Our Staff

We treat your pets like family.

Dr. Sharon Payne

Dr. Sharon Payne


Dr. Sharon is a partner at Animal Care Clinics and a graduate of the University of Illinois. She worked at Care Animal Hospital in Arlington Heights before joining the Animal Care Clinic staff in 1997. Her special interest is in feline medicine as well as environmental and behavioral enrichment for cats. She believes in making each visit as low-stress and pleasant as possible for all of her patients. 

Dr. Sharon and her husband Scott share their home with five cats: Maximus, Sheldon, and three Cornish Rex cats named Leonard, Bernadette and Penny. 

Fun facts about Dr. Sharon:

Favorite pizza topping? All veggies!

Hidden Talent: I can Hula Hoop for hours.

First car: Chevy S10 pickup truck

Dr. Nicole Conway

Dr. Nicole Conway


Dr. Nicole is from Lake in the Hills, and she has been bringing her pets to the Animal Care Clinic for years. She received her Bachelor’s degree in Animal Sciences from the University of Illinois before going to the University of Missouri College of Veterinary Medicine. 

Dr. Nicole joined the Animal Care Clinic in June 2017 and has a special interest in preventative medicine and cardiology. She enjoys running, baking, and spending time with her family as well as her dog, Ember. 

Fun facts about Dr. Nicole:

If you could be an animal, what would you be? A cat owned by Dr. Sharon!

What was your first job? Laboratory technician.

Do you prefer books or movies? Movies.

Dr. Dan Markwalder

Dr. Dan Markwalder


Dr. Dan is a graduate of Purdue University School of Veterinary Medicine and has been a practicing veterinarian for 26 years. He established the Animal Care Clinic in Algonquin in March 1994 to provide an environment of high-quality care for his patients. Dr. Dan has a passion to partner with clients in providing the best care for their pets. He attends over 80 hours of continuing education each year; skydived on his 50th birthday, is a die-hard Cubs fan, grew up in Indiana and has an extensive baseball card collection.

Dr. Dan married his college sweetheart. They have four sons and a daughter, along with a Mini Goldendoodle named Maggie, a parakeet and one bearded dragon.

Fun Facts about Dr. Dan:

If you could go anywhere, where would you go? To see the pyramids of Egypt.

Are you a morning person or a night person? I am definitely a morning person!

If you could have one superpower, what would you choose? To be able to teleport.

Dr. Paul Bierlein

Dr. Paul Bierlein


Dr. Paul is a graduate of Michigan State University College of Veterinary Medicine. After graduation, he moved to Illinois and practiced in Arlington Heights with Dr. Sharon at Care Animal Hospital, then practiced in Fox Lake at Fox Lake Animal Hospital. Dr. Paul joined the Animal Care Clinic staff in August 2005. His special interests include soft tissue surgery and orthopedic surgery. 

Dr. Paul and his wife Sue are the proud parents of Michaela and Drew. They share their home with a dog, a fish, and a snake. 

Fun facts about Dr. Paul:

If you could travel anywhere, where would you go? Europe.

Favorite pizza topping: Green pepper.

First car: Pontiac J 2000.

Dr. Cassandra Lewis

Dr. Cassandra Lewis


Dr. Cassandra is a 2009 graduate of the Purdue University School of Veterinary Medicine. Originally a Hoosier, she moved from Indiana to Illinois upon graduation to complete a surgical and lameness internship at the Kendall Road Equine Hospital. She was excited to join the Animal Care Center in September 2016. Her special interests are surgery, preventative care, and internal medicine. 

Dr. Cassandra and her husband currently share their home with their two dogs Nova and Stewart Francis, as well as two cats named Reva and Halo. She occasionally fosters all kinds of animals for a variety of rescues that she supports. She also loves the Blackhawks and riding motorcycles. She has a huge collection of teddy bears that are dressed up as different animals. 

Fun facts about Dr. Cassandra:

If you could be any animal, what would you be? A bald eagle, because I’m protected and can fly and have mad vision!

What was your first job? Wendy’s–flipping burgers!

Are you a morning person or a night person? A night person, for sure.

Dr. Sarah Massarani

Dr. Sarah Massarani


Dr. Sarah’s interest in veterinary medicine began after volunteering for local animal shelters in high school. She attended Loyola University of Chicago where she majored in Biology and Ecology. Before attending veterinary school at The University of Minnesota, Dr. Sarah worked as a veterinary assistant at a general practice in McHenry. While in veterinary school, Dr. Sarah worked as an assistant for the university’s canine and feline blood donor program and intensive care unit. After graduating from veterinary school, Dr. Sarah completed a year-long small animal rotating internship program with Premier Veterinary Group in Chicago.
Dr. Sarah currently lives in Barrington with her cats Betty and Juno. In her free time, she enjoys being outdoors (hiking, biking), practicing yoga, traveling, reading and spending time with her friends and family. Dr. Sarah is bilingual, a Chicago sports fan, knows how to play the clarinet and crochet. She is excited to be working at The Animal Care Clinic and looks forward to taking care of your furry family members. 
Fun facts about Dr. Sarah:

Favorite pizza topping? Veggies!

Hidden Talent: An impressive Jar Jar Binx impersonation 

First car: 1997 Toyota Camry

Dr. Alex Kozysa

Dr. Alex Kozysa


Dr. Alex is a graduate of the University of Illinois, where she obtained both her undergraduate degree in Animal Sciences and veterinary degree. While in school, she volunteered at the Wildlife Medical Clinic for 6 years and gained experience caring for and treating native wildlife species. She is also interested in exotic animal medicine and enjoys working with small mammals (rabbits, ferrets, guinea pigs, rats, etc.), reptiles and birds. Other interests in veterinary medicine include ophthalmology and dermatology. 
Dr. Alex grew up in Lake in the Hills and is excited to practice in the clinic she brought her pets to. In her free time, she enjoys playing piano, painting, traveling and binge watching Netflix (her favorite show is Friends). She has a cat, Onyx, and a California king snake, Wilma. Dr. Alex is also bilingual and speaks fluent Polish. 

Fun facts about Dr. Alex:

Favorite pizza topping? Jalapeno! 

Morning or Night Person: Definitely a night person

First car: 2002 Toyota Camry

Contact Us

230 Stonegate Road
Algonquin, IL 60102


(847) 462-6162


Mon - Fri: 7:00 am - 7:00 pm
Sat: 8:00 am - 2:00 pm
Sun: 10:00 am - 1:00 pm

Have a question?

Complete the form below and a member of our team will get back to you as quickly as possible. If you need immediate assistance, please call us at 847-854-8387.