"Juventus's medical department specifies that it acted in respect of health procedures and ethical rules in an emergency intervention in August following the deterioration of the clinical condition after an insect bite," read a statement on the club website.
"On this occasion a pharmacological therapy was administered that was indispensable to prevent complications, including lethal ones."
The Italian Olympic Committee (CONI) said Cannavaro had requested an exemption after being treated for the bite but did not receive it before he was dope tested.
CONI added that after the exemption request arrived it had written to the former Ballon d'Or winner asking for a doctor's certificate.
Cannavaro, Italy's most capped player and the cornerstone of their 2006 World Cup-winning side, has been summoned to a hearing with CONI's anti-doping prosecutor Ettore Torri, CONI said.
Italian media reported this would take place on Friday and said Cannavaro was given a cortisone-based anti-allergic medication to treat a wasp sting.
The Juventus defender had been expected to join the Italy squad this weekend for next Wednesday's World Cup qualifier against Cyprus in Parma. He is suspended for Saturday's match against Ireland in Dublin, when a draw will suffice to book the Azzurri's place in South Africa next year.
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