Video 1 indicates that the procedure to get an RFID implanted into a dog or cat is painless... like getting an immunization  injection.

Video 2 demonstrates that getting an implant removed from a human body is not without some effort.

In this paper co-authored with MG Michael we note:

Recently, decade-old experimental studies on microchip implants in rats have come to light tying the device to tumors [29]. The American Veterinary Medical Association [3] was so concerned that they released the following statement: 
The American Veterinary Medical Association (AVMA) is very concerned about recent reports and studies that have linked microchip identification implants, commonly used in dogs and cats, to cancer in dogs and laboratory animals. . . . In addition, removal of the chip is a more invasive procedure and not without potential complications. It’s clear that there is a need for more scientific research into this technology. [bold eds.] 
We see here evidence pointing to the notion of “no return” – an admittance that removal of the chip is not easy, and not without complications. The Norplant System was a levonorgestrel contraceptive insert that over 1 million women in the United States, and over 3.6 million women worldwide had been implanted with through 1996 [2]. The implants were inserted just under the skin of the upper arm in a surgical procedure under local anesthesia and could be removed in a similar fashion. As of 1997, there were 2700 Norplant suits pending in the state and federal courts across the United States alone. Most of the claims had to do with
“pain or damage associated with insertion or removal of the implants . . . [p]laintiffs have contended that they were not adequately warned, however, concerning the degree or severity of these events” [2].
Thus, concerns for the potential for widespread health implications caused by humancentric implants have also been around for some time. In 2003, Covacio provided evidence why implants may impact humans adversely, categorizing these into thermal (i.e., whole/partial rise in body heating), stimulation (i.e., excitation of nerves and muscles), and other effects most of which are currently unknown."