Our Veterinarians

Dr. James Hosek

DVM, Owner, Veterinarian

Dr. Hosek has worked at Merrick Animal Hospital since 1984 and has been the owner since 2008. He also has a house call practice on the north side of Chicago, and spent several years doing relief work in and around the Chicago area. At one point, Dr. Hosek was able to spend 6 months working at a veterinary practice in Georgetown, Grand Cayman in the British West Indies. He has had a strong interest in veterinary medicine since high school and has always loved cats in particular.

Dr. Hosek majored in Animal Science at the University of Illinois before starting Veterinary School in 1984. It was during his time in vet school that he discovered his love for feline medicine and the special way that he is able to connect with cats. He likes to help all animals and make sure they are able to enjoy as healthy a life as possible. In addition to his practice of general medicine and preventative care, Dr. Hosek is credentialed in stem cell therapy.

Dr. Hosek has been married since 1997. His wife is a practicing OB/GYN in Chicago and their two boys are active in cub scouts and boy scouts, love to design new Lego creations, playing computer games and Magic, The Gathering (with their dad!). The Hosek household is made complete with two cats: Sonyonia, a female black short hair born in 2005 and Hedwig, a boy brown tabby from a litter found by the doctor’s sister-in-law under her back porch in 2012 . The cats have adopted the Hosek’s sons and become a much loved part of the family. Sonyonia sticks with their older son, preferring to sit on the backs of chairs and sofas and stare down over her domain. Hedwig hangs out with the younger boy and is amazed with how his cats toys seem to move by themselves when he hits them.

In addition to his passion for veterinary medicine, Dr. Hosek has been interested in gardening, woodworking and writing for as long as he can remember. He has a small greenhouse in his backyard that lets him extend his gardening season. His wood shop turns out plenty of pinewood derby cars for the cub scouts every year as well as a dozen or so major projects over the years. Dr. Hosek has also been fortunate enough to have a short story published in Analog Science Fiction/Science Fact Magazine and his first novel, “A Really Good Day” is available on Amazon.com. He is currently working on a second novel about a house call vet who practices in Chicago.

Dr. Hosek is very active in his son’s scouting activities, having enjoyed scouting himself as a kid and reaching the rank of Eagle. During his time living in the Caribbean, he also learned how to scuba dive and really enjoyed the night dives he got to go on. Unfortunately, he doesn’t get to go golfing as much as he’d like, but he enjoys walloping his brother during the annual summer tournament in Michigan when they try to get in 100+ holes.

Most recently, Dr. Hosek has started training for the next season on American Ninja Warrior along with staff members Mason and Carmen. They hope to stand at the top of Mount Midoriyama together.

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Dr. Cassandra Martin

DVM, Veterinarian

Dr. Cassie Martin is from Olney, Maryland in the suburbs of Washington, DC. She spent most of her childhood practicing at Hill’s Gymnastics, where she began taking classes at Hill’s Gymnastics at the age of 5. She continued to move up the levels, eventually practicing up to 37 hours per week and winning the USA Gymnastics’s Junior Olympic National Championship. Dr. Martin earned an athletic scholarship to The University of Alabama where she competed with the NCAA Alabama Gymnastics team while earning her self-designed degree in Interdisciplinary Sciences.  

Dr. Martin was considering applying for medical school to become a doctor, but that changed when she adopted her first cat, Kitty, and soon thereafter her companion, Greg, at the end of her junior year. For the first time, it occurred to her that she could become a veterinarian and practice medicine while enjoying her love of animals. Dr. Martin then began studying for her veterinary degree at the Virginia-Maryland College of Veterinary Medicine at Virginia Tech in Blacksburg, Virginia. 

During her time there, she joined the Virginia Tech Gymnastics Club and continued to participate in gymnastics, competing through the National Association of Intercollegiate Gymnastics Clubs (NAIGC). While attending a weekend retreat at a gymnastics camp in Crossville, Tennessee, she met John, a firefighter-paramedic from Addison, Illinois. A relationship emerged, and she began her move towards the Chicago area upon her graduation from veterinary school in 2014. In order to gain additional experience in emergency and specialty care, Dr. Martin completed a small animal rotating internship in Indianapolis from 2014-2015 where she worked under the guidance of a board-certified surgeon, ophthalmologist, and two internal medicine specialists in addition to a number of experienced emergency doctors.  

