The gorillas had moved into a bamboo thicket by the time we were ready to treat Ururabo's infant. The dense vegetation offered plenty of good hiding places for darting, but the trackers felt the place wasn't safe enough for an intervention, especially given a 39-member group that includes five silverbacks. As they explained, the tall stalks give aggressive gorillas more confidence. We'd be safer in a clear area, where the four trackers could more easily surround the vet team and scare away any challengers.

We moved slowly through the bamboo, following our patient. No matter how we played it, at least one silverback, Igisha, would be nearby. He's very likely the father of Ururabo's baby; the three are often together.

Chief silverback Kurira leads the Susa Group gorillas.

I waited for my cue, listening to Elisabeth and Jean Felix talk back and forth with the trackers — Leonard, Antoine, Fidel and John Bosco. They asked me to hold off firing the dart until the situation improved.

The chief silverback, Kurira, seemed to be leading his group out of the bamboo and into a clearing studded with celery. The trackers hoped he would lead the gorillas out of the bamboo zone entirely, perhaps leaving Ururabo far enough behind that we could do the procedure on the edge of the clearing without his noticing.

The time of day concerned me. It was already 2:00 p.m., I still had to get the dart in, and we needed a few hours of daylight for Ururabo to recover from the anesthesia. I couldn't tell from the clouds what the weather would do, but we didn't want this baby getting wet and cold.

Ururabo, coughing and listless, carries her limp infant the morning before intervention.

Thirty minutes later, I asked again. Our position wasn't perfect, but most of the gorillas had indeed moved off. For the most part, Ururabo was alone with her back to us. We were downhill from her and could hear Igisha eating bamboo shoots somewhere up the hill.

I stood just behind a fallen tree with Magda and Jean Felix to my right, shielding the dart gun from the view of any gorillas that might approach from that side. Elisabeth and the four trackers — each ready with a long stick — stood to my left. It was time. Everyone said OK.

The dart landed in Ururabo's left shoulder. She screamed, pulled it out, threw it to the ground and walked away from us up into the bamboo. Igisha charged out of the bamboo thicket, mouth open, canines showing.

We'd been lucky with interventions on Nyiramurema and Umoja; neither had made a noise. Not so today. Elisabeth and the trackers raised their sticks and yelled at Igisha. It worked — he turned away instantly and headed after Ururabo.

I couldn't see where she went, but I heard her cough once ahead of us. The anesthetic (medetomidine plus ketamine) works within minutes. We needed to find Ururabo quickly in case she fell asleep in a bad position, one that could make it even harder for her baby to breathe.

Igisha clued us in, charging when we turned toward the place where Ururabo sat with her back against several bamboo stalks, her head hanging down, the baby in her lap, eyes and mouth open.

Then the silverback's screaming resumed. People yelled to move Igisha. He screamed at us; I called to the trackers to keep trying. We had to get in there.

Drs. Lucy Spelman and Magdalena Braum with Ururabo under anesthesia.

There was no easy way to move the mother gorilla out of her cage of bamboo. I calculated that in the time it would take to squeeze her through the tall stalks and move her to a wider, more open area. She's big, about 90 kilos (200 pounds), and bamboo surrounded us. I decided we'd stay put and keep going. The most important thing was to get antibiotics into mother and baby.

Magda and I squeezed in with Ururabo, working fast to give our patients their vital medicine while everyone else tried to scare off Igisha. I glanced up to see the shadow of the silverback a bit farther away. We continued, repositioning Ururabo a little so that more of us could work around her. Igisha moved farther away. Magda started swabbing noses and mouths. Jean Felix knelt at an impossibly awkward angle and collected blood samples from Ururabo.

Ururabo's baby undergoes treatment for presumptive secondary bacterial pneumonia.

I checked the mother's vital signs (heart rate 70, respiratory rate 40, oxygen saturation 100 percent) — all good — and then tried to assess the baby. He was alert but weak, his gums pale and his breathing labored. He rasped and wheezed at a rate of about 100 times a minute. I couldn't even hear his heart rate well enough to count, nor did I try for very long. We could reposition him, even turn him over, but I didn't want to cause more stress just to get a number. Meanwhile, the baby's positioning was perfect, inside his mother's arms.

I could see daylight ahead. Once the lip biopsy of Ururabo's herpes-like lesion was finished, we could reverse her. I glanced up, looked past Elisabeth, and saw only Antoine sitting quietly among the bamboo stalks. Igisha had left.

Magda re-assessed the baby's hydration: his skin tented. She estimated him to be at least 7.5 percent dehydrated. She'd already given him a syringe-full of fluids subcutaneously, but wanted to give more. While she did that, I tried to get a blood sample from the baby. But the tiny veins running down his legs were just too small. To get a sample from a larger vein would mean restraining him, and that might kill him.

Ururabo anesthetized for treatment and sample collection.

Just then, Ururabo moved an arm. As anticipated, our anesthetic was wearing off 40 minutes after I'd given it. We quickly cleared away our gear and I gave the mother gorilla one last injection — the reversal drug. Our team backed off and checked on her every few minutes. Twenty minutes after the reversal, Ururabo appeared well recovered — sitting up, holding her baby and grooming it.

At this point we should have been smiling. Instead, we felt stressed. Susa Group had moved at least a kilometer away. Ururabo would have to find them on her own. Had she been too young to survive a night apart from the group, we might have anesthetized her again and carried her to them — but only if we'd had enough light left in the day and enough people to make such a move safely. Our only option now was to follow her slowly and, by our presence, encourage her to move in the right direction if she chose the wrong one.

Magda and Jean Felix left to process samples, while Elisabeth and I stayed with the trackers. Part of me wanted to leave, too. I also had the sense that Ururabo might not want us around anymore, but the trackers preferred to stay with her for at least another hour.

