Meet Our Skilled Team of Vets & Hospital Manager

Spencer Animal Hospital has some of the most committed, caring veterinarians in Pasadena and a dedicated hospital staff! We are a group of passionate, pet-loving professionals who strive to deliver the highest level of excellence to each and every one of our patients. Learn about us online, and make an appointment soon to meet us in person! Call us at (281) 476-0066 to schedule an appointment today.

Interested in joining our team? Apply online!

Dennis Mangum, DVM

Dennis Mangum


A 1971 graduate of the College of Veterinary Medicine at Texas A&M University, Dr. Dennis Mangum loves interacting with people and their pets. He made veterinary medicine his career decision when he was in the fourth grade. After graduating from high school in the East Texas town of Canton, Dr. Mangum continued his studies, never wavering from his goal—to become a veterinarian. After receiving his DVM, Dr. Mangum settled in Pasadena, where, in 1974, he opened the original Spencer Animal Hospital in a small shopping center. In 1979, that practice relocated to our current award-winning facility dedicated to the continuation of providing quality animal health care.

Dr. Mangum’s professional credits include memberships in the American Veterinary Medical Association, Texas Veterinary Medical Association, Harris County Veterinary Medical Association, and the Texas Academy of Veterinary Practice. Additionally, Spencer Animal Hospital is accredited by the American Animal Hospital Association, of which Dr. Mangum is also a member.

Outside of veterinarian medicine, Dr. Mangum serves as a Deacon of his church and enjoys flying (he is a Certified Flight Instructor). His other hobbies include running and biking. Dr. Mangum and his wife have three daughters, four grandsons, and two granddaughters. Two of his daughters and a son-in-law followed his footsteps to Texas A&M. His middle daughter, Alaina, is the Practice Manager of Spencer Animal Hospital.

Dr. Penn

Andrew Penn


Dr. Andrew Penn grew up locally in Pearland, Texas. He received his bachelors in Biomedical Science from Texas A&M University in 2014, and was granted his Doctorate of Veterinary Medicine in early 2020 also from Texas A&M University.


Dr. Penn is a doting cat dad of two neutered male domestic shorthair cats named Calvin and Hobbes.


Dr. Penn likes to spend his downtime spending time with his cats and has recently been training them to run on an exercise wheel. His other hobbies include ballroom dancing, which he has competed in collegiately during both his times at A&M.

Dr Wysocki

Deborah Wysocki


Dr. Deborah Wysocki earned her degree in Veterinary Medicine at Oklahoma State University in 1984. Being a veterinarian was a dream of hers since she was 8 years old and she started working for a veterinarian at the age of 15. Dr. Wysocki has a passion for performing soft tissue surgery, including high quality high volume low cost spays/neuters and solving complicated medical cases. She has extensive experience in various areas of veterinary medicine including exotics, feline medicine (and of course canine medicine), shelter and rescue medicine, urgent veterinary care, emergency veterinary care and general practice. She is fear free certified. She believes in being and advocate for the pets she treats. Her love is especially for shelter and rescue pets and she has numerous rescue dogs herself. Outside of work, some of Dr. Wysocki's favorite things to enjoy are walking her dogs, reading, yard work and work around the house. But overall, she lives her life for her pets.



Hospital Manager

Alaina has worked at Spencer Animal Hospital since graduating from Texas A&M University in May 2004—although really, she’s been around Pasadena since she was born. Dr. Mangum is her father and has had her doing things around the hospital since she can remember. Alaina loves her job! And getting to be around furry pets in a loving atmosphere is an excellent perk, too.

She spends her spare time flying and having fun with her son, daughter, and husband.

Call us at 281-476-0066 to schedule your next visit with one of out expert veterinarians today.