Previously, bovine viral diarrhea virus (BVDV) had been found in prolonged testicular infections following acute infection of immunocompetent bulls. The primary purpose of this research was to evaluate the production and maintenance of prolonged testicular infections after exposure to BVDV of seronegative bulls in varying circumstances. The secondary objective was to initiate assessment of the potential for transmission of BVDV via semen of bulls exhibiting a prolonged testicular infection. In total, 10 research trials were conducted. The first trial examined the duration of detectable virus in semen after intranasal inoculation of peri-pubertal bulls. The second to fifth trials examined the potential for prolonged testicular infections resulting from natural exposure of seronegative bulls to persistently infected heifers. In the last five trials, the potential for viral transmission from bulls exhibiting prolonged testicular infections to a small number of exposed animals (n=28) was evaluated. Results of this research demonstrated that prolonged testicular infections could result in detection of viral RNA in semen for 2.75 years with infectious virus grown from testicular tissue 12.5 months after viral exposure. A type 1b strain of BVDV caused prolonged testicular infection after natural exposure of seronegative bulls to a persistently infected heifer. However, transmission of BVDV to susceptible animals was not detected in the final five trials of this research. In conclusion, BVDV can persist in testicular tissue after acute infection for several years, but the potential for viral transmission from these prolonged testicular infections appears to be low.

Currently, a variety of tests are used to detect bovine viral diarrhea virus (BVDV) in persistently infected (PI) cattle. These tests include immunohistochemical staining (IHC), antigen capture enzyme-linked immunosorbent assay (ACE), virus isolation (VI), and reverse transcription-polymerase chain reaction (RT-PCR). However, a lack of methods standardization could compromise the ability to consistently identify animals infected with BVDV. This study evaluated the diagnostic proficiency of current methods for detecting BVDV in infected cattle using intra- and interlaboratory comparisons. Samples were collected from 4 animals more than 7 months of age (2 BVDV negative animals, a PI animal, and a PI animal that previously lacked detectable virus in serum as determined by VI). Samples were submitted to 23 participating diagnostic laboratories using the respective laboratory's standard submission protocol. Samples collected for submission included: 1) serum for ACE, RT-PCR, and VI; 2) whole blood for RT-PCR and VI; and 3) skin biopsies for ACE and IHC. The ACE performed on skin provided the greatest consistency in detecting positive samples and a perfect level of agreement among laboratories. Reverse transcription-polymerase chain reaction and IHC performed well by correctly identifying ≤85% of samples positive for BVDV. Virus isolation performed on serum yielded the lowest consistency in detecting positive samples and the lowest level of agreement. The level of agreement between laboratories for detecting BVDV in persistently infected cattle ranged from perfect to less than expected by chance. The variation between laboratories suggests a need for training opportunities in standardized laboratory protocols and proficiency testing.

Case Description-A 2.5-year-old spayed female Persian cat was evaluated for acute inability to close its mouth.Clinical Findings-A wry-mouth malocclusion was evident, and the right side of the mandible was longer than the left side. The right mandibular tooth row appeared to be lowered. The lower jaw was persistently maintained in an open position. The presumptive diagnosis was open-mouth jaw locking. Diagnostic imaging with computed tomography and 3-dimensional reconstruction was performed for definitive diagnosis and to achieve a better understanding of the lesions. Imaging revealed locking of the right ramus of the mandible, which was displaced ventrolaterally, causing the coronoid process to impinge on the right zygomatic arch.Treatment and Outcome-A bilateral partial ostectomy of the rostroventral margins of the zygomatic arches with an autogenous fat graft implantation was performed. The cat recovered without complications and by the following morning was bright, alert, and responsive and eating canned cat food comfortably. One year after surgery, the owner reported that the cat had continued to function well, was eating normally, and had not had any observed locking episodes since surgery.Clinical Relevance-Unlike radiographic imaging, computed tomography may be used to create 3-dimensional reconstructions of structures in cases of suspected open-mouth jaw locking; improve evaluation of the lesions;, and improve decision-making and client education for diagnosis, treatment options, and prognosis.

