You could try contacting a golden retriever rescue group in that area? Maybe one of their foster homes could take care of your MIL's dog while she's with you? If not, they may have some other suggestions that could help? Here are a couple of groups in Mississippi that I found:
MISSISSIPPI
Gulf South Golden Retriever Rescue
Territory Service: Louisiana, Mississippi, Alabama, and Florida Panhandle
J & L Golden Retriever Rescue
Territory Serviced: Gulf Coast of Mississippi, Alabama, & Florida Inland To: Montgomery & Birmingham, Alabama, Jackson, Mississippi and Baton Rouge, Louisiana
Contacts:
MF11654@aol.com lkh5@mchsi.com
Sending prayers for your husbands cure and prayers too for you and your family.