A word of warning re the use of Nexgard, our dog had a negative reaction. Hyperactive, would not sleep, constant overnight barking. Took her to the vet who prescribed Kalma to address the side effects. No other variables likely to have caused this, problems stated just hours after giving Nexgard. Have reported the negative reaction to the Australian Pesticides and Veterinary Medicines Authority (APVMA).
Subsequent on-line research had revealed (if I have read it correctly) that Nexgard and it's active ingredient, Afoxolaner, is only available by veterinary prescription in the USA. An even greater concern is that there is no mention of possible side effects on the packaging or in the supplied treatment guide.