The objectives of this research were to evaluate the risk of prolonged testicular infection as a consequence of vaccination of peri-pubertal bulls with a modified-live, noncytopathic strain of BVDV and to assess vaccine efficacy in preventing prolonged testicular infections after a subsequent acute infection. Seronegative, peri-pubertal bulls were vaccinated subcutaneously with an approximate minimum immunizing dose or a 10× standard dose of modified-live, noncytopathic BVDV or were maintained as unvaccinated controls. Forty-nine days after vaccination, all bulls were intranasally inoculated with a noncytopathic field strain of BVDV. Semen and testicular biopsies collected after vaccination and challenge were assayed for BVDV using virus isolation, reverse transcription-nested PCR, or immunohistochemistry and the identity of viral strains was determined by nucleotide sequencing of PCR products. The vaccine strain of BVDV was detected in testicular tissue of vaccinated bulls as long as 134 days after immunization. Prolonged testicular infections with the challenge strain were detected only in unvaccinated bulls as long as 85 days after challenge. Whereas vaccination caused prolonged testicular infection in some bulls, it did prevent subsequent infection of testicular tissue with the challenge strain. This research demonstrates that subcutaneous vaccination of naïve, peri-pubertal bulls with a noncytopathic, modified-live strain of BVDV can result in prolonged viral replication within testicular tissue. The risk for these prolonged testicular infections to cause venereal transmission of BVDV or subfertility is likely to be low but requires further investigation.

A commercial vaccine containing modified-live bovine viral diarrhea virus (BVDV; types 1 and 2) was administered to one group of 22 peripubertal bulls 28 days before intranasal inoculation with a type 1 strain of BVDV. A second group of 23 peripubertal bulls did not receive the modified-live BVDV vaccine before intranasal inoculation. Ten of 23 unvaccinated bulls--but none of the vaccinated bulls--developed a persistent testicular infection as determined by immunohistochemistry and polymerase chain reaction. Results of this study indicate that administration of a modified-live vaccine containing BVDV can prevent persistent testicular infection if peripubertal bulls are vaccinated before viral exposure.

Teaser bulls may be surgically created by penopexy in the ventral perineal region utilizing a 3 inch brass bull nose ring. The technique reported here is a modification of a similar method utilizing a bull ring developed by Dr. Bill Frazee, Coffeyville, KS and utilized in Kentucky by Drs. Jim Crouch, Glasgow, KY and Patty Scharko, University of Kentucky Extension Veterinarian, Lexington, KY. These practitioners place bulls in lateral recumbency, either in range situations with chemical restraint or on a tilt table.

Trichospirura leptostoma is a spirurid nematode that inhabits the pancreatic ducts of the common marmoset, Callithrix jacchus, and other New World primates. This parasite was diagnosed in members of this species at the Marmoset Research Center in Oak Ridge, Tennessee colony after their importation from multiple colonies outside the United States. Animals with few parasites in the pancreas had few tissue changes, whereas those with many parasites had moderate to severe fibrosis replacing exocrine tissue. Trichospirura leptostoma can cause chronic pancreatitis, resulting in subclinical to clinical pancreatic insufficiency and secondary malnutrition. Clinical signs of pancreatic insufficiency in affected marmosets included weight loss (despite good appetite) and increased fecal volume. Because earlier reports did not mention treatments, experimental therapeutic regimens were attempted to eliminate infections from the marmosets. In the clinical studies, different doses and treatment periods with ivermectin and fenbendazole were evaluated for therapeutic efficacy. Fenbendazole given daily at a dosage of 50 mg/kg of body weight by gavage for 14 days was the most effective treatment (PI 0.052). Control of the cockroach vector, as well as treatment of infected animals, is needed to prevent Trichospirura leptostoma-induced disease.

Beginning in the Fall of 1992 the Society for Theriogenology adopted a new form for evaluation of breeding soundness of bulls. To be a satisfactory potential breeder under these guidelines, a bull must pass all four parts of the examination. The four parts consist of an acceptable physical examination, minimum scrotal circumference based on age, minimum progressive motility of 30%, and minimum morphology of 70% normal cells. Failure to meet the standards of any portion of the examination means unsatisfactory or deferred classification. The three possible classifications are satisfactory potential breeder, unsatisfactory potential breeder, or deferred classification. Deferred classification replaced the old classification of questionable potential breeder and allows for reevaluation at a specified time for conditions which might improve.