to be affordable and successful, with no residue risks. The other heifer was more severely wounded, and despite the administration of fluid therapy, pain management, anti-oxidants and anti-microbials, after initial stabilization, the animal's condition worsened, leading to euthanasia. This confirms that the treatment of burnt cattle is possible but challenging due to the late onset of multi-organ failure.

A Missense Variant in PLP2 in Holstein Cattle with X-Linked Congenital Mast Cell Tumor.

Congenital tumors occur infrequently in cattle. The aim of this study was to detail the clinicopathological phenotype of a Holstein calf with a congenital mast cell tumor and to identify the genetic cause by a whole-genome sequencing (WGS) trio-approach. An 18-day-old male Holstein calf was clinically examed and revealed multifocal, alopecic, thick and wrinkled skin lesions over the entire body. At 6 months of age, the general condition of the calf was characterized by retarded growth, poor nutritional status, and ulceration of the skin lesions. Histopathological examination revealed a primary cutaneous, poorly differentiated embryonal mast cell tumor with metastases in the lymph nodes and liver. Genetic analysis revealed a private X-linked variant in the PLP2 gene (chrX:87216480C > T; c.50C > T), which was present only in the genomes of the case (hemizygous) and his mother (heterozygous). It was absent in the sire as well as in 5365 control genomes. The identified missense variant exchanges the encoded amino acid of PLP2 at position 17 (p.Thr17Ile), which is classified as deleterious and affects a protein that plays a role in tumor growth and metastasis. Therefore, we suggested that the detected PLPL2 variant could be a plausible cause for this congenital condition in the affected calf.

Use of Electrodiagnostics in the Diagnosis and Follow-Up of Brachial Plexus Syndrome in a Calf.

Electrodiagnostic testing by using electromyography (EMG) and nerve conduction studies (NCS) is essential in the evaluation of patients with traumatic brachial plexus injury as it facilitates the localization of the lesion and the prognosis. In this case report, we present a long-term electrodiagnostic follow-up of a 5-day-old female Holstein calf with brachial plexus syndrome. Electrodiagnostic studies were carried out at 2 weeks, 5 weeks, 7 months and 12 months after admission. Initially, EMG confirmed the damage to the brachial plexus, potentially indicating a condition of neurotmesis or axonotmesis. However, motor NCS and the repeated electrodiagnostic follow-up, along with the evolution of the clinical signs, allowed a more favorable diagnosis of axonotmesis to be made. In fact, EMG showed a slow but gradual reduction and finally the disappearance of spontaneous pathological activity, while motor NCS revealed an increase in the amplitude and areas of the compound muscle action potentials. The animal was deemed fully recovered 12 months after admission. To the authors' knowledge, this is the first report on the use of motor NCS in bovine medicine and it demonstrates that electrodiagnostics represent a useful and practical tool for the evaluation and prognosis of brachial plexus injury cases in cattle.

Navel Healing and Calf Fitness for Transport.

Dairy male calves are at risk of welfare compromise as they are usually transported at a very young age. The European Union has set a "completely healed navel" requirement for calf transport; moreover, a minimum age is established for longer journeys. However, this requirement has proven to be prone to misinterpretation. This study aimed to clarify what is meant by "navel healing" and to provide strong elements for reaching a consensus. The navels of 299 dairy calves (55 males, 244 females) aged 0-90 days were examined and scored 1 to 5 according to their healing status. Based on our results, a completely dry and shriveled navel (score 3) would imply a 25.5-38.0% risk of transporting too young calves. Alternatively, the presence of a scab covering the umbilical wound (score 4) would entail a 4.3% risk of transporting calves less than 10 days old and could be considered good practice for transporting calves (except for journeys exceeding 8 h). Conversely, complete navel healing (score 5) guarantees that calves that are too young are not transported; therefore, it should be considered best practice for transporting calves in general and the minimum requirement for transporting calves for journeys exceeding 8 h.

A homozygous missense variant in laminin subunit beta 1 as candidate causal mutation of hemifacial microsomia in Romagnola cattle.

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.

Bovine viral diarrhoea virus 1b infection associated with congenital tremor and hypomyelination in Holstein calves.

Hypomyelination is a rare consequence of in utero bovine viral diarrhoea virus (BVDV) infection. We describe a BVDV outbreak in a naïve Holstein dairy herd in northern Italy, with an unusually high prevalence of calves with neurological signs, generalised tremors and ataxia. Histological analysis showed that hypomyelination was the predominant lesion and that the most typical BVDV neuropathological findings (e.g. cerebellar hypoplasia) were absent. Virological and molecular analyses showed that non-cytopathic BVDV genotype 1b was associated with the calves' neurological signs and excluded other viruses responsible for congenital infection or neurological disorders. Whole-genome sequencing of BVDVs from the brain of a calf with neurological signs and the whole blood of a persistently infected herd-mate with no such sign showed >99.7 % sequence identity. Analysis of the quasispecies distribution revealed the greatest variation rates in regions coding for the structural proteins E1 and E2. Variation was slightly greater in the brain- than in the blood-derived sequence and occurred at different sites, suggesting the occurrence of distinct evolutionary processes in the two persistently infected calves. Molecular characterisation of BVDV genomes from five other calves with neurological signs from the same farm confirmed that the E1 and E2 regions were the most variable. Several factors, including genetic variability and host factors, appear to have contributed to the observed unique BVDV disease phenotype, characterised by hypomyelination and neurological signs.

