Ivomec is a brand name for the chemical ivermectin, a wormer used in the beef and lamb industries that has somehow become viewed as a potential go-to wormer in goat dairy operations, despite the fact that it is illegal to do so in commercial cattle dairy operations due to the long-term persistence of ivermectin residues found in the milk. Milk Withdrawal Data If you click this publication, http://www.farad.org/publications/digests/092000ExtralabelIvermectinMoxidectin.pdf Look at Table 2 on page 2 for the milk withdrawal times for Ivermectin in goats. Food Animal Residue Avoidance Databank recommended Milk Withdrawal Intervals (WDI) for ivermectin in Dairy Goats: If dosed at a rate of 0.2 mg/kg of body weight on a standard breed goat it can be: 40 days for SC (subcutaneous injection) [and no, that is not a typo] 6 days for oral route of administration If dosed at a rate of 0.2-0.4 mg/kg of body weight on a standard breed goat it can be: 9 days for oral route of administration Applied topically at rate of 0.5 mg/kg of body weight on a standard breed goat it can be: 7 days for topical application "Those withdrawal times are just guidelines though. FDA regards the complete absence of ivermectin in milk as the only acceptable situation, Van Dyke says, and any trace amount in milk, even if below the tolerance level established for other cattle, is a violation." "Finally, Van Dyke points out that even veterinarians cannot use ivermectin in dairy cows. Provisions for "extra-label drug use" allow veterinarians to use certain drugs for purposes or in classes of animals not specified on the label, but only if there is no approved, effective drug available for the intended purpose. In the case of parasite control in lactating dairy cattle, there are approved, effective drugs available with no milk withdrawal times, and extra-label use of ivermectin in [dairy] cattle remains illegal." "Dr. Tom Van Dyke, with Merial animal health, stresses that ivermectin is not approved for use in lactating dairy heifers or cows under any conditions." [In other words, if it is an animal intended for meat, that is the 'other cattle' that there is a tolerance level for, so there is a certain level of ivermectin residue acceptable for meat consumption, but not for milk, which must be completely free of any residue.] Why? Because Ivermectin is very different than other wormers in that it is lipid soluble, and therefore can be problematic for a dairy animal being how it will stay stored in her body for an extended period of time. It is not legal to use in cattle dairies for this reason. And any trace of ivermectin found in commercial milk intended for human consumption is not allowed. Metabolism rates vary from individual to individual, thus withdrawal times can vary according to each individual animal's ability to metabolize (process, detoxify, get rid of) the drug. An animal with a compromised immune system will take longer to metabolize a toxin thereby resulting in a longer withdrawal time. The FARAD guidelines represent the minimum withdrawal periods. The FDA takes ivermectin residue seriously enough to fine commercial dairies for violations if found in the milk supply. Our government agencies are not known to be concerned about much, you can have cattle diseased with Johne's for example, and they are still allowed to remain in dairies producing milk for human consumption even though there are concerns that consuming such milk may be linked to Crohn's disease. So someone in the FDA must have reason to consider ivermectin residue in milk to be more dangerous than meets the eye. An excellent article on why ivermectin for dairy animals is not a good idea: When Not to Use Ivermectin. The Dangers of Ivermectin Use in Lactating Dairy Cows ----- Note: The FARAD recommended withdrawal times were based on studies that were performed on a standard size breed of goat. So for miniature breeds there haven't been any studies to provide any guidelines on a safe withdrawal time period and being how other drugs are supposed to be adjusted in dosage for minis that should be taken into consideration. Miniature breeds have a different metabolism rate so it isn't as simple as a mere body weight conversion. The reason I mention this is that the potential for overdosing a miniature breed of goat is high, and most vets are not well informed about this. Generally the higher the dose the longer it will stay in their system and thus equal longer withdrawal times. Also of note, the recommended meat withdrawal times for ivermectin vary and can be shorter or longer in duration depending on the route of administration, but this discussion is about milk withdrawal so if anyone is interested they can check the above FARAD link for that data. ----- Further reading: A study on Ivermectin use and resulting milk residues: https://www.ncbi.nlm.nih.gov/pmc/articles/PMC1914318/ There was also a study done on how it impacts soil health and biodiversity: "Environmental impact of ivermectin excreted by cattle treated in autumn on dung fauna and degradation of faeces on pasture." The Dangers of Ivermectin Use in Lactating Dairy Cows When Not to Use Ivermectin ----- Some Little Known Facts about Ivermectin: "Care should be taken when using ivermectin for treatment of nonlactating animals on a dairy farm. Treating dry cows can result in ivermectin residues in milk if insufficient time elapses between treatment and parturition" "Ivermectin is exceptionally potent, with effective dosages levels that are unusually low." "Due to the high lipid solubility of ivermectin, this compound is widely distributed within the body." Milk containing traces of ivermectin has been found to be harmful for dog consumption "Ivermectin also deposits in adipose tissue, which act as a reservoir that contributes to the long persistence of this drug in the body." "The response to ivermectin... can last for 6–12 months." Ivermectin is not approved for lactating animals. Also, for humans "ivermectin is... not recommended for use in pregnancy or in children under 5 years of age."