Overview Of Ultrasound Health Assessments Of Male And Female Giant Pandas

The Berlin Zoo

Ultrasound examinations have been conducted since 1997 in the male and female giant panda at the Berlin Zoo, with and without anaesthesia. Anaesthesia induction was achieved with ketamine hydrochloride (10 mg kg-1 body weight, BW) administered via blowpipe dart injection. Anaesthesia was then maintained using isoflurane gas delivered via a face-mask (2.5-3.0 volume percentage with oxygen flow of 2-4 l per minute). Transabdominal assessments were carried out using a portable ultrasound unit (Sonosite, Inc., Bothell, WA) equipped with a 4-2 MHz convex transducer (Fig. 17.1a). When the animal was assessed fully conscious, the scan head was mounted on an extension rod for safety. The female was behaviourally conditioned to fixate on a handheld

Figure 17.1. Use of ultrasound for health assessments and artificial insemination (AI) of giant pandas at the Berlin Zoo. (a) Transabdominal ultrasound examination for pregnancy diagnosis; (b) transcutaneous and transrectal ultrasound of the female; (c) endoscopic and ultrasound-guided AI; (d) transcutaneous sonogram (3.5 MHz) of the lower abdominal region of the male showing accumulated ascites (As) and free-floating intestinal loops (In, arrow heads); (e) transcutaneous sonogram (3.5 MHz) of the upper abdominal region of the male showing ascites (As) surrounding a liver lobe (Li) containing an anechoic-appearing blood

Figure 17.1. Use of ultrasound for health assessments and artificial insemination (AI) of giant pandas at the Berlin Zoo. (a) Transabdominal ultrasound examination for pregnancy diagnosis; (b) transcutaneous and transrectal ultrasound of the female; (c) endoscopic and ultrasound-guided AI; (d) transcutaneous sonogram (3.5 MHz) of the lower abdominal region of the male showing accumulated ascites (As) and free-floating intestinal loops (In, arrow heads); (e) transcutaneous sonogram (3.5 MHz) of the upper abdominal region of the male showing ascites (As) surrounding a liver lobe (Li) containing an anechoic-appearing blood

Female Pelvic Ultrasound

vessel and part of the gall bladder (GB, arrow heads); (f) transcutaneous sonogram (3.5 MHz) of the female pelvic region showing part of the urinary bladder (Bl) and the uterine body (Ut, arrow heads);

(g) transcutaneous sonogram (3.5 MHz) of the lower abdominal region of the female showing an inactive ovary (Ov, arrow heads);

(h) transcutaneous (3.5 MHz) ultrasound-guided abdominal puncture with needle (Ne) to drain the ascites (As) in the male panda (In, intestine);

(i) drainage of abdominal fluid (AF) from the male panda; (j) transrectal

vessel and part of the gall bladder (GB, arrow heads); (f) transcutaneous sonogram (3.5 MHz) of the female pelvic region showing part of the urinary bladder (Bl) and the uterine body (Ut, arrow heads);

(g) transcutaneous sonogram (3.5 MHz) of the lower abdominal region of the female showing an inactive ovary (Ov, arrow heads);

(h) transcutaneous (3.5 MHz) ultrasound-guided abdominal puncture with needle (Ne) to drain the ascites (As) in the male panda (In, intestine);

(i) drainage of abdominal fluid (AF) from the male panda; (j) transrectal target in the standing position, thus allowing the veterinarian to conduct several consecutive, two-minute ultrasound scanning sessions. This approach was particularly useful for assessing the status of the uterus and confirming no pregnancy after AI.

Transcutaneous and transrectal ultrasound examinations were performed on both sexes during annual physical examinations while each animal was anaesthetised (see Fig. 17.1b). These procedures relied on a portable ultrasound system (Hitachi EUB 405; Physia GmbH, Nei-Isenburg, Germany) equipped with a 3.5-MHz convex transducer (EUP-C 318T) and a miniaturised intraoperative 7.5-MHz ultrasound probe (EUP-F 334). The specific curved linear array transducer was 35 mm long and 12.5 mm wide and had a minimum head of 9 mm at the top and 14 mm at the end. Additionally, a stationary colour-flow Doppler ultrasound unit (HDI1000; ATL Ultrasound, Inc., Bothell, WA) equipped with a miniaturised linear transducer (LI9-5, 5.0-9.0 MHz) was used for imaging the ovarian blood supply. The dimension of this transducer was slightly larger (48 x 18 x 25 mm) but could be introduced easily into the rectum. Both scan heads were inserted using three probe extensions (Arno Schnorrenberg Chirurgiemechanik, Inc., Schonewalde, Germany) as shown in Figure 17.2. The TR-500 (500 mm in length by 12 mm diameter) was developed for use with large carnivores to visualise the uterine horn, ovary, kidney and adrenal gland. The TR-250 (250 mm in length by 12 mm diameter) was used to image the caudal urogenital tract. The TR-150 (150 mm in length by 12 mm diameter) was designed to view scent glands in large felid and ursid species.

