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I was hoping someone has had some experience with a Parvo strain that is lasting more than the common 3-5 days.  My Blk Mouth Cur puppy is 13wks and has been hospitalized for 4 days but showing symptoms for 6 as of today.  All symptoms fall under a possible Parvo case but my vet is concerned because she has never seen a case continue to decrease or not stabilize within 5 days.  Two Parvo tests have been negative. All CBC blood work is good.  Radiographs are good.  Exploratory surgery was performed last night revealing only enlarged lymph nodes.  If anyone has any info it would be appreciated.  My vet is aggressively pursuing this still as a Parvo with IV and antibiotic.  Thanks!