Dr Mark Handel


From the moment Dr. Handel read James Herriot’s novel All Creatures Great and Small, he knew veterinary medicine was his path in life. 30 years later, he still loves going to work every day to care for Vista’s pets!

Mark was born and raised in St. Louis, Missouri, and attended the University of Missouri for both his Bachelors of Science in Biochemistry and his DVM degree. He worked at a clinic in Laguna Hills before becoming the manager and medical director of the South Orange County Emergency Clinic in Orange County. In 1987 he moved to Vista and purchased Palomar Animal Hospital.

Dr. Handel particularly enjoys ultrasound, internal medicine, dentistry, and soft tissue surgery. He also works closely with animal rescue groups that save unwanted pets from local shelters.

At home, Mark lives with his wife, a registered dietician, and the family’s three dogs: two Chihuahuas named Toby and Chica, and a Cattle dog rescue from Utah named Bryce. The Handel’s are proud of their two adult sons who are pursuing their careers in college.

In his spare time, Dr. Handel enjoys horticulture, gardening, golfing, fishing and hiking. In 2013 Mark and friends reached the 14,505 foot summit of Mt. Whitney, a trek that took 14 hours!

Read More

Photo of Dr Mark  Handel

Dr Linda Knox

Associate Veterinarian

Since elementary school, Dr. Knox had been telling everyone who would listen that she wanted to be a veterinarian when she grew up. When it came to apply for college, she had already settled on UC Davis, the only veterinary school in California at that time.

Dr. Knox grew up in the San Fernando Valley with her mom, brother, and the family dogs. After completing her undergraduate degree in Zoology, she stayed at UC Davis for her veterinary degree, then spent another year there completing her Master’s degree in preventative medicine. She worked part-time for a small animal practice while getting her Master’s, and loved it so much that she’s still doing it to this day!

Dr. Knox says her favorite days are those filled with a variety of cases—she likes the way it keeps things interesting and challenging. Her special interest is in exotic species, including rabbits, pocket pets and birds. She also loves interacting with people and appreciating the unique bonds they have with their pets.

At home, Dr. Knox lives with two pets of her own: Fiona, a dog that Dr. Knox rescued from the clinic during her second year here, and Bogart, a 20-year-old Senegal parrot she hand-raised. When she’s not spending time with her pets, Dr. Knox enjoys playing tennis, bicycling, skiing, hiking, and scuba diving. She’s also an avid traveler, and has visited Europe, Australia/New Zealand, Africa, South America and many Caribbean islands to date.

Read More

Photo of Dr Linda  Knox

Dr Jennifer Nissen

Associate Veterinarian

Although she majored in biology during college and thoroughly enjoyed her studies, Jennifer could not imagine sitting behind a lab bench for the rest of her career. She thought back to her love of animals, and realized veterinary medicine was the perfect way to combine her scientific interests with her passion for helping others!

Originally from Massachusetts, Dr. Nissen slowly worked her way across the country; she completed her Bachelor’s degree at the University of Chicago in 1996, then received her veterinary degree from Michigan State University in 2002. After completing a year-long rotating internship at a small animal, exotics, and specialty hospital in Arizona, Dr. Nissen moved to San Diego to be closer to family. She worked at two separate small animal and exotics hospitals before joining Palomar Animal Hospital’s team in July of 2013.

In addition to avian and exotics medicine, Dr. Nissen’s special interests include dermatology, nutrition, soft tissue surgery and ultrasound. Dermatology is her favorite professional aspect of her job. She says it’s one of the most common issues presented to her, but one of the most challenging! She loves helping out pets and their owners who have been struggling with skin issues for years.

At home, Dr. Nissen lives with her husband Corby, a stay-at-home dad, and their two children. Bella, a Poodle/Bichon mix, rounds out the family.

Outside of the hospital, Jennifer enjoys knitting, biking, and reading. She especially enjoys science fiction and fantasy novels, and actually met her husband at a science fiction convention!

Dr. Nissen is proud to be a part of Palomar Animal Hospital. She recognizes the strong bond between people and their pets, and looks forward to providing you with the information, support, and care that you need to protect all of your pets’ health for their entire life.

Read More

Photo of Dr Jennifer  Nissen