After successfully completing her internship, as well as nearly three years of a long distance relationship, Dr. Martin moved to the Chicago area and now calls Addison home. She and John live with their two cats – the much beloved Kitty and her awkward sidekick, Greg – who enjoy napping in their laps, cuddling under the covers, and surveying the kitchen counters whenever they think they won’t be caught. John and Dr. Martin both serve as volunteer advisers on the NAIGC’s  Board of Directors and enjoy traveling, gardening, cooking, taking the occasional flying trapeze class, and spending time with family and friends in their free time. Dr. Martin loves  all furry creatures, but takes a special interest in cats due to their sassy, quirky personalities.

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Dr. Meg Sullivan

DVM, Veterinarian

Dr. Meg Sullivan knew from an early age that she wanted to dedicate her life to veterinary medicine.  As she considers being a veterinarian her calling, Dr. Sullivan is very grateful to be able to combine her love for animals, as well as that for science and medicine, into her daily life.  Dr. Sullivan grew up in the Chicago suburb of Wheaton, Illinois, and obtained her undergraduate degree from Augustana College.  Upon graduating from the University of Illinois College of Veterinary Medicine, Dr. Sullivan worked in both the Chicagoland area and central Illinois before finding her home at Merrick Animal Hospital.

Dr. Sullivan is a member of the American Veterinary Medical Association as well as the Illinois State Veterinary Medical Association.  While Dr. Sullivan enjoys all aspects of veterinary medicine, she has special interests in oncology, geriatric medicine, and soft tissue surgery.

When she is not at work, Dr. Sullivan enjoys spending time with her husband Drew (also a veterinarian), and their two adopted dogs Haley and Oskee (an 11-year-old shepherd mix and a 7-year-old border collie mix, respectively).  Dr. Sullivan also enjoys cheering on her beloved Chicago sports teams; go Cubs, Bulls, Bears and Hawks!  Her and her husband also love watching their alma mater Fighting Illini, and attend games as able.  Having recently relocated to the city, Dr. Sullivan is excited for all that Chicago has to offer!

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Dr. James Antonicic


Born and raised in Westmont, Dr Antonicic has always been drawn to animals. Besides the family pets of a dog, a cat, and a rabbit, he would become the temporary guardian of garter snakes caught in the field, tadpoles caught in the pond, and anything else his mother would let him bring in the house. While studying biology at Illinois Wesleyan University and considering a possible career in ecology, he decided that veterinary medicine was a far better fit for his passion for animals. From there, he went on to veterinary school at the University of Illinois, graduating in 1994 and returning to the western suburbs to begin practice in a clinic that treated dogs, cats, and all manner of exotic animals.
Exotic animal medicine remains one of Dr. Antonicic’s favorite pursuits. He enjoys the challenge of treating these unique pets, and has worked with birds, snakes, lizards, turtles, tortoises, ferrets, rabbits, guinea pigs, sugar gliders, prairie dogs, hamsters, gerbils, rats, mice, and the occasional chicken. Not only does he make sure the pet is healthy, but he makes sure the owners know all the food and housing choices needed to keep these pets from needing to come see the vet too soon!  

Dr. Antonicic also enjoys surgery, ultrasound, and is intrigued by and continues to learn about adjunctive therapies.
When not taking care of clients and their pets, Dr. Antonicic spends his time in the city of Chicago, soaking up the urban verve of concerts, theater, museums and restaurants. He enjoys reading, cooking, bicycling, photography and taking classes to keep his French up to date. He has been known to attend the occasional yoga class when his wife, Jenni, guilts him into taking one of her classes. At some point he would like to get back to learning the Argentine tango.
Dr. Antonicic and his wife also enjoy traveling together, especially internationally. Two years ago they both took a sabbatical and traveled around the world, stopping in Fiji, Australia, India, Turkey, Bulgaria, Macedonia, Croatia, Italy, France, and Ireland.
Dr. Antonicic is indentured to two cats, Sassella and Quintus. While both are calico, Sassella is bold and sassy while Quintus is petit and demure. Both are equally lovable.

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