Eradication of lice is essential for successful mohair production given the severity of ensuing fleece and skin damage. However, several factors must be considered when treating animals for lice; the lice themselves, shearing cycle, drug efficacy and worm management protocol.  

Lice

• Lice are roughly classified as sucking lice (like flies) or biting lice (like mosquitoes). Biting lice tend to cause more severe damage however the overlap is significant. Because of this overlap, the extent of fleece damage does not determine what type of lice you have. This can only be determined microscopically. Which lice you have determines which type of product is going to be effective i.e a dip works best on both types, while oral or injectable treatments work better for biting lice. Using a product that treats both means determining which type of lice is present unimportant.
• Lice are species-specific. This means that although the lice will be present on the skin of other animals, the lice cannot reproduce on anything but goats. Making sure you treat every goat on the property will ensure eradication. Failing to do so will cause a persistence of the infection and further treatments.

Shearing Cycle

• Different types of products will have different efficiency depending on how much fleece is on the goats.
• Dips and backlines are effective only on animals that are just shorn up to about 3weeks off shears. The drug has best access to the skin and absorption. Although there are products that claim efficacy when animals are in full fleece, these tend to be directed at sheep rather than angoras. Given the differences between a full sheep fleece and a full goat fleece, this claim is unlikely to be substantiated.
• Oral and injectable lice treatments have a similar efficacy regardless of the amount of fleece on the animal.

Drug Efficacy

• Rather than going through each product on the market, this is a list of drugs that will treat lice on goats.
• Pyrethrins and synthetic pyrethroids: Commonly found in cat and dog flea shampoos. Effective against both sucking and biting lice. Available as dip and pour on.
• Avermectin (ivermectin, doramectin) and moxidectin: Commonly found in worm drenches for livestock. Effective against sucking lice and partially against biting lice. Available as pour on and subcutaneous injection. Drenches containing these drugs do not treat lice.
• Fipronil: Commonly found in cat and dog ‘spot-on’ flea treatments. Effective against sucking and biting lice. Cat and dog ‘spot-on’ flea treatments used on goats.

Worm Management Protocol

• As mentioned above, avermectins are found in many worm drenches. IF you choose to use an avermectin product, you must withhold oral drenching for 4weeks. The pour-on or injections will treat intestinal worms for this time.

(For more information head to http://www.wormboss.com.au/programs/goats.php )

Other Considerations

• Regardless of the treatment used, no product is completely effective against eggs and nits. For this reason, repeat treatment in 10-14days is recommended.
• Remember a lot of products available are not registered for use in goats. This does not mean these products cannot be used in goats but it does mean that the drug company will not be responsible for any adverse effects of using their products on goats. Provided an appropriate dose is determined (talk to a local vet), most sheep products can be used in goats.

Recommendations

• Off shears: Pyrethrin based backline. Repeat treatment 10-14days.
• Partial or full fleece: Avermectin injection withholding oral drenching if due. Repeat treatment 10-14days. Treat with pyrethrin backline when off shears as above.
• REMEMBER you must treat every goat on your property. If you have a feral goat problem, it is recommended to integrate a lice control protocol into your yearly management plan. If not, instigating a quarantine protocol for new introductions will eliminate the need to treat the entire herd once the lice is eliminated.