Selenium Deficiency (White Muscle Disease)


• Selenium deficiency generally occurs in spring and early summer on clover-dominant pastures.


• Generally seen in spring born lambs at 3-4 weeks of age.

• Affected lambs walk with a stiff gait and appear weak.

• Severe cases die of starvation, exposure or predation.

• Some lambs die of heart failure and others recover but suffer a growth setback.


• A tentative diagnosis can be made by examining the animals for pale muscle tissue on post mortem.

• A definitive diagnosis can be made by taking a blood sample from the animal and submitting it to the laboratory.


• Selenium can be administered to affected sheep by injection or as a drench.

• There is a very small safety margin in regards to selenium so treatment should only be administered where muscle disease has been diagnosed and treatment should be strictly given in accordance to manufacturer’s advice.


• Selenium supplements are available as vaccines and drenches as well as slow release pellets.

• Care must be taken to not overdose by supplementation with repeat vaccination/drenching.

Use of the information/advice in this guide is at your own risk. The Farmow and its employees do not warrant or make any representation regarding the use, or results of the use, of the information contained herein as regards to its correctness, accuracy, reliability, currency or otherwise. The entire risk of the implementation of the information/ advice which has been provided to you is assumed by you. All liability or responsibility to any person using the information/advice is expressly disclaimed by the Farmow and its employees.