Assalaamo alaykom,
I am a student and my thesis and future work might need injuring the heart of animal, treat the heart with substances, and then killing the animals and then remove their heart to analyze the result of our therapy. I wanted to know wehether there is a hadith from hadhrat Muhammad PBUH like this: abstain from dissecting the dead even if it be a dead dog? Does it apply to my situation?

All perfect praise be to Allaah, The Lord of the Worlds. I testify that there is none worthy of worship except Allaah, and that Muhammad is His slave and Messenger.

First of all, we are not aware of any Hadeeth with the wording that you mentioned in the question, and we have not come across a Hadeeth about this among the books of Hadeeth that we have at hand.

We have already clarified in Fatwa 87849 that it is permissible to use animals in scientific experiments provided some particular conditions are met; so please refer to the above Fatwa.

On the other hand, it is forbidden, in principle, to transgress against a Muslim as his blood (life) is inviolable. This is something known in religion with absolute evidence. Similarly, respecting his honor when he is dead is like respecting it when he is alive. ‘Aa’ishah narrated that the Prophet said: “Breaking a dead person's bone is like breaking the bone of a live person.” [Abu Daawood and Ibn Maajah]

Ibn Hajar said: “What we can conclude from this Hadeeth is that the sanctity of a believer after his death is still preserved in the same manner as it was when he was alive.”