Doses - GRISEOFULVIN (MICROSIZE), GRISEOFULVIN (ULTRAMICROSIZE)
Note: all doses are for microsize preparations unless otherwise indicated.Dogs:
For susceptible dermatophytic infections:
a) Microsize: 50 mg/kg/day divided q8-12h PO; Ultramicrosize: 25 mg/kg/day divided q8-12h PO. Give following a fatty meal or administration of corn oil. Continue until noclinical evidence of disease remains (6-8 weeks). (Schultz 1986)
b) Microsize: 20 - 50 mg/kg in divided doses with fat divided bid for 4-6 weeks for M.canis; and until cultures are negative for Trichophyton.
Ultramicrosize: 5 - 10 mg/kg PO once daily. Duration as above. (Foil 1986)Cats:
For susceptible dermatophytic infections:
a) Microsize: 50 mg/kg/day divided q8-12h PO; Ultramicrosize: 25 mg/kg/day divided q8-12h PO. Give following a fatty meal or administration of corn oil. Continue until noclinical evidence of disease remains (6-8 weeks). (Schultz 1986)
b) For feline M. canis: After total body clip, griseofulvin 80 - 130 mg/kg PO once dailywith a fatty meal or 2.5 - 5 ml of corn oil. Re-clip after one month and continuetreatment until signs of infection have disappeared and cultures are negative. (Thoday 1986)
c) Microsize: 20 - 50 mg/kg in divided doses with fat divided bid for 4-6 weeks for M.canis, and until cultures are negative for Trichophyton.
Ultramicrosize: 5 - 10 mg/kg PO once daily. Duration as above. (Foil 1986)
Cattle (and other ruminants):
For susceptible dermatophytic infections:
a) Ultramicrosize: 10 - 20 mg/kg PO once daily for 1-2 weeks. 100 mg/kg PO given twice(or more) 1 week apart may also be effective. Not approved for use in food animals andcan be very expensive. (Pier 1986)
b) 20 mg/kg PO once daily for 6 weeks. (Howard 1986)Horses:
For susceptible dermatophytic infections:
a) 10 mg/kg PO once daily (Robinson 1987)
b) 10 mg/kg PO (in feed) daily for 7 days (Brumbaugh 1987)Swine:
For susceptible dermatophytic infections:
a) 20 mg/kg PO once daily for 6 weeks. (Howard 1986)
Monitoring Parameters -1) Clinical efficacy; culture 2) Adverse effects 3) CBC q2-3 weeks during therapy 4) Liver enzymes (if indicated)
Client Information - Clients should be instructed in procedures used to prevent reinfection(destruction of old bedding, disinfection, periodic reexaminations, hair clipping, etc.) and the importance of compliance with the dosage regimen. Should animal develop adverse effects other thanmild GI disturbances, they should contact their veterinarian.
Dosage Forms/Preparations/FDA Approval Status/Withholding Times - Veterinary-Approved Products:
Griseofulvin (Microsize) Powder 2.5 g griseofulvin in 15 g sachets
Fulvicin-U/F® Powder (Schering-Plough); (Rx) Approved for use in horses.
Griseofulvin (Microsize) Tablets 250 mg, 500 mg (scored); Fulvicin-U/F® Tablets (Schering-Plough); (Rx) Approved for use in dogs and cats.
Griseofulvin (Microsize) Oral Suspension 125 mg/5 ml in 120 ml; Grifulvin V® (Ortho Derm);(Rx)
Griseofulvin (Ultramicrosize) Tablets 125 mg, 165 mg, 250 mg, 330 mg; Fulvicin P/G®(Schering); Grisactin Ultra® (Wyeth-Ayerst); Gris-PEG® (Allergan Herbert); generic. (Rx)
Dogs: 
For susceptible dermatophytic infections: a) Microsize: 50 mg/kg/day divided q8-12h PO; Ultramicrosize: 25 mg/kg/day divided q8-12h PO. Give following a fatty meal or administration of corn oil. Continue until noclinical evidence of disease remains (6-8 weeks). (Schultz 1986)
b) Microsize: 20 - 50 mg/kg in divided doses with fat divided bid for 4-6 weeks for M.canis; and until cultures are negative for Trichophyton.
Ultramicrosize: 5 - 10 mg/kg PO once daily. Duration as above. (Foil 1986)
Cats: 
For susceptible dermatophytic infections: a) Microsize: 50 mg/kg/day divided q8-12h PO; Ultramicrosize: 25 mg/kg/day divided q8-12h PO. Give following a fatty meal or administration of corn oil. Continue until noclinical evidence of disease remains (6-8 weeks). (Schultz 1986)
b) For feline M. canis: After total body clip, griseofulvin 80 - 130 mg/kg PO once dailywith a fatty meal or 2.5 - 5 ml of corn oil. Re-clip after one month and continuetreatment until signs of infection have disappeared and cultures are negative. (Thoday 1986)
c) Microsize: 20 - 50 mg/kg in divided doses with fat divided bid for 4-6 weeks for M.canis, and until cultures are negative for Trichophyton.
Ultramicrosize: 5 - 10 mg/kg PO once daily. Duration as above. (Foil 1986)
Cattle (and other ruminants):
For susceptible dermatophytic infections:
a) Ultramicrosize: 10 - 20 mg/kg PO once daily for 1-2 weeks. 100 mg/kg PO given twice(or more) 1 week apart may also be effective. Not approved for use in food animals andcan be very expensive. (Pier 1986)
b) 20 mg/kg PO once daily for 6 weeks. (Howard 1986)
Horses: 
For susceptible dermatophytic infections: a) 10 mg/kg PO once daily (Robinson 1987)
b) 10 mg/kg PO (in feed) daily for 7 days (Brumbaugh 1987)
Swine: 
For susceptible dermatophytic infections: a) 20 mg/kg PO once daily for 6 weeks. (Howard 1986)
Monitoring Parameters -
Client Information - Clients should be instructed in procedures used to prevent reinfection(destruction of old bedding, disinfection, periodic reexaminations, hair clipping, etc.) and the importance of compliance with the dosage regimen. Should animal develop adverse effects other thanmild GI disturbances, they should contact their veterinarian.
Dosage Forms/Preparations/FDA Approval Status/Withholding Times - Veterinary-Approved Products:
Griseofulvin (Microsize) Powder 2.5 g griseofulvin in 15 g sachets
Fulvicin-U/F® Powder (Schering-Plough); (Rx) Approved for use in horses.
Griseofulvin (Microsize) Tablets 250 mg, 500 mg (scored); Fulvicin-U/F® Tablets (Schering-Plough); (Rx) Approved for use in dogs and cats.
Human-Approved Products:
Griseofulvin (Microsize) Capsules 250 mg; Grisactin® (Wyeth-Ayerst); (Rx)Griseofulvin (Microsize) Tablets 250 mg, 500 mg; Fulvicin-U/F® (Schering); Grifulvin V®(Ortho); Grisactin 500® (Wyeth-Ayerst); (Rx)Griseofulvin (Microsize) Oral Suspension 125 mg/5 ml in 120 ml; Grifulvin V® (Ortho Derm);(Rx)
Griseofulvin (Ultramicrosize) Tablets 125 mg, 165 mg, 250 mg, 330 mg; Fulvicin P/G®(Schering); Grisactin Ultra® (Wyeth-Ayerst); Gris-PEG® (Allergan Herbert); generic. (Rx)