Characteristics of unilateral and bilateral bovine twin foetuses.

Twin pregnancy in cattle is undesirable for a number of reasons, including a higher abortion risk compared to pregnancies with a single foetus. Yet, the abortion risk is significantly influenced by the intrauterine location of the foetuses, that is, the abortion risk is several times higher if they are implanted in the same uterine horn (unilateral twin pregnancy) than if they are implanted with one foetus in each uterine horn (bilateral twin pregnancy). The reason for the higher abortion risk in unilateral twin pregnancies is unknown, but it may be related to malnutrition of the outermost foetus due to a limited placental capacity, as is the case for equine twin foetuses. A slaughterhouse study was performed and the foetuses of cattle pregnant with twins were measured. We identified 65 cases of twin pregnancies, of which 35 were unilateral twin pregnancies and 30 were bilateral twin pregnancies. There was no significant difference between the outermost and the more centrally located foetus in unilateral twin pregnancies in terms of body weight and length of the metacarpal diaphysis. Growth retardation of the outermost foetus could therefore not be confirmed as the cause of the higher abortion risk in unilateral bovine twin pregnancies. Four cases of pre-slaughter foetal mortality were identified. In three of these cases, both twins were dead, of equal size and at a comparable level of degradation. In the fourth case, with approximately 40-day-old twin foetuses of equal size, only one of the foetuses showed signs of pre-slaughter death.

Congenital syndromic Chiari-like malformation (CSCM) in Holstein cattle: towards unravelling of possible genetic causes.

BACKGROUND: Chiari malformation type II (CMII) was originally reported in humans as a rare disorder characterized by the downward herniation of the hindbrain and towering cerebellum. The congenital brain malformation is usually accompanied by spina bifida, a congenital spinal anomaly resulting from incomplete closure of the dorsal aspect of the spinal neural tube, and occasionally by other lesions. A similar disorder has been reported in several animal species, including cattle, particularly as a congenital syndrome. A cause of congenital syndromic Chiari-like malformation (CSCM) in cattle has not been reported to date. We collected a series of 14 CSCM-affected Holstein calves (13 purebred, one Red Danish Dairy F1 cross) and performed whole-genome sequencing (WGS). WGS was performed on 33 cattle, including eight cases with parents (trio-based; group 1), three cases with one parent (group 2), and three single cases (solo-based; group 3). RESULTS: Sequencing-based genome-wide association study of the 13 Holstein calves with CSCM and 166 controls revealed no significantly associated genome region. Assuming a single Holstein breed-specific recessive allele, no region of shared homozygosity was detected suggesting heterogeneity. Subsequent filtering for protein-changing variants that were only homozygous in the genomes of the individual cases allowed the identification of two missense variants affecting different genes, SHC4 in case 4 in group 1 and WDR45B in case 13 in group 3. Furthermore, these two variants were only observed in Holstein cattle when querying WGS data of > 5,100 animals. Alternatively, potential de novo mutational events were assessed in each case. Filtering for heterozygous private protein-changing variants identified one DYNC1H1 frameshift variant as a candidate causal dominant acting allele in case 12 in group 3. Finally, the presence of larger structural DNA variants and chromosomal abnormalities was investigated in all cases. Depth of coverage analysis revealed two different partial monosomies of chromosome 2 segments in cases 1 and 7 in group 1 and a trisomy of chromosome 12 in the WDR45B homozygous case 13 in group 3. CONCLUSIONS: This study presents for the first time a detailed genomic evaluation of CSCM in Holstein cattle and suggests an unexpected genetic and allelic heterogeneity considering the mode of inheritance, as well as the type of variant. For the first time, we propose candidate causal variants that may explain bovine CSCM in a certain proportion of affected calves. We present cattle as a large animal model for human CMII and propose new genes and genomic variants as possible causes for related diseases in both animals and humans.

Two cases of congenital lipomatosis in calves.

Fetal tumours in domestic animals are considered rare. Congenital lipomatous changes have been sporadically reported in fetal, neonatal and young bovids. Their prognosis is often guarded compared with benign lipocytic tumours and depends on their location and degree of infiltration. They can infiltrate the subcutis, deeper musculature and even the skeleton. Four cases of congenital infiltrative lipomatosis have been described in bovine fetuses and young calves. In this report we describe an additional two cases in a neonatal Belgian Blue White calf and a fetal dairy calf. A potential role in bovine abortion needs further investigation. Furthermore, a suggestion is made to adapt the nomenclature from infiltrative lipoma to lipomatosis in order to emphasize the poor prognosis due to the local infiltrative behaviour of these lesions.

