Giardia – a close look at the canine disease

When dog owners get talking about parasites, it is usually about fleas, lice and sometimes also ticks. Even though these bloodsuckers are admittedly thoroughly annoying, there are other parasites that occur just as frequently and can have some very unpleasant effects for dog and owner. We are talking about giardia.

Giardia – stubborn intestinal parasites

Giardia are intestinal parasites that can affect many different species of mammal. It is not uncommon for giardia to be transmitted from dog to human and vice versa – which in technical terms is called a zoonosis. They are tiny, single-celled flagellates that nest in the mucous membrane of the small intestine and – depending on the state of health of the affected organism – either trigger symptoms of illness or not. Whether or not the giardia show symptoms: the host's excretions always pose a risk of infection and can infect other animals.

Young dogs up to about two years old are the most commonly affected group, as the digestive tract and immune system are usually not yet sufficiently stable at this age. However, the parasite can certainly also affect older dogs, even though pronounced symptoms are much rarer here. In the vast majority of cases, transmission occurs through the ingestion of infected faeces or through a smear infection – when, for example, one dog greets another with its snout at the rear end. In addition, standing water in puddles is increasingly becoming a source of giardia. For transmission, the little intestinal parasites encapsulate themselves in cysts and, under favourable conditions, can survive and remain infectious for several months.

Typical symptoms and course of the illness

Basically, the symptoms of a giardia infestation are quite easy to recognise. An affected dog suffers from severe, sometimes slimy, yellowish and foul-smelling diarrhoea. Diarrhoea can, of course, also have many other causes – but if the symptoms are observed over several days, the faeces should be examined at a veterinary practice with a rapid test for giardia, so that treatment can be started if in doubt.

In many cases, however, a giardia infestation runs entirely without symptoms. The parasites have indeed nested in the host's intestine and are excreted with infectious faeces, but cause no acute complaints whatsoever. Only when the parasites get out of hand for some reason – for instance through a smouldering infection, an inadequate supply of nutrients, stress or some other weakening of the organism – do the symptoms appear. The insidious thing about giardia is that they weaken the whole organism by hindering the absorption of nutrients in the intestine. The coat becomes dull, the dog has stomach ache and, despite a sufficient supply of food, becomes ever thinner. The immune system also suffers massively as a result.

Therapy and treatment options

The good news: after a diagnosis, the infestation with the intestinal parasites can be treated reliably. Once the giardia have been detected in the faeces, the vet administers targeted medication that must be given as instructed. In addition, during walks you must be sure to collect your dog's faeces, as this is the only way to prevent other dogs from becoming infected too. You should also thoroughly clean and hot-wash or steam all objects the dog comes into contact with – such as blankets, bowls and toys – to prevent re-infection.

Caution is also called for when several animals live in the household. Be sure to bear in mind that the parasites can be transmitted not only from dog to dog, but also to other mammals and likewise to us humans. That is why it is often a wise decision, in the event of illness, to have all animals living in a household tested for giardia at once and, if necessary, treated. From the point of view of animal naturopathy, it is also advisable to rebuild the intestinal flora after treatment.

Prevention and support

One thing first: there is no hundred-percent protection against giardia. Neither do conventional worming treatments help preventively, nor does a vaccine exist. Wherever dogs meet or wild animals are about, there is a risk of infection. That does not mean, however, that you can do nothing. For example, a sensible approach is to collect stool samples at regular intervals and send them in for examination, in order to rule out that your own dog is affected unnoticed.

This article serves as general information and to raise awareness of your dog's intestinal health.