Congenital Tumours and Tumour-Like Lesions in Calves: a Review.

Congenital tumours and tumour-like lesions represent a group of rare disorders in both veterinary and human medicine that arise from tissue remnants and are detected during pregnancy or within the first 2-3 months of life. Different forms of congenital tumours and congenital tumour-like lesions have been reported in calves and their development is poorly understood. They often pose a diagnostic challenge and the referring nomenclature occasionally may be equivocal. Previous reports regarding tumour-like lesions, soft tissue tumours, vascular tumours, round cell tumours and neoplasms of the nervous, peritoneum and urogenital systems are summarized in this review, and the role of genetic factors in the development of these conditions is discussed.

Congenital Suborbital Undifferentiated Sarcoma in a Crossbred Calf.

Undifferentiated sarcomas are rare conditions that represent a group of unclassified sarcomas. The purpose of this study is to describe the clinical and pathological features of a calf showing a congenital infiltrating suborbital mass suggestive of undifferentiated sarcoma. The animal was referred because of respiratory distress and the presence of a right suborbital mass since birth. At ultrasonography, the mass displayed an irregular shape with multiple cavities. Radiographs revealed a diffuse, poorly defined mass with different densities overlying the bony structures of the skull. Endoscopy showed a co-involution of the mass in the right side with extension into the nasopharynx. Post-mortem examination showed a round, poorly demarcated neoplasia infiltrating the nasal turbinate and displacing the nasal septum. Histologically, the subcutis was expanded by lobules and bundles of densely cellular neoplastic spindle cells. The neoplasm infiltrated the underlying muscles, bone and the right retromandibular lymph node. The neoplastic cells had a diffuse intense cytoplasmic immunexpression to vimentin, and were negative to cytokeratin AE1/AE3, desmin, MUM1, IBA1, melan A, chromogranin and synaptophysin.

A Heterozygous Missense Variant in the COL5A2 in Holstein Cattle Resembling the Classical Ehlers-Danlos Syndrome.

Classical Ehlers-Danlos syndrome (cEDS) is a heritable connective tissue disorder characterized by variable degrees of skin hyperextensibility and fragility, atrophic scarring, and generalized joint hypermobility. The purpose of this study was to characterize the clinicopathological phenotype of a cEDS-affected Holstein calf and to identify the causative genetic variant associated with the disorder by whole-genome sequencing (WGS). A 3-day-old female Holstein calf was referred because of easily induced skin detachment and hyperextensibility in the neck. A complete clinical investigation was performed in the calf, dam, and maternal-grandmother. The calf and dam showed hyperextensibility of the neck skin and atrophic scarring; additionally, the calf presented skin fragility. Moreover, the histopathology of biopsies from the calf and its dam showed that the collagen bundles in affected skin areas were wavy, short, thin, and surrounded by edema and moderate to severe acute hemorrhages. Genetic analysis revealed a private heterozygous missense variant in COL5A2 (c.2366G>T; p.Gly789Val) that was present only in the calf and dam. This confirmed the diagnosis of cEDS and represents the first report of a causal variant for cEDS in cattle and the first COL5A2-related large animal model.

KDM2B-associated paunch calf syndrome in Marchigiana cattle.

BACKGROUND: Chianina, Romagnola, and Marchigiana are the 3 most important Italian breeds of cattle raised in the Apennine Mountains. Inherited disorders have been reported in the Chianina and Romagnola breeds but not in the Marchigiana breed. Recently, a case resembling recessively inherited KDM2B-associated paunch calf syndrome (PCS) in Romagnola cattle was identified in Marchigiana cattle. HYPOTHESIS/OBJECTIVES: To characterize the features of the observed congenital anomaly, evaluate its possible genetic etiology, and determine the prevalence of the deleterious allele in the Marchigiana population. ANIMALS: A single stillborn Marchigiana calf was referred for clinicopathological examination because of the presence of PCS-like morphological lesions. METHODS: The animal was necropsied and the calf and its parents were genotyped. A PCR-based direct gene test was applied to determine the KDM2B genotype and 114 Marchigiana bulls were genotyped. RESULTS: The pathological phenotype included facial deformities, enlarged fluid-filled abdomen, and hepatic fibrosis. The affected animal was the offspring of consanguineous mating and homozygous presence of the KDM2B missense variant was confirmed. Both parents were heterozygous for KDM2B and the prevalence of carriers in a selected population of Marchigiana bulls was <2%. CONCLUSIONS AND CLINICAL IMPORTANCE: The characteristic malformations and genetic findings were consistent with the diagnosis of PCS and provide evidence that the deleterious KDM2B variant initially detected in Romagnola cattle also occurs in the Marchigiana breed.

