Regular Weighing Keeps Animals Healthy at Hamilton Zoo

Thursday is weigh-in day at Hamilton Zoo. Cheetah, African Hunting Dogs, Fishing Cats, Meerkats, Porcupine, Black and White Lemurs, Red Panda and Sumatran Tigers all line up to test the scales.

“It’s just the same as farmers weighing their stock, except most of our animals have slightly sharper teeth!” says Hamilton Zoo Carnivore Keeper Shaun Whittle.

Hamilton Zoo has been regularly weighing its carnivores using Gallagher’s weighing gear. The weekly process helps manage the animals’ waistlines and lets the keepers know if any of them might be unwell. 

“It’s all to do with managing their health,” says Shaun. “If they are losing weight we can assess if there is something wrong with their health or if they’re stressed for some reason.”

Keepers also want to know if the animals are putting on too much weight. Just like humans, as they get older, middle age spread can become a problem, causing issues with joints and even arthritis.

Regular weighing plays an important role in monitoring the health and wellbeing of the Zoo's carnivores. By weighing the animals regularly, we can identify changes in condition early and make informed decisions around their health and care.

The animals have been taught to enter their housed enclosure and step onto the scales in exchange for some meat or milk, which they suck out of a syringe.

“They stand there freely, and we get a weight and then they go out again,” says Shaun.

Zoo staff have found the Gallagher weigh scales accurate to within 0.01 kg– an essential feature when weighing some of the smaller carnivores, like the Fishing Cats. Their weight ranges between 7kg and 12kg and they are known to put on weight quickly if they’re being overfed.

“We use Gallagher’s cattle weigh platform for the larger cats, which has sides on it to keep the cats on it. It’s also made from aluminum, which makes it nice and light for the keepers to carry around,” says Shaun.

All the animals go through a fasting day on Wednesday before weigh-in.

“We try to mimic what would happen in the wild. They wouldn’t eat every day in the wild or they would put on too much weight. On the Wednesday, we’ve found they will eat a lot of grass, which is really good for their stomachs,” says Shaun.

Weighing the animals on an empty stomach ensures the Zoo team gets a consistent reading every week.

While the Zoo had been using different scales in the past to weigh the animals, Shaun says the readings were patchy and inconsistent, with weights still being recorded manually.

Using Gallagher’s system, the readings are all recorded in the weigh scale, which staff can access at the touch of a button.

“It’s so easy. The technology has been great and the keepers really trust it. We can access all the past weigh-in information at the touch of a button and see if anything has changed,” says Shaun.

The scales were purchased with the help of fundraising by Friends of The Hamilton Zoo. Shaun says the plan is to roll out the weighing across the Zoo to cover its hooved animals, primates and even the birds.

“We need some pretty heavy-duty scales for the Rhinos because they can each weigh up to two tonnes. We’re looking at hanging scales for both the primates and the birds. The birds are trained to fly onto a perch so we can add a T-bar to Gallagher’s hanging scales and get them to sit on it,” says Shaun.

“With Wi-Fi across the entire property, we can link together all the Gallagher products the Zoo is currently using, making day-today management of our animals so much easier,” says Shaun.

• Improved animal health monitoring: Regular weighing helps identify weight changes early, allowing potential health or welfare issues to be addressed sooner.
• Better-informed care decisions: Consistent weight data helps guide nutrition, health, and animal management decsions.
• Accurate and reliable records: Digital weight capture delivers consistent readings and removes the inaccuracies of manual recording.
• Access to historical trends: Stored weight records make it easy to review past data, monitor long-term trends, and track animal performance over time.

Products used

TWR-1 Weigh Scale & Reader G02602	Cattle Weighing Platform G05804	2500kg Load Bars - 600mm G06000	Animal Performance Software (web and app)