Worming, or “dosing “dogs for control of internal parasites, has been part of farming husbandry for years. Control of roundworms, hookworms, whipworms, and tapeworms affects the health and wellbeing of our four-legged work mates, but the control of dog tapeworms is also important in meat hygiene and human disease.
Hydatids disease, caused by the dog tapeworm Echinococcus granulosus, has been all but eliminated in New Zealand, through a successful treatment and testing programme run from the late 1950s to the late 1990s. A second dog tapeworm, Taenia ovis, causes a similar disease called Sheep Measles. Control of Sheep Measles has not been as successful as that of hydatids.
The adult tapeworm lives in the intestine of the dog and produces eggs. A single tapeworm can produce 250,000 eggs per day, and some dogs will carry 3-4 worms. The eggs are picked up by sheep and goats when they graze. These eggs can develop into encysted larvae in the muscle of these animals. These cysts are unsightly in the meat and result in excess cutting or downgrading of carcasses.
The meat has small spots in it, which is where the common name for this disease, Sheep Measles, comes from. When affected meat is eaten by a dog, the tapeworms develop into mature, egg- producing adults in 35 days. The control of this disease lies in killing the encysted larvae in meat so that they cannot infect dogs who eat it, and by killing the adult worms (using worming drugs) before they have a chance to produce eggs. The New Zealand Farm Assurance programme is requiring a 30-day dosing regime for Sheep Measles control, and other QA programmes are likely to follow.
The practice of feeding our working dogs with home-killed or purchased meat has been the norm for years. According to figures from the Vetlife TeamMate `The New Zealand Working Dog Project`, 96% of owners feed meat as part of their dogs` regular diet. Cysts are killed by freezing meat to a minimum of -10 degrees Celsius for 10 days or cooking it to a core temperature of more than 72 degrees Celsius.
The second point of control lies in dosing dogs with a drug called praziquantel every 30 days. This is the least expensive and most effective way to control tapeworms in dogs. This drug can be purchased as a tapewormer only, or in combination with a roundworm, hookworm, and whipworm treatment in “allwormer” products.
Best practice recommends your dogs should be wormed every 30 days in a 3-month rotation. Use a broad spectrum allwormer product the first month, then a straight praziquantel product for the next 2 months. Dosing should be regular and consistent, using the correct dose for each dog’s bodyweight. All dogs should be treated, and dogs coming onto your farms should be required to be treated as well. This ensures that dogs will be free of parasites and prevents contamination of pasture with tapeworm eggs that will infect sheep and goats.
Roundworms and hookworms are of greatest concern in puppies, who are often infected at birth or shortly afterwards. Pups should be wormed from 2 weeks of age with an allwormer type product, repeating the dose every 2 weeks until 4 months of age, then every month until 6 months, and then as above for adult parasite control.
Note: for complete information of control of sheep measles refer to Ovis Management website: www.sheepmeasles.co.nz.
Lori Linney
Vetlife Alexandra
