The Clinic Specializes in the Treatment and Research of Cat All Behavior Issues
Licensed and Certified, Harvard and Oxford-trained, Award-winning Cats-exclusively Behavior Help Scientifically Observing and Analyzing Your Cat’s Gene-encoded Behavior From a Behavioral Cognitive, Ethological, and Feline Evolutionary Point of View
Cats Exclusively with More Cat Owners Purring Than Anyone in Over 30 Countries
View 350 Client Success Cases

Mieshelle’s Book is Curriculum to Certify Many Cat Experts You See Today. The Cat Behavior Clinic is the Recipient of the “Gold Purr Award” and the “2020 Business Award for Exemplary Businesses and People in the Field of Animal Behavior”. (Photo: Mieshelle with her partner who is also a veterinarian).
- Zoom Appointment Update: We are scheduling our doctor and cat behaviorist team through October 31st. Through October 4th receive the study participation reduced fee for urination or defecation appointments. Become a part of Mieshelle’s 2-time Academy Award-winning cat behavior show production on Discovery Plus Channel (the most watched cat behavior show in the world with over 1 billion viewers).
How to Schedule for Cat Owners
- In-home, phone, or Zoom cat behavior appointments: to learn more about the process or to schedule, please call the clinic at 503-267-8888. You can also schedule through this clinic website online here. We guarantee an appointment within 1 to 7 days.
- Cat behavior exclusively, we specialize in urination, defecation, all forms of aggression, and excessive vocalization. Read about our outstanding clinic success rate for common cat behavior issues.
- Urination or defecation consultations receive the $125.00 study discount by participating in our feline study. You will be helping cats just like yours that are experiencing litter box issues. You can call the clinic to schedule or visit online here.
- Dietary Questions?: Mieshelle is also the cat nutritional research and development expert for the largest cat food company and manufacturer in the world. Our clinic believes diet is the cornerstone for a behaviorally thriving cat.


Founder of the clinic, Mieshelle Nagelschneider, studied animal behavior at Oxford University, Harvard University, and the University of Edinburgh Royal School of Veterinary Studies. She is also the new host for the award winning television show “My Cat From Hell” for Discovery Plus Channel with over 1 billion viewers internationally.

Cat Behavior Areas of Specialization: Cat Urination, Defecation, Spraying, Aggression and Vocalization Behavioral Issues
The Cat Behavior Clinic is the first Cats Exclusively behavior clinic in Portland, Oregon. Our skilled doctors and certified cat behaviorist have more cat owners purring than anyone. Conducting several thousand urination, defecation, and cat aggression cat behavior consultations, our cat behaviorist is also a cat behavior expert and researcher for National Geographic and the host for the television show “My Cat From Hell” on Discovery Channel. Please visit our home page to view common cat behavior issues we work with and to schedule an appointment. The clinic routinely works with cat owners who feel they have tried everything to solve their cat’s behavior issues. Learn more about our team here.

Applying the sciences of gene-encoded wild felid behavior, animal psychology, feline learning and memory and biology to effectively correct a cat’s behavior long term.
An in-depth scientific analysis of cat behavior based on the evolutionary biology of the cat, has enabled the clinic to help thousands of cat owners for over two decades not only in Portland, but remotely in over 30 different countries. Because of a lack of board certified veterinary behaviorists specializing in cats and credentialed cat behaviorists has always been an ongoing issue (and still is) not only in Portland, Oregon, but around the world, the clinic has helped cat owners from New Zealand to Kuwait. In addition to our cat behaviorist conducting local in-home, phone or video consultations, our veterinarians perform local in-home or vet-to-vet remote consultations.
What’s New with Mieshelle on National Geographic?

As a cat behavior science author she is also a long-time cat expert and researcher for many of National Geographic’s published works on the 37 species of wildcats, tigers, and every breed of the domestic house cat. You can also watch Mieshelle with Howie Mandel on National Geographic’s Animals Doing Things as their cat expert and other cat behavior documentaries by Nat Geo Wild (Wild Side of Cats – 2010).
Founder of the Clinic and Our Cat Behaviorist is a New York Times Acclaimed Cat Behavior Science Author – Random House Publishing

Cat Behavior Testimonials for Portland, Oregon
View 350 solved case studies and cat behavior testimonials.
Cat Behaviorist Portland Testimonial: “I was extremely pleased with my experience with The Cat Behavior Clinic. I have been dealing with litter box issues for a very long time and my experience was a world away from working with an animal behaviorist vs. a cat behaviorist. The cat problems I’d been dealing with were extreme and long term and after the consultation and following the instructions, my cats began using the litter box 100% of the time (before my consult it was 75% of the time) within 4 days. I would strongly recommend working with someone who specializes in cats because if they don’t, they really have no idea what to do with cat behavior and I learned this the hard way after spending $1500.00 just to get in the door at another behavior clinic that got me not one ounce of success. I will be letting my referral vet know what a great experience it was working with you guys. All the Best, J. M. and 6 Perfect and Happy Felines. Finally!” Portland, Oregon
World-renowned Oxford-trained Cat Behaviorist Mieshelle Nagelschneider, The Cat Whisperer™️
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