A recessive variant is responsible for delayed-onset retinal degeneration in Hereford cattle.

Thirteen American Hereford cattle were reported blind with presumed onset when ~12-mo-old. All blind cattle shared a common ancestor through both the maternal and paternal pedigrees, suggesting a recessive genetic origin. Given the pedigree relationships and novel phenotype, we characterized the ophthalmo-pathologic changes associated with blindness and identified the responsible gene variant.

A de novo mutation in CACNA1A is associated with autosomal dominant bovine familial convulsions and ataxia in Angus cattle.

Bovine familial convulsions and ataxia (BFCA) is considered an autosomal dominant syndrome with incomplete penetrance. Nine Angus calves from the same herd were diagnosed with BFCA within days of birth. Necropsy revealed cerebellar and spinal cord lesions associated with the condition.

White coat color of a Black Angus calf attributed to an occurrence of the delR217 variant of MITF.

A white calf, with minimal pigmented markings, was born to two registered Black Angus parents. Given the possibility of an unknown recessive or de novo dominant mutation, whole-genome sequencing was conducted on the trio of individuals. A 3-bp in-frame deletion in MITF was identified; this mutation was unique to the calf but identical to the delR217 variant reported in both humans and murine models of Waardenburg syndrome type 2A and Tietz syndrome.

Mandibulofacial Dysostosis Attributed to a Recessive Mutation of in Hereford Cattle.

In spring 2020, six Hereford calves presented with congenital facial deformities attributed to a condition we termed mandibulofacial dysostosis (MD). Affected calves shared hallmark features of a variably shortened and/or asymmetric lower mandible and bilateral skin tags present 2-10 cm caudal to the commissure of the lips. Pedigree analysis revealed a single common ancestor shared by the sire and dam of each affected calf.

Investigation of congestive heart failure in beef cattle in a feedyard at a moderate altitude in western Nebraska.

Right-sided congestive heart failure (brisket disease) commonly occurs in cattle raised at elevations >2,500-3,500 m. We investigated clinical cases resembling brisket disease at a western Nebraska feedyard at a moderate altitude (1,369 m). Over a 15-mo period (2009-2010), we examined 17 cases (16 steers and 1 heifer), all purebred Angus.

Evidence for a de novo, dominant germ-line mutation causative of osteogenesis imperfecta in two Red Angus calves.

A genetic disorder, osteogenesis imperfecta (OI) is broadly characterized by connective tissue abnormalities and bone fragility most commonly attributed to alterations in Type I collagen. Two Red Angus calves by the same sire presented with severe bone and dental fragility, blue sclera, and evidence of in utero fractures consistent with OI congenita. Comparative analyses with human cases suggested the OI in these calves most closely resembled that classified as OI Type II.

Experimental acute infection of alpacas with Bovine viral diarrhea virus 1 subgenotype b alters peripheral blood and GALT leukocyte subsets.

Bovine viral diarrhea virus (BVDV) is a pathogen in cattle and alpacas ( Vicugna pacos), causing acute and persistent BVDV infections. We characterized the effect of acute BVDV infection on the immune system of alpacas by determining lymphocyte subpopulations in peripheral blood and gut-associated lymphoid tissues (GALT) as well as serum interferon levels. Alpacas were experimentally infected with BVDV-1b (strain CO-06).

Distribution of lymphoid depletion and viral antigen in alpacas experimentally infected with Bovine viral diarrhea virus 1.

It was hypothesized that acute postnatal Bovine viral diarrhea virus 1 (BVDV-1) infection leads to leukopenia and lymphoid depletion of gut-associated lymphoid tissues similar to acute disease in calves. The objectives of the current study were to characterize the pathologic effects, viremia, viral shedding, and viral antigen deposition in 6-24-month-old, acutely infected alpacas following experimental infection with noncytopathic BVDV-1 subgenotype 1b (BVDV C0-6). The BVDV-1 isolate was obtained from a cria with naturally occurring persistent infection.

A deletion mutation in bovine SLC4A2 is associated with osteopetrosis in Red Angus cattle.

Background: Osteopetrosis is a skeletal disorder of humans and animals characterized by the formation of overly dense bones, resulting from a deficiency in the number and/or function of bone-resorbing osteoclast cells. In cattle, osteopetrosis can either be induced during gestation by viral infection of the dam, or inherited as a recessive defect. Genetically affected calves are typically aborted late in gestation, display skull deformities and exhibit a marked reduction of osteoclasts.

Effect of the viral protein N(pro) on virulence of bovine viral diarrhea virus and induction of interferon type I in calves.

Objective: To characterize the influence of the viral protein N(pro) on virulence of bovine viral diarrhea virus (BVDV) and on type I interferon responses in calves.

Animals: 10 calves, 4 to 6 months of age.

Procedures: BVDV virulence and type I interferon responses of calves (n = 5) infected with a noncytopathic BVDV with a deleted N(pro) were compared with those of calves (5) infected with a noncytopathic BVDV with a functional N(pro).

Prevalence of bovine viral diarrhea virus infections in alpacas in the United States.

