Fantastic 2014 TED talk by Laurel Braitman on animal depression: "Depressed dogs, cats with OCD: what animal madness means for us humans". What I like best is her conclusion that we need to see each animal as an individual, and that interspecies bonding is very real and very rewarding, with scientific studies of raised oxytocin levels confirming it. This talk also reminds us that the pharma industry tested all the depression drugs on animals first...and notes that same as individual humans, each individual animal reacts in their own way to their environment. Includes a nuanced take on anthropomorphism too. This TEDtalk was recommended by a student on the Coursera course on Animal Behavior and Welfare offered by Edinburgh Uni. It's well worth the twenty minutes.