Four of Mogo Zoo’s tigers have undergone dental surgery via the generous support of Sydney’s Small Animal Specialist Hospital (SASH)
Mogo veterinarian Sam Young said canine fractures are the most common dental ailment in big cats in captivity, mostly because they can become aggressive at feed time and bite at the wire.
In older Sumatran tigers it is not unusual to see periodontal problems including tartar build-up, gingivitis, gingival recession, enamel chip fractures and crown fractures; particularly on incisors and premolars.
Young said Mogo tries to thwart dental problems through diet and preventative medicine.
“We try to feed all of the carnivores them as many whole pieces as possible, for example the tigers regularly receive half legs with hide and big bits of bone; something that provides a balanced diet and also requires the animals to chew vigorously to pull food apart,” she said.
“Every 12-24 months all of the tigers get a full check under general anaesthesia to inspect their dental health, scale any tartar and treat any other dental problems, along with a comprehensive health check including kidney and other organ function.”
A specialist veterinary dentist from SASH, Nadine Fiani, visited Mogo Zoo in January to perform several root canal treatments on the tigers.
Fiani traveled down for the weekend, bringing lots of equipment and a dental nurse. SASH, Nadine and Chris donated their time to perform the surgeries.
Due to the length of a tiger’s canine root canal, Fiani had to have special files made up.
“In tigers the root canal is roughly 70-100 mm in length, and we’ve got a couple of lions that need doing on her next visit,” Young said.
Male lions have a canine root canal up to 120mm.
“This is the second time Nadine has come down to Mogo Zoo,” Young said.
“She came 12 months ago to do a root canal treatment on another tiger, and while she takes care of the mouth end, I do the rest such as induce and monitor the anaesthesia, collect blood and urine and perform a thorough physical examination as part of their comprehensive health check.
“It’s a very involved procedure right from when they’re injected since they’re dangerous animals.”
Though it is usually necessary to dart the tigers, there are occasions when they can be hand injected with anaesthetic induction agents through the wire.
Once they are deeply anaesthetised they are placed on a stretcher and moved out of their enclosure, through the zoo and in to the vet department.
“Moving them through the zoo is of particularly high risk,” Young said.
“If they woke up during this process there could be dramatic consequences.”
After the animal is brought into the surgery, the teams administers isoflurane gas in oxygen during the procedure, which is the same as is used on dogs and cats in dental procedures.
“Generally the same concentration of gas is used to keep both a tiger and a domestic cat asleep during the procedure, but the rebreathing bag on the anaesthetic machine is bigger, and the endotracheal tube is a little bigger, too; about 16 to 18mm,” Young said.
“This time around we did surgery on four tigers and a black-capped capuchin, and we x-rayed a South American tapir, in a 36-hour period over the weekend.”
Three of the tigers had root canal treatments and one had several tooth extractions. The capuchin, which came to the zoo in a group of 12 animals Mogo received from New Zealand in November, also received a root canal treatment.
“This capuchin is the patriarch of his group; he had a draining sinus on his cheek caused by a canine tooth root abscess, present before his arrival in Australia, that was in urgent need of treatment,” Young said.
The animals are reported to be doing well, with three of the four tigers recovering without incident.
18 year old Thelma (who has a sister named Louise at another zoo) required a couple of extractions and has more complicated dental problems which will require follow-up treatment.
“She’s now on a diet of lean meat with no bones, and is on pain relief as a part of her post-surgical care,” Young said.
Young added that she is very hopeful SASH will continue to maintain a relationship with Mogo and that Fiani can visit every four to six months.
“(She) certainly seems very keen to help us out, and Mogo Zoo is very grateful for the generous support of SASH and Nadine,” she said.
“The South American Tapir needs at least one root canal treatment, so hopefully we will be able to do her and two of our mature male lions at Nadine’s next visit.”
SAM WORRAD