Diane T. Cosko, DVM, JD, MSc Veterinary Forensic Sciences
Veterinarian, Lawyer, Hospital Owner & Manager

Born and raised in Southern California, I couldn’t ask for a better place to live than the Greater Frazier Mountain Area. Each day I look forward to coming into work. Veterinary medicine is my passion. I feel so very lucky to be doing what I do in such a beautiful environment.
Over time, many, many years ago, I received 3 degrees from UC Davis. A Bachelor in Science degree for Behavioral Genetics, another Bachelor in Science degree for Veterinary Science and, in 1987, a Doctor of Veterinary Medicine degree. After spending a large amount of time dealing with animal law, I finally did get a law degree and passed the California State Bar in 2010 so I can now do even more as far as different aspects of animal law are concerned.

Not yet satisfied, I earned a Master’s degree in Veterinary Forensics to bridge what I do with law and medicine from University of Florida in 2019. It’s as exciting as one would envision from all of the television programs but not so much hoopla! I have been working as a veterinarian in the Frazier Park area since 1988. Out of necessity for the community, I started Mountain Aire Veterinary Hospital in July of 1989. I have lived in Pine Mountain Club, Frazier Park and now Lebec, with my husband, Bob Leonis and always enjoy a house full of “4-legged” children.

Although my hobbies are many, my free time to enjoy them is scant. But I especially enjoy the arts (sculpture, drawing and tile-painting) and traveling (if anyone knows me, they know my favorite place to visit is Tasmania!) Unfortunately, most of my free time is spent weeding out those horrific plants called ‘Foxtails’ that can and do harm the animals.

Prior to moving up here full time in 1990, I worked in San Diego and West Los Angeles – for all of their conveniences and diversity, I would hate to have to move back – it’s just too beautiful up here. Many of my clients that I have known since the late eighties and early nineties are still bringing their pets to me today, as are their now-grown children, who are now adults and have their own children! – it makes for one very large, extended family.


Sarah Halks
Senior Veterinary Assistant, Customer Service Specialist

Hi my name is Sarah. I’ve always had a special connection with animals, and found myself involved in the veterinary field from an early age. Like most in this field, I started out cleaning kennels, and worked my way up to senior veterinary assistant over the last 19 years. My areas of interest include dentistry, nutrition, and practice management.

When I’m not evaluating a pet’s dental status, or working clients on their pet’s diet, and caloric requirements, or maintaining the hospital inventory, I can be found at home with my kids. Besides the fur-less children, I have 2 dogs- Sam and Tucker. I also enjoy scrap booking, cooking and spending time camping with my crew.


Catherine “Cat” Whitelock
Senior Veterinary Assistant, Customer Service Specialist, Hospital Graphic Design & Social Media

I started out as a volunteer waaaay back in 1995. After about 18 months I graduated high school and went on adventures pursuing a Bachelor of Arts at Scripps College (’00 Behavioral Psychology), then a Bachelor of Science at The Art Institute of Pittsburgh (’03 Graphic Design) while working as a horse trainer and then a zookeeper (California Living Museum). I returned to Mountain Aire in late 2002 as Director of Boarding Kennels and Baby Tech just before finishing my second degree.

Since then, I’ve become a familiar face in the hospital itself working my way up to a Senior Technician/Veterinary Assistant and Customer Service Representative. In 2013 I completed courses at Veterinary Allied Staff Education (Veterinary Technician), and in January 2022 became Fear Free Certified. My husband and I opened Los Padres Kung Fu San Soo in Lake of the Woods in December 2015.

If all of that doesn’t keep me busy enough, I’m also the Vice President of the Mountain Memories Association (since 2009). We bring you the annual Ridge Route Run Car Show, Fiesta Days, and Mountain Communities Holiday Faire events each year. You’ll often see me at any community event in very colorful attire accompanied by my senior American bully Vera or Dogo Argentine puppy Penelope pond; both of whom are officially the ‘Public Relations PAWficer’ mascots of our festivals and an ambassa-dog for their breeds. Their lives are very busy wagging tails, shaking hands, and kissing babies….or anyone who’s close enough.

During the spring, summer, and fall months I also help as the snake handler for Rattlesnake Avoidance Training for dogs with Ma’N Paw Kennels.

Last, but definitely not least, I spend one day a week at Shelter on the Hill helping assure our local adoptable pets are as happy and healthy as they can be for future fur-ever homes.

DeAnn Zarkowski
Veterinary Assistant, Kennel Manager and Animal Trainer

Pursing her innate passion for nature and animals, De Ann earned her degree in Animal Training and Management in 1991. Over the past 25 years she has cared for over 200 species, trained animals around the world for various film productions and taught in-home obedience as well as collaborated in the development of group classes; teaching as many as 13 classes per week! De Ann also enjoys horseback riding, hiking, camping and volunteering for pet and wildlife rescue.

Heidi Noyola
Veterinary Assistant, Paperwork Manager, OSHA and Housekeeping Oversight
Heidi has been such a great lover of animals all her life, that working at a vet’s office was her “dream job.” She wanted to run her own rescue when she grew up.

Tracy Haramia
Kennel Attendant
Bio coming soon.

Tami Kearney
Veterinary Technician Assistant on Dental Hygienist Days, “Go-To” Person for Pet Behavior Questions, Certified Dog Trainer and Owner of Mtn Top K9 Training

Hi, my name is Tami. I initially started as a client back in 1991 and was impressed with how friendly everyone was and how they cared for my pet. I eventually asked if I could volunteer, which turned into my applying, going to school and becoming a certified Vet Tech. I am a big animal lover and I have always had them since I was a little girl. Taking care of animals has always come natural to me, and my coworkers say I even talk their language. That is why I went back to school and became a Certified Dog Trainer, as well.

I currently live in Cuddy Valley with my husband Patrick (of Shanpat Construction) 3 dogs Chloe, Nala and Timber, and one cat Smokey. Talk about Pet Insurance! I’m hoping to have horses someday also.