Success rate and complication prevalence of peripheral catheterization of the cephalic, lateral saphenous and marginal ear veins in pet rabbits

Background

Intravenous catheter placement is a routine procedure in exotic pet medicine, yet the selection of the optimal venous site for catheterization in rabbits (Oryctolagus cuniculus) remains controversial. Recommendations differ between countries and authors, and lack evidence-based data. This prospective study aimed to document and compare the prevalence and types of complications secondary to peripheral venous catheterization in domestic rabbits as related to the vein catheterized.

Methods

Catheterization events (n = 151) were randomly attributed to three groups, named according to the venous site selected: cephalic (n = 39), lateral saphenous (n = 58) and marginal ear vein (n = 54). Rabbits that needed a catheter for fluid therapy, surgery, or imaging, were included in the study. Catheters were placed by three veterinarians following a standardized method. Data regarding the patient, the type of catheter, and the treatment were recorded. Complications were evaluated every day after the catheter placement, at removal and after 15 days.

Results

Minor complications that were observed included catheters which were bent at the elbow or removed by the rabbit, and twisted or chewed tubing. Ear necrosis and signs of phlebitis were considered major complications. Catheter placement failure was significantly higher in the “cephalic” group (odds ratio = 4, 95% Confidence Interval = [16.67,1.04], P = 0.048), without differences between the operators. For the marginal ear vein, there was also a significant association between the failure rate and the length of the rabbit's ear (Wilcoxon effect size = 0.42, 95% CI = [0.14,0.64], P = 0.003). No major complication was observed in any groups. Minor complications occurred without significant differences between the groups.

Conclusions and clinical relevance

The results suggest that intravenous catheters in rabbits do not carry significant complications irrespective of the chosen site, but cephalic vein placement carries the highest risk of failure.