Ururabo follows a Susa Group trail two hours after awakening from anesthesia.

Ururabo picked up a fresh gorilla trail and moved in exactly the right direction. I felt a bit energized. But she was in no rush; she stopped several times to rest, then to eat. We heard the main group squabbling over food, a welcome sound — they were within earshot! Ururabo would certainly head in their direction. But no, she wandered about, going toward them generally, but in anything but a straight line.

About an hour later, Ururabo disappeared into a stand of trees, a good place for a night nest. When the trackers tried to check her location she charged, mouth open, teeth bared. She'd had it with us and wanted to rest. I felt the same way — exhausted. We left, planning to return the next day with two teams: one to find Ururabo and one to check on the rest of our potential patients.

To be continued...

[Rwanda, 2008. Pictures: Dr. Lucy Spelman/MGVP]

Ururabo's baby seemed to recover completely after his two-day episode of runny nose and soft cough. We'd been checking him daily, along with all of the mothers and infants. Magda had seen him the day before, and he'd looked normal compared to the infants of both Ruvumu and Rwandarushya, who were now coughing along with their mothers. Dufatayne had recovered and her baby had yet to show any symptoms. When I arrived to check on the group, the mothers and infants were again the priority.

Byishimo, one of the 4-year-old twins in Susa Group, is sick.

We hadn't yet opened our medical bags for the Susa outbreak, but we'd come close twice. Though Poppy had improved, one of her 4-year-old twins, Byishimo, had become progressively sicker. He'd been struggling with a cough and lethargy for over a week and then stopped eating. When he began lagging behind the group, our level of concern shot up.

Once again, Magda, Elisabeth and I visited as a team and brought the kit (Jean Felix felt better but still had a cough.) Fortunately, Byishimo bounced back the next day. His wet-sounding cough persisted, but his attitude and appetite had improved.

Rwandarushya's 6-month-old infant acting very quiet and
coughing lightly on Day 20 of the respiratory outbreak.

My initial impression of the group on this morning, Day 20, was that many gorillas had improved. Maybe we'd turned the corner on the outbreak. Then I cautioned myself, remembering the number of infants in the group and the time it takes for this disease to cycle through everyone.

Sure enough, Rwandarushya appeared with her baby. First she coughed and then her infant coughed. His eyes looked bright enough, but he seemed very quiet. Ruvumu had regained her appetite and looked much improved, but her infant had a thick nasal discharge and frequent cough. He's a bigger, older baby, however.

Then we found Ururabo, coughing with nearly every breath, sitting head down and not eating. The baby lay limply in her arms, eyes closed, mouth open, wheezing. They were clearly the sickest of the 39 gorillas today. This little one had come down with the disease six days earlier — plenty of time to develop pneumonia, sometimes called the silent killer.

Ururabo and her 3-month-old infant both very sick with
respiratory disease, including a near-constant cough on Day 21.

Elisabeth, the trackers and I felt we should anesthetize Ururabo, treat her and the infant as quickly as possible, collect samples and hope for the best. We called park officials, Magda and Jean Felix. All agreed we should intervene. Although this meant we might not be able to help other sick infants the following day, we'd be treating today's sickest animals and could collect the samples needed to diagnose the disease.

We'd have to wait to export the samples for virology, of course, but we could do the bacterial cultures at our lab. While waiting for the team and the kit (if only we'd all come today!), I speculated about why this mother/infant pair might be sicker than the others.

We only partially understand why some individuals develop secondary bacterial infections after viral ones. The body's immune system plays a role. If a gorilla's immune system is fighting another infection, or has been suppressed by severe stress, even a mild infection can take a turn for the worse.

Ururabo has lesions on her upper lip, thought to be
herpes-like, which are also seen in other individuals.

Ururabo did have evidence of another infection — scabby, crusty lesions along her upper lip, a problem seen in other mountain gorillas, including half a dozen in the Susa Group during this outbreak. While these lesions have long been assumed to be due to a herpes virus infection, possibly the same one that afflicts humans, the assumption has yet to be proved. If there was anything good about this intervention, it was that we'd have a chance to biopsy the lesion.

Our vet team had talked through this intervention several times already. I'd do the anesthesia and exam on the mother and monitor the infant. Elisabeth would help, making sure we kept the mother’s neck at the right angle and kept her from crushing the infant. He wasn't breathing well anyway, and we'd need to minimize any additional stress that could cause his lung function to deteriorate. He could even die. We'd decided not to try to administer oxygen. It would help only temporarily, and besides, the baby would probably fight a mask.

Magda would give each gorilla an injection of antibiotic (Ceftriaxone), take nose and mouth swabs for virus and bacteria culture, biopsy Ururabo's lip lesion, and give the baby subcutaneous fluids if needed. Jean Felix would take blood samples from the mother and work with Magda to keep all other samples organized. Obviously, we’d need to work quickly to get the mother down and up, give the antibiotic to both, and take the samples.

To be continued …

[Rwanda, 2008. Pictures: Dr. Lucy Spelman/MGVP]

On Day 15 of the Susa Group respiratory outbreak, a cool, rainy morning, I stood in one place for two hours watching three sick gorillas. The longer I stayed, the more I worried about what we'd find the next day.

Ururabo, a first-time mother with a 3-month-old baby, coughed and picked her nose. Her baby coughed and sneezed; white fluid ran down from each nostril. He breathed through his mouth's pursed lips. Poppy, the oldest female in the family, sat motionless, huddled with her two older offspring. She'd been sick for almost two weeks.

Rwandarushya holds her infant with one hand
and picks her nose with the other.

Earlier, I'd gotten a good look at the other three females with infants less than a year old. Dufatayne, also a first-time mother, coughed loudly but ate ravenously, while her 3-month-old baby seemed bright and alert.

