Contact Us

Welcome to Lange Animal Clinic

Your Veterinarian in Pekin,IL

Call us at (309) 347-4679

Pet Emergency? Call us right away at (309) 347-4679!

Dr. Colleen O'Rourke


"Thank you for visiting us. We have proudly served the Pekin, IL community and surrounding areas for over 40 years. We look forward to providing your pet and you with First Class Service!

If you live in Pekin or the surrounding area and need a trusted veterinarian to care for your pets – look no further. Your pets’ health and wellbeing are very important to us, and we take every possible measure to give your animals the care they deserve.

Lange Animal Clinic is a full-service animal hospital and welcomes both emergency treatment cases as well as pet patients in need of routine medical, surgical, and dental care. We have years of experience treating serious conditions and offering regular pet wellness care. Beyond first-rate pet care, we make our clinic comfortable, kid-friendly, and calm, so your pet can relax in the waiting room and look forward to meeting our Pekin veterinarian.

We are happy to offer a number of resources that enable you to learn about how to take better care of your pets. Please feel free to browse our site, particularly the informational articles. The best veterinary care for animals is ongoing nutrition and problem prevention, so becoming knowledgeable about preventative pet care is essential to the ongoing success of your animal’s health. If you have any questions, call (309) 347-4679 or email us and we'll promptly get back to you. Our Pekin veterinarian office is very easy to get to -- just check out the map below! We also welcome you to subscribe to our newsletter, which is created especially for Pekin pet owners.

At Lange Animal Clinic, we treat your pets like the valued family members they are.

Pekin Veterinarian | Lange Animal Clinic | (309) 347-4679

1305 Black Street
Pekin, IL 61554

Shop Online:

Visit our online store & order dietary products, medications, and supplies shipped directly to your home or work!

Meet Our Doctors

  • Dr.
    Colleen O'Rourke
    Owner & DVM

    I joined Lange Animal Clinic in the fall of 2000.  I enjoy helping pet owners in the Pekin community provide healthier lives for their pets.  I hope that I can make a difference in the lives of my clients as well as my patients.

  • Dr.
    Gail Mercier

    I have been an associate veterinarian at Lange Animal Clinic since 2001.  I enjoy spending time with both the pets and their people, many who have been life-long clients.


Read What Our Clients Say

  • "A wonderful group of people that truly care about yours and your animals well being. The service and care that Lange provides is second to none. I highly recommend Lange Animal Clinic for all of your pet's needs."
    Michael P.
  • "Great doctors, Great staff and they all care for your animals like they are their own. So if you're looking for an Animal Doctor this is the place you're looking for."
    Darryl R.
  • "I have taken my pets to Lange Animal Clinic for years. In fact, it goes back to the 1960s. When Dr. Lange retired and Dr. O'Rourke took over I remained with him. I have never had a bad experience. I find all of the staff to be compassionate, caring, and provide very lovingly care for all of God's little creatures that we love so much. Their expertise takes into consideration possible upcoming problems as your loved one ages and tries to prevent or slow the process by explaining clearly what you can or cannot do about the condition. I have the utmost respect and confidence in all of the Drs. and staff there. Thank you for all the care have given us."
    Sharon B.
  • "I just love this vet, been going here for over 30 years. Each employee truly cares for each animal. I had never had a problem. I know my fur babies are in great hands. Keep up the awesome work."
  • "Thank you Lange Animal Clinic for managing my dog's care until the very end. I just had to put my dog down today and I am very grateful for the care your clinic, technicians and doctor provided in handling the event. Thank you."
    Renee W.
  • "The friendly and professional staff at Lange is truly amazing. I would never take my pets anywhere else. They know you by name as well as know the pets by name as soon as you walk in the door. Been going here for 16 years and Dr. Colleen is wonderful. Highly recommended."
    Paula S.

Featured Articles

Read about interesting topics

  • The Most Common Vaccinations for Your Cat and Dog

    Do you know what vaccines your cat or dog needs? ...

    Read More
  • Preparing for Your Kitten’s Developmental Milestones

    Need to hone in on your kitten knowledge? Check out the milestones your new pet will reach during its first year. ...

    Read More
  • What Is Ataxia in Dogs?

    Could balance or gait issues mean your dog has ataxia? ...

    Read More
  • Fish

    If you’re thinking of getting a pet fish, you should know that your veterinarian has a lot of good advice about pet ownership. Fish can be very rewarding as pets, and you just may be surprised about how much fish actually interact with their owners. Here’s more valuable information about choosing ...

    Read More
  • Caring for Senior Cats

    Thanks to advancements in veterinary care, today’s cats can live well into their teen years. It is not uncommon for cats to live to be 18 or even older. However, in order for cats to live a long full life, they need proactive veterinary care to stay healthy. As cats age, they are at greater risk for ...

    Read More
  • Feline Stomatitis: Treatments

    Cats rarely display their pain, but cats with feline stomatitis are often the exception. If your cat appears to have mouth pain, is reluctant to eat, doesn't want to groom, is drooling, and doesn't want you to open its mouth, it may be suffering from this debilitating, degenerative oral condition, and ...

    Read More
  • Feline Leukemia Virus: What You Need to Know

    Feline leukemia (FeLV) is a virus that weakens your cat's immune system. Unfortunately, when the immune system does not function properly, your cat may be more likely to develop other diseases, such as cancer and blood disorders. How Cats Contract Feline Leukemia Cats get feline leukemia from other cats. ...

    Read More
  • Family Cats and Pregnant Women: Take Measures to Prevent Toxoplasmosis Infection

    Nothing must spoil the joys of becoming a new parent. Not even your pets. But family cats with normal, every day habits can pose a risk to expectant women. Women's immune systems can be disturbed by a parasite carried in fecal matter. If you're the primary caretaker of your family's feline friend it ...

    Read More
  • Create an Environment Your Cat Will Love

    The Journal of Feline Medicine and Surgery confirms that feline emotional wellbeing, behavior and physical health are a result of how comfortable they are in their environment. Understanding how our cats interact with their environment can help us create a space for owners and cats to mutually thrive ...

    Read More
  • Catnip: Why Cats Love It

    Few things stimulate a cat's pleasure faster than catnip. Exposure to this simple herb can reveal a new side to their feline personality. Many cats will go crazy at the smell of this plant. Catnip has a reputation of being a feline drug and many cat owners wonder if it is safe to give it to their pet. ...

    Read More

Newsletter Signup

Sign up for more articles


Find us on the map

Office Hours

Our Regular Schedule

Pekin Office


8:00 am-12:00 pm

1:00 pm-5:00 pm


8:00 am-12:00 pm

1:00 pm-5:00 pm


8:00 am-12:00 pm

1:00 pm-5:00 pm


8:00 am-12:00 pm

1:00 pm-5:00 pm


8:00 am-12:00 pm

1:00 pm-5:00 pm


8:00 am-12:00 pm