So educate me - i’m looking for a GPS tracker that i could insert and link to an app? i’d like a long term sustainable battery life - or other energy supply.
basically i want to insert this into my dog, as he keeps running away and continues to lose his collar (with GPS tracker).
The implants produced by DangerousThings or any other implant producer are not viable to be used as trackers. They don’t have any batteries so only get power when scanned by a reader (which is only able to get within range at an inch or two)
Its not feasible to put a battery in an implant at this time.
It is worth looking into something like
https://eshop.v.vodafone.com/uk/v-pet-tracker-pod-3
Is your dog willing to sit still for 4 hours every day in a wireless charger? 
That would be nice to have, but we’re not there yet. Different lithium chemistries are being tested for implantation, but I would not consider any of them safe enough at this point. Even the Lithium-Iodide cells used in pacemakers are questionable.
Charging via a port through the skin is courting infection. Wireless charging is an issue for the reasons already stated. Plus, charging batteries get very hot. It would be rather inhumane to subject your dog to that.
As for “other energy supply”, present energy harvesting methods don’t produce enough current to operate something as power hungry as a GPS antenna. Piezo, peltier, and betavoltaic elements are neat, but don’t do the job.
I am not fully aware of your situation, but it seems like the easiest path forward is training the animal.