Congenital localized cutaneous Langerhans cell histiocytosis in a Holstein calf.

Distinct solitary dermal nodules, either covered by an alopecic, or sometimes ulcerated, epidermis, were noticed on the head of a stillborn Holstein calf. The head was submitted for autopsy, and the nodules were found to consist of homogeneous, diffuse pale-yellow, soft-tissue masses with distinct margins that elevated the epidermis above the adjacent skin. Histologically, the dermal nodules were well-delineated on the deep margin approaching the cutaneous muscle and consisted of perivascular neoplastic infiltrates of round cells that in some places coalesced into sheets that extended into the dermis and subcutis. Neoplastic cells separated adnexa and collagen. Immunohistochemistry revealed intense tumor cell expression of vimentin, Iba1, E-cadherin, and CD204; expression of CD18 was faint. The masses were diagnosed as Langerhans cell histiocytosis. Congenital cutaneous Langerhans cell histiocytosis has not been reported previously in cattle, to our knowledge, and should be included in the differential diagnosis of congenital nodular skin lesions.

Epidemiology of Chuzan Virus Infection in Free-Ranging and Farmed Cervids in South Korea: A Seroprevalence Survey.

Chuzan virus is teratogenic in cattle and causes congenital abnormalities, such as hydranencephaly and cerebellar hypoplasia, in calves. Chuzan virus seroprevalence among free-ranging and farmed cervids in South Korea was found to be 4.4% (38/873), confirming exposure to this virus in cervids in South Korea.

Congenital heart defects in calves.

This focus article describes some of the cardiac anomalies detected in calves submitted to APHA Veterinary Investigation Centres and other postmortem examination providers.

Designing, optimization, and validation of whole blood direct T-ARMS PCR for precise and rapid genotyping of complex vertebral malformation in cattle.

BACKGROUND: DNA testing in the cattle industry undergoes multiple hurdles. Successful genotyping involves the transportation of samples from the field to the laboratory in a chilled environment followed by DNA extraction, and finally, a specific genotyping protocol is followed. Various researches are focused on overcoming these issues. Microcards offer blood transportation at ambient temperature. Direct PCR methods can save the time of DNA extraction but available only for simplex PCR. Tetra Primer-Amplification Refractory Mutation System based Polymerase Chain Reaction (T-ARMS PCR) can make DNA testing faster in a low-cost setting. The present study was aimed to design, optimize, and validate a T-ARMS PCR for faster DNA testing of SNP responsible for Complex Vertebral Malformation (CVM)-an important genetic disease of the cattle industry. Further, a direct T-ARMS PCR from whole blood was developed to avoid the DNA extraction steps. Lastly, using the optimized protocol, genotyping of blood spotted on Microcard eliminates the need for cold chain maintenance in the transportation of samples. RESULTS: The present study demonstrated a novel T-ARMS PCR-based genotyping of the SNP rs438228855, which is responsible for CVM. Here, wild genotypes were recognized by 389 bp and 199 bp bands in agarose gel, while the carrier genotype showed an additional 241 bp band. The developed protocol was validated using PCR-Primer Introduced Restriction Analysis (PCR-PIRA) and sequencing. The present study further established a direct T-ARMS PCR for this SNP from whole blood. Different conditions such as heparin and EDTA treated blood, the need for pre-treatment, and two different DNA Polymerases for the direct PCR were optimized. Finally, our optimized protocol successfully genotyped the whole blood samples dried on Insta™DNA cards. CONCLUSIONS: The present study reported the usefulness of primer modified T-ARMS PCR for detecting CVM for the first time. To the best of our knowledge, direct PCR in T-ARMS PCR has never been reported. Lastly, the use of microcards in the developed protocol can make the assay useful in the DNA testing of field samples.

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 segmental intestinal anomalies in calves.

This focus article has been prepared by Alwyn Jones, veterinary investigation officer with SRUC Veterinary Services.

Clinical, MRI, and histopathological findings of congenital focal diplomyelia at the level of L4 in a female crossbred calf.

