Ultrasound at the Zoo

Zoo medicine is quite the paradox. In one way, zoo veterinarians are specialists in that what we do daily; it is very unique and specialized and there are few licensed veterinarians that are employed as full-time clinicians in zoological parks. On the contrary, zoo veterinarians are also the ultimate general practitioners as our patients include everything from invertebrates to great apes and elephants (and all life forms in-between)… and for this wide variety of patients, we attempt to be their pediatrician, surgeon, dermatologist, cardiologist, radiologist, etc. I am fortunate to be the Senior Staff Veterinarian at the Louisville Zoo in Louisville, Kentucky.

In terms of imaging modalities, most zoo hospitals are equipped with plain radiography (film or digital) and have some ultrasound capabilities. A few of the larger zoos in the country have computed tomography (CT) in their on-site hospitals. In Louisville, when one of our patients requires advanced imaging, we make arrangements with local facilities with CT or MRI capabilities.

For ultrasound imaging, we have a portable Sonosite M-Turbo unit with both a curvilinear, 5-2 MHz transducer for primarily transabdominal imaging, and a linear array, 10-5 MHz transducer for primarily transrectal imaging. In addition, we have several donated large rolling Phillips Sonos units with an assortment of probes for both echocardiography and transabdominal imaging. One remains in the Zoo’s Animal Health Center and others are stored and used in animal areas for pregnancy diagnosis, echocardiograms on awake gorillas (through the mesh barrier), or just training/conditioning animals for awake ultrasound exams.

Zoo animals may present unique challenges when ultrasound imaging transcutaneously. In the case of fish and amphibians, imaging through a water bath (without even touching the patient!) can be very effective and noninvasive. The rough scaly skin of some reptiles makes a warm water bath similarly effective as a conductive medium for imaging snakes and lizards. Birds are not often examined via ultrasound because of the extensive respiratory (air sac) system they possess that interferes with the sound waves. For mammals, different species present different challenges. Many mammal species are thickly furred necessitating clipping of hair to establish good contact between the transducer and the skin. For transabdominal imaging, some species are very gassy (hippos, gorillas), which may complicate diagnostic imaging. Large or dangerous mammals that are examined awake via training need to be conditioned to present the body part of interest (chest, abdomen) at the barrier mesh and trust their trainer/keeper to allow contact with the probe. Often the greatest hurdle is habituating the animal to the ultrasound gel! When performing transabdominal imaging in our pregnant African elephant cow, rather than go through gallons of ultrasound gel smeared on her flank to fill in all the cracks and crevices in her thick skin, we run water from a hose just above wherever the transducer is placed.

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As general practitioners, zoo veterinarians have variable amounts of training in ultrasonography. We strive to do the best we can and are constantly learning, but the high variability in our daily tasks makes becoming an expert in ultrasound very difficult. So “it takes a village,” and we will regularly utilize specialists in our community to assist us in providing the best medical care for our patients. If I have a zebra or related species that requires a reproductive ultrasound exam, we will reach out to a local equine veterinarian that can apply their expertise in horses to a related species. Great apes have a high incidence of heart disease so whenever a gorilla or orangutan is anesthetized for an exam, part of the comprehensive care they receive is an echocardiogram by a human sonographer. Female great apes may get attention from our volunteer gynecologic sonographer as part of a reproductive evaluation. If the ultrasound exam is on a sea lion, wolf, or bear, I may contact a veterinary radiologist or veterinary internist competent in ultrasonography to assist.

In summary, ultrasonography represents a valuable, noninvasive, diagnostic tool for the zoo veterinarian.

Have you ever performed an ultrasound examination at a zoo? What was your experience? Comment below, or, AIUM members, continue the conversation on Connect, the AIUM’s online community. 

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Zoli Gyimesi, DVM, is the Senior Veterinarian at the Louisville Zoo in Louisville, Kentucky.

