An antigen capture ELISA test using monoclonal antibodies for the detection of Mycoplasma californicum in milk

The use of monoclonal antibodies to detect Mycoplasma californicum was investigated in an antigen capture microtitre format. The finalized test was highly specific and no cross-reactions were detectable with any of the mastitis associated mycoplasma or bacterial antigens tested. Using a concentration step involving centrifugation, the sensitivity of the test could be improved from 10(5)-10(7) to 10(3)-10(5) colony forming units per ml with pure broth cultures, and from 10(7) to at least 10(6) colony forming units per ml in milk samples from two experimentally infected cows. The antigen detected was partially identified by immunoblotting, which demonstrated two polypeptides of 40 and 46 kD.     

Randomized blind trial of a commercial FeLV vaccine

A randomized blind trial of a commercial FeLV vaccine was conducted to evaluate its performance in cats under conditions of long-term natural exposure. Seventy-nine nonviremic, seronegative cats were randomized into 2 groups. Cats were given 3 doses of either FeLV vaccine or placebo (killed rabies virus vaccine) sc at weeks 0, 3, and 9 of the trial. Six weeks later, 44 known-viremic cats were added to the colony. Cats were housed in a single large room and food dishes and litter pans were used in common. Blood samples were collected at 4, 8, and 12 months after the addition of the viremic cats and were assayed for viremia by use of ELISA. Twelve-month samples were also assayed independently by use of indirect fluorescent antibody testing. Investigators conducted assays on coded samples without knowledge of the cat's vaccination status; neither the investigators nor colony personnel knew which cats had been given the FeLV vaccine and which had been given the placebo until the twelfth month of exposure. After 12 months of cohabitation with infected cats, vaccinated cats had a significantly (P less than or equal to 0.02) lower incidence of persistent viremia (defined as 2 positive ELISA test results at least 8 weeks apart or 1 positive indirect fluorescent antibody test result), compared with the placebo-inoculated cats. The incidence of persistent viremia was approximately 3 times greater among the placebo-inoculated cats than among vaccinates.     

Shedding of Mycobacterium bovis in the nasal mucus of cattle infected experimentally with tuberculosis by the intranasal and intratracheal routes

Four groups of six calves were infected experimentally with either a low dose of approximately 10(4) colony-forming units (cfu) or a high dose of approximately 10(6) cfu of Mycobacterium bovis. Each dose was delivered by the intranasal and intratracheal routes. More severe disease was observed in the groups inoculated with the high dose. Visible lesions were identified in 21 of the 24 animals, all of which also gave positive skin tests and interferon-gamma (IFN-gamma) responses. Nasal shedding was detected in 15 of the 24 animals and the frequency of shedding was influenced by both the route and the dose of infection; no shedding was observed in the group infected intratracheally with the low dose. Two of the 15 confirmed shedders had no visible lesions at postmortem examination; both of these calves gave IFN-gamma responses but only one was skin test positive.     

Canine viral enteritis. Recent developments.

Two apparently novel viral gastroenteritides of dogs were recognized in 1978: one caused by a parvo-like virus (CPV) and one by a corona-like virus (CCV). A rotavirus has also been tentatively associated with neonatal pup enteritis. Canine viral enteritis is characterized by a sudden onset of vomiting and diarrhea, rapid spread and high morbidity. Treatment is only supportive but must be initiated promptly. Infected animals should be isolated immediately; the extremely contagious nature of these diseases makes them difficult to contain. Feces from infected dogs appear to be the primary means of transmission. Sodium hypochlorite solutions (eg, Clorox) are recommended for disinfection. The development of effective vaccines is an immediate and pressing problem.     

