Bengal-hybrid tiger treated for eyelid tumor

Falcor, an 11-year-old, 412-pound white Bengal-hybrid tiger, was treated by UC Davis ophthalmologists for a tumor on his eyelid. (Image courtesy of UC Davis College of Veterinary Medicine)

The Performing Animal Welfare Society (PAWS) is a sanctuary located in San Andreas, California and home to 25 rescued, abused, abandoned, or retired captive wild animals including elephants, bears, primates, and other species. PAWS has an onsite veterinary care team as well as a dedicated group of caretakers who monitor the animals closely. Each caregiver on the property is trained to look for health issues whenever they feed, clean, or care for animals.

In 2023, Falcor, an 11-year-old, 412-pound white Bengal-hybrid tiger at PAWS, had a soft tissue sarcoma mass removed from around his left eye and was completed with clean margins with no recurrence seen since the removal.¹ Renae Smith, lead tiger supervisor at PAWS, has been with the sanctuary for 17 years and was the original caretaker to notice the mass.Smith then immediately alerted Jackie Gai, DVM, PAWS director of veterinary services.

Gai then called the Ophthalmology Service at the UC Davis veterinary hospital, which recently acquired a new laser equipment as Lauren Charnock, DVM, MS, was going through the hiring process at the hospital. Charnock trained on the equipment while she was in her comparative ophthalmology residency at Auburn University.

Although there is a state-of-the-art hospital at PAWS, the team performed Falcor’s procedure within his enclosure to reduce the amount of time under anesthesia. PAWS has portable gas anesthesia, imaging, and other equipment on site that veterinary teams can use within the field and is easily transportable. The team then darted Falcor and once it was safe, Gai and her team created a makeshift operating room within the enclosure.¹

Gai was joined by Jennifer Glavis, DVM, MVPM, and Lynn Dowling, RVT, who all had worked together at PAWS for over 10 years. Glavis, who is serving as a part time staff veterinarian at PAWS, and Dowling, a full time swing swift supervisor, also both work at the UC Davis veterinary hospital.

During the procedure, the team from PAWS was responsible for anesthesia induction and monitoring, blood collection, and other ancillary procures as Charnock and Kathryn Good, DVM, DACVO, chief of the Ophthalmology Service, removed the tumor and performed photodynamic therapy.¹ This laser treatment has been used on other species at UC Davis, mostly those with cancer on and/or around the eye.

Lauren Charnock, DVM, MS, performing hotodynamic therapy on Falcor.

According to UC Davis, normally the tumor is removed surgically first, as was done with Falcor, and then a specific photo-sensitive dye is injected into the surgical site.¹ Here are therapeutic properties in the die that are activated by the laser, emitting particular light wavelengths.This procedure then creates an immediate scab to protect the surgical site from infection, attempts to target and kill remaining cancer cells, and then ‘seals’ the site without requiring sutures.

Patient that receives this treatment typically tend to have minimal tissue swelling and appear to be quite comfortable after surgery. This treatment also helps reduce the risks of the tumor spreading or regrowth by allowing more tissue to be removed during the surgery, which also then increases the chance of obtaining clean margins during the removal. Overall, the anesthetization, comprehensive eye exam, and eyelid tumor surgery took the team 76 minutes and Falcor remained stable throughout the procedure.¹ Falcor is recovering well.

Falcor receiving care from his veterinary team

Most likely, there are no white tigers like Falcor remaining in the wild and only 1 in 10,000 born in the wild are a white cub. Because it is believed there is only 5,000 tigers still in the wild, the chance a white cub will ever be born again in the wild is extremely rare.¹ Currently, Falcor is one of about 200 white tigers in captivity worldwide. Gai explained that the Association of Zoos and Aquariums as well as any other legitimate breeding organization does not support the breeding for white tigers.

“Not only is the white color recessive, but so are other conditions like dwarfism, cleft palate, vision problems, deformed limbs, and deformed facial features. With inbreeding, eventually, you end up with white tigers with too many health problems,” explained Gai.

Falcor’s team does not believe that his melanoma is the result of inbreeding, but they are an issue with white or gray animals because they have a higher incidence of melanoma than more pigmented tigers.²

PAWS is working to keep Faclor’s future bright, but he has had an ‘infamous’ past as well. Falcor was part of a major government action against Jeff and Lauren Lowe, owners of a private zoo in Oklahoma and who were featured in the Netflix series “Tiger King.” Within the government action, 68 big cats were seized by the US Department of Justice and the US Department of Agriculture from the facility to alleged violations of the federal Endangered Species Act as well as the Animal Welfare Act.

References

1. Ophthalmologists Treat White Tiger with New Laser Technology. News release. UC Davis College of Veterinary Medicine. August 20, 2024. Accessed August 21, 2024. https://www.vetmed.ucdavis.edu/news/ophthalmologists-treat-white-tiger-new-laser-technology
2. van der Weyden L, Brenn T, Patton EE, Wood GA, Adams DJ. Spontaneously occurring melanoma in animals and their relevance to human melanoma. J Pathol. 2020;252(1):4-21. doi:10.1002/path.5505