Jack Russell can be aggressive with other dogs, and in fact more than two should never be kept together unattended. There have been many instances of terriers being hurt, even killed by their fellow terriers, dogs more than eight weeks must be carefully monitored. It 's essential that future owners of Jack Russell terrier to understand this part of nature. And distribution of special plants are absolutely necessary to have a Jack Russell, especially when having two or more of Jack Russell. Their natural hunting instinct also brings aggression to other pets such as cats, hamsters, guinea pigs, etc.
It is said that the value of the Jack Russell is never in doubt, no doubt, a true statement, as has often been known to have an opponent twice (or more) dimensions. We require the delivery, the signature line, in charge, but is very intelligent, resolute and courageous (sometimes to the point of abandonment, which can be fatal).