He is best known for being the first to detail the clinical signs and anatomical changes related to diphtheria which he published privately in a pamphlet.
In 1745 he studied diseases of livestock and wrote a report to Francesco Roncalli Parolino (1692-1769) who published it in 1747.
In 1749 he reported on malignant angina, in fact diphtheria, comparing it with livestock diseases.
Ghisi described the climate and conditions when the epidemic occurred and then described paralysis of the velum palatinum and the tumefaction of the submaxillary glands.
He also examined changes in the bronchi, pulmonary edema and the strain it caused to the right side of the heart.