- May be caused by subcutaneous injections
- Granulomatous nodules form with central necrotic and foreign material
- Macrophages and multinucleated giant cells around the centre
- Surrounded by granulation tissue, perivascular lymphocytes that may form lymphoid follicles, eosinophils
- Cats may develop fibrosarcomas secondary to vaccination
- Dogs, especially poodles, may develop lymphoplasmacytic panniculitis and perivasculitis, vasculitis and follicular atrophy secondary to killed rabies vaccine