Rwandarushya walked by me, coughing, and then sat down to groom her 6-month-old, hiding him from view. He's usually very active, but not on this day. His condition became a question mark in my mind. Ruvumu sat quietly, picking her nose and coughing. Her 11-month-old played in a patch of celery.

Ruvumu's infant, a Susa youngster

When Magda monitored the group yesterday, her tally came to 23 sick gorillas out of 39, including Ururabo and the three mothers with young infants. Most of the other adult females had also shown signs of illness, though not their offspring — yet.

I'd found one adult female recovered today. Adding Ururabo's baby to the list of sick gorillas kept the tally at 23. If Rwandarushya's infant turned out to be a new case tomorrow, the count would be higher. We'd reached the need for daily visits.

These results made me nervous. Of the four mothers with infants less than a year old, all were coughing, and one baby was clearly sick. The likelihood that the other babies would soon show signs of illness seemed high. And we hadn't even begun to see illness in the other Susa youngsters, a group that includes seven older, more independent infants and eight juveniles.

Poppy might also be developing pneumonia. She seemed awfully quiet. While a deep, productive cough is the most prominent sign of infection in the lungs, other clinical signs include fever, loss of appetite and dehydration.

Dufatayne and her infant

Concerned about Ururabo's baby, Poppy, and the other four mother/young infant pairs, I decided to return the next day with Elisabeth, Magda and the medical kit, just in case. If this turned out to be the day when one of the animals needed antibiotic treatment, it would help to have the equipment and team together from the start.

Getting to Susa Group in a rush is difficult, as they're usually at fairly high altitude (at least 3,000 meters/9,500 feet.) But we're also in a weather pattern of late-morning rain, and our work is less arduous if we can complete it before the skies open up.

Poppy and her infant

Most patients let us know in one way or another if they need our help. Ururabo's baby would either be better or much worse. Poppy would either have started eating or become weaker. The other infants would show signs of illness or not. Our plan was to intervene only if necessary.

If the patient was Ururabo's baby, we'd have to anesthetize Ururabo as well. If Poppy was the sickest, we might choose to dart her with antibiotics and save an intervention for a later time, depending on how Ururabo's baby looked.

Susa Group gorillas

We weren't a full team when we arrived the next day. Jean Felix had gone home sick with a cough. He'd visited Susa Group to do a check on the outbreak a week earlier, and we all wondered if he had gotten sick from the gorillas. It was certainly possible. We spend five to 10 minutes observing each animal, and a total of two or three hours in the group, watching and listening for a cough or sneeze. With so many adult gorillas coughing in the heavy mist, aerosolized particles could stay in the air long enough to reach our own noses. Distance alone does not protect us, studies have shown.

Ubuntu holds his head.

Even so, the field vets and trackers try to keep a seven-meter distance from the gorillas. Yet there are times when we must move closer — to see inside a nostril or to hear a baby's soft cough, for example. Wearing masks would protect us (and the gorillas), a measure under consideration during recent discussions about tightening visitation rules.

The general feeling, though, is that since the animals aren't accustomed to visitors wearing masks, they're likely to associate them with the threat of an intervention. We'll have to habituate them to this new look slowly. As we climbed the mountain, I wished we'd already started.

Ururabo's infant chews on celery.

But to our great relief, we found all of the sickest gorillas looking a bit better. Poppy rested during periods of sunshine and finally got up to eat. Ruvumu and Rwandarushya coughed repeatedly and forcefully, to the point of nearly retching, but their infants seemed fine. Ururabo's baby slept, nursed and actively played with bits of plant within reach. He had a tiny bit of crusty nasal discharge but no cough that we could hear. His mother also appeared to feel better, despite an even louder cough.

We thought Ururabo's baby had made it through the worst. We were wrong.

[Rwanda, 2008. Pictures: Dr. Lucy Spelman/MGVP]

On the sixth day of the respiratory outbreak it was my turn to visit Susa Group. The coughs from the sick silverbacks reverberated through the forest. Kurira had barely moved his family from where they'd foraged the day before. Juveniles and infants played — again, as if nothing were wrong.

My optimism didn't last long. I heard a gorilla cough softly and knew the sound didn't come from a male. It was Poppy, the oldest female in the group. She had watery eyes and a runny nose. At least she was eating. The trackers confirmed they'd heard her cough the day before. Two of her offspring climbed trees nearby, behaving normally. Minutes later, we found another new case, Izuru, also a female. In order to nurse, her apparently healthy 2.5-year-old had to hang on tightly as his mother's body shuddered with each cough.

Susa Group's oldest adult female, Poppy, lethargic and coughing but allowing her infant to nurse.

As expected, the animals' clinical signs were consistent with a viral-induced upper respiratory tract infection. In addition to watery eyes, runny noses, coughing and probably sore throats, I saw Poppy clasp her hands over her head, an indication of a headache or sinus congestion. The sick gorillas seemed lethargic and ate very little. The coughs were loud, but not from the lungs; the nasal discharge was clear to off-white but not green.

Based on past history, what we know about upper respiratory diseases in people and the recent studies in chimpanzees, the causative organism could be any number of viruses. The list includes respiratory syncytial virus, rhinovirus (the type that causes the common cold), flu or parainfluenza virus.

Air sacs extend under the neck and armpits in male mountain gorillas and can become infected.

I spent quite awhile aiming my binoculars at each of the males, examining the area under the neck and armpits. I remember a silverback from Pablo Group, Umurava, who died several months after the 2006 respiratory outbreak with a severe air sac infection and pneumonia — this after we thought he'd recovered completely.

In retrospect, I wonder if bacteria had been percolating in there for months, a secondary infection that settled in after the respiratory virus. I didn't see any sign of fluid-filled swellings in these areas, but it's probably too early in the outbreak for this complication to develop.

