Make sure that you get a copy of the insurance policy and read it to see exactly what is excluded. Often, the canine exclusion is only for certain breeds of dogs. If the breed at issue isn't mentioned, then coverage would still exist.
If the dog is excluded from the coverage, then the home owner will not have coverage. You could still pursue the action and ultimately get a judgment against them. Whether they are ever able to pay it is a different matter. If you don't believe that this person will have the means to pay you, then it will be a long drawn out fight for no recovery.
I hope you find a way to activate the coverage.
This response applies to California Law only and does not create any legal relationship between the attorney and the person who submitted the question.
If you are the potential plaintiff, you should immediately consult with a local personal injury attorney. If you are the potential defendant and you policy has such an exclusion , consult with a personal injury attorney
To get the HO ins on the hook you will need to show they improperly altered your policy and did not provide proper notice, etc... It is unlikely to have punitive damages awarded in a dog bite case, but there isn't enough facts here to address. If there are puni's awarded they will not be discharged through a BK