BACKGROUND: This case report describes the clinical signs of a calf with focal diplomyelia at the level of the fourth lumbar vertebra. Magnetic resonance imaging (MRI) images and histological findings of the affected spinal cord are included in this case report. This case differs from previously reported cases in terms of localization and minimal extent of the congenital anomaly, clinical symptoms and findings during further examinations. CASE PRESENTATION: The calf was presented to the Farm Animal Health clinic, Faculty of Veterinary Medicine, Utrecht University, with an abnormal, stiff, 'bunny-hop' gait of the pelvic limbs. Prominent clinical findings included general proprioceptive ataxia with paraparesis, pathological spinal reflexes of the pelvic limbs and pollakiuria. MRI revealed a focal dilated central canal, and mid-sagittal T2 hyperintense band in the dorsal part of the spinal cord at the level of the third to fourth lumbar vertebra. By means of histology, the calf was diagnosed with focal diplomyelia at the level of the fourth lumbar vertebra, a rare congenital malformation of the spinal cord. The calf tested positive for Schmallenberg virus antibodies, however this is not considered to be part of the pathogenesis of the diplomyelia. CONCLUSIONS: This case report adds value to future clinical practice, as it provides a clear description of focal diplomyelia as a previously unreported lesion and details its diagnosis using advanced imaging and histology. This type of lesion should be included in the differential diagnoses when a calf is presented with a general proprioceptive ataxia of the hind limbs. In particular, a 'bunny-hop' gait of the pelvic limbs is thought to be a specific clinical symptom of diplomyelia. This case report is of clinical and scientific importance as it demonstrates the possibility of a focal microscopic diplomyelia, which would not be evident by gross examination alone, as a cause of hind-limb ataxia. The aetiology of diplomyelia in calves remains unclear.

A large deletion in the COL2A1 gene expands the spectrum of pathogenic variants causing bulldog calf syndrome in cattle.

BACKGROUND: Congenital bovine chondrodysplasia, also known as bulldog calf syndrome, is characterized by disproportionate growth of bones resulting in a shortened and compressed body, mainly due to reduced length of the spine and the long bones of the limbs. In addition, severe facial dysmorphisms including palatoschisis and shortening of the viscerocranium are present. Abnormalities in the gene collagen type II alpha 1 chain (COL2A1) have been associated with some cases of the bulldog calf syndrome. Until now, six pathogenic single-nucleotide variants have been found in COL2A1. Here we present a novel variant in COL2A1 of a Holstein calf and provide an overview of the phenotypic and allelic heterogeneity of the COL2A1-related bulldog calf syndrome in cattle. CASE PRESENTATION: The calf was aborted at gestation day 264 and showed generalized disproportionate dwarfism, with a shortened compressed body and limbs, and dysplasia of the viscerocranium; a phenotype resembling bulldog calf syndrome due to an abnormality in COL2A1. Whole-genome sequence (WGS) data was obtained and revealed a heterozygous 3513 base pair deletion encompassing 10 of the 54 coding exons of COL2A1. Polymerase chain reaction analysis and Sanger sequencing confirmed the breakpoints of the deletion and its absence in the genomes of both parents. CONCLUSIONS: The pathological and genetic findings were consistent with a case of "bulldog calf syndrome". The identified variant causing the syndrome was the result of a de novo mutation event that either occurred post-zygotically in the developing embryo or was inherited because of low-level mosaicism in one of the parents. The identified loss-of-function variant is pathogenic due to COL2A1 haploinsufficiency and represents the first structural variant causing bulldog calf syndrome in cattle. Furthermore, this case report highlights the utility of WGS-based precise diagnostics for understanding congenital disorders in cattle and the need for continued surveillance for genetic disorders in cattle.

An unusual presentation of developmental anomalies of the cardiovascular system including tetralogy of fallot, double outlet right ventricle, patent foramen ovale and persistent right aortic arch in a Friesian calf.

