197-200
Renal Agenesis in New Zealand White Rabbit
by Anjan J. Nath, Ramesh C. Juyal, R Venkatesan, MJ Mahesh Kumar & P Nagarajan

This report describes some cases of unilateral renal agenesis, a congenital anomaly, in a breeding colony of New Zealand white rabbits, detected on physical and necropsy examination. The cases show absence of one of the kidneys, without involvement of the other parts of the genitourinary system or any other part of the body. The animals exhibited no clinical sign of renal failure. Serum biochemical and urine analysis of the animals showed a decrease in specific gravity of the urine with slight increase in the blood urea with no marked changes in other blood and urine parameters.

205-210
A Fatal Outbreak of Campylobacter jejuni Enteritis in a Colony of Vervet Monkeys in Kenya
by M Ngotho, RM Ngure, DM Kamau, JM Kagira, C Gichuki, IO Farah, PD Sayer & J Hau

In a group of 50 wild-caught vervet monkeys trapped for experimental studies, 23 developed severe diarrhoea during the quarantine period. While 10 of these responded well to routine treatment with metronidazole, kaomycin and oral electrolytes, 13 initially showed slight improvement but later relapsed. Five of these failed to respond altogether and were euthanised. Fresh faecal samples were collected from the surviving eight monkeys and analysed for microbiology and drug sensitivity. Campylobacter jejuni, sensitive to erythromycin, was isolated from all the faecal samples. Following treatment with erythromycin, seven monkeys recovered fully within ten days but one died before the end of therapy. This study indicates that wild non-human primates may play a significant role as a reservoir of C. jejuni, whereby they may act as natural carriers of this human pathogen. Screening for Campylobacter sp in newly acquired monkeys is advisable as part of the quarantine procedures.

215-221
Leporine Experimental Arthritis Induced by Whole Synovial Fluid from Patients with Rheumatoid Arthritis and Osteoarthritis
by A. Staponas, V. Graziene & L. Leonaviciene

The value of experimental arthritis models in animals depends on their morphological and immunological similarities to rheumatoid arthritis even if they are not exact counterparts of the human diseases. Many uncertainties regarding rheumatoid arthritis pathogenetic mechanisms persist, including unknown factors and the liberation of arthritogenic antigens. The purpose of the study was to compare experimental arthritis in rabbits induced by intra-articular injections of whole synovial fluid obtained from patients with active rheumatoid arthritis and osteoarthritis, which followed sensitization with synovial fluid in complete Freund’s adjuvant. The results showed that rheumatoid synovial fluid-induced arthritis is very reproducible and strikingly similar to the rheumatoid arthritis where the arthritis exacerbations and immunological processes occur all the way from cellular immunity to persistent chronic arthritis.

227-235
Comparison of Blunt Versus Surgical Dissection for Aortic Flow Probe Placement in the Dog
by Z.Y. Peng, L.A.H. Critchley & A.E. James

In animal research placement, of a flow probe on the aorta provides more accurate cardiac output measurements than alternative clinical methods, such as thermodilution. However, good advice on how to place such a probe in the laboratory setting is lacking. In twenty anesthetized dogs midline sternotomy and left thoracotomy approaches to the ascending aorta, using surgical (forceps with scissors) or blunt finger dissection to separate the aorta from the adjacent pulmonary artery (four groups of five dogs), were compared. A Transonic A-probe was placed around the aorta. Hematocrit was compared before and after surgery. The operative site was inspected for bleeding at post mortem. Two dogs died from massive pulmonary artery hemorrhage in the surgical dissection groupings. At post mortem, bleeding around the probe had occurred in five dogs in the surgical dissection groupings. Significant decreases in hemoglobin occurred in the sternotomy and surgical dissection groupings (P<0.05). Thoracotomy with blunt finger dissection to mobilize the aorta was associated with minimal operative blood loss. It was subsequently used successfully for flow probe placement in over fifty dog experiments each lasting 8-12h.

243-252
Refinements for Intragastric Gavage in Rats
by Kai Õkva, Egle Tamoševiciute, Agne Ciziute, Paavo Pokk3, Osvaldas Rukšnas & Timo Nevalainen

Intragastric (IG)-gavage is widely used in laboratory rats in pharmacological, toxicological and pharmacokinetic studies. This technique has been claimed to result in severe stress and a variety of complications. This study was designed to compare the stress response caused by IG-gavage with steel and teflon probes, to determine whether any habituation occurred to repeated gavaging and to find out whether the use of different administration volumes within the recommended range influenced the stress response. Telemetrically registered cardiovascular responses were used to assess the stress-producing effects. During laparoscopy, transmitters with a catheter extending into the abdominal aorta were implanted into the peritoneal cavity of male Wistar rats. IG-gavage induced a significant increase in diastolic and systolic blood pressure and heart rate, lasting for about 40 minutes. IG-gavage with a stainless steel probe induced greater changes in cardiovascular parameters. It can be concluded that teflon probes are preferable because they elicit less discomfort to the animals. Repeating the IG-gavage with a teflon probe daily evoked a decrease of all parameters on the fourth day as compared with the previous days, but this did not occur in the stainless steel group. The volume administered through IG-gavage had significant effects on diastolic blood pressure, systolic blood pressure and heart rate. Surprisingly, volumes of 2 and 4 ml/kg body weight resulted in a greater response in cardiovascular parameters than volumes of 6 and 8 ml/kg. It appears that there is a window of preferred administration volumes. A routine cage change induced an increase in diastolic blood pressure, systolic blood pressure and heart rate comparable to the changes observed after IGgavage. In conclusion, our data indicate that use of IG-gavage with a soft teflon probe and volumes 6 and 8 ml/kg are obvious refinements for the procedure.