CFS is a diagnosis of exclusion and the criteria referred to (CDC working case definition) apply to humans not other species.
Besides that, as any good vet or doctor will tell you, bacterial (Staph) septicaemia is treated with antibiotics, not arsenicals.
Blood cultures proved Staph-positive and micrococci-like organisms in the blood were repeatedly observed in the 3-year period preceding the arsenical therapy, during which several medicaments, including antibiotics, proved unsuccessful. Following treatment with a low dosage arsenical drug (potassium arsenite 0.5%, im., 1 ml/12 h, for 10 days) both patients experienced complete remission. At the post-treatment control made 1 month later, micrococci had disappeared from the blood, and the CD4/CD8 ratio was raising.