Successful AI of giant pandas in China typically relies on a transcervical approach under anaesthesia, whereby catheter passage is aided

(7.5 MHz) ultrasound-guided catheterisation (Ca) of the urinary bladder (Bl) of the male; (k) transrectal sonogram (7.5 MHz) of the caudal part of the elongated spleen (Sp, dotted line) surrounded by omentum; (l) transrectal sonogram (7.5 MHz) of part of the lobulated kidney (Kd); (m) transrectal sonogram (7.5 MHz) of part of a kidney (Kd) showing generalised focal parenchyma degeneration. Arrow heads mark the outer border of three renculi and the central renal blood vessels; (n) transrectal sonogram (7.5 MHz) of an altered iliac lymph node (LN); (o) sonogram (7.5 MHz) of a lymph node near a healthy left adrenal gland (Ad) and the aorta (Ao). The white bar represents 10 mm.

Figure 17.2. Probe extensions (TR-150, TR-250, TR-500) and the 7.5-MHz convex transducer (arrow) used for the transrectal ultrasound examinations.

by using a speculum and insemination tube. Ideally, sperm are deposited into the uterus, but in many cases it is possible to pass the catheter only into the cervix or at the external os. For AI of SB 378 at the Berlin Zoo, a technique using both endoscopy and ultrasound permitted semen deposition directly into the uterus (see Fig. 17.1c). Endoscopic imaging of the cervical portio was used to insert a catheter (5.5 French; Jansen-Anderson Intratubal Transfer Set; Cook Deutschland GmbH, Weyarn-Holzolling, Germany) into the cervix, while transrectal ultrasound facilitated catheter passage through the cervical canal and sometimes into the uterus. As described in more detail below, this approach provided a safe and easy way to place the semen deep within the giant panda's reproductive tract.

Ultrasound also aided reproductive procedures in the male. Transrectal ultrasound was used to monitor catheterisation of the urinary bladder (see Fig. 17.1j) to prepare for semen collection by electroejaculation. Urine was removed using a flexible 10-French embryo-flushing catheter (Cook Veterinary Products Australia, Inc.,

Banyo, QLD, Australia) and the bladder refilled with 50 ml of culture medium (Medium 199; Sigma Chemical Co., St Louis, MO). This was done to prevent sperm death (resulting from urine contamination) and to allow collecting any retrograde ejaculated sperm from the bladder. In 1991 (when male SB 208 was about 16 years old), a good quality electroejaculate (with 85% sperm motility) was cryopreserved and used to artificially inseminate SB 214 at the London Zoo in 1992 and again in 1993; both inseminations were unsuccessful. When SB 208 was electro-ejaculated again in January and March 1996, no sperm were obtained. The following year, just before the breeding season (February 1997), transcutaneous ultrasound revealed a pathological accumulation of ascites in the lower abdominal region which resulted in free-floating intestines (see Fig. 17.1d). As shown in Figure 17.1e, the ascites was observed near a liver lobe containing an anechoic-appearing blood vessel and part of the gall bladder. Transcutaneous ultrasound was used to monitor an ultrasound-guided abdominal puncture with a 100 mm long, 16-gauge needle to drain the accumulated fluid (see Fig. 17.1h); 8l of ascites fluid were removed (see Fig.17.1i). The echogenic needle tip was easily visualised, optimising needle positioning and preventing the accidental puncture of other abdominal organs, such as the free-floating intestinal loops (see Fig. 17.1d). The cause of the progressive ascites buildup appeared to be acute pancreatitis. Administering diuretics and broad-spectrum antibiotics daily for one week brought about a rapid recovery that was confirmed by a follow-up ultrasound examination five weeks later. Interestingly, a normal spermic ejaculate was obtained at that time, and this male then continued to exhibit normal seminal traits.

