Ectoparasiticides in the pregnant and lactating bitch
3-year-old Andalusian Ratter bitch, 5 weeks pregnant, with fleas and the odd tick. The owner wants to treat her and protect the future puppies.
Which statement is correct?
chevron_right Show answer and explanation
A. Choose a product whose product information authorises use during pregnancy and lactation (e.g. oral fluralaner, selamectin or fipronil); not all isoxazolines have proven safety
Correct. Some isoxazolines have studies in breeding, pregnant and lactating bitches, while for others safety has not been established. Treating the dam protects the litter from fleas and anaemia.
B. No ectoparasiticide can be used during pregnancy: you must wait until weaning
There are products licensed for pregnancy and lactation. Waiting exposes the dam and puppies to fleas, anaemia and Dipylidium.
C. All isoxazolines have the same safety profile, so any of them will do
Although they share a mechanism, each molecule has its own studies. The product information of several states that their safety in pregnancy and lactation has not been established.
D. It is enough to treat the newborn puppies with an isoxazoline
Isoxazolines are not licensed in neonates, and if the dam remains infested the puppies are continuously reinfested.
lightbulb Key takeaway
In pregnant, lactating or breeding females, and in puppies, always check the product information: authorisation varies between products of the same class. Treat the dam and the environment before whelping so that the litter is born into a flea-free environment.
Test yourself with 10 random questions
Parasitic diseases · 100 questions, a different test every time
Related questions
Updated: October 31, 2026 · Educational content for veterinary professionals. It does not replace current clinical guidelines or the judgement of the attending veterinarian.