Worming Farm Dogs

Over the years we (vets and farmers) have focused on controlling parasites in growing and
fattening stock. We support regular sampling to identify the issues, correct dosing of the
stock to ensure efficacy and use the appropriate anthelmintic to treat the challenges.
Unfortunately, this attention to parasite control has not extended to working (and pet) dogs on
the farmstead. Perhaps a cursory dosing, to add to the drug book just before your farm
inspection is due, judging by the comments we get at the front desk.

In Wales, over the last forty years we have seen several initiatives aimed at worming working
farm dogs to help reduce the incidence of hydatid disease in the human populations. Even in
2018, we still diagnose cases of this parasite in the community.
These efforts by The Welsh Assembly were aimed at reducing the disease in humans.
However, what is evident today is that we are seeing more cases of carcass downgrading or
loss of income, from the ‘fifth’ quarter due to cysts (Cysticercus ovis & Cysticercus
tenuicollis) in our lamb crop. This could have serious effects on the value of our lamb,
particularly as we are aiming to achieve the highest quality. It should be noted that these
parasites are also problematic in our major competitors’ flocks, in New Zealand. So
concerned are they, regarding the damage that could be done to their income, that they have
instituted an industry wide initiative to reduce this parasite. Have a look at
www.sheepmeasles.co.nz for more insight.

Let’s briefly look at the tapeworms and some pithy facts. The dog (working and pet) contracts
the parasite by eating contaminated sheep carcasses. When anyone arrives on your farm, the
first concern for them is to be greeted by a dog or several, running free!
This is not about personal safety, but more importantly, these free roaming dogs can and do
have their fill of whatever they chose, even that dead carcass on the back of the quad you
picked up earlier.

Once a dog has consumed some of a contaminated carcass, the tapeworms develop inside the
dog’s abdomen and in as few as five weeks, the collie (or spaniel etc) will be potentially
passing many segments. These are around the size of a grain of rice, containing thousands of
eggs. One dog, infected with one tapeworm, can produce 250,000 eggs per day. The collie’s
morning poo could contain in excess of this number, with the added consideration that the
eggs can remain infective on the pasture, to lambs, for six months. In addition, any hay crop
taken off the field could also remain infective for many months.

Thus, the story continues, the tapeworm eggs (so small as to be invisible) once released from
the little segment, are then consumed by the grazing lambs. Inside these accidental
intermediate hosts, the eggs develop into cysts. These cysts then develop into hard white
nodules, either on the muscle surface or deeply hidden in the muscle tissue. Some have a
predilection for the liver (known as bladder worms). Over a period of several months, these
damaging cysts are killed by the lamb’s immune system, leaving behind hard, fibrous or
calcified lesions, which will be found at processing (rejection of liver) or more damaging to
our industry, in your roasted leg of Welsh lamb, hidden until you slice open the Sunday joint
at the table.....

The New Zealand meat industry have realised several years ago that this will have a very
detrimental effect on the value of their product. They are aiming for a high quality product
and this issue with tapeworms is just not acceptable to the consumer. We are several years
behind the competition, so now is the time to catch up. We can and do produce the finest
lamb in the world, so let us ensure this issue does not affect our market.

1. All dogs on the farm (working or pet, including the Jack Russell), should be wormed
with a broad spectrum wormer, such as Drontal. (This will also deal with canine
roundworms in the dogs, which is no bad thing, as they can infect us).

2. Worm all dogs every month. Vets can send out text reminders to help.

3. Clean up faeces from dogs or have a limited exercise area for the farm dogs, fenced
off. (This will also help reduce Neospora caninum).

4. Do not allow dogs to roam free at any time.

5. Clean up and secure all fallen stock carcasses.

6. Loose box contaminated bedding (where the dogs are kennelled at night) should be
burned or buried deep. Putting dogs’ bedding onto the dung heap is the wrong thing to
do as this will increase Neospora and roundworm contamination of the pasture).

7. All visiting dogs (hunts/shoots) should be wormed before entry to your farmstead.

8. Erect guidance signs for all users on footpath access to farmland with a clear message,
i.e. ‘only wormed dogs allowed' and ‘clean up after your dog’.