Treating gut infections such as SIBO or candida overgrowth, or occult infections like Lyme disease, if present (nicolejardim.com)
«Single sex heartworm infections, host immune responses affecting the presence of circulating microfilariae and the administration of heartworm preventives can be factors which produce occult infections in dogs.» (dogsnaturallymagazine.com)
Subsequently, eosinophil counts vary but are usually high in dogs with immune - mediated occult infections, especially if eosinophilic pneumonitis develops (< 10 % of total infections). (forpetssakeveterinarycenter.com)