This dark depiction of A Young Man with a Cat and a Dog has been attributed to Dossi Dossi (1486/7 – 1541/2). 
It has been suggested that the two animals symbolise the opposite sides of the young man’s character, and the intimate nature of the portrait could hint at it being a reflection of the artist himself.
Some attributes connected with dogs during this period: loyalty, intelligence, guidance, watchfulness, love, sexual promiscuity, “human bestiality” and sin*.
Cats, on the other hand, a little discussed animal on this blog, was thought to be easily irritated, treason, domestic tranquillity and intellectualism, while da Vinci said “Even the smallest feline is a masterpiece”**.
*Cohen, S. (2008). Animals as Disguised Symbols in Renaissance Art. [online] Google Books. Available at: https://books.google.co.uk/books?id=FOZVPjSTznwC&pg=PA136&lpg=PA136&dq=symbolism+of+a+dog+in+renaissance+art&source=bl&ots=M_EtqcZ6QI&sig=oRKjR1h7U4mLapr05haIe3HAcOg&hl=en&sa=X&ved=0ahUKEwjy74TV2IHVAhXSJlAKHZShC_MQ6AEIpQEwGw#v=onepage&q=symbolism%20of%20a%20dog%20in%20renaissance%20art&f=false [Accessed 11 Jul. 2017].
**http://www.thegreatcat.org/cats-in-renaissance-art/
Caravaggio's Dog 