Giardiasis

Hello need your help, my cat was diagnosed with Giardiasis but he isn't having diarrhea, is that still Giardiasis ?

Hello - yes, cats can carry Giardia and not currently be suffering from diarrhoea.  They cat still infect other cats. Good questions for your vet are 'What makes you think that my cat has Giardia?'   'What do you think we shod do now?'    'What would be the advantages and disadvantages of doing tests in order to try to prove it?'  I don't know much about the case you have in front of you, but this should direct the conversation along the right sort of lines.

they can still infect other cats - my apologies for the typo