Albendazole is a benzimidazole anthelmintic used mainly in livestock against susceptible gastrointestinal worms, lungworms, tapeworms and adult liver flukes. Activity and dosing depend on the host and parasite.
Historical small-animal regimens exist, but bone-marrow injury makes other drugs preferable for routine canine or feline giardiasis. Extended courses and avian use require particular caution.
Assess parasite-specific efficacy, including fecal testing when appropriate. During extended courses or when adverse signs develop, monitor CBC and hepatic enzymes; discontinue and investigate unexplained cytopenias or jaundice.
Adult liver-fluke activity does not establish efficacy against immature flukes. Select treatment according to parasite stage, host and susceptibility.
Binding to parasite beta-tubulin disrupts microtubule formation and dependent cellular functions. Host rapidly dividing tissues can also be injured, explaining marrow and intestinal toxicity.
Up to 3 days; Do not use in: First 45 days of pregnancy, Pre-existing marrow suppression; Historical regimen; safer alternatives are preferred because serious marrow toxicity can occur. Monitor CBC.
Respiratory parasites
50 mg/kg
PO
Every 24 h
Up to 14 days; Do not use in: First 45 days of pregnancy, Pre-existing marrow suppression; Historical 10-14 day course with substantial marrow-toxicity concern; other treatments are preferred. Monitor CBC.
Giardiasis
25 mg/kg
PO
Every 12 h
Up to 2 days; Do not use in: First 45 days of pregnancy, Pre-existing marrow suppression; Historical regimen; safer alternatives are preferred because serious marrow toxicity can occur. Monitor CBC.
Paragonimus kellicotti infection
25 mg/kg
PO
Every 12 h
Up to 14 days; Do not use in: First 45 days of pregnancy, Pre-existing marrow suppression; Parasite-specific regimen; marrow suppression remains a concern. Monitor CBC and consider safer alternatives.
Filaroides hirthi infection
25 mg/kg
PO
Every 12 h
Up to 5 days; Do not use in: First 45 days of pregnancy, Pre-existing marrow suppression; A repeat course after two weeks has been described. Monitor respiratory response and CBC.
Filaroides hirthi infection
50 mg/kg
PO
Every 12 h
Up to 5 days; Do not use in: First 45 days of pregnancy, Pre-existing marrow suppression; Separate higher-dose regimen with a repeat after 21 days; respiratory signs can worsen after parasite death. Monitor CBC.
Oslerus osleri infection
25 mg/kg
PO
Every 12 h
Up to 5 days; Do not use in: First 45 days of pregnancy, Pre-existing marrow suppression; Repeat after two weeks has been described. Monitor CBC and clinical response.
Capillaria plica infection
50 mg/kg
PO
Every 12 h
Up to 14 days; Do not use in: First 45 days of pregnancy, Pre-existing marrow suppression; Reported course 10-14 days; anorexia and marrow toxicity are concerns. Monitor CBC.
Cats
Use / stage
Dose
Route
Schedule
Instructions
Intestinal helminths
25–50 mg/kg
PO
Every 12 h
Up to 3 days; Do not use in: First 45 days of pregnancy, Pre-existing marrow suppression; Historical regimen; safer alternatives are preferred because serious marrow toxicity can occur. Monitor CBC.
Respiratory parasites
50 mg/kg
PO
Every 24 h
Up to 14 days; Do not use in: First 45 days of pregnancy, Pre-existing marrow suppression; Historical 10-14 day course with substantial marrow-toxicity concern; other treatments are preferred. Monitor CBC.
Giardiasis
25 mg/kg
PO
Every 12 h
Up to 2 days; Do not use in: First 45 days of pregnancy, Pre-existing marrow suppression; Historical regimen; safer alternatives are preferred because serious marrow toxicity can occur. Monitor CBC.
Paragonimus kellicotti infection
25 mg/kg
PO
Every 12 h
Up to 14 days; Do not use in: First 45 days of pregnancy, Pre-existing marrow suppression; Parasite-specific regimen; marrow suppression remains a concern. Monitor CBC and consider safer alternatives.
Birds
Use / stage
Dose
Route
Schedule
Instructions
Helminth infection
50–100 mg/kg
PO
Every 24 h
Up to 9 days; Reported 2-9 day range spans different avian species; species-specific tolerance is not established by this generic bird entry.
