Our mission: To provide accessible and affordable, high-quality spay/neuter services for companion animals and free roaming cats.

Our vision: To eliminate euthanasia as a means of animal population control.

Princess Barnhart



Altered Tails was founded in 2003 with a mission of providing affordable and accessible spay and neuter services. We began our journey by offering services through a mobile clinic that could travel to the poorest communities in the metro Phoenix area where many residents had no means of transportation. 

In 2007, local philanthropists Bea and Dick Barnhart donated the building at 950 W. Hatcher Road, honoring their love for Princess and their passion for spay and neuter. Their generosity helped open our first stationary clinic and it was named the Altered Tails Barnhart Clinic in their honor.   The doors to the new clinic opened in 2009 and by 2012, Altered Tails had become the first and only Humane Alliance-certified clinic in Arizona and spay and neuter surgeries topped 8,000 annually.

In 2013, the Mesa clinic was opened to expand the reach of services, and the  two clinics performed more than 17,000 surgeries by the end of 2014.  The W.A.G.S. (Wheels for Animals Getting Spayed/Neutered) program was launched a year later, designed to provide transport assistance for pet owners without the means of getting the animal to the clinic for surgery.

Today, Altered Tails provides services for owned pets, rescue organizations preparing their animals for adoption and groups practicing Trap Neuter Return with free-roaming cats.  We remain committed to offering high-quality services at an affordable price. On average, the cost to alter a pet at one of our clinics is about three times lower than that of full service veterinary clinics.  Since 2003, more than 200,000 dogs and cats have been sterilized by Altered Tails.  

Executive Director

Dr. Goetz joined Altered Tails in 2019. She received her DVM in 2005 and her MPH in 2017. Dr. Goetz and her husband (also a veterinarian) share their lives with an assortment of cats, dogs, and two guinea pigs named Grace Potter and Jean Luc Picard.

About Dr. Goetz

Dr. Nellie Goetz


Meet our Leadership Team


Board of Directors

Dick Barnhart

Melissa Williams

Catherine Crandall

Jeff Hollahan

Dan Williams

Advisory Board

Brad Braun, Esq.

Buff & Ron Burns

Crystal Castro-Giovanni

Sybil Francis & Michael Crow

Janet & Clive Cussler

Rose Erato

Roz Johnson

Nils & Amy Lofgren

Bari Mears

Alfredo Molina