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PhytoMast® is a plant-based formula successfully used by hundreds of veterinarians and farmers across the US, Canada and around the world on thousands of animals. And while it is fairly simple to use, we want to make sure you get the best results from using PhytoMast® by answering a few common questions. If you have any questions not covered here, feel free to contact us. If you need further in-depth advice on your specific situation, Dr. Karreman is also available for paid consultations.



  • Thymol is a well-known compound and its use in veterinary medicine is found in many textbooks and product catalogues dating back to 1900. 

  • Thymol has been used primarily as a disinfectant due to its antibacterial properties. Thymol has also been included in veterinary formulas against parasitism (internal and external), fungal skin infections, upper respiratory issues and dental needs.

  • Thymol is an active ingredient in the Haver-Glover product of 1928 sold for cows and called “H-G Intramammary Disinfectant” (A Manual Of Veterinary Therapeutics. Haver-Glover Laboratories, Kansas City, MO 1928, pg. 98). On this basis, PhytoMast with Thymol is presented for drying-off cows.

  • Thymol is considered GRAS (Generally Recognized As Safe).

  • PhytoMast with its active ingredient of thymol has had its pharmacokinetics, milk and meat residues, in-vitro efficacy, and clinical efficacy for dairy cows and goats written up in 8 peer-reviewed journal publications (including the Journal of Dairy Science) and studied in-depth for a successful PHD.

  • PhytoMast is a phytoceutical (type of plant medicine). Because of the multitude of biochemicals in any plant, there is a near zero chance of antibiotic resistance. Not culturing milk and checking for appropriate antibiotic selection and then continually using the same antibiotic to dry-off cows goes against basic medical principles and leads to antibiotic resistance. 

  • PhytoMast does NOT trigger the Delvotest P nor Charm SL Beta-lactam tests, which are commonly used to check for antibiotic residues.

  • PhytoMast is manufactured and packaged in the USA. (Many products for dry-off are manufactured in India and China.)

  • PhytoMast is OMRI approved.

  • Can PhytoMast® be used on goats?
    Yes! Most of our customers are dairy farmers or vets looking to treat cows, but PhytoMast® is equally effective with dairy goats.
  • What’s the difference between regular formula PhytoMast® and PhytoMast® CBO?
    The easy initial answer is that PhytoMast® CBO uses cinnamon bark oil, whereas regular formula PhytoMast® does not. If you or your veterinarian suspects a germ known to have biofilms, you would want to choose PhytoMast® CBO, as the cinnamon bark oil is very potent against these types of infections. PhytoMast® CBO should be used during lactation at the initial onset of any symptoms of flaky milk or high somatic cell count, especially if germs like staph aureus, pseudomonas and others that have bio films are suspected. If you do not suspect that a germ containing biofilms is present, you should be fine using regular formula PhytoMast®.
  • How do you use PhytoMast®?
    For both formulas, you’ll want to use 1 tube per effected quarter as needed to cleanse teats in fresh cows. Insert the tube tip directly into the teat for the affected quarter only and empty the entire tube. During use and 24 hours after the last use, withhold milk from the treated quarters and do not mix it with other milk. Withheld milk can be fed to calves, and might even help with digestion if the calf has a problem with digestion. Suggested Withholds: Not to be used within 13 days of calving. Milk from treated cows must not be used for food during the first 72 hours after calving.
  • Can I use PhytoMast® for other things?
    PhytoMast® is primarily used for teat and udder health, but it can be used as a cleanse for other places. However, this ONLY applies to regular formula PhytoMast®. Regular formula PhytoMast® can be used to cleanse eyes, ears and skin.
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