Heterotopy ("Error loci") of the spiral loop of the ascending colon in cattle.

The term heterotopy of the spiral colon encompasses a dysmorphological condition in which the spiral loops of the ascending colon (SLACs) do not form an orderly spiraling mass adjacent to the left side of the mesojejunum. As a consequence, the spiral loops are spread over a larger surface, making them more or less movable. It has been hypothesized that the abnormal position of the spiral loops of the ascending colon might constitute a predisposing factor for an intestinal obstruction or an ileus condition. The objective of the present study was to evaluate the anatomy of the spiral loops of the ascending colon in a population of healthy calves and to determine the prevalence of dysmorphism. The investigation was carried out on 1113 slaughtered veal calves. In 472 out of the 1113 calves, the spiral loops showed conformational aspects different from what has so far been described as normal in reference textbooks. In 91 calves the condition was definitely considered a pathological deviation from normality: in fact, the spiral colon had lost its typical spiral shape with random spacing between the loops, and it was nearly or completely detached from the mesojejunum. The lack of a broad attachment of the spiral loops of the ascending colon to the mesentery could provoke an alteration of the intestinal centre of gravity, enhancing the already asymmetrical distribution of weight between the jejunum and the descending colon.

A frameshift mutation in MOCOS is associated with familial renal syndrome (xanthinuria) in Tyrolean Grey cattle.

BACKGROUND: Renal syndromes are occasionally reported in domestic animals. Two identical twin Tyrolean Grey calves exhibited weight loss, skeletal abnormalities and delayed development associated with kidney abnormalities and formation of uroliths. These signs resembled inherited renal tubular dysplasia found in Japanese Black cattle which is associated with mutations in the claudin 16 gene. Despite demonstrating striking phenotypic similarities, no obvious presence of pathogenic variants of this candidate gene were found. Therefore further analysis was required to decipher the genetic etiology of the condition. RESULTS: The family history of the cases suggested the possibility of an autosomal recessive inheritance. Homozygosity mapping combined with sequencing of the whole genome of one case detected two associated non-synonymous private coding variants: A homozygous missense variant in the uncharacterized KIAA2026 gene (g.39038055C > G; c.926C > G), located in a 15 Mb sized region of homozygosity on BTA 8; and a homozygous 1 bp deletion in the molybdenum cofactor sulfurase (MOCOS) gene (g.21222030delC; c.1881delG and c.1782delG), located in an 11 Mb region of homozygosity on BTA 24. Pathogenic variants in MOCOS have previously been associated with inherited metabolic syndromes and xanthinuria in different species including Japanese Black cattle. Genotyping of two additional clinically suspicious cases confirmed the association with the MOCOS variant, as both animals had a homozygous mutant genotype and did not show the variant KIAA2026 allele. The identified genomic deletion is predicted to be highly disruptive, creating a frameshift and premature termination of translation, resulting in severely truncated MOCOS proteins that lack two functionally essential domains. The variant MOCOS allele was absent from cattle of other breeds and approximately 4% carriers were detected among more than 1200 genotyped Tyrolean Grey cattle. Biochemical urolith analysis of one case revealed the presence of approximately 95% xanthine. CONCLUSIONS: The identified MOCOS loss of function variant is highly likely to cause the renal syndrome in the affected animals. The results suggest that the phenotypic features of the renal syndrome were related to an early onset form of xanthinuria, which is highly likely to lead to the progressive defects. The identification of the candidate causative mutation thus enables selection against this pathogenic variant in Tyrolean Grey cattle.

Deletion in the EVC2 gene causes chondrodysplastic dwarfism in Tyrolean Grey cattle.

During the summer of 2013 seven Italian Tyrolean Grey calves were born with abnormally short limbs. Detailed clinical and pathological examination revealed similarities to chondrodysplastic dwarfism. Pedigree analysis showed a common founder, assuming autosomal monogenic recessive transmission of the defective allele. A positional cloning approach combining genome wide association and homozygosity mapping identified a single 1.6 Mb genomic region on BTA 6 that was associated with the disease. Whole genome re-sequencing of an affected calf revealed a single candidate causal mutation in the Ellis van Creveld syndrome 2 (EVC2) gene. This gene is known to be associated with chondrodysplastic dwarfism in Japanese Brown cattle, and dwarfism, abnormal nails and teeth, and dysostosis in humans with Ellis-van Creveld syndrome. Sanger sequencing confirmed the presence of a 2 bp deletion in exon 19 (c.2993_2994ACdel) that led to a premature stop codon in the coding sequence of bovine EVC2, and was concordant with the recessive pattern of inheritance in affected and carrier animals. This loss of function mutation confirms the important role of EVC2 in bone development. Genetic testing can now be used to eliminate this form of chondrodysplastic dwarfism from Tyrolean Grey cattle.