狗急跳牆
gǒu jí tiào qiáng
"dog hurry jump wall"
(Here, the "急 jí / hurry" character can also mean "desperate", hence = hurry: to be desperate because one's in a hurry, or to be in a hurry because one's desperate. The best example I can think of is the Cantonese saying 急 for needing to go to the loo desperately, therefore must hurry [to find / get to one], or there might be embarrassing consequences.)
狗急跳牆 gǒu jí tiào qiáng is another expression that is very visual when you look at the meanings of all the characters in it: when the dog is desperate or in a hurry, no wall will be any barrier, the dog will jump over it. The English equivalent is Desperate times call for desperate measures.
With my perverse sense of humour, I used it on myself in Taiwan when I was working there (1975–6). A Taiwan-born colleague (of Nanjing parentage) laughed at me, saying, "No, no, no, you can't use the phrase on yourself!"
Note: The Chinese sense of hierarchy wouldn't permit comparing a human (especially oneself) to a dog, unless it was as a criticism / denunciation (cf. Shakespeare's use of the word "cur"). My own impression is that in the old Chinese tradition, dogs were pretty much treated like slaves – often mis-treated, to go by our modern standards: they were around to guard the house, rarely (if ever) kept as pets; given scraps to eat; maybe kicked at in a fit of pique, etc.