Cattle
Use / stage
Dose
Route
Schedule
Instructions
Susceptible helminths and adult liver flukes
10 mg/kg
PO
Once
Do not use in: First 45 days of pregnancy, First 45 days after bull removal, Female dairy cattle of breeding age; For Valbazen 11.36%: meat withdrawal 27 days; not for female dairy cattle of breeding age.
Sheep
Use / stage
Dose
Route
Schedule
Instructions
Susceptible helminths and adult liver flukes
7.5 mg/kg
PO
Once
Do not use in: First 30 days of pregnancy, First 30 days after ram removal; For Valbazen 11.36%: meat withdrawal 7 days.
Goats
Use / stage
Dose
Route
Schedule
Instructions
Adult liver flukes
10 mg/kg
PO
Once
Do not use in: Lactating does, First 30 days of pregnancy, First 30 days after buck removal; Nonlactating goats. For Valbazen 11.36%: meat withdrawal 7 days; this regimen is specific to adult liver flukes.
Horses
Use / stage
Dose
Route
Schedule
Instructions
Dictyocaulus arnfieldi infection
25 mg/kg
PO
Every 12 h
Up to 5 days; Historical equine regimen; assess alternative anthelmintics and susceptibility.
Strongylus vulgaris infection
50 mg/kg
PO
Every 12 h
Up to 2 days; Historical high-dose regimen; assess alternative anthelmintics and susceptibility.
Pigs
Use / stage
Dose
Route
Schedule
Instructions
Susceptible helminths
5–10 mg/kg
PO
Do not use in: Early pregnancy; Reported oral dose; the repeat interval is not specified. Establish an appropriate food withdrawal interval.
Rabbits
Use / stage
Dose
Route
Schedule
Instructions
Encephalitozoon cuniculi infection
20 mg/kg
PO
Every 24 h
Up to 10 days; Do not use in: Pregnancy, Pre-existing marrow suppression; Reported alternative; fenbendazole is generally preferred. Monitor CBC because benzimidazole-associated marrow injury can occur.
Up to 30 days; Do not use in: Pregnancy, Pre-existing marrow suppression; Reported initial course followed by the lower maintenance dose; assess ocular disease separately and monitor CBC.
Up to 30 days; Do not use in: Pregnancy, Pre-existing marrow suppression; Follows the initial course; monitor CBC and clinical response.
Chinchillas
Use / stage
Dose
Route
Schedule
Instructions
Giardiasis
50–100 mg/kg
PO
Every 24 h
Up to 3 days; Do not use in: Pregnancy, Pre-existing marrow suppression; Reported chinchilla regimen; do not extrapolate this high exposure to other small mammals.
Early pregnancy: avoid during the first 45 days in cattle; Valbazen excludes the first 30 days in ewes and does.
Dogs and cats can develop severe marrow suppression, including idiosyncratic reactions.
Prolonged or high-dose courses increase toxicity risk.
Valbazen must not be used in female dairy cattle of breeding age or in lactating does; product-specific food restrictions remain essential.
Do not assume that a livestock regimen or safety margin applies to birds.
Pigeons and doves can be particularly susceptible to intestinal crypt injury and marrow suppression.
Severe diarrhea, neutropenia and fatal sepsis have been reported in alpaca crias given high repeated doses.
Rabbits can develop severe marrow aplasia with benzimidazole exposure; prefer better-supported alternatives when treating encephalitozoonosis and monitor CBC during prolonged treatment.
Bone-marrow toxicity may be dose-related or idiosyncratic, particularly in cats. Stop treatment if suspected and monitor serial CBCs; cytopenias require supportive management. Early gestational exposure can harm the embryo or fetus.
Valbazen 11.36% Oral Suspension Shake well. Cattle meat withdrawal 27 days; sheep/goat meat withdrawal 7 days. Not for female dairy cattle of breeding age or lactating does. Store at room temperature protected from freezing.
Oral Liquid
113.6 mg / mL
PO
Zentel 400 mg Chewable Tablets
Tablet
400 mg / tablet
PO
Zentel Oral Suspension 400 mg/10 mL Shake well; concentration is 40 mg/mL. Store at room temperature protected from freezing.
