Brand: ADAMS PLUS FLEA & TICK Collar for Large Dogs


FORMULATION: «collar» impregnated with insecticides/tickicides 


  • TETRACHLORVINPHOS: 145.5 g/kg (= 14.55%)
  • METHOPRENE = (S)-methoprene: 10.2 g/kg (= 1.02%)

CHEMICAL CLASS of the active ingredient(s):


PARASITES CONTROLLED* (spectrum of activity)

  • Fleas
  • Ticks
  • This collar will provide continuous protection against fleas, ticks, and flea eggs for up to 7 months.

* Can be slightly different in some countries: read the product label!


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: 465-1480 mg/kg for tetrachlorvinphos, >34000 mg/kg  for methoprene
  • LD50 (acute dermal) in rats: n.a. for the collar: for the active ingredients: > >2000 mg/kg for tetrachlorvinphos, >2000 mg/kg  for methoprene

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 to organophosphates, with cross-resistance to carbamates. For this reason efficacy and protection provided by this product against these parasites may be lower or shorter than expected.

So far there are no reports on resistance of fleas to methoprene, but this compound does not kill fleas, it only inhibits their development, and it has no effect whatsoever on ticks.

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 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**?

  • Tetrachlorvinphos: GENERIC (introduced in the 1960s)
  • Methoprene: GENERIC (introduced in the 1970s)

*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): USA
GENERIC BRANDS available? YES, this product contains generic tetrachlorvinphos and (S)-methoprene

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


ADAMS PLUS FLEA & TICK Collar for Large Dogs is an insecticide-impregnated collar from CENTRAL GARDEN & PET containing generic active ingredients.

Tetrachlorvinphos is a veteran organophosphate pesticide introduced in the 1960s. It has a broad-spectrum of efficacy against numerous insects. It has been poorly used in Animal Health but more in Crop Protection. However, as most organophosphates it has been vastly replaced by more modern pesticides in numerous countries in the last decades. Current use in livestock or pets is marginal.

Methoprene (also called (S)-methoprene) is a veteran insect development inhibitor introduced in the 1970s (by ZOECON) used moderately in pets and agriculture. It has no effect whatsoever on ticks, only on fleas. The logic of combining both active ingredients is to ensure that if a few fleas survive the killing effect of the adulticide (what usually happens) development of their offspring is inhibited, because the eggs of the surviving fleas won't developed.

According to the label this product provides up to 7 months control of fleas and ticks, but efficacy may be lower and protection shorter than expected in case of resistance.

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.