"I want to expand them, and get rid of the corruption and inefficiency that characterizes them," Capriles told Reuters on a recent campaign tour, adding that more than half the Barrio Adentro clinics in his Miranda state were abandoned.
That message, however, has not reached those in the queue for animal neutering in La Vega.
"The opposition wants to stop all this," said Hilda Jimenez, cradling a couple of cats. "Governments did nothing for the poor in the past. Only Chavez has bothered with us."
The opposition paraphernalia plastered all over middle-class Caracas neighborhoods was entirely absent from the tatty streets around her. Instead, the ubiquitous red of Chavez's ruling Socialist Party, and images of "El Comandante", were everywhere.
Down the hill, dozens lined up to shop in a state-run Mercal store, where basic products like milk, chicken, oil, rice, beans and sugar are sold at a quarter of the normal price.
Shop workers scoffed when asked about photos in opposition media showing largely empty Mercal stores.
"As soon as products come in, people buy them immediately because the prices are incredible!" one said. "It's laughable the right-wing tries to present that as something bad."
Despite their visceral hatred of opposition leaders, whom they broadly view as representatives of an old, discredited political elite who never had any interest in Venezuela's poor majority, grassroots Chavez activists are realistic.
They know they have a fight on their hands to stop the energetic Capriles from developing momentum. They plan to highlight his "bourgeois" background in contrast to Chavez's humble upbringing by his grandmother in a rural shack.
They will also seek to target Capriles for his role in a murky episode at the Cuban embassy in 2002 when he was accused of fomenting a riot during the chaos surrounding a short-lived military coup against Chavez. He says he was mediating.