BACKGROUND: Congenital heart diseases are occasionally encountered in the bovine species. Ventricular septal defects (VSD) and atrial septal defects (ASD) are reported to be the most common; however, a vast collection have been reported [1, 2]. Congenital heart diseases is thought to represent less than 3% of all congenital abnormalities in calves [3]. Various cardiac anomalies arise due to defective embryologic development such as defects of the septae or the cardiac chambers [2]. The exact aetiology of these congenial heart anomalies remains to be fully elucidated [4]. VSDs appear to be the most common congenital cardiac anomaly in calves. Other diseases can be subdivided into cyanotic (e.g. ASD or patent ductus arteriosus) and non-cyanotic (e.g. tetralogy of fallot or eisenmengers complex) [5, 6]. An exceptional presentation of an array of congenital anomalies was identified in a Friesian heifer calf. To the authors' knowledge this concurrent collection of congenital abnormalities has never been reported in this species. CASE PRESENTATION: A 3-day old Friesian heifer presented with a history since birth of regurgitation post feeding. The main finding on clinical examination was tachypnoea with a holosystolic murmur. Echocardiography identified a VSD, patent foramen ovale (PFO) (both with left to right blood flow) and tricuspid insufficiency. The calf was subsequently euthanised and underwent gross post-mortem examination. A persistent right aortic arch (PRAA) was identified. The cardiac anomalies identified on the echocardiogram were confirmed along with additional abnormalities; double outlet right ventricle (DORV), partial transposition of the great vessels, pulmonic stenosis, hypoplasia of the right branch of the pulmonary artery and right ventricular hypertrophy. The final diagnosis was Tetralogy of Fallot with DORV, PFO and PRAA. The lungs appeared oedematous and congested due to cardiac malfunction and cranioventral aspiration pneumonia. Free serous fluid was identified in the thoracic cavity. Unilateral renal agenesis of the left kidney was an incidental finding but is of note due to its coexistence with the cardiac abnormalities. CONCLUSIONS: This is an unusual case as it features numerous congenital abnormalities that appeared to negate each other allowing capability with life. To the authors' knowledge, this collection of concurrent cardiac anomalies has not been previously reported in bovines.

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.

Arthrogryposis multiplex congenita in Aberdeen Angus cattle in Uruguay / Artrogripose múltipla congênita em bovinos Aberdeen Angus no Uruguai

Arthrogryposis multiplex congenita is reported for the first time in the Aberdeen Angus (AA) breed in Uruguay. In a commercial herd of 30 purebred Aberdeen Angus cows, two calves with severe musculoskeletal malformations died at birth. The cows had been inseminated using semen imported from Argentina from one elite AA sire only. At necropsy, one calf showed severe muscular atrophy, arthrogryposis affecting all four limbs and the spine, kyphoscoliosis and torticollis. Histopathology showed muscular atrophy with marked fiber size variation and abundant fibroadipose fibers. The central nervous system only showed congestion and edema due to dystocia, whereas the peripheral nerves and the number of motor neurons in the spinal appeared normal. DNA analysis confirmed arthrogryposis multiplex congenita. It is concluded that disease in Aberdeen Angus cattle is due to failure in the neuromuscular junction.(AU)

Artrogripose múltipla congênita é relatada pela primeira vez em bovinos Aberdeen Angus (AA) no Uruguai. Num rebanho comercial de 30 vacas a Aberdeen Angus, dois bezerros com graves malformações musculoesqueléticas morreram logo após o nascimento. As vacas foram inseminadas utilizando sêmen importado da Argentina, de apenas um touro de elite de AA. Na necropsia, um dos bezerros apresentava atrofia muscular grave, artrogripose afetando todos os quatro membros e a coluna vertebral, cifoscoliose e torcicolo. A histopatologia demonstrou atrofia muscular com acentuadas variações no tamanho das fibras e abundantes fibras fibroadiposas. O sistema nervoso central apresentava apenas congestão e edema devido à distocia, enquanto os nervos periféricos e o número de neurônios motores na medula espinhal pareciam normais. A análise de DNA confirmou artrogripose múltipla congênita. Concluiu-se que a doença em bovinos Aberdeen Angus se deve a falha na junção neuromuscular.(AU)

Study of congenital Morgagnian cataracts in Holstein calves.

Cataracts are focal to diffuse opacities of the eye lens causing impaired vision or complete blindness. For bilateral congenital cataracts in Red Holsteins a perfectly cosegregating mutation within the CPAMD8 gene (CPAMD8:g.5995966C>T) has been reported. We genotyped the CPAMD8:g.5995966C>T variant in Holstein calves affected by congenital bilateral congenital cataracts, their unaffected relatives and randomly selected herd mates. Ophthalmological examinations were performed in all affected individuals to confirm a congenital cataract. Whole genome sequencing was employed to screen variants in candidate genes for the Morgagnian cataract phenotype. In the present study, 3/35 cases were confirmed as homozygous mutated and 6/14 obligate carriers. Further 7/46 unaffected animals related with these cases were heterozygous mutated for the CPAMD8:g.5995966C>T variant. However 32 cases with a congenital cataract showed the wild type for the CPAMD8 variant. We did not identify variants in the candidate genes CPAMD8 and NID1 or in their close neighborhood as strongly associated with the congenital cataract phenotype in Holstein calves with the CPAMD8 wild type. In conclusion, the CPAMD8:g.5995966C>T variant is insufficient to explain the majority of Morgagnian congenital cataract phenotypes in Holsteins. It is very likely that congenital bilateral cataracts may be genetically heterogeneous and not yet known variants in genes other than CPAMD8 and NID1 are involved.

