Our Veterinary Team
At Island Cats Veterinary Hospital, our dedicated veterinarians in Mercer Island, WA, and skilled veterinary staff are passionate about providing the highest level of feline-focused care. We believe in a gentle, low-stress approach tailored to the unique needs of cats and their owners.
Meet Our Veterinarians in Mercer Island, WA
Our experienced vets in Mercer Island bring years of expertise, a deep understanding of feline medicine, and a commitment to compassionate care. Learn more about the veterinarians and staff who make Island Cats Veterinary Hospital a trusted name in feline healthcare.
Our Veterinarians
Dr. Timarie Simmons, DVM
Feline Medicine & Surgery | Brachycephalic Breeds | Client Education
Dr. Simmons has been practicing veterinary medicine since 1998 but has been working in the field since 1985. She enjoys medicine and surgery and has had a long-term interest in animal welfare medicine. Although she has practiced medicine on exotics, dogs and cats, her love for cats led her to seek out an opportunity to focus on just feline medicine. She has a special interest in brachycephalic breeds but loves all types of cats! She believes owner education and communication is important in making care plans that work for each client’s family and their pet.
Dr. Valerie Hargett, DVM, MS
Geriatric & Internal Medicine | Diagnostic Problem-Solving | Client Communication
Dr. Hargett graduated from Washington State University College of Veterinary Medicine in 2000 and went on to earn a Master of Science in Veterinary Infection and Disease Control from the University of Liverpool in 2008. With over 2 decades of experience, she has a special passion for geriatric medicine, guiding families through their pets’ senior years with compassion and individualized care. She also enjoys the challenges of internal medicine and unraveling complex cases.
Dr. Hargett is known for her ability to partner with pet owners through clear communication and collaborative care, ensuring every family understands their options and feels empowered in their pet’s treatment.
Outside of the clinic, she enjoys gardening, camping, canoeing, traveling, and cooking with her husband, Marshall. A lifelong Eastside native, she still lives in her Bellevue childhood home and proudly cheers on the Seahawks and Mariners. At home, she dotes on her beloved calico, Tortie, and any strays that claim her backyard as their own.
Dr. Colleen Cassidy, DVM
Feline Internal Medicine | Ultrasonography | Long-Term Wellness Care
Dr. Cassidy graduated from Cornell University in 2014 and completed a rotating internship in small animal medicine and surgery at Pieper Memorial Veterinary Hospital in Middletown, Connecticut in 2015. Wishing to escape the snowy northeast winters, she moved to Seattle later that same year. Since then, she has spent the last nine years enjoying the mix of sun and rain, while working as a small animal general practitioner with cats and dogs. Now, she’s excited to be on the team at Island Cats and to focus on her favorite species. She has a special interest in feline internal medicine, and ultrasonography, and loves partnering with cat owners to provide lifelong care to their pets. Outside of the clinic Dr Cassidy enjoys training in aerial circus arts, contra dancing, tide pooling on the beach, and walking adventures around Seattle. She shares her home with one human and three cats – Ember, Asher, and Keenan, and loves that the cats outnumber the humans and keep them on their toes!
Our Veterinary Support Team
At Island Cats Veterinary Hospital, our skilled veterinary support team plays a critical role in feline patient care. From assisting in cat dentistry, surgery, and diagnostics to providing client education and compassionate support, our team is dedicated to your cat’s health and well-being.
Practice Manager
Melanie
Licensed Veterinary Technicians & Veterinary Support Staff
Hayla, Licensed Veterinary Technician
Naomi, Lead Veterinary Assistant
Nora, Veterinary Assistant
Dom, Veterinary Assistant
Client Care & Administrative Team
Libby, Lead CSR
Lindsey, CSR & Veterinary Assistant
Katie, CSR
Jeff, Head of HR
Why Choose Our Veterinary Team in Mercer Island, WA?
Feline-Exclusive Expertise
Our vets in Mercer Island specialize in cat health, ensuring feline-friendly care.
Compassionate, Stress-Free Approach
We use low-stress handling techniques to make vet visits easier for your cat.
Advanced Veterinary Care
From preventative care to specialized diagnostics, we offer comprehensive feline healthcare.
Trusted by the Community
We server Mercer Island, Bellevue, Seattle, and surrounding areas with expert cat care.
Get in Touch
We proudly serve the pets of Mercer Island, Bellevue, Seattle, Redmond, Renton, Sammamish, Issaquah, Kirkland, and Bothell. We understand the unique psychological and physical characteristics of cats and strive to maintain an environment focused on minimizing stress and illness in our feline patients.