Depends on what kind of jack russell here is a picture of some.
What Does A 9 Wk Old Jack Russel Look Like?
Is it a smooth coat, wire coat or broken coat? Here's the parent club you can visit and bookmark and get lots of breed specific information. :-)
www.therealjackrussell.com www.dogfoodanalysis.com
www.therealjackrussell.com www.dogfoodanalysis.com