Gorilla Doctors

Category: Monitoring Visits | Date: Mar 17 2008 | By: admin

A wild gecko with healthy eyes, Rwanda.

We’ve had very few calls about gorillas with eye problems since I joined the vet project—until this past month, when we had two. That means we’ll have a third case soon. I believe in the rule of threes when it comes to veterinary cases. Once we’ve seen two-of-a-kind, there’s undoubtedly a third on the way, though not a fourth. There’s no logic to this rule, of course. It’s just my way of managing expectations about what the future holds, good or bad.

Metal snare on Rukundo’s hand, Nyakagezi Group, RW. Photo by Dr. Benard Ssebide MGVP.

For example, when I started working for MGVP, it had been several years since the vet team had taken a snare off a gorilla. Our last three anesthetic procedures, or interventions, have all been to remove snares. Dushishoze in Pablo Group was the first case, in July 2007. The second case turned up a month later–, Magayane in Kwitonda Group. Dr. Benard Ssebide treated the third in February 2008, Rukundo, in Uganda’s Nyakagezi group. If the rule holds—and I hope it does—we won’t see another snare for years.

Ndeze and Ndakasi play on their climbing structure in Goma, DRC.

The orphaned gorillas also fit the rule of threes. We care for one male mountain gorilla, one male Grauer’s gorilla, and six female Grauer’s gorillas. No pattern there. However, we also care for three female mountain gorillas, all of whom lost their mothers to poachers in the forest. Maisha was the first to be rescued, in December 2004. Ndakasi came next in June 2007, followed by Ndeze in August 2007. Again, I hope the rule of three holds true.

Muntu, an adult female mountain gorilla in Isabukuru Group, Rwanda.

The first eye case was Muntu, an adult female in Isabukuru Group. The trackers reported that she had swollen eyes and couldn’t see, but was eating normally. I ran through the possibilities in my mind as we hiked up to see her. Injury was the most likely. Though eye injuries can be serious, they rarely fall into the category of human-induced or life-threatening, so it was unlikely that we’d end up treating her. But I wanted to be sure Muntu didn’t have some sort of communicable infectious disease.

Muntu closes her eyes, a sign of pain or blepharospasm.

My first glimpse of Muntu made me worry that she had a serious problem. She sat in the shade with both eyes closed tightly, a sign of pain, or blepharospasm. Then she got up and began to forage, moving around with her left eye fully open and her right mostly open. Once we caught up with her in sunlight, I could see the problem. She had a cloudy circular area covering about half of the surface of her right eye, a sign of a healing corneal ulcer. Over the next hour, she squinted at times but mostly held both eyes open.

Muntu has a cloudy right eye, the result of a healing ulcer.

The eyelid acts as a natural Band-Aid for damage to the cornea, so squinting protects the eye and helps it heal. The cloudiness results from the healing process. Muntu may have scratched her cornea in a scuffle with another gorilla, or simply by brushing her eye against a nettle. I did notice that Muntu had a pale scar on the right side of her face, a lesion that looked herpes-like, and considered briefly that the problem could be infectious. We haven’t seen this combination before but will look out for it from now on.

Inziza, adult female mountain gorilla in Shinda Group, Rwanda.

The second case of the month was another adult female, Inziza, in Shinda Group, also reported to have a swelling on her eye. The gorillas were foraging on a steep slope covered with nettles, which made it very difficult to see them. We were lucky to come across Inziza soon, sitting calmly while she ate. At first, both of her eyes looked normal. Then she turned her head to the left. I could see an odd, blister-like swelling on the upper edge of her left eye and a small amount of white discharge.

The swelling on Inziza’s left eye is evident even with her eyes closed.

Inziza sat perfectly still while I peered at her left eye through my binoculars and then took a series of photographs. The lesion seemed to arise from the surface of the eye, or cornea. Most of the time, she held the eye wide open and showed no sign of pain, which surprised me. When she closed her eyes, the swelling created a slight bulge in her eyelid. Maybe she’d been poked in the eye by a stick or thorn. It could be eye cancer, but this hasn’t been described in mountain gorillas and Inziza is only 14-years old.

Imvune, a female mountain gorilla in Shinda Group, Rwanda.

After observing Inziza for some time, I went on to check the rest of the gorillas in the group. I wanted to make absolutely certain that Inziza’s was the only case of its kind among them. Given the dense vegetation, eyes and faces were about all I could see anyway. We found one individual, a young female, Imvune, with a different sort of eye problem, a tiny scratch below her lower right eyelid, which was lined with a film of white discharge. It seemed a very minor injury, but I took photos just in case.

Inziza in Shinda Group with an eye injury.

I reviewed Inziza’s photos later that day with regional field vet Dr. Magdalena Braum, using the computer to enlarge the images. With magnification, we could see more easily that her left pupil was abnormally shaped, narrow and slit-like. The iris, the muscle that controls the size of the pupil, may even be attached to the inner surface of the cornea. Magda wondered if Inziza could see out of this eye. Imvune’s photos confirmed the scratch along the lower eyelid of her right eye. I emailed the images to my friend Dr. Seth Koch, a veterinary ophthalmologist in Washington D.C. for his opinion; Magda planned to return to Shinda Group in a few days.

Nyakalima, a lone silverback in Rwanda with a chronic eye problem, Rwanda.

Given my rule of threes, it’s possible I’ve already seen the third eye case. (Imvune’s eyelid scratch doesn’t count because no one called us to check her.) A few months ago, I was called to check on a lone silverback, Nyakalima, who lost his left eye in a fight with another male and has a chronic infection. Aggression among silverbacks is natural and normal, so we haven’t intervened. He’s a magnificent-looking animal aside from his damaged eye. With any luck, we won’t see any new eye problems for a while. Then again, we might.

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