Clinical and postmortem findings of pentalogy of Fallot in an 18-month-old Holstein heifer.

An 18-month-old female Holstein Friesian heifer presented with a history of stunted growth and a recent onset of anorexia; she presented with cyanosis and eventually died. A postmortem examination revealed obstruction of the right ventricular outflow tract, ventricular septal defect, overriding aortic root, right ventricular hypertrophy, and an atrial septal defect, indicating a pentalogy of Fallot (POF). In addition to POF, the heifer also had pulmonary artery dilatation, although she did not present with patent ductus arteriosus. This heifer had the longest lifespan among the Holstein cattle reported to have POF, which may be secondary to delayed pulmonary obstruction due to deformation of one of the pulmonary valves.

Congenital hypotrichosis in a Simmental cross heifer.

BACKGROUND: Congenital hypotrichosis is defined as a less than normal amount of hair, obvious at birth or in the first weeks of life. Causes are nongenetic or genetic. OBJECTIVES: To describe the clinical presentation and histological features of a novel form of hypotrichosis in a heifer. ANIMAL: A 15-month-old Simmental cross-bred heifer was presented with a history of progressive hair loss, which started at four months of age and progressed to severe generalized hypotrichosis. METHODS AND MATERIALS: Anamnestic data, detailed clinical examination, haematological investigation, selected biochemistry profile, RT-PCR and ELISA for bovine viral diarrhoea virus did not suggest a cause for the hypotrichosis; skin samples were examined histologically. RESULTS: Histopathology of the skin showed a 50% reduction in the number of hair follicles and dysplastic hair follicles; these findings led to a diagnosis of congenital hypotrichosis. The distribution of the hair and some of the histopathological characteristics were potentially consistent with viable hypotrichosis. A marked reduction in follicle density, hypertrophy of sebaceous glands, hypoplasia of arrector pili muscles and moderate acanthosis with hyperkeratosis, which have not been described previously in viable hypotrichosis or other forms of congenital hypotrichosis, were also observed. CONCLUSION AND CLINICAL SIGNIFICANCE: This case may represent a novel form of congenital hypotrichosis.

[Melanosis of adipose tissue in a 17-month-old German Fleckvieh bull (Bos taurus)]. / Melanose von Fettgewebe bei einem 17 Monate alten Stier der Rasse Deutsches Fleckvieh (Bos taurus).

At meat inspection of a 17-month-old bull (German Fleckvieh), patchy dark discoloration of various organs and tissue sites was noted that was most prominent in perirenal adipose tissue. Microscopic analysis revealed melanosis, that is a congenital melanocytic dystopia, as the underlying cause. To the best of our knowledge, this is the first case of melanosis detected in adipose tissue in cattle. We speculate that there is a possible pathogenetic link between obesity and melanosis in the animal.

Imaging and genetic investigations of neural tube defect in a calf: case report and review of the literature.

A 15-d-old female crossbreed calf was referred because of paraplegia since birth. Clinical examination revealed a skin defect covered by hair on the dorsal midline in the thoracic area of the spine. Thoracolumbar spinal cord neuroanatomic localization was determined based on neurologic examination. Computed tomography of the thoracolumbar spine revealed incomplete fusion of the vertebral arches from T6 to T10 and duplication of the vertebral arch of T7. At the level of T6-T7, duplication of the spinal cord with 2 segments completely separated by a septum of hyperattenuating, probably cartilaginous, tissue was noted. Histologically, the spinal segments had different degrees of duplication. Three central canals were detected in one region. Genetic investigation for the presence of methylenetetrahydrofolate reductase (MTHFR) polymorphism, which has been investigated in both human and veterinary medicine as a possible cause of neural tube defects and abortion, was carried out and was negative in both the calf and her dam.