Mycobacterium nonchromogenicum in nasal mucus from cattle in a herd infected with bovine tuberculosis

Skin test negative cattle from a herd containing an unusually high proportion (194/382) of tuberculin skin test positive cattle were investigated for remaining Mycobacterium bovis infected animals. Blood samples from the skin test negative cattle, analysed by an antibody ELISA and an interferon-gamma assay, were mostly test negative for M. bovis. Radiometric culture of nasal mucus samples from 48 of the cattle yielded 22 culture positives with acid-fast bacilli and cording in 6 of these. Subculture on solid media was successful for 7, including 2 with cording of the 22 radiometric culture positives. Mycobacterium tuberculosis complex DNA probe testing using the Accuprobe (Gen-Probe, Inc.) and M. tuberculosis complex-specific PCR amplification, performed on the solid media subcultures, were negative. 16S rRNA PCR and sequence analysis were successful for 6 of the 7 solid media subcultures obtained and revealed the presence of Mycobacterium nonchromogenicum in all 6 subcultures. This is the first report of M. nonchromogenicum in nasal mucus of cattle. The observation highlights the importance of integrating definitive tests such as the PCR for diagnosis of bovine tuberculosis and indicates a possible zoonotic risk.     

A comparison of florfenicol and tulathromycine for the treatment of undifferentiated fever in feedlot calves

The purpose of this study was to compare the relative cost-effectiveness of florfenicol with that of tulathromycin for treatment of undifferentiated fever (UF) in feedlot calves at ultra-high risk of developing UF that receive metaphylactic tulathromycin on arrival at the feedlot. Calves that received therapeutic florfenicol had lower overall mortality (P=.045) and bovine respiratory disease mortality (P=.050) compared with calves that received therapeutic tulathromycin, but no significant differences were detected in feedlot performance, carcass characteristics, or other animal health variables. There was a net advantage of Can$41.19/treated animal in the florfenicol group versus the tulathromycin group. This study demonstrates that it is more cost-effective to use florfenicol than tulathromycin for the initial treatment of UF in feedlot calves at ultra-high risk of developing UF that receive on-arrival metaphylactic tulathromycin.     

Single and multiple-dose pharmacokinetics of tepoxalin and its active metabolite after oral administration to rabbits (Oryctolagus cuniculus)

The anti-inflammatory agent, tepoxalin, was administered to eight healthy 6-month-old female New Zealand white rabbits once daily at an oral dose of 10 mg/kg. Blood samples were obtained immediately before and at 0.25, 0.5, 1, 2, 3, 4, 6, 8, 12, and 24 h postadministration on days 1 and 10. Tepoxalin and its active metabolite, RWJ 20142, concentrations were determined in plasma by use of high-performance liquid chromatography with mass spectrometry. C _max of the parent compound was reached between 3 and 8 h of drug administration, with a harmonic mean t _1/2 of 3.6 h. Peak tepoxalin plasma concentrations were 207 ± 49 ng/mL. After oral administration, the metabolite RWJ 20142 achieved C _max in plasma 2–8 h after administration, with a t _1/2 of 1.9–4.8 h (harmonic mean 2.8 h). Peak plasma concentrations of RWJ 20142 on day 1 were 2551 ± 1034 ng/mL.     

Transpalpebral eye enucleation in 40 standing horses

Objective— To report a technique for eye enucleation in standing sedated horses and to report outcome in 40 horses.
Study Design— Retrospective study.
Animals— Horses (n=40) requiring eye enucleation.
Methods— The eye was enucleated using a transpalpebral technique in 40 horses restrained in stocks and sedated. Anesthesia of orbital structures was provided by local nerve blocks and infiltration of the surgical site with local anesthetic solution.
Results— Affected eyes were successfully enucleated with the horse standing. Short-term complications included moderate swelling (5 horses) and wound discharge (1). Long-term complications were not observed.
Conclusions— A diseased eye can be safely enucleated with a horse standing.
Clinical Relevance— Enucleating an equine eye in the standing position eliminates the risks and costs of general anesthesia.     

Sclerosing odontogenic carcinoma in the mandible of a horse

A 15-year-old Cob mare was presented for investigation of a mandibular mass. Radiography identified an oval-shaped mass occupying the intramandibular space, with a heterogeneous osseous opacity throughout the left hemimandible. Histopathology combined with immunohistochemistry was consistent with a diagnosis of sclerosing odontogenic carcinoma, which to date has only been described, rarely, in human patients. The mass was removed using a mandibular-sparing surgical technique allowing preservation of the dental arcade. Follow-up 5 years after surgery confirmed no signs of regrowth. This case report describes the successful treatment of a previously unreported mandibular neoplasm in the horse.