Acid-base balance and ventilation during sternal and lateral recumbency in field immobilized black rhinoceros (Diceros bicornis) receiving oxygen insufflation: a preliminary report.

Posture, ventilation, and acid-base balance using auricular venous blood values (pH, lactate, base excess [BE], HCO(3)(-), PO(2), SO(2), and PCO(2)), oxygen saturation of hemoglobin (SpO(2)), and end-tidal carbon dioxide (P(ET)CO(2)) were compared between sternal (STE) and lateral (LAT) recumbency in free-ranging black rhinoceros (Diceros bicornis bicornis) receiving oxygen insufflation. Data are reported as median, minimum, and maximum (median [minimum, maximum]). Thirty-six desert-adapted black rhinoceros (20 male, 16 female; age 8 [1.5, 33] yr) were immobilized in Namibia in March and April of 2008, from a helicopter, by remote intramuscular injection with etorphine HCl, azaperone, and hyaluronidase. Time from darting to recumbency was 6.0 (3, 15.5) min. Data were organized into two sampling periods: sample period 1 (P1, collected within 0-20 min postdarting; 13 [6.5, 19] min) and sample period 2 (P2, collected between 20-40 min postdarting; 32 [22.3, 39] min). All animals were acidemic (pH 7.24 [7.07, 7.32]) and hypoxemic (PO(2) 51 [38, 95.2]; SO(2) 78 [64, 96] mmHg) after capture. Lactate at P1 was 7.2 (3.2, 16.8) mmol/l and decreased (P=0.01) to 4.6 (1.2, 10.9) mmol/l at P2. At P2, lactate was less (P=0.06) in LAT 3.5 (1.2, 8.6) mmol/l than in STE posture 7.4 (3.1, 10.9) mmol/l. In P2, PO(2), SO(2), and SpO(2) were higher (P=0.02, 0.10, and 0.01, respectively) in STE than in LAT. End-tidal carbon dioxide in LAT was 38 (26, 47) mmHg and increased (P<0.001) rapidly to 48 (37, 55) mmHg when animals were moved into STE; no corresponding change in PCO(2) was observed. These preliminary findings suggest that STE posture in recumbent black rhinoceros reduces dead-space ventilation and improves oxygenation. Lateral posture was associated with lower blood lactate, quicker lactate recovery, or both. It is possible that the posture of recumbent rhinoceros after capture affects lactate accumulation and clearance, or both, and procedures should consider positioning in order to enhance perfusion.

First Report of Asian Soybean Rust Caused by Phakopsora pachyrhizi on Kudzu in South Africa.

Asian soybean rust was first reported on soybean in South Africa (SA) in 2001 (3). The disease has occurred in all ensuing seasons, particularly in the humid, eastern production regions, causing significant losses in soybean fields not protected by fungicides. In April 2005, rust-infected Pueraria lobata (kudzu) was detected near Nelspruit, Mpumalanga, SA. At this location (25°20'41″S, 30°43'30″E), kudzu plants occurred abundantly on road sides, edges of pine plantations, and in natural vegetation. Most vines were infected, with abaxial surfaces of older leaves often showing 100% severity. Following inoculation with rust spores collected from kudzu, soybean line PI200492 (Rpp1) produced tan lesions typical of a susceptible reaction for Asian soybean rust. PI230970 (Rpp2), PI462312 (Rpp3), and PI459025 (Rpp4) showed red-brown lesions typical of a resistant reaction. Using Ppm1/Ppa2 and Ppm1/Ppm2 primer combinations, the amplification profiles of the internal transcribed spacer region (1) of rust DNA extracted from primary leaves of line PI200492 infected with spores collected from kudzu positively identified the pathogen as Phakopsora pachyrhizi. The Ppm1/Pme2 primer combination specific for P. meibomiae (1) did not yield an amplification product. The Qualiplate ELISA test kit (EnviroLogix Inc., Portland, ME) verified the identification of P. pachyrhizi on an original kudzu sample as well as the leaf material used for DNA analysis. A survey of kudzu at the Nelspruit site during July 2005 confirmed the presence of the pathogen during the offseason for soybean. At that time, incidence of kudzu rust remained high, but few leaves showed high severity. The susceptibility of kudzu to Asian soybean rust has been reported in controlled infection studies in SA (2). To our knowledge, this is the first report of P. pachyrhizi causing rust on a large, naturally occurring kudzu population in SA. References: (1) R. D. Frederick et al. Phytopathology 92:217, 2002. (2) A. Nunkumar. M.Sc. thesis. University of KwaZulu-Natal, South Africa, 2006. (3) Z. A. Pretorius et al. Plant Dis. 85:1288, 2001.