According to Deco Alerta– Portuguese Association for Consumer Protection and reported by idealista/news there are specific rules in place in Portugal that pet owners need to be aware of.
The first rule is very clear: pets can only stay in an apartment or house, in urban areas, if there are good housing conditions, without risk to the health of neighbours or hygiene problems.
In an apartment, up to three dogs or four cats can cohabit, without the total number of all pets ever exceeding four.
This number can only be exceeded, up to six, with the authorisation of the municipality, after the favourable opinions of the municipal veterinarian and the health delegate.
The presence of animals inside the apartment can only be included in the condominium regulations if it is unanimously approved. Condominium regulations can, however, be stricter and establish a lower limit and even prohibit the presence of animals in the autonomous fractions.
Although the joint owners cannot prohibit the existence of animals in the apartments of the neighbours, unless there is an agreement between them or if this prohibition is established in the constitutive title of horizontal property, the same does not apply to common areas. Therefore, they can decide by simple majority to prohibit the permanence of animals in these areas, safeguarding the proper passage to and from housing.
For example, a dog of a breed classified as potentially dangerous cannot circulate alone in the common areas of the building, it must always be accompanied by the owner and use a leash and functional muzzle.