The value of working with veterinarians, students and clients from other countries can not be fully appreciated without first hand experience. However there are a few points to keep in mind to make this experience valuable for both you and the communites that you serve:

It is critically important  that you research the program for which you are volunteering and find out something about their protocols.  There are  welfare organizations, sometimes very well meaning, that do not use sterile instruments when doing surgery, maintain records, provide anesthetic monitoring or provide analgesia to their surgical patients.  There is no reason why these basics principals of good practice cannot be provided to all animals.  They do not significantly increase procedure cost, take extra time, or require special equipment. They do require a commitment to individual animal welfare, similar to what you would expect for your own pet in the USA.  Doing elective surgery, that puts your patient's life at unnecessary risk or causes undo pain or postoperative complications will only serve to teach you bad habits, not to mention being inhumane.  If you are looking for an opportunity to learn at the expense of your patient, you need to rethink your career choice. Remember; first do no harm.

A few questions you might ask when looking for a program:

How are instruments prepared for use during surgery?
How closely are sterile techniques monitored during surgery?
What kinds of records are kept?
What kind of anesthetic monitoring is performed during surgery?
How much monitoring takes place during the recovery process?
What analgesics are used and on what percentage of the patients?
What anesthetic and surgical complications is the program prepared to deal with?

If the answer you get is: “we never have any problems” this suggests a lack of follow-up or candor. Surgery is surgery and anesthesia is anesthesia. Animals living in poor communities have the same physiology and are deserving of the same care that you would expect for your own.

Programs with known ethical practices include the following:
Other Veterinary Animal Welfare Organizations Working Around the World

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Providing volunteers with multifaceted learning and equitarian opportunites.