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!
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. Cesar Simon-Vazquez was born in Madrid, Spain. Due to the love he had for medicine and animals, he knew that being a Veterinarian was in his future.
Dr. Simon first began working on a rabbit farm in Spain around 1990, and then moved his way up through practicing as a freelance surgeon. In 1995, Dr. Simon began practicing as a veterinarian for a small animal practice. He moved to England, UK around 1998 and practiced veterinary medicine for about 10 years. In 2008, he moved to Bastrop, Texas. In 2011, Dr. Simon passed his North American Veterinary Licensing. In 2013, he became certified through the Educational Commission for Foreign Veterinary Graduates. Lastly, in 2013, Dr. Simon became certified through the Texas Board of Veterinary Medical Examiners.
Dr. Simon has a Texas-born son and a greyhound mixed breed, Flaca, which was rescued from the Houston SPCA. Last, but certainly not least, he has a bearded dragon named Shaggy!
Dr. Simon enjoys spending time with his son, as he is the joy of his life. If time allows, he will hit up the gym to get in a good workout. Dr. Simon also enjoys reading with a special interest in history, philosophy and psychology.
We are so pleased Dr. Simon is a part of our practice. Did we mention that he is bilingual?
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. Elizabeth West was born and raised in Alto, a tiny rural east Texas town. Growing up in the country offered Dr. West a wonderful childhood with many opportunities to learn about agriculture and animal growth and development. These experiences shaped her passion and love for animals.
Dr. West earned her undergraduate degree in Animal Science from Texas A&M University in 2017. She continued her studies at Texas A&M’s College of Veterinary Medicine and graduated in May 2021.
Following veterinary school, Dr. West moved to Pasadena to join her fiancé who is a chemical engineer at Valero. They are excited to be starting their newlywed life together.
Since joining Spencer Animal Hospital, she has thoroughly enjoyed helping animals by providing high quality medical services and building relationships with their owners. It is her goal to serve her clients and their beloved pets for many years to come.
In her free time, Dr. West enjoys spending time with family and her black Labrador, Sadie. She also enjoys shopping, fishing, traveling, spending time on the lake, and flying.
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.