A head cold in a person rarely develops into a life-threatening bacterial infection. It can happen, of course, but most of us do not need antibiotics to survive a week of cough and congested sinuses. The medical history of the mountain gorillas shows that at least one individual per family group has either died or become severely ill, requiring treatment, during these bouts of cold-like respiratory illness. Chimpanzees are even more susceptible to life-threatening secondary bacterial infections as the Tai Forest paper showed.

Susa Group's Nyabantidore sick with respiratory illness.

We don't fully understand the reasons for these differences, but there are plenty of viruses that cause mild illness in one species and severe illness in another closely related one. Environmental factors such as weather and altitude may play a role. Our normal bacterial flora could be different enough to suppress or favor superinfections. I left the forest that day thinking about how much we have yet to learn about the health of the great apes — and ourselves. Maybe this outbreak would teach us something new.

Susa Group female Rwandarushya with her 6-month-old baby, still healthy.

Twelve days after the first reported case, I made another monitoring visit. The silverbacks were clearly improving, including the chief. Kurira ate bamboo shoots hungrily, having finally changed locations. Rwandarushya's 6-month-old baby cautiously crawled away from his mother. She pulled him right back. I tried not to think of this baby as a future patient. But the outbreak wasn't even half over.

Byishimo, one of the Susa twins, sick with a runny nose.

On this day, 18 of 39 gorillas were sick, including Byishimo, one of Nyabantidore's two 4-year-olds, the first mountain gorilla twins known to survive. Later, I replayed a short stretch of video I'd taken. The sound of multiple animals coughing made me uncomfortable, and a range of what-ifs ran through my head that night.

Though we understand a lot about respiratory illness in people, gorillas and chimpanzees, we have plenty of unanswered questions. We don't — and cannot — know precisely how far droplets of moisture-containing viruses travel after a cough or sneeze, or how long these tiny particles remain infectious. (The answers depend on the shape of the microbe, temperature, wind, humidity and the type of virus.) One thing is certain: by visiting wild animals who share susceptibility to human diseases, we introduce risk.

Many of Rwanda's younger habituated mountain gorillas frequently approach human visitors.

The risk of disease transmission is one of the main reasons there are rules in place for visiting gorillas. Unfortunately, they're not consistently observed or enforced. Some guides, researchers and tourists obey the visitation rules; others don't. We've just been through a series of workshops to restate and explain them — again. They're simple and easy to follow: only healthy people are to enter the forest with clean boots, rain gear and hands; everyone keeps the recommended distance from the animals, currently seven meters; if a visitor coughs unexpectedly, he or she should put on a mask and leave the group.

The gorillas don't know the rules, of course. In Rwanda, they've become so habituated to people that the seven-meter rule is difficult to maintain. The gorillas often walk right up to and past visitors, sometimes touching them. At MGVP, we believe the responsibility for following the rules falls on each individual person (certainly not on the gorillas!). We humans have created the risk in the first place, and we're equally capable of taking appropriate action to minimize it, like moving a step back.

View of heavily cultivated farmland near Parc National des Volcans, Rwanda.

Some scientists believe respiratory outbreaks naturally occur among free-living chimps and gorillas and that intervening to treat or confirm the diagnosis is not warranted. But when people are the primary reservoir for a virus that infects the great apes — and can kill them, as shown by the chimp researchers — I'm not sure we can call such infections natural. Humans live closer to the great apes than ever before. Our proximity to them, coupled with shrinking natural habitats, increases the risk.

When I meet eco-tourists on the trail, I introduce myself and the vet project. Most are pleased to know the gorillas have doctors, and they want to know more. Some say simply, "Thank you for doing your work," and ask how they can help. My answer: enjoy your visit and, if you have time, find us on the Web and make a donation. Just search mountain gorilla vet or gorilla doctors!

[Rwanda, 2008. Pictures: Dr. Lucy Spelman/MGVP]

I'll always remember the day Umoja yelled at me and then crawled swiftly toward his mother on two elbows and one knee. Five days after surgery, he no longer needed our help. Nothing in his behavior or appearance suggested that a second intervention with antibiotics would be necessary.

My own feet felt light that day as I scrambled down the rocky path out of the forest — until I spoke to Elisabeth. She'd just received worrisome news from the trackers in Susa Group: four gorillas were coughing.

Chief silverback Kurira with nasal discharge and lethargy
at the start of the Susa Group respiratory outbreak.

The next morning, Elisabeth and I spent two hours recording the first cases of upper respiratory tract disease in the 39-member Susa Group. One black back and four of five silverbacks, including the chief, Kurira, yawned, coughed, picked their noses and generally looked uncomfortable.

These big males barely moved while juveniles and sub-adults played nearby. I carefully checked the youngest infants and their mothers. All appeared healthy for now. But it would be only a matter of time before the illness spread.

Susa Group silverback, Igisha, sick with respiratory disease.

Back at the office, I made a general plan with Magda, Jean Felix and Elisabeth. We'd continue to keep an eye on Umoja, but we needed to shift our focus to Susa Group — and pace ourselves. These outbreaks take weeks to run their course, and each of us would be up and down the mountain repeatedly to check the group.

I put routine health checks for the other groups on hold. One or two of us would monitor the Susa gorillas regularly and carefully document the spread of respiratory signs.

Healthy juvenile in Susa Group at the start of the respiratory disease outbreak

We'd be looking for individuals hit hardest by the disease. Right now, since the sick gorillas were all older animals, we could probably visit every three days and check in with the trackers every afternoon.

Once the younger gorillas began to show signs, we might need to visit daily. Unless this particular infection had circulated recently and the mothers had some immunity, all of the infants in the group could potentially become very sick.

Silverback Kurira picks his nose.

I've experienced two respiratory disease outbreaks among Rwanda's habituated mountain gorilla groups: Kwitonda Group in May 2007 and Pablo Group in November 2006. In each instance, most of the gorillas in the group came down with the illness and at least one infant died.

