At 10:00 on October 30, 2007, Walter weighed 45 lb / 20.4 kg.
Although it feels like his growth is slowing, Walter is still putting on at least 5 oz a day. He peaked in September, at 5.5 oz/day; now he's down to 5.1 oz/day.
I think the reason we feel like his growth is slowing is perceptual: he's putting on a pound every three days, but it's harder to see on a bigger dog.
Note: I was going to call this post "Walter takes his foot off the gas" as an allusion to our illusory perception of deceleration. Unfortunately, this is not an appropriate metaphor.