A brown and black dog, possibly a Belgian Malinois, walking through tall, golden grass in a natural outdoor setting, possibly a field or meadow.
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Experienced K9 detection training

Underdog Detection Services offers K9 detection training for sport competitors, working dog handlers, and agencies in the San Antonio area. Every session is built around your dog and your handler — not a fixed program.

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Services

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All sessions are held at a location of the owner’s choosing, or a location the group agrees on. Travel outside 50 miles from San Antonio: $1 per mile.

Five K9 nosework clients standing outdoors near a tree and an old car, posing for a training session group photo.

Group training sessions

Sessions for 3–4 dog teams covering scent detection, search patterns, odor recognition, and handler technique. Structured but flexible to what your group needs that day.

$50 per team · 1–2 hrs

A woman in a blue hoodie and jeans kneeling on the floor of an indoor dog training facility, training a golden retriever puppy sitting in front of her. There are scent jars or containers on the floor nearby.

UPWADA certification

If your K9 team is working toward UPWADA certification, we can help you understand exactly what's expected, where your team currently stands, and what it takes to close the gap. No guesswork — just honest preparation for what the evaluation actually requires.

Inquire for availability and pricing.

A nosework client in a white shirt and blue jeans training a dog in a grassy backyard. The dog is brown and black, and appears to be a border collie. They are scent work training.

Private training

One-on-one sessions built around your dog's specific strengths and gaps. Ruben watches your team closely — no cookie-cutter curriculum, no assumptions carried over from other dogs.

$100 · 1.5 hrs

Ruben Pena and several of his scent work clients posing with their competition awards. They are smiling in a rustic setting after a day of scent trials with their dog.

Seminars & workshops

Can provide 3–5 day seminars or 1–3 week workshops, upon request. Topics include scent theory, training aid management, search behavior, problem solving, and tracking and trailing. Available for groups and organizations.

Inquire for availability and pricing.

A woman with red hair, wearing a gray cap, black vest, and blue jeans, is walking a black dog on a trail in a forest with dense green and brown foliage.

evaluations & assessments

A structured, objective review of your K9 team. Ruben identifies what's working, where the gaps are, and what to do about it — whether you're preparing for certification or just want to know where you stand.

Inquire for details.

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nosework judge

Available to judge nosework trials and events for sanctioned sport dog organizations. Grounded in real-world detection work, the focus is on what the dog is actually doing — how it searches, how it communicates, and how the handler reads it.

Inquire for availability and pricing.

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Ruben Pena

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Founder, Underdog Detections Services · San Antonio, TX

Ruben began his career as a K9 handler and trainer in the U.S. Air Force Security Police. Over 37 years that followed, he trained domestic and international law enforcement and military teams in narcotics and explosives detection, built complete K9 programs for the U.S. State Department's landmine and unexploded ordnance initiatives, and served as a K9 Trainer, Instructor, and Supervisor with the Department of Homeland Security's TSA — preparing detection teams for agencies including Federal Protective Services, TSA, and the U.S. Coast Guard.

His approach is patient, individualized, and grounded in the understanding that every dog and handler team is different. The goal is always the same: a reliable team that knows what it's doing and why.

  • Accredited United Police Work Dog Association (UPWDA) Master Trainer - K9 Certifications

  • National Association of Canine Scent Work (NACSW) Judge

ruben pena k9 instructor active duty

“Ruben is a highly skilled K-9 trainer and handler with many decades of real life experience. he matches your abilities with your particular dog — he’s not a one size fits all trainer.”

— Doris Blake, Client

“Ruben has taught Team CCleo so many things. But one of the most important lessons is to have fun and Enjoy your dog!”

— Kathy Haygood, Client

“I have trained three dogs with Ruben for over 10 years. Training with Ruben is tailored to the needs of the specific dog and handler to help them be the best team possible.”

— Patricia Schwartz, Client

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A Belgian Malinois dog sitting on tiled floor with ribbons and awards in front. The dog has an award ribbon on its neck. The room has a large window, wooden chairs, a glass-fronted cabinet, and various decorations, with trees visible outside.
Three elderly people, two women and one man, stand outdoors in front of a large tree, with two German Shepherd dogs sitting nearby. The man wears a cap and casual clothing, the woman in the middle wears a light gray hoodie, and the woman on the right wears a vest and a black t-shirt. The scene appears to be in a park or a yard on a sunny day.
A woman with curly, gray hair and glasses smiling while holding a yellow Labrador retriever puppy with a birthday bandana sitting on her lap, in front of a wooden wall.
A person in a blue shirt and gray jeans is hugging a white dog with black spots, wearing a harness with an orange leash in a green outdoor area.
A person in a blue shirt and gray jeans is hugging a white dog with black spots, wearing a harness with an orange leash in a green outdoor area.
A young Belgian Malinois dog lying on a table in front of a fireplace, with award ribbons hanging from the table. The dog has a brindle coat and large pointed ears, looking directly at the camera.
Two dogs, one black and white and one golden, sitting side by side on a tiled floor against a textured beige wall. Both dogs are wearing large pink and black ribbons with award labels.