Successful Laparoscopic Oviductal Artificial Insemination in the Endangered Tsushima Leopard Cat (Prionailurus bengalensis euptilurus)

Abstract

The Tsushima leopard cat (Prionailurus bengalensis euptilurus) is an endangered wild felid that lives solely on Tsushima Island, Nagasaki, Japan. Japan's Ministry of the Environment is working with the Japanese Association of Zoo and Aquariums for ex situ conservation of this species. However, considering genetic diversity, it is difficult to conduct captive breeding programs by natural breeding alone; hence, assisted reproductive technologies are required. This study aimed to breed Tsushima leopard cats, which otherwise cannot be paired, using laparoscopic oviductal artificial insemination (AI). Female Tsushima leopard cats (female 1, aged 7 years; female 2, aged 6 years) were treated with 200 IU equine chorionic gonadotropin, followed by administration of 1000 IU porcine luteinizing hormone (pLH) after 96 h to induce ovulation. Laparoscopic AI was performed 32 h post-pLH administration. Females 1 and 2 were inseminated in the oviduct with 2.4 × 10⁶ and 3.3 × 10⁶ motile spermatozoa, respectively, collected from two males. Pregnancy was confirmed by radiography 45 and 51 days post-AI in females 1 and 2, respectively; one fetus was found in female 2. Moreover, female 2 had spontaneous delivery of a female kitten 66 days post-AI. This is the first successful case of AI in a Tsushima leopard cat.

Keywords: Tsushima leopard cat; equine chorionic gonadotropin; ex situ conservation; laparoscopic oviductal artificial insemination; porcine luteinizing hormone.

Figure 1

Laparoscopic view of intraoviductal artificial insemination (AI) using the AI needle. The white arrow indicates the position of the left ovary. Bar = 10 mm.

Figure 2

Fecal hormone concentrations of the two female Tsushima leopard cats studied. The blue line represents estradiol-17β (E2), whereas the orange line represents progesterone (P4). Day 0 indicates the day of artificial insemination (AI). The day of administration of each equine chorionic gonadotropin (eCG) and porcine luteinizing hormone (pLH) are noted for each female.

Figure 3

Representative pictures of the ovary observed through laparoscopy in the two Tsushima leopard cats after stimulation with 200 IU equine chorionic gonadotropin followed by 1000 IU porcine luteinizing hormone (pLH) 96 h later. Observations were made 32 h post-pLH administration: (a) female 1, right ovary; (b) female 2, left ovary. White arrow and black arrow indicate follicles (diameter, ≥2 mm) and corpus hemorrhagicum, respectively. Bar = 10 mm.

Figure 4

(a) Pregnancy diagnosis by radiography 51 days post-AI is confirmed by mineralized skeleton of a fetus (white circle). (b) Image of the Tsushima leopard cat kitten two days after birth.