Yes, side effects can occur, though side effects from frontline can also include swelling particularly of the face, lips and tongue, rash or hives, lethargy, vomiting or severe/lengthy diarrhoea, excessive salivation, uncoordinated movements, seizure, unresponsiveness or coma - although these tend to occur from overdosing (more often from a dog who is on the bottom end of the treatment dosage guidelines)
Only one of my dogs had an allergic reaction to Frontline (hives and swelling round his neck). Unfortunately Frontline is now completely ineffective on fleas where we are
Since we have roaming dogs and cats not to mention goats, sheep, and other interesting critters wandering everywhere (and it is a wooded area) mine need treatment pretty much year round for fleas and ticks are a MASSIVE problem in the spring. Urgh!
Citronella is a good natural repellent.
Post Edited (silly sheep) : 3/28/2017 1:37:12 PM (GMT-6)