There are lot of views on Pets and vastu shastra or feng shui. While many believe nurturing animal is a good thing, may have a completly different view. Many time people just associate things/events with their Pets. In many places a death of any pet is associated to an incoming danger to the family (which killed the pets and hence saved the family). so if something bad happens in the family, they just blame the poor pet.
Vastu shastra is very prominent in Asia and not in western part of the world. To many it does not make any sense, that vastu shastra works in Asia but is not in Europe or America.
To me Pets has nothing do with our fate. Nurturing any animal is extremely good for the family as a whole. In India keeping cow is considered auspicious, lot of people feed the dogs on the street for, and many just take care of animal because they like it.
While keeping care of pets is a good thing, it is important to understand their specific need otherwise you may end up with an unhappy pet. So what ever pet you like, make sure you do a good research before you bring them home.
Many do not encourage keeping pets especially when small baby, sick or old aged around because most pets carries virus and affect their family members. Others avoid pets, they will develop attachment and my end up with abandonment due to disease or old age.
However, cat may be of better choice as it has lesser attachment with human being and has greater ability to survive in case of abandonment.
Please note, keeping pets may not be cheap (depending on where you live and what pet you want to keep), in some countries, you need licence to keep exotic animals and you may need special arrangement if you want to keep them.