Transcutaneous ultrasound examinations of the female pelvic region were conducted yearly, usually outside the February breeding season, allowing multiple views of the urinary bladder and uterine body (see Fig. 17.1f). However, image quality and resolution were insufficient to characterise endometrial activity, especially compared to sonograms generated by transrectal ultrasound. Transcutaneous sonography was effective for determining that the ovaries were inactive during the nonbreeding season (see Fig. 17.1g). This finding was supported by noninvasive urinary steroid monitoring, which also indicated a lack of ovarian cyclicity (Meyer et al, 1997).

As part of the yearly health assessments, other internal organs, including the spleen, kidney and lymph nodes, were evaluated using transrectal ultrasound. In Figure 17.1k, the border of the caudal part of the elongated spleen was clearly distinguishable from the omen-

tum and was surrounded by anechoic abdominal fluid indicating ascites. The splenic parenchyma was characterised by a homogeneous, moderate echogenicity. The absence of major blood vessels, except in the hilus region, easily distinguished it from the liver, which was more vascularised. The giant panda kidney is lobulated with 15 to 18 lobes (renculi) (Davis, 1964; see also Chapter 16). A sonogram of part of the lobulated kidney, with the outer border marked by white arrowheads, is shown in Figure 17.1l. Each single lobe measured 20 to 30 mm in diameter and had its own capsule with a common minor calyx. The calyx centre was fluid filled and anechoic, whereas the periphery was more echoic. The echogenicity of the cortex and medulla did not differ sonographically in a healthy individual, and overall was less echoic than the spleen. In Figure 17.1m, the kidney of male SB 208 showed clear signs of generalised focal parenchyma degeneration. The white arrows mark the outer border of three renculi and central renal blood vessels. White spots noted in the sonogram were interpreted as scar tissue replacing necrotic parenchyma. This was the first sonographic evidence of chronic kidney degeneration found in connection with a severe case of pancreatitis in 1997 (see above). Although the latter condition was successfully resolved with antibiotics, the kidney problem was not. It is believed that an attack of acute nephritis together with the pancreatitis (and possibly a bacterial infection as indicated by an altered iliac lymph node noted during the same period) probably resulted in the chronic kidney degeneration. As shown in Figure 17.1n, there were white echogenic spots in the cortical region of the lymph nodes that indicated replacement of parenchyma by scar tissue due to extensive cell death. Several altered abdominal lymph nodes were observed during the sonographic examination in 1997, but none since. Lastly, Figure 17.1o shows a healthy, normal-sized left adrenal gland located near the aorta. Characteristic of the adrenal gland are the relatively large nutritive blood vessels shown between the adrenal gland (top) and the aorta (bottom) in cross-section. However, it was difficult to differentiate sonographically between the adrenal medulla and cortex in a normal-sized gland.

The San Diego Zoo

Transabdominal ultrasound has been used to evaluate abdominal organs in the giant pandas at the San Diego Zoo. Anaesthesia was also induced with ketamine hydrochloride (10 mg kg-1) administered via remote dart (Telinject USA, Inc., Saugus, CA) and then maintained using isoflurane (IsoSol; Vedco, Inc., St Joseph, MO) or sevoflurane (SevoFlo™; Abbott Laboratories, North Chicago, IL) administered via a face-mask. Examinations were conducted using an Aloka ultrasound unit (Aloka Co. Ltd., Wallingford, CT) and a 3.5- or 7.5-MHz transducer. Varying amounts of free abdominal fluid (ascites) were observed in all of the zoo's adult animals (Fig. 17.3). Fluid samples were collected via ultrasound-guided abdominocentesis using a 16- or 18- gauge, 7-cm long spinal needle. Cytological examination of the fluid was consistent with a transudate to modified transudate with eosinophils as the primary cell type. No organisms were isolated after bacteriological culture of this fluid. However, the presence of eosinophils suggested a possible link to gastrointestinal parasitism, although this was not proven. The significance of ascites needs to be considered in more detail. However, based on our observations and those from the CBSG Biomedical Survey (see Chapter 4), it is apparent that small to moderate amounts of ascites

Images Build Fluid Around The Liver
Figure 17.3. Transabdominal ultrasound image illustrating abdominal fluid around the liver of an adult female giant panda at the San Diego Zoo.

occur, even in apparently healthy animals. Thus, at this time, this phenomenon must be considered incidental.

Investigations at the San Diego Zoo also revealed that renal architecture was easier to evaluate in younger than older giant pandas. Figure 17.4 depicts the kidneys of SB 487 at 28 months of age.

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  • Rina
    How was diagnose usg male or female?
    3 months ago

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