Dectomax Pour-On: Product Information

DECTOMAX POUR-ON- doramectin solution
Zoetis Inc.

(doramectin topical solution)


0.5% pour-on solution for cattle
5 mg/mL


Dectomax Pour-On solution is a ready-to-use, systemically active, clear, light blue solution containing 0.5% w/v doramectin (5 mg/mL). It is formulated to deliver the recommended dosage of 500 mcg/kg (227 mcg/lb) of body weight when given by topical administration at the rate of 1 mL/22 lb (10 kg) of body weight.


Dectomax Pour-On solution is a highly active, broad-spectrum parasiticide for topical administration to cattle. It contains doramectin, a novel fermentation-derived macrocyclic lactone discovered by Pfizer Inc. Doramectin is isolated from fermentations of selected strains derived from the soil organism Streptomyces avermitilis.

A primary mode of action of macrocyclic lactones is to modulate chloride ion channel activity in the nervous system of nematodes and arthropods. Macrocyclic lactones bind to receptors that increase membrane permeability to chloride ions. This inhibits the electrical activity of nerve cells in nematodes and muscle cells in arthropods and causes paralysis and death of the parasites. In mammals, the neuronal receptors to which macrocyclic lactones bind are localized within the central nervous system (CNS), a site reached by only negligible concentrations of doramectin.

One dose of Dectomax Pour-On solution effectively treats and controls a wide range of roundworm and arthropod parasites that impair the health and productivity of cattle.

Studies have demonstrated the safety margin of doramectin. In USA trials, no toxic signs were seen in cattle given up to 25 times the recommended dose of Dectomax Injectable solution. A study using Dectomax Injectable solution also demonstrated safety in neonatal calves treated with up to 3 times the recommended dose. In breeding animals (bulls, and cows during folliculogenesis, organogenesis, implantation, and through gestation), a dose 3 times the recommended dose of Dectomax Injectable solution had no effect on breeding performance. A pharmacokinetic study demonstrated that systemic exposure to doramectin from Dectomax Pour-On was less than systemic exposure to doramectin from Dectomax Injectable solution.


Dectomax Pour-On solution is indicated for the treatment and control of the following species of gastrointestinal roundworms, lungworms, eyeworms, grubs (see PRECAUTIONS), biting and sucking lice, horn flies, and mange mites in cattle. Consult your veterinarian for assistance in the diagnosis, treatment, and control of parasitism.

Gastrointestinal roundworms
Ostertagia ostertagi (adults and L4 , including inhibited larvae)
O. lyrata (adults)
Haemonchus placei (adults and L4 )
Trichostrongylus axei (adults and L4 )
T. colubriformis (adults and L4 )
Cooperia oncophora (adults 1 and L4 )
C. pectinata (adults)
C. punctata (adults and L4 )
C. surnabada (adults)
Bunostomum phlebotomum (adults)
Oesophagostomum radiatum (adults and L4 )
Trichuris spp. (adults)

Lungworms (adults and fourth stage larvae)Dictyocaulus viviparus

Eyeworms Grubs
Thelazia gulosa (adults) Hypoderma bovis
T. skrjabini (adults) H. lineatum
Lice Horn Flies
Biting Lice Haematobia irritans
Bovicola (Damalinia) bovis Mange Mites
Sucking Lice Chorioptes bovis
Haematopinus eurysternus Sarcoptes scabiei
Linognathus vituli
Solenopotes capillatus

Dectomax Pour-On solution has been proved to effectively control infections and to protect cattle from reinfection with Cooperia oncophora, Dictyocaulus viviparus, Ostertagia ostertagi , and Oesophagostomum radiatum for 28 days; and Cooperia punctata and Haemonchus placei for 35 days after treatment.

Dectomax Pour-On solution has been proved to effectively control infestations and to protect cattle from reinfestation with Bovicola (Damalinia) bovis for 77 days and Linognathus vituli for 42 days after treatment.

Efficacy below 90% was observed against adult C. oncophora in some clinical studies.

Management Considerations for Horn Flies

Dectomax Pour-On solution provides 7 days of persistent activity against horn flies. The product should be used as part of an integrated control program and be combined with other methods for extended horn fly control. For optimal horn fly control, consult with your veterinarian or a livestock entomologist.


Administer Dectomax Pour-On solution to cattle topically at a dosage of 500 mcg doramectin per kg (227 mcg/lb) of body weight. Each mL contains 5 mg of doramectin, sufficient to treat 22 lb (10 kg) of body weight.

For the best results, Dectomax Pour-On solution should be a part of a parasite control program for both internal and external parasites based on the epidemiology of these parasites. Consult a veterinarian or an entomologist for information regarding the most effective timing of applications.

Do not underdose. Ensure each animal receives a complete dose based on a current body weight. Underdosing may result in ineffective treatment, and encourage the development of parasite resistance.


Dectomax Pour-On solution should be applied topically along the mid-line of the back in a narrow strip between the withers and tailhead.

Dosing Cup (250-mL and 1-L bottles)

A dosing cup is provided for use with Dectomax Pour-On solution supplied in 250-mL and 1-L bottles. The Dectomax Pour-On solution dosing cup should be installed by rotating the cup on the bottle neck until tight. When installed correctly, the spout is aligned at the mid-point on the wide side of the bottle.

The curved end of the dosing cup tube should be positioned at the bottom of the bottle on the side opposite the spout. When the dosing cup is in the closed position (“zero” at set dosage mark on screw), product does not enter the cup reservoir. Select a dose [1 mL per 22 lb (10 kg) of body weight] by twisting the dosing screw on the top of the dosing cup to the desired position. The first complete turn of the dosing screw will set the dose at 10 mL (“10″ shows on the screw at set dose mark). Each additional turn increases the dose in 5 mL increments until a maximum dose of 50 mL (“50″ is the bottom number showing on screw at the set dose mark) is reached. When body weight is between weight markings on the dosing cup, use the higher dose volume.

To fill the dosing reservoir, hold the bottle upright and squeeze it until a slight excess has been delivered as indicated by the calibration lines. Release the pressure and excess will automatically drain from the reservoir and return to the bottle.

Tilt the bottle to deliver the dose. Dectomax Pour-On solution should be delivered to cattle on the back in a single pass from the withers to the tailhead.

Applicators (2.5-L and 5-L bottles)

Applicators are available for use with Dectomax Pour-On solution supplied in 2.5- and 5-L backpacks. Directions for 2 recommended applicators are provided below. Some applicators may be incompatible with this formulation.

Phillips Pour-on Applicator System

  • Replace the shipping cap on 2.5- or 5-L backpack with the draw-off cap provided and tighten firmly.
  • Thread the draw-off tubing through the anti-kink spring. Attach the tube to the draw-off cap. Screw the spring counter clockwise over the tubing and draw-off spigot.
  • Invert the backpack.
  • Set the dose to maximum (50 mL). Gently prime the applicator, checking for leaks. To prime, place the nozzle into a clean, dry receptacle and depress lever fully. Pump 3–4 short strokes ensuring that the piston reaches the end of the cylinder, and then release the lever completely to fill the cylinder. A small air bubble may appear within the cylinder. This will not affect the dosing accuracy.
  • Set the required dose and administer.
  • To disconnect the system, proceed as follows:
    • a)Set backpack in upward position.
    • b)Discharge residual material from the applicator and draw-off tubing into a separate, clean, dry receptacle.
  • Follow the manufacturer’s recommendation for care and maintenance of the dosing applicator.
  • Remove the draw-off cap. Replace with the original cap and tighten firmly.
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