MGVP field vets have documented other outbreaks in the past. Magda has dealt with similar problems among habituated chimpanzee groups in Tanzania (where the mortality rates were much higher). Not only do we know what to expect here, we have a pretty good idea of where the disease comes from: us.

Wild chimpanzees eating figs in Nyungwe National Park, Rwanda, where ecotourism is just beginning.

Respiratory disease in groups of chimpanzees habituated for research and tourism has recently been proven to be caused by viruses of human origin. In a paper describing events in the Tai Forest, Ivory Coast, Africa (see news story: Human sniffles kill endangered chimps; see also Chimpanzee Park blog), scientists demonstrated unequivocally that chimps sickened and died from respiratory viruses introduced to them from people. The data also showed there were both local and foreign sources of these infections. When the disease originated outside of Africa, the clinical signs and death rates among the chimps were more severe.

Black back Kiki in Susa Group, coughing and lethargic,
is sick with signs of upper respiratory tract infection.

We have every reason to believe the same thing is true of mountain gorillas — that they can contract both local and foreign respiratory viruses from human visitors. But for clinical purposes, there's a major difference between the two species: Since many more chimps die during respiratory outbreaks than gorillas, they generate numerous samples for analysis.

Our quandary with the gorillas is always whether and when to intervene for sample collection in the middle of an outbreak. Since intervention is stressful to the animals, we generally try to reserve it for the really sick gorilla that will most certainly die without treatment.

Healthy adult female Igiti in Susa Group before she became ill.

One of our goals is to collect data and samples whenever possible. At the same time, we know from past experience, including postmortem exams on gorillas as well as chimps, that it's not necessarily the virus itself that causes death, but rather secondary bacterial invaders.

These super infections create most of the life-threatening complications in gorillas, infecting their air sacs, airways or lungs. We can treat these cases with antibiotics with excellent results if our timing and choice of antibiotic is correct.

Largely because of his young age, Rwandarushya's 6-month-old-infant is
at even greater risk of severe illness during the outbreak of respiratory disease in Susa Group.

But here again lies the difficult choice we face during such outbreaks. Bigger gorillas can be darted with antibiotics, bypassing anesthetic intervention (and thus sample collection). Babies can be treated only if we anesthetize the mother, so if we've already intervened in another case to collect samples and thus disrupted the group, we may not have a chance to intervene again and save an infant.

As a result, our strategy is to check, check, check — and when one individual appears very ill, to think through all the ramifications of intervening on its behalf. Susa Group has 15 gorillas between the ages of 3 months and 5 years old. We knew we had our work cut out for us.

[Rwanda, May 15, 2008. Pictures: Dr. Lucy Spelman/MGVP]

For the better part of a week, I woke up at odd moments during the night thinking about Umoja and Nyiramurema. I felt sorry for the mother with her injured eye and missing foot, yet amazed by her strength and stamina. I wished we could relieve Umoja's pain.

Magda told me she wasn't sleeping well either. Circumstances were beyond our control, as is often the case in wildlife medicine. We'd begun by worrying about whether we'd have a chance to treat the infant and waiting for the two gorilla groups to separate. After the intervention, we wondered if we'd operated in time.

Umoja in June 2007, a healthy infant in Kwitonda Group.

Only during the two hours when the gorillas were anesthetized were we in control. It was clear that Umoja was slowly dying. Surgery was his only chance, despite less than ideal conditions for a procedure involving an open abdominal cavity. Both puncture wounds went through skin and muscle straight into his abdomen. They'd begun to heal, clamping down on his intestines. We did our best — Magda and I, Elisabeth and the five trackers, Pierre, Peter, Leon Dace, Aaron and Jerome. But was it good enough?

As soon as the infant and his mother rejoined the group, our ability to influence the outcome ended. We could give Umoja more antibiotics after 72 hours if we felt it would make a difference and if we could get a dart off; however, the main event was over. If he suddenly weakened or the wounds reopened, it was unlikely that we could or would intervene a second time.

Vets have post-operative control of their patients in many situations, especially when the animal can be confined or hospitalized, but not in this one. The next few days were up to the two gorillas. Umoja would either heal or develop complications. His mother would continue to carry him and let him nurse — or not.

Kwitonda silverback with his family, Feb. 2007.

Magda checked on Umoja the day after surgery. When we'd left the group after the intervention, we felt optimistic about his immediate survival, but I didn't relax until she called with an update. The trackers had found the group near where we left them — in a shady stand of bamboo. Umoja was clinging to his mother and his surgical wound looked intact.

Not unexpectedly, Kwitonda singled out Magda and displayed with a false charge, letting her know that he knew something had happened. Nyiramurema was nervous, too, though she allowed Umoja to nurse in front of Magda. So far, so good. Magda kept her visit short, knowing the gorillas would relax if left alone.

Umoja, two days post-op, riding on his mother's back as they leave their night nest.

The next day I did the Umoja re-check. As we walked quietly through the forest, I could sense the trackers' relief. They'd observed the infant nursing many times during the previous day after Magda's visit, and he'd regained some strength.

I heard Umoja whimpering even before we reached the gorillas, who were just leaving their night nests. The sound was a good sign. He'd been too weak or depressed to make any sort of vocalization for three days. I snapped my only photo of the day (it was too dark farther inside the forest): Umoja riding on Nyiramurema's back, bright-eyed and alert.

Kwitonda silverback, May 2008

We followed the group slowly, in the hope that I could get a good view of the abdominal incision. Akareveru, the older of two black backs, felled a tree filled with flower buds and began to eat. Several other gorillas moved in to join him.

Suddenly, Kwitonda appeared out of nowhere and ran at us. He stopped just a meter away, puffing out his upper lip and glaring at me. I stepped behind the tracker, Pierre; the silverback moved forward, backing us up farther.