Objective: To determine the prevalence of bovine viral diarrhea virus (BVDV)-infected alpaca herds in the United States and investigate factors associated with seropositive herd status and, subsequently, determine the proportion of animals within seropositive alpaca herds that are persistently infected (PI) carriers for BVDV, obtain information regarding previous herd exposure to BVDV, determine titers of anti-BVDV antibodies of dams, and ascertain whether individual seropositive crias had received supplemental colostrum at birth.

Design: Prevalence study.

Animals: 63 alpaca herds with >or= 12 registered female alpacas.

Characterization of protection against systemic infection and disease from experimental bovine viral diarrhea virus type 2 infection by use of a modified-live noncytopathic type 1 vaccine in calves.

Objective: To evaluate protection resulting from use of a modified-live noncytopathic bovine viral diarrhea virus (BVDV) type 1 vaccine against systemic infection and clinical disease in calves challenged with type 2 BVDV.

Animals: 10 calves, 5 to 7 months of age.

Procedures: Calves were allocated (n = 5/group) to be nonvaccinated or vaccinated SC on day 0 with BVDV 1 (WRL strain).

Defective splicing of Megf7/Lrp4, a regulator of distal limb development, in autosomal recessive mulefoot disease.

Mulefoot disease (MFD) is an autosomal recessive disorder of phenotypically variable expression that causes syndactyly in certain strains of cows. MFD maps to a narrow interval on bovine chromosome 15 that is syntenic to human chromosome 11p12-p11.2.

Herd-level risk factors for Neospora caninum seroprevalence in dairy farms in southern Brazil.

A cross-sectional study was used to test the relationship between herd seroprevalence to Neospora caninum and various potential herd-level risk factors in 60 dairy farms located in two distinct regions in southern Brazil. Thirty farms were randomly selected from within each region. A questionnaire was designed to summarize each farm's production system as it might relate to N.

Characterization of protection from systemic infection and disease by use of a modified-live noncytopathic bovine viral diarrhea virus type 1 vaccine in experimentally infected calves.

Objective: To evaluate protection against systemic infection and clinical disease provided by use of a modified-live noncytopathic bovine viral diarrhea virus (BVDV) type 1 vaccine in calves challenged with NY-1 BVDV.

Animals: 10 calves, 5 to 7 months of age.

Procedures: Calves were allocated (n = 5/group) to be nonvaccinated or vaccinated SC on day 0 with BVDV type 1 (WRL strain).

Outcome of equids with clinical signs of West Nile virus infection and factors associated with death.

Objective: To determine outcome of equids in the western United States with clinical signs of West Nile virus (WNV) infection and identify factors associated with risk of death in infected equids.

Design: Cross-sectional study.

Animals: 484 equids in Nebraska and Colorado.

Parelaphostrongylus tenuis in captive pronghorn antelope (Antilocapra americana) in Nebraska.

Lesions in four captive pronghorn antelope (Antilocapra americana) naturally infected with Parelaphostrongylus tenuis in eastern Nebraska (USA) are described in this report. Animals were bright and alert with hind limb ataxia that progressed to sternal or lateral recumbency between July 28 and October 17, 1998. Animals were euthanized due to disease progression despite therapy.

Comparative virulence of isolates of bovine viral diarrhea virus type II in experimentally inoculated six- to nine-month-old calves.

Objective: To determine the comparative virulence of 5 isolates of bovine viral diarrhea virus (BVDV) type II by inoculating 6- to 9-month-old beef calves with isolates originating from the tissues of cattle affected with naturally occurring, transient, acute, nonfatal infections or naturally occurring, peracute, fatal infections.

Animals: 22 calves that were 6 to 9 months old.

Procedure: The study used BVDV isolates 17011, 713, and 5521 that originated from fetuses aborted from cows with transient, nonfatal, acute BVDV infections and isolates 23025 and 17583 that originated from the tissues of cattle with peracute, fatal BVDV infections.

Effect of infection with bovine viral diarrhea virus alone, bovine rotavirus alone, or concurrent infection with both on enteric disease in gnotobiotic neonatal calves.

Objective: To compare experimentally induced concurrent infection with bovine viral diarrhea virus (BVDV) and bovine rotavirus (BRV) with infection of either virus alone in calves.

Animals: Seventeen 1-day-old gnotobiotic calves.

Procedure: Calves were allotted to 8 treatments as follows: group 1, mock-infected control calves (n = 2); group 2, inoculated with BVDV on day 1 (2); groups 3, 5, and 7, inoculated with BRV on days 1 (2), 4 (1), or 7 (2), respectively; and groups 4, 6, and 8, inoculated with BVDV on day 1 and with BRV on days 1 (2), 4 (2), or 7 (4), respectively.

A familial degenerative neuromuscular disease of Gelbvieh cattle.

A degenerative skeletal muscle disease with vascular, neurologic, and renal lesions and a probable familial distribution was identified in 4-20-month-old purebred Gelbvieh cattle. Thirteen affected animals were confirmed from 6 separate beef herds, with a mortality rate of 100%. Clinical signs in affected animals consisted of ataxia, weakness, and terminal recumbency.