Brenda on a dog or cat is the same genre of comedy as Brad or Gary: a thoroughly mid-century American woman's name that lands on a pet and becomes, against all odds, perfect. Brenda hit her US naming peak in the 1950s and 60s, which means she's now vintage enough to be charming and specific enough to be funny.
The Vintage Human Name Aesthetic
The trend of giving pets solidly human, thoroughly un-cool names has been building among millennial and Gen Z pet owners for several years. Brenda, Karen, Linda, Sharon: names associated with a specific generational moment that carry an ironic warmth when applied to a dog or cat. It's affectionate mockery of naming conventions, and the pets seem entirely unbothered by it. This is the same instinct that names a cat Gerald or a hamster Brad.
The Brenda Lee and Brenda Song Effect
Brenda has genuine pop culture anchors in country legend Brenda Lee and actress Brenda Song, giving the name warmth beyond the pure irony read. Owners who choose it earnestly are making a valid choice; owners choosing it ironically know exactly what they're doing. Both groups can share the name peacefully. The human name Brenda has Old Norse roots meaning "sword blade," a fun origin to reveal after the fact.
The Counter-Reading: The Karen Problem
Brenda sits adjacent to Karen in the cultural-moment name category, and Karen has acquired associations that Brenda hasn't, yet. That adjacency is worth noting. For the same vintage-feminine energy without any cultural baggage, Betty or Doris occupy the same era with cleaner contemporary readings.