title: Problems of booster vaccinations.
mesh_terms: D000818:Animals; D004216:Distemper / Q000517:prevention & control; D004283:Dog Diseases / Q000517:prevention & control; D004285:Dogs; D006524:Hepatitis, Viral, Animal / Q000517:prevention & control; D007117:Immunization, Secondary / Q000662:veterinary*; D014611:Vaccination / Q000191:economics / Q000662:veterinary*