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Roundworm in puppies

Roundworm in puppies

Toxocara canis  is a type of roundworm that most often affects puppies, but can infect dogs of any age. T. Canis is a roundworm that populates the large intestine of their definitive host, the dog. Many pups will show no outward symptoms. In severe infesations, however, the consequences can be quite serious. In some puppies the roundworm will migrate to the lungs and cause pneumonia, I other severe cases the roundworms may obstruct or even perforate the intestine.

The symptoms that might indicate your dog or puppy has roundworm include:

-         Dull coat
-         Weight loss
-         Appetite loss
-         Pot-bellied appearance
-         Coughing
-         Diarrhoea
-         Vomiting
-         Anaemia
-         Lethargy
 
Transmission between dogs

Dogs are primarily infected when they come into contact with the infective stage of the T. canis egg. The pre-infective stage is usually shed into the environment in the faeces of an infected dog – it becomes active after a period of maturation in the environment, the duration of which will vary depending on the ambient temperature. After these infective eggs have been ingested by a dog they will hatch, and cross the intestinal wall. At this stage they will migrate to the liver followed by the lungs. From the lungs they either pass back into the bloodstream end up in other body tissues (like the muscles) where they lie dormant unless the dog becomes pregnant, or they may be coughed up and swallowed. Those that are swallowed pass back into the intestines, where they develop into the mature adult worm, and start to produce their own eggs after about 6 weeks.
 
T. canis can also pass readily between a bitch and her pup, both whilst she is pregnant and whilst she is feeding the pups. When a bitch becomes pregnant any larvae that are lying dormant in her body tissues become activated and will migrate across the placenta, infecting the pups. These larvae may also migrate into the mammary gland (breast tissue) and then into the milk.
 
The risks to your family

Of equal importance to the risk posed to puppies is the risk that this worm poses to people. After they have matured in the environment the T. canis eggs are not only infective to dogs, but to humans as well. First-rate hygiene is essential in preventing infection in young children. Children may come into contact with the parasite if they pick contaminated sand or dirt up and put it in their mouths, or more indirectly just by putting their fingers in their mouths after playing in contaminated sand or dirt or touching a dog that has eggs stuck to its coat.  Children should always wash their hands when coming from the garden and before they eat.  Making sure dog faeces in your garden are picked up on a daily basis will also help – this way most of the eggs will be being removed from the child’s environment before they become infective. The eggs may be killed by long periods of exposure to sunlight – the sunnier parts of your garden will therefore represent lower risk to your children.
 
Infection in children can cause blindness if the larvae migrate to the eye. They can also migrate to other organs, causing a variety of symptoms.   If you suspect your child has come into contact with old dog faeces it is highly advisable for you to consult your GP for advice on treatment and prevention.
 
Treatment and prevention
 
Puppies should be wormed at 2 weeks of age and then every 2 weeks until they are 12 weeks old. Breeding bitches should be wormed before mating, during the pregnancy and whilst lactating. The specific dosage recommendations during pregnancy and lactation will depend somewhat on the particular product used – to make sure you are treating your bitch correctly we advise you to consult your vet.  Adult dogs need to be wormed less often, every 3months.
 
There are several different types of wormer available. Choosing the right one for your dog depends on a number of factors. To make the right choice you need to take into consideration which, if any, other anti-parasitic medications you are already using, whether or not the dog is to be used for breeding, whether you are worming the dog to treat a known infestation or as a preventative measure, and of course the age of the dog or puppy. For example, not all wormers will be safe to use during pregnancy and lactation and not all wormers are safe in very young pups etc. There are a number of good quality all-wormers that are available without a prescription, including Drontal and Panacur.  There are also several prescription-only wormers available. The spectrum of worms that each of these products will be effective against does vary a little – you should consult your vet as to which one will be best for your dog.