Abstract. This study charted 237 fatal cases of bovine respiratory disease (BRD) observed from

Between 1994 and 2002, a total of 390 (46.3%) Mannheimia haemolytica, 292 (34.7%) Pasteurella multocida, and 160 (19.0%) Histophilus somni were isolated at the Oklahoma Animal Disease Diagnostic Laboratory from lungs from 6–18-month-old beef cattle with pneumonia. The ratio of M. haemolytica isolations to P. multocida isolations decreased from 3.1 in 1994 to 0.8 in 2000 while increasing to 1.5 in 2002. Mannheimia haemolytica isolations significantly ( P < 0.05) decreased from 62.5% in 1994 to between 30.6% and 50.4% in 1998–2002. Pasteurella multocida isolations significantly ( P < 0.05) increased from 20.0% in 1994 to between 28.6% and 47.4% in 1998–2002. Histophilus somni isolations were <19% except in 1998 (40.8%) and 1999 (23%). Antimicrobial susceptibilities for M. haemolytica significantly declined for erythromycin ( P = 0.0001), florfenicol ( P = 0.0004), spectinomycin ( P = 0.0001), and tilmicosin ( P = 0.03). For P. multocida, antimicrobial susceptibilities significantly declined for erythromycin ( P = 0.0001), florfenicol ( P = 0.004), spectinomycin ( P = 0.03), sulfachloropyridizine ( P = 0.028), tetracycline ( P = 0.017), tilmicosin ( P = 0.0001), and trimethoprim/sulfamethoxazole ( P = 0.0003). Antimicrobial susceptibilities for H. somni were variable for spectinomycin and sulfachloropyridizine, whereas susceptibilities to other antibiotics remained consistently high.

These results should help direct future research with regard to investigation of risk factors for equine MRSA infection in community and hospital populations.

Eleven cats from 10 different households or catteries were diagnosed with Bordetella bronchiseptica (B. bronchiseptica) infections. Seven cases proved fatal, in which B. bronchiseptica pneumonia was a primary or significant cause of death. The majority of cases (seven of 11) were in kittens less than eight weeks old. A universal complaint was coughing. Bacterial cultures from transtracheal washes or lung tissue were successful in diagnosing bordetellosis in all cases. This report indicates that B. bronchiseptica should be a consideration in a cat presenting with a primary complaint of coughing and may be a relatively common disease in catteries or shelter environments.