Am I wrong?

I was being bashed quite badly just for uploading a picture of me and a dog licking my face, on Facebook. My school teacher PMed me and asked for explanation, as to why I was eager enough to the extent of uploading a picture with a dog. My friend also PMed me, and asked me to change that picture into another one. My other friend said that it is wrong, and asked for explanation. 

I am currently at a lost of words. At first, I tend to ignore all these people for not truly understanding their own religion; I apologize if I hurt other people by saying this. Sekai wa zankokudesu, people just don't accept mere explanations.

What is wrong actually? I'm currently a third year veterinary medicine student of UPM. Was it wrong for a dog to lick my face? In the future, if Allah wills, I become a vet, would it be wrong if my patient starts showing affection? Do I have to shove it aside just because it licks my face and dirtying my clothes with its little paws? Should I go say to the owner of this dog that I don't treat dogs since my religion don't allow me to? Just because a few Malays don't quite understand how our Prophet have explained in His Hadith that I've been bashed this hard?

People, before you bash anyone, do some research at least. Proof to me that I'm wrong. Show me an Ayat for the Quran that says holding dogs is Haraam to Muslims. Show me proof that says holding a dog would be categorised as a large sin. I dare you to show me if you can.

If I'm wrong, then what does this Hadith tells you?

Sabda Nabi SAW; “Apabila anjing minum dalam bekas kamu, basuhlah bekas itu sebanyak tujuh kali” (Soheh al-Bukhari; 172. Soheh Muslim; 279/90. Dari Abu Hurairah RA)

That Hadith clearly states how to handle yourself after handling dogs. Why is it so difficult to understand? Nowadays we even have sabun taharah. Wouldn't that be enough?
 
I have cut open carcass of dogs countless times during my anatomy lab. If this is categorised as a large sin, then how many time have I sinned these 3 years just for holding dogs? If I'm wrong, proof to me that I'm wrong. I won't post up bizarre things just because I'm not ready for it.