WORMS

There are three main worms that like to become friends with our pigs, and thus cause a knock on affect with further health issues whereby our pigs will eat but not gain weight as they are sharing their food with their internal friends, therefore causing our pigs unable to get to good weight for slaughter and at the end the value of the meat will be sufficiently unsatisfactory. At farrowing we will see small piglets, sow unable to feed to full potential and therefore we will see us putting time, money and effort in getting every one to a satisfactory weight and looking ship shape. Therefore decreased efficiency, increase time to market, and decrease carcass value.

The names these worms go by, and very elaborate if I may add are:

1. Ascaris suum – the large roundworm
2. Trichuris suis – the whipworm
3. Oesophagostomum spp – the nodular worm

The Large Roundworm

Ascaris suum is the most common and we see a large number of herds infected both indoor as well as outdoor keeping. It is also the largest of the worms measuring more than eight inches in length. The adult worm lives in the small intestine where it swims against the flow of the intestinal contents. They can sometimes migrate into the pig’s stomach where they cause the pig to vomit and it will be visible to see the feed and worms. These worms compete for nutrients in the intestine, which will then lead to high costs to us as we will observe feeding our pigs resulting in not putting on weight or slow to gain weight which will give a poor carcass weight. The cost will be significant especially if the pig is heavily infected and goes un-noticed. Frighteningly, a single female can lay up to one million eggs a day. It is worth noting that the eggs can remain active in the environment up to thirty years! They become infective 10 days after being laid. They can be swallowed by a host allowing larvae to be released, which migrates through the intestinal wall, travels via the blood stream to the liver and then to the lungs. Ascaris suum are then coughed up, swallowed and return to the intestines to complete their cycle. The entire process takes approximately seven to eight weeks to complete. Major damage can be caused by the larvae as they migrate through the liver and lungs. During the liver migration white scar lesions are formed which are commonly referred to as “milk spots”. The lung migration makes the pig more susceptible to respiratory problems such as mycoplasma and viral pneumonias also on slaughter if milk spots are present you will not see your liver returned.

Whipworm

Trichuris suis can infect our pigs at any age, but is often associated with scour problems in growers and can be confused with swine dysentery. Whipworm infection can be the most economically devastating common worm, with heavy infections costing untold amount of money per animal due to decreased feed efficiency and weight gain.

The adult worm is about two inches long and lives in the large intestine where it burrows into the intestinal wall disrupting nutrient absorption and allowing secondary bacterial and viral infections to infect the pig. The females lay eggs that are past in the faeces and can become infective in approximately three weeks. These eggs are also very hardy and can last in the environment up to ten years. Another pig ingests the infective egg which then hatches into a larvae and travel to the large intestine to become an adult and start the cycle all over again.

Nodular Worms

Oesophagostomum spp. are about an inch long when they reach their adult stage in the large intestine. This parasite is most common in herds where sows are outside during their gestation period or are in heavily bedded areas. The eggs of the nodular worm, which are passed in faeces, are not as hardy as those of the roundworm and whipworm. They require bedding, manure, or some other form of protection from moisture. When conditions are right the egg will form a larvae within a week that is swallowed by a pig. The larvae migrate to the large intestine and burrow into the walls forming nodules.

Infected pigs may have diarrhoea, decreased appetite and poor weight gain. Piglets as young as two to three week of age can be infected leading to a grayish-yellow diarrhoea. This problem can be corrected by treating infected sows and improving the hygiene of the farrowing area.

PREVENTION

Some of us worm regularly some of us conduct worm egg counts on the faeces. It is true to say that worming should be done but done when necessary. Therefore, only you can assess this within your own herd, where and how you keep them to when and how you worm your herd. The monitoring of worms can be achieved by techniques where we have seen our members often comment:

1. Abattoir monitoring – particularly with respect to liver damage of growers due to migrating Ascaris A report will be given to you from your abattoir advising you of such recordings.
2. Worm egg counts on faeces. There are useful procedures for monitoring nodular and stomach worms in sows as part of a long-term strategy. Eggs are floated in salt solution and examined microscopically, with quantitative analysis possible. It should be noted that Ascaris suum adults within sows and boars are only very intermittent excretors of eggs and it is less likely that these will be detected in single samplings. Also in growing pigs e.g. with Trichuris, clinical disease (scour) may be apparent before worms and mature eggs are produced. Speak to your veterinary practice as you may find that if they do not conduct a faecal count they can send samples away for analysis.

Available wormers

There are various oral wormers available from spreading on feed to adding in water. Then there are injectable wormers where some of these are dual purpose in solving other issues such as lice and mange. Your appropriate worming strategies will depend upon the specific worm burden involved and a discussion with your vet will help you through this.