I was aware that Nyiramurema was approaching from the left and clearly Kwitonda was, too. I got the message: he knows me as well as Magda and isn't happy about either of us. As soon as the female sat down to eat, Kwitonda did the same.

Umoja, three days post-op, riding on his mother's back; his surgical wound is healing.

Nyiramurema didn't seem to notice me, or if she did, she felt safe in Kwitonda's presence and showed no reaction. She pulled up a bamboo shoot and let Umoja slide to the ground. He rolled onto his back and lay quietly.

Through my binoculars, I could see that the skin around his incision was puffy and moist on the surface. A major concern had been that the sutured tissue would break down, or dehisce. Since we expect some inflammation at 48 hours post-op, this was no cause for worry, especially given that other gorillas had undoubtedly been picking at the wound.

Umoja, three days post-op nursing.

Nyiramurema got up to find another shoot, leaving Umoja several feet away. He whined, turned over on his belly, and immediately crawled over to her, dragging his broken leg. Though he whimpered the whole way, he covered the distance quickly. A few minutes later, he nursed for some time.

Once I was away from the group, I called Magda and Elisabeth with the good news: Umoja was stronger, vocalizing and still nursing, and the incision looked OK. On the following day, Magda's photos showed an even brighter and stronger Umoja. He nursed at every opportunity. The swelling around the incision had decreased, and the surface was dry.

Kwitonda Group gorillas eating bamboo.

Elisabeth checked Umoja on the fourth day after surgery. He whimpered throughout her visit, but nursed well and appeared strong. When I returned on day five post-op, the trackers were all smiles. We found Kwitonda and his group eating bamboo shoots in a dark, vine-filled patch of forest, close to where they'd been foraging all week.

The trackers believe — and I agree — that the silverbacks know not to move too far or too fast when a member of the group has a problem. (This is noticeable when there's a newborn baby.) Kwitonda stopped eating briefly to glance sideways at me. We found Nyiramurema nearby, sitting upright with her back against a tree.

Umoja, seven days post-op (photo courtesy of
Louise Hurst, who visited Kwitonda Group as a tourist.)

At first, I couldn't see Umoja. He lay on his back on the ground behind his mother. As she had the other day, Nyiramurema got up to look for more food, walking calmly past me at a distance of about 4 meters. She moved uphill, doubling the distance between us, leaving Umoja behind and to my left.

He stayed quiet for a few seconds, then began to crawl after her, using his elbows and left knee while holding his right leg off the ground — and whimpering loudly. Halfway there, he turned to look at me and started to scream. He screamed all the way until he climbed onto his mother's back. She simply continued eating.

Jerome looked at me, smiling, and whispered, "They think you are the enemy; the doctor is the enemy." But never mind — I'll take that in exchange for a healed patient any day.

[Rwanda, May 4, 2008. Pictures: Dr. Lucy Spelman/MGVP]

After Umoja's successful surgery, his mother, Nyiramurema, headed downhill in the wrong direction as she tried to shake the anesthesia. The trackers quickly fanned out around her, forming a semi-circle to encourage her to reverse direction.

She seemed to realize her mistake. She turned sharply and headed uphill before the trackers even got close. Still woozy from the anesthetic, she tried to run, limping as usual and stumbling in the effort to carry her infant. It didn't help that she’s blind in one eye.

I followed her dark outline through the dense vegetation. She navigated several obstacles holding onto Umoja, then fell on her belly. Umoja slipped off her back. He barely moved and made no sound. Nyiramurema didn't even glance back at him as she rose; instead, she took off at a run. In a few seconds, she disappeared.

Umoja nurses from Nyiramurema the day before surgery.

A wave of fear hit me. Healthy juvenile gorillas can find their way back to their mothers and family group if placed nearby, but this was a 2-year-old with a broken leg. If Nyiramurema rejoined the group without her infant, would she look for him later? If Kwitonda figured out that we'd intervened, he might move even faster uphill, away from the infant. Umoja needed his mother's milk, body heat and protection. The group might not find him in time. Or, he might be rejected.

I looked at the trackers, raising my eyebrows in an effort to signal "Should we carry him to the mother?!" (They speak mostly Kinyarwanda.) I asked the same to Elisabeth in English. Nobody moved or said a word. For a moment, we were all at a loss — we could no longer hear Nyiramurema. I asked Magda what she thought. My instinct was to pick up Umoja and run uphill in the hope that we could still find his mother and set him down near her, ideally on a trail leading back to the group.

Umoja covering his eyes, a sign of agitation and discomfort the day before surgery.

Magda agreed we should make the effort. Elisabeth nodded her head. I put my mask and gloves back on and picked Umoja up with my right arm under his buttocks, trying not to knock his broken leg or touch the surgery site, and my left arm under his left armpit. It didn't feel right to be holding a wild gorilla so closely, but I didn't see any other way.

The infant barely reacted, raising his hands over his head. I began climbing, knowing I'd need help from one of the trackers soon. We needed to quickly get between the mother and the rest of the gorillas so that we could leave the infant in her path.

Kwitonda Group trackers

I ran out of strength after 10 minutes. Umoja weighs only about 15 pounds, but I'm not used to carrying that weight uphill on uneven ground. I didn't want to slip and fall or run completely out of energy — the vet work might not be over.

I asked again for help from the trackers. Pierre, the tallest and strongest of them, took the infant from me. He carried Umoja carefully and with ease. Elisabeth called back and forth on the radio, trying to find out from the trackers where we should be heading.

Suddenly, we heard gorillas. We stopped, hoping to intercept Nyiramurema as she caught up with the group.

Dr. Lucy Spelman tries to warm up Umoja without getting too close to him.