Vascular Access for Fiona

Life as a vascular access nurse can be very challenging and diverse in a pediatric hospital. A typical day is fast-paced and includes neonatal, pediatric, and adult patients. Veins may be small, tortuous and often found in unusual locations, eg an extremity or scalp vein. For many patients, imaging tools such as ultrasound are essential for successful placement of IVs, midline catheters, and PICCs. The Vascular Access Team sees patients in both the inpatient and outpatient settings. While many of our procedures are routine, a phone call in February 2017 forever changed the way we view our specialty of vascular access.

The caller on the phone was Amy from the Cincinnati Zoo Marketing Department. She described an urgent clinical situation with Fiona, a 3-week-old premature hippo who was dehydrated and needed IV access. The Zoo staff was desperate as Fiona was not taking any bottles and her IVs were only lasting 8–12 hours. Amy had previous experience with the Vascular Access Team when her daughter had surgery at our institution. She referred to our team as the “Vein Whisperer.” Amy wanted to know if we would be able to use the same tools we used on her daughter to gain IV access with Fiona.pic 8

Fiona was already a star in the eyes of the Cincinnati community. Fiona was born on January 24, 2017, the first premature hippo on record to survive. Fiona was small, around 30 pounds, and was being cared for by a specialized team of experts at the Zoo. Her day-to-day progress was being reported on social media and the local news.

My answer to Amy was, “Of course we can help Fiona!” In my mind, I was thinking of all the things we would need to bring to the Zoo. Supplies included an ultrasound machine, probe cover, ultrasound gel, skin antisepsis, varying sizes and lengths of IV and midline catheters, dressings, etc. I kept thinking…this is a premature hippo, what will we need to insert and maintain the catheter? I asked my colleague Blake to accompany me to the Zoo. Blake is an experienced vascular access nurse and is always up for a challenge! We gathered all our supplies and began our journey to the Zoo.

We arrived in the Hippo Cove area of the Cincinnati Zoo. We met two of the veterinarians who updated us on her condition. Fiona was dehydrated, on oxygen, and extremely weak. They described her condition as critical. We put on special scrubs and removed our shoes. As we were led into the small room where Fiona was, the room temperature was very warm as an effort to maintain Fiona’s body temperature. Fiona was on the floor, laying on a blanket.

Fiona was surrounded by 2–3 Hippo team specialists. Amid their worried looks, they quickly reviewed Fiona’s history, IV access issues, and her inability to take a bottle. Fiona was receiving nutrition through an intermittent naso-gastric tube.

Time was of the essence; we began setting up the 2D ultrasound machine and the necessary supplies. Initially, I scanned her head to assess for any scalp veins, there were no visible veins identified. Blake began scanning her hind leg; she was able to locate a viable vein, about 0.2 cm below the skin. The vein easily compressed and had a straight pathway. Based on her assessment and fluid requirements, we decided to use a 3Fr 8cm midline catheter.

The vein was accessed under ultrasound guidance, using a transverse approach. The midline catheter initially threaded with ease but we were unable to advance it fully. Fluids were connected to the catheter but it only lasted 20 minutes before leaking. The midline catheter was discontinued. Another vein was visualized under ultrasound guidance on the hind leg; the midline catheter was trimmed to 7 cm and threaded with ease. The midline catheter flushed and aspirated with ease.

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Due to Fiona’s occasional activity of standing up, we really wanted a secure catheter. The midline catheter was sutured to her skin and a dressing was applied. We discussed the care and maintenance with the veterinary staff, and the decision was made to infuse continuous fluids through her midline catheter to maintain patency.

Over the next 2 days, Fiona gradually began to regain her strength. She began slowly taking her bottles and standing up. Fiona received 5 liters of fluids over 6 days through her midline catheter. The catheter was discontinued on day 6.

Fast forward and now Fiona has celebrated her 1st birthday. She did so with the Hippo team that provided the delicate care that she needed. The Vascular Access Team is so proud to have been part of her care. On that cold February day, we were able to use our 20+ years of experience and knowledge to provide the right catheter under imaging to provide her with the lifesaving fluids she needed.

Have you performed ultrasound in an unusual situation? Tell us your story by commenting below or letting us know on Twitter: @AIUM_Ultrasound.

Darcy Doellman MSN, RN, CRNI, VA-BC, is Clinical Manager of the Vascular Access Team at Cincinnati Children’s Hospital.