Source: https://www.nytimes.com/2006/05/07/books/review/07krugman.html
Roughly analogous medium-resolution-summary of passage:
P1 - cats and dogs in contradiction
P2 - description of cats / description of dogs
P3 - description of the contradiction, i.e. anatomically being a cat means not being a dog
P4 - vets focused only on dogs (not b/c they like them more, but because dog anatomy is easier to understand)
P5 - vets finally understand cat anatomy and can focus on them too (great, people do keep cats as pets)