A great deal is constituted by courage, decisiveness and evident valiancy.
 
It is loyal to its owner and family and children. Its loyalty has become proverbial in Brazil. It always seeks the company of its master.
 
One of its characteristics is suspicion of strangers.
 
It is calm and its self-confidence and self-assurance cannot be shaken by any unknown noise, nor new environments. As a guard dog, it cannot be surpassed, its instincts predetermine it for big game hunting and cattle guard dog.
 
Appendix: temper test described below is necessary in the country of origin to be awarded the title of champion.
 
Temper test
 
It is common for filas older than 12 months if they want to compete for the title of the winner. As champions they must have a proof they passed the test. This test is carried out at all special dog shows. At big dog shows, it is optional and depends on the judge.
The prerequisite is that it is a public event and is carried out outside the ring.
The test consist of:
 
- Attact with a staff
The dog is expected to attack the attacker from the front without any support from the master. The person showing the dog should not stir. It is prohibited to touch or hit the dog.
 
- The test of indifference to shooting
Shots are discharged 5 metres away from the dog. The dog should express attention and self-confidence and assurance at the same time.
 
During the showing in the ring, the judge should analyze the behaviour and nature of the fila and pay special attention to its expression. During the temper test these should be observed:
 
- Resentment of strangers
 
- Self-assurance, courage, decisiveness and valiancy of individual dogs