Semen Collection and Evaluation in Two Tigers (Panthera tigris) and Two Leopards (Panthera pardus)

Assisted reproduction techniques play a significant role in veterinary medicine, and although they are widely used in domestic animals, they are also becoming increasingly relevant in clinical practice for wild felids, especially in the conservation efforts for endangered species. In this study, the result of two semen collection techniques, urethral catheterization after pharmacological induction (Ur.Ca.P.I.) and electroejaculation, are described, aiming to provide new practical information about sperm collection using the Ur.Ca.P.I. technique and electroejaculation in tigers and leopards, describing the authors' experience and presenting new data and observations. The following descriptive study included two subjects of Panthera tigris species and two of Panthera pardus. These subjects, after general anesthesia, underwent sperm collection initially with Ur.Ca.P.I. and, subsequently, with electroejaculation. Sampling was made possible in both species thanks to the use of electroejaculation. Sperm volumes in leopards ranged from 0.3 to 0.5 mL and in tigers from 0.5 to 2.177 mL. Sperm concentration in leopards ranged from 136 × 10⁶ to 280 × 10⁶ sperm/mL, and in tigers, from 21.5 × 10⁶ to 354 × 10⁶ sperm/mL. Urethral catheterization gave positive results in leopards, with sperm volumes ranging from 25 up to 150 µL and a concentration ranging from 110 × 10⁶ up to 1082 × 10⁶ sperm/mL. In tigers, unlike in leopards, the use of the Ur.Ca.P.I. technique encountered difficulties that did not allow satisfactory results to be obtained. Therefore, it would be useful to test the feasibility of urethral catheterization on a larger group of individuals in order to have more meaningful feedback. Finally, because electroejaculation always allowed semen collection in tigers, with a higher sperm quality than samples collected by Ur.Ca.P.I., we currently consider it the technique of choice for the collection of semen material in this species.