Vav does not take a dagesh, but a dot inside of it (which looks exactly like a dagesh) marks it as a matre lectionis. See: Shuruq.

See Dagesh Lene.

See Dagesh Forte.

Any of the Matres Lectionis (alef, heh, vav, or yod) may have a dot inside of them (which looks identical to a dagesh). This is called a Mappiq, and means that the consonant should be fully pronounced.

For a vav, this is quite rare and may seem confusing as it will appear as what would normally be a shuruq, but the presence of a following vowel will be the clue that it is actually a mappiq.