I took Umoja back from Pierre, thinking we should set the infant down in the vegetation near the gorilla group sooner rather than later. But our patient now felt cold and his hair was damp. He had been relatively dry at the end of his surgery, but had since been carried through the wet forest on his mother's back. If I put him down, the other gorillas ignored him and the mother didn't appear soon, he could become hypothermic.

Sweating from the effort of having carried him uphill, I decided to sit with the infant in my lap, let my body heat warm him and wait quietly, hoping Elisabeth and the trackers would soon confirm the mother's location.

Kigoma, one of two black backs in Kwitonda Group.

A few minutes later, I caught a glimpse of a gorilla in a tree to my left nearby. Magda and Elisabeth confirmed the group was very close. Umoja's brother, Chiri, was also nearby, a good sign. I hoped they couldn't see me holding the infant. They would have every right to charge me.

Umoja had begun to warm up and regain some strength, moving his arms a bit and opening his mouth. His broken leg trembled, but he seemed amazingly calm otherwise.

Nyiramurema eating bamboo shoots with Umoja lying on his back
nearby, after medical intervention.

Seconds later, the vegetation crackled to my right. No matter which gorilla it was, I was in a dangerous position with Umoja in my arms. We thought it could be the mother. I put the infant on the ground in a pile of recently eaten bamboo shoots. He rolled downhill a bit and we all backpedaled.

Seconds later, Nyiramurema appeared. She paused only briefly, then picked Umoja up matter-of-factly, as if she'd expected to find him there, and went on her way. Twenty minutes later we watched her eating bamboo with the main group, the infant at her side and Chiri once again nearby.

Umoja's mother, Nyiramurema

The infant lowland gorilla at the national zoo whose wound I'd repaired grew up with no recognition of me as a bad person. His mother, however, has never forgotten. Every time I've gone back to visit, she regards me with what I would characterize as a glare.

Nyiramurema never saw the dart and never saw me holding her infant, but will she know me or Magda? We'll find out soon enough. One of us will check on Umoja every day until he's out of danger. We're crossing our fingers that he'll live long enough to learn to recognize his doctors.

[Rwanda, April 29, 2008. Pictures: Dr. Lucy Spelman/MGVP]

We gave up trying to dart and treat Umoja after three hours. The group stayed together, and the opportunity to dart never came.

We did watch Umoja nurse, and we photographed his wounds. We could see holes in the exposed intestinal tissue and interpreted them to be in the omentum, the fatty tissue that covers and protects the bowel, rather than the intestinal wall. Had his intestines been punctured, we didn't think he'd still be alive, let alone have an appetite.

At one point, three gorillas gathered around the infant and groomed his wounds, licking and picking at bits of dead tissue. We could only hope we were right about those holes.

Umoja with Nyiramurema; parts of his small intestine
protrude from a wound in his abdomen.

Magda, Elisabeth and I returned to the forest first thing the next day. After spending another hour and a half in cautious pursuit, I finally had my chance. Nyiramurema sat down to eat a bamboo shoot. Umoja lay at her side. There were other gorillas nearby, but not Chiri. All were busy eating.

I darted the mother. She pulled out the dart, dropped it on the ground, got up and walked away to the next bamboo shoot. Five minutes later, she wobbled to her knees and fell asleep, anesthetized. I darted Umoja while he clung to her side. He too was unconscious a few minutes later.

Umoja anesthetized and ready for surgery

My job over the next hour or so was to keep the two gorillas safely under anesthesia, with Elisabeth assisting, while Magda did the surgery. Our operating theater was a tiny clearing surrounded by bamboo and vine-covered trees.

I felt a bit trapped, but also sure that none of the other gorillas in the area knew anything out of the ordinary was taking place. If we tried to move to a better site, they might hear us. The trackers stood quietly 30 feet away, listening for the rest of the group, ready to chase them away if necessary.

MGVP's Dr. Magdalena Braum prepares Umoja's injured abdomen for surgery;
he had several loops of bowel protruding through two puncture wounds.

Magda zeroed right in on the surgery. On Umoja's right side, she found not one but two canine-sized punctures through the skin into the abdominal cavity, with several short sections of bowel protruding through each one. Umoja's intestines were intact, but the skin had begun to heal around them, constricting the herniated tissue.

Magda removed small bits of unhealthy tissue, rinsed all with sterile fluids, released the pressure on the bowel loops, pushed them back in and then closed the wounds with buried sutures.

ORTPN vet tech Elisabeth Nyirakaragire treats Umoja with fluids and antibiotics.

While Magda worked, Elisabeth gave Umoja subcutaneous fluids and injections of antibiotics. I collected blood samples from him and Nyiramurema, satisfied that the anesthetic drugs (Medetomidine and Ketamine) were working well, but not entirely comfortable with the situation.

It's challenging enough to anesthetize one mountain gorilla, never mind two at the same time. I kept my focus on anesthetic depth, frequently checking both patients for an increase in muscle tone. If Umoja began to wake up, surgery would be disrupted. If she woke up too soon, we'd all be in trouble, given our cage-like OR.

Umoja lying next to his mother the day before surgery, favoring his injured right wrist.

Umoja's right wrist was badly damaged by a deep gash, more severe than we'd anticipated. One of two major flexor tendons running along the underside of the arm was severed and the joint capsule was torn open. The end of the ulna, one of the two bones in the lower arm, was exposed.

Magda sutured the tendons and a piece of muscle, knowing the repair might not hold but hoping to protect the tissue temporarily. Umoja may never regain full use of the wrist, but the wound should heal eventually. At worst, if the bones became infected or necrotic, he could lose his hand.

Umoja's right foot is curled as he guards the break in his leg
above the ankle; his left foot is uninjured.

We palpated Umoja's lower right leg and confirmed a fracture of both the tibia and fibula midway between the knee and ankle. While this injury is the least worrisome in terms of healing (young animals heal major bone fractures quickly), it is clearly the most painful. Umoja will not be able to walk, climb, play or feed normally for weeks.

