Maybe the shortages are in certain areas. I checked and saw this report from Florida:
https://www.actionnewsjax.com/news/local/animal-supply-stores-report-shortage-livestock-de-wormer-people-self-medicate-covid-19/APOGTTT4FBH2NEQ6XHR6B6UOPE/
One more in a long list of media gaslighting stories on Ivermectin produced in the last week.