Brand: BOLFO ®


FORMULATION: «collar» impregnated with insecticides/tickicides 

ACTIVE INGREDIENT(S)*: PROPOXUR: 94 g/kg (= 9.4%; in some countries 9.87%)

CHEMICAL CLASS of the active ingredient(s): CARBAMATE


PARASITES CONTROLLED* (spectrum of activity)


Collars in different sizes for SMALL DOGS, LARGE DOGS, and CATS. Since the active ingredients are released slowly from the collar's matrix, it is not possible to calculate the exact dose that the animals are exposed to in a particular moment.


  • LD50 (acute oral) in rats: n.a. for the collar: for the active ingredients: 47-69 mg/kg for propoxur
  • LD50 (acute dermal) in rats: n.a. for the collar: for the active ingredients: >5000 mg/kg for propoxur
  • Estimated Toxicity Class according to the WHO: II moderately hazardous (calculated based on the LD50, learn more)

Suspected poisoning? Read the article on propoxur safety

WARNING !!!: Never use on cats collars approved only for dogs.  Learn more about insecticide-impregnated collars and their safety.

You may be interested in the following articles in this site dealing with the general safety of veterinary products:


Risk of resistance? YES, moderate in:

There are reports on resistance of fleas and brown dog ticks (Rhipicephalus sanguineus) to carbamates, with cross-resistance to organophosphates. For this reason efficacy and protection provided by this product against these parasites may be lower or shorter than expected.

Alternatives to prevent resistance through product rotation:

*F = effective against fleas; T = effective against ticks.

These alternative products may not be available in all countries, or may not be available as collars.

Resistance of fleas and brown dog ticks to pyrethroids is not uncommon in several countries, including the USA.

Learn more about resistance and how it develops.


Are the active ingredients of this product ORIGINAL* or GENERICS**?

  • Propoxur: GENERIC (introduced in the 1960s)

*Meaning that they are still patent protected and generics are not yet available
**Meaning that they have lost patent protection and may be acquired from manufacturers of generic active ingredients other than the holder of the original patent.

COUNTRIES where this product is marketed (maybe under other TM): parts of the EU and elsewhere
GENERIC BRANDS available? YES, maybe not in this particular composition.

Click here to learn more about GENERIC vs. ORIGINAL drugs.


BOLFO is an original insecticide-impregnated collar for dogs and cats from BAYER with propoxur, BAYER'S original carbamate effective against fleas and ticks. This particular collar claims to slowly release the active ingredient in the form of a powder.

Propoxur is a veteran broad-spectrum non-systemic carbamate pesticide introduced in the 1960s (by BAYER). It was abundantly used in pets and livestock until the 1980s, but since then has been largely replaced by more modern insecticides. It is still used in topical products for pets (shampoos, soaps, sprays, powders, etc.). It is also used in agriculture and in domestic pesticides.

According to the label this product provides 3-5 months control of fleas and ticks (approved length of protection varies in different ciuntries) but efficacy may be lower and protection shorter than expected in case of resistance.

BAYER marketed other insecticide-impregnated collars in some countries, SERESTO (with imidacloprid and flumethrin, for dogs and cats) and KILTIX (with propoxur and flumethrin, only for dogs).

Topical products (mainly spot-ons and insecticide-impregnated collars) have some advantages over systemic products (mainly tablets for oral administration and injectables):

  • Most topical products kill or sterilize the parasites before they bite and suck blood on the pet, whereas systemic products kill or sterilize the parasites only after their blood meal.
  • Topical products cannot be vomited.
  • Spot-ons and collars are very convenient to administer.
  • There is a larger choice of topical products.

But topical products have also some disadvantages:

  • Topical products contaminate the pet's hair coat and it is advisable for children and also adults to avoid contact with the pet for several days after treatment.
  • Topical products may not control parasites in some parts of the pet's body (e.g. the ears, below the tail, between the legs, etc.), whereas systemic products reach the blood-sucking parasites through the blood wherever they are.
  • Efficacy of topical products may be reduced or shortened through exposure to dirt, sun, shampooing, washing, rain, baths, etc., whereas efficacy of systemic products is independent from these factors.

For an overview and a list of the most popular pet antiparasitics for flea, tick, lice and/or mite control click here.


This article IS NOT A PRODUCT LABEL. It offers complementary information that may be useful to veterinary professionals and users that are not familiar with veterinary antiparasitics. 

Information offered in this article has been extracted from publications issued by manufacturers, government agencies (e.g. EMEA, FDA, USDA, etc.) or in the scientific literature. No guarantee is given on its accuracy, integrity, sufficiency, actuality and opportunity, and any liability is denied. Read the site's DISCLAIMER.

In case of doubt contact the manufacturer or a veterinary professional.