While waiting for a chance to dart the day before, we'd watched as one of the other infants tried to start a game of rough and tumble. Umoja pushed his former playmate away, tucked his head and curled up in a ball.

MGVP's Dr. Lucy Spelman administers the anesthetic reversal to Nyiramurema
at the end of Umoja's surgery.

The scary part came at the very end of the procedure. As mother and infant recovered from anesthesia (I gave each a reversal drug), Nyiramurema started moving away in search of the group, stumbling a bit as she struggled to burn off the remaining anesthetic. Umoja rode on her back.

In her pursuit of a gorilla trail, she had to make her way through a dense thicket. Our patient hung on — at first. Unfortunately, Nyiramurema headed downhill, the wrong way. The trackers quickly fanned out around her, forming a semi-circle to encourage her to reverse direction.

To be continued …

[Rwanda, April 29, 2008. Pictures: Dr. Lucy Spelman/MGVP]

Jean Felix got the first call about Umoja. The 2-year-old mountain gorilla infant had been badly injured during a fight between his family, Kwitonda Group, and Nyakagezi Group. Sometimes these two groups interact peacefully, but not this time.

Umoja's intestines were hanging out and he couldn't walk. Jean Felix relayed the information to me, adding that trackers felt there was nothing we could do at this time. The situation was unstable and likely to remain so for several days.

We intervene with medical treatment when a problem is life-threatening or human-induced — and only then if we can act without undue disruption to healthy gorillas. It sounded as if Umoja needed surgery, which meant we'd have to dart him, and probably his mother as well, with anesthetic.

Kwitonda and his family were already nervous and would be especially protective of the injured infant. We'd need to drive them away with loud noises, adding to the tension and raising the risk of another aggressive encounter with the Nyakagezi gorillas.

With a broken leg, cut wrist and herniated intestines,
Umoja was able to crawl, but very slowly.

I knew we could do nothing until the gorillas went their separate ways, unless Umoja lagged behind. But I'd treated a similar case once before and knew the infant had a chance if he survived his initial injuries.

I asked for more history: "What was happening right now — was the infant alert, moving, vocalizing?" The answers all came back, "Yes." He was calling for his mother, Nyiramurema, to carry him. She'd picked him up a few times but hadn't held him for long. This female had lost a foot many years ago, probably from a snare, and had all but stopped carrying Umoja in recent months: He'd grown too big. His brother, Chiri, carried him instead.

Umoja clinging to his mother, Nyiramurema,
and surrounded by other gorillas.

As we later confirmed, Umoja had two puncture wounds in his lower abdomen, a broken right lower leg (tibia and fibula), and torn flexor tendons in his left wrist. Even so, he was able to hold onto his mother, nurse and crawl short distances.

I thought back to a Sunday morning emergency at the National Zoo in Washington D.C. The lowland gorillas had a fight and the youngest member of the group, an infant male, got caught in the middle. Though several loops of bowel hung from a hole just below his rib cage, his intestines had not been damaged. We closed the wound surgically and he lived.

Umoja's mother Nyiramurema

I suggested we check Umoja if possible and at least document his injuries. Jean Felix called Elisabeth, the park's vet tech. She agreed but warned we might not be able to get all the way to the group. I added surgical packs to our field kit just in case.

My mind flipped through the options as we drove to the park. Maybe the interaction between the gorillas would be over by the time we reached Umoja and we'd be able to intervene. We might be lucky and find him alone with Nyiramurema. She's blind in one eye, the result of another recent fight, which might enable me to get off a dart off without her seeing it.

An injured Umoja lies next to his mother.

We hiked about 40 minutes into the park and met the trackers. Instead of welcoming us with smiles, they looked serious. We found Umoja and Nyiramurema easily — but in the midst of other gorillas.

The infant lay uncomfortably at his mother's side while she nibbled on a vine. When she got up to move, he whimpered and reached out toward her. She picked him up once, but not a second time. He tried to follow, dragging his right leg. A bundle of red tissue bulged from his abdomen on the right side. Through our binoculars, Jean Felix, Elisabeth and I were unable to determine if the intestines were damaged or simply exposed.

Kwitonda and Nyakagezi Groups often interact, especially during bamboo-shoot season.

Light rain began falling. The mist rolled in. The Kwitonda Group gorillas formed a big circle, huddling together with females and infants in the middle to protect them from their would-be aggressors. We could hear the Nyakagezi gorillas in the bamboo nearby. We looked at each other in silent agreement: there was no way to intervene.

I tried to convey my apologies to the trackers. Umoja could live on for three, maybe five days. Watching him die would be hard and sad, but nature is not always gentle. We left for the day with plans to return if and when the trackers thought intervention possible.

Umoja nurses." />
Umoja nurses.

I spent the next morning reorganizing the field kits and lab supplies while I waited for an update, too distracted to sit down at my desk. The report came in mid-morning: the Kwitonda gorillas were still very nervous and had charged the trackers. The Nyakagezi gorillas remained nearby. Umoja could no longer drag himself along the ground and was being carried by his mother and several other gorillas, including Chiri. The good news: the infant was nursing.

Umoja, two days after the fight

On the third day, Elisabeth called from the forest. It was safe to intervene — the gorilla groups had gone their separate ways. Umoja appeared weak, she said, but continued to nurse.

Magda and I hurried to the site (Jean Felix was off for the weekend.) I made two darts, one for Nyiramurema and one for the infant. We began patiently following the group, waiting for the right time and place to fire the darts. It would do no good to anesthetize Umoja and his mother in a situation where another gorilla — mostly likely Chiri — might carry him off. And if I missed and the gorillas noticed, we'd only upset them again.

To be continued …

[Rwanda, April 29, 2008. Pictures: Dr. Lucy Spelman/MGVP]

]]>