Gorilla Doctors

Category: Field Procedures | Date: Oct 07 2008 | By: Dr. Jan Ramer for gorilladoctors

The Nkuringo Group of gorillas live in Uganda’s Bwindi Impenetrable Forest.

Benard and I left early for our new snare case.  We were on the road to the ranger station at six a.m., hoping to catch up with the gorillas by nine or so.  Any time we intervene with anesthetic, it’s best to get an early start.  We need time to get the dart in, perform the procedure, and wake the patient up; and in this case, tourists would be arriving by late morning.  Uganda has very few habituated groups–one had just disappeared into DR Congo—so these visits are carefully arranged.  Unlike Rwanda, where visitors gather at one location and are dispatched into the forest  from there, tourists in Uganda are assigned to a particular group, with no possibility of  switching at the last minute.

Park officials with the Uganda Wildlife Authority (UWA) generally prefer that  tourists visit the gorillas first, with vets doing any necessary work afterward.  This is mainly because an intervention can disrupt the group, and thus the visit.  It’s a system I find hard to accept, as I’m always anxious to get to the patient.  Fortunately, Benard had convinced the Nkuringo warden that in this particular case we could get our work done before the guests arrived– assuming we found our patient promptly.  If there’s such a thing as an easy intervention, it’s with a blackback or lone silverback.  Since these males usually roam on the edge of the group, we can often intervene without the leader’s knowing that anything out of the ordinary has happened.  (Of course, this is impossible when the patient is a breeding female or infant.)

The snare around Kirungyi’s right leg, #4 for 2008 in Uganda.

Benard and I arrived at the ranger station on schedule at 7:30 a.m., and were disappointed to find that neither our tracker nor the porters had arrived.  We had no choice but to wait.  At least the advance tracking team had already left, we were told.  I paced, glancing anxiously at the cloudy sky and trying to keep a polite distance from the one tourist who’d already arrived, someone I’d met at dinner the night before.  It helped to know I could run down this trail faster than most people who’d never done it before.  The route to Nkuringo Group was down, not up–hard on the knees, rocky and slippery, but quicker than climbing.  Our intervention team could gain a good chunk of time before the tourists’ arrival if we ran it—and we did.

Though we reached the bottom of the ravine swiftly, I was dismayed to hear one of the porters coughing repeatedly.  Our lead tracker, who mostly works as a UWA guide, said nothing.  Why hadn’t we encountered the tracking team yet? I asked.  he told me not to worry.  It was he who’d seen the gorillas yesterday and reported the snare.  There was nothing I could do now about lack of coordination among the trackers, but I could and did send the porter home.   I reminded everyone that a cough means you may be carrying an infection.  One of the other porters nodded in agreement and picked up the extra bag.

Blackback gorilla Kirungyi climbed a tree easily despite the wire snare around his leg.

Thirty minutes later we found the group, and our patient, a full-sized blackback gorilla named Kirungyi.  Despite the wire snare wrapped around his leg, he easily climbed a tree and sat eating amidst the vegetation.  As we approached to get a closer look, he got up to move.  A long piece of bicycle brake cable wire trailed behind him.  It encircled his lower right leg, which was swarming with flies.  I caught a whiff of dead tissue, a sour smell.  Seemingly out of nowhere, the rest of the trackers arrived.  Benard and I resolved to have a serious discussion later with the park warden about their performance.  But for the moment we had work to do.  At least the gorilla appeared strong, so much so that he promptly climbed into another tree just as Benard was ready with his dart.

I took some video of the gorilla in the tree (if I can figure out how to download it, I’ll post it online).  Kirungyi looked as if he wanted to find a comfortable place to rest and put his feet up, literally.  But his sore leg kept hampering him, and he couldn’t get comfortable. The trackers slapped the tree trunk with a stick until the gorilla returned to the ground to look for a more peaceful place to rest.  Benard got the dart in a few minutes later.

 Lucy and Benard work on Kirungyi.

We calculate our anesthetic dose by estimating the weight of the patient.  We use its age class as an overall guide; the choices include infant, juvenile, sub adult, adult female, black back, and silverback.  If the gorilla is on the small side (infant up to small adult female), we can weigh him or her during the procedure, using our meat scale, and find out how accurate our guess was.  This patient was too big for that, and although he fell asleep readily enough under the effects of the drug, it took him eight minutes to go down rather than the six we’d predicted.  I guessed he’d need more anesthetic.  Once we had our hands on him, we decided he weighed closer to 150 than 130 kilograms.  When we tried to reposition our sizable patient by pulling on his arms to roll him onto his back, he moved his powerful head—but we were ready for that.  Benard gave him another injection, and we were set to begin work.

While Benard removed the snare, I silently wished that gorillas could somehow learn how to use wirecutters themselves.

The snare injury could have been much worse, and would have been after a few more days.  The wire was embedded in the gorilla’s leg and there was a lot of swelling; but there was no evidence of dead, or necrotic, tissue beneath a few centimeters where the wire dug into his skin.  His swollen toes were warm, a sign that blood was still circulating.  Having just seen the gorilla moving about and eating, we knew the damage couldn’t be too severe, unless he had an infection brewing.  We’d give him antibiotics to play it safe.  As I watched Benard cut off the snare, I silently wished that gorillas could somehow learn how to use wire cutters themselves.

We collect blood on every patient as soon as the snare is off; Kirungyi had a high white blood cell count.
Time flies during these procedures.  We didn’t want to inject the gorilla again with more anesthetic, so Benard and I worked as quickly as possible.  He collected blood while I monitored anesthesia and did a general physical.  Next I cleaned the snare wound while Benard administered the antibiotics, then took nose and throat swabs.  As time began to run short—we have a window of about 40 minutes once the animal is stable—we moved all of our equipment out of the way, hoping to accomplish a few more things.  Benard started body measurements while I prepared a second antibiotic for an intravenous limb perfusion.  It wouldn’t hurt, and the medicine would find its way into the swollen foot tissue more quickly than via the intramuscular injection.

Lucy cleans Kirungyi’s snare wound.

Unfortunately, Kirungyi took a deep breath, moved an arm, and suddenly rolled over on his stomach.  He clasped the mask we’d put on his face to protect his eyes and pulled it off.  Once again, we were ready.  I grabbed the mask out of his hand and yanked the tarp out from under him, tumbling back on my rear end as Benard gave the reversal drug.  The gorilla got up and walked away.  Fifteen minutes later we watched him eating.  The fast recovery from anesthesia (medetomidine combined with ketamine) never ceases to amaze me.

Although Kirungyi’s foot was very swollen, his toes were warm to touch, a sign of good circulation.
We packed up our kits and encountered the tourist group just minutes later.  They’d only just arrived.  I briefly explained what we’d been up to and wished them a good visit.  Unfortunately for them, and for us, it started to rain.

The rain felt good at first–I’d worn too many layers during the procedure, fearing I’d be cold as usual; but soon I was uncomfortably hot under my rain gear.  I packed it away and hurried back up the hill faster than most of the group, made possible by the fact that I don’t carry a bag.  The gloomy weather helped propel me, as the rain was soon accompanied by thunder and lightning.  I told myself I should be able to generate enough beads of warm sweat to counteract the icy drops pelting my arms and face.  The rain won, but I kept walking.  As the climb steepened, I stopped thinking about Kirungyi (he would recover) or the poor performance of the trackers (we’d definitely point it out) or the rain (nothing I could do about it), and concentrated on just one thing: putting one foot in front of the other.

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