Veterinary Drug Handbook (VDH) is the reference veterinarians turn to when they want an independent source of information on the drugs that are used in veterinary medicine today.



For heartworm prophylaxis:
a) 6.6 mg/kg PO once a day preceding infection and for 60 days following last exposureto mosquitos. In dogs who become microfilaremic while on DEC, may continue, but donot interrupt daily DEC therapy. (Knight 1988)
b) 6.6 mg/kg PO daily from beginning of mosquito season and for two months thereafter.
Should be given year-round in areas where mosquitos are active throughout the year.
Re-examine 3 months after starting therapy and at 6 month intervals for microfilaria.(Todd, Paul, and DiPietro 1985)
c) 2.5 - 3 mg/kg PO daily; begin prior to mosquito season. (Rawlings and Calvert 1989)
d) 5 - 7 mg/kg PO daily. Begin before infection is likely and continue 60 days aftermosquito season. Some areas will require year-round treatment. (Calvert and Rawlings1986)
For treatment of susceptible parasites (other than heartworm¯must not be used in microfilariapositive patients):
a) For ascarids: 55- 110 mg/kg PO; may be used as a preventative for ascaridiasis whendosed at 6.6 mg/kg PO per day. (Todd, Paul, and DiPietro 1985)
b) For lungworms (Crenosoma vulpis): 80 mg/kg PO q12h for 3 days. (Todd, Paul, and DiPietro 1985)


For Ascarids:
a) 55 - 110 mg/kg PO (Todd, Paul, and DiPietro 1985)
For heartworm prophylaxis:
a) 5.5 mg/kg PO once a day. (Randolph 1986)


For the treatment of early stages of Dictyocaulus viviparous infestations:
a) 22 mg/kg IM for 3 successive days; or 44 mg/kg IM once. (Note: DEC is available in an injectable dosage form containing 400 mg/ml in the U.K., no approved injectable form is available in the U.S.A.) (Brander, Pugh, and Bywater 1982)
Monitoring Parameters -
  • 1) Microfilaria, when used for heartworm prophylaxis
  • 2) Clinical efficacy, when used as an anthelmintic
    Client Information - Give all doses as directed. Dogs must be checked for microfilaria before restarting DEC in the spring. Dogs receiving DEC year around should be checked every six months.
    Dosage Forms/Preparations/FDA Approval Status/Withholding Times - All DEC products are available via prescription only (Rx).
    Veterinary-Approved Products:
    Diethylcarbamazine Citrate Tablets (plain or film-coated) 50 mg, 100 mg, 200 mg, 300 mg, 400 mg (Rx)
    Diethylcarbamazine Citrate Chewable Tablets 60 mg, 120 mg, 180 mg; Filaribits® (SKB)
    Diethylcarbamazine Citrate Oral Liquid (Syrup) 60 mg/ml
    Diethylcarbamazine Citrate Combination Products (refer to product literature for more information): Filaribits® Plus (Pfizer) Tablets containing Diethylcarbamazine Citrate/Oxibendazole in 60 mg/45 mg, 180 mg/136 mg strengths.

    Human-Approved Products:

    Diethylcarbamazine Citrate Tablets 50 mg; Hetrazan® (Lederle); (Rx)
  • ...