What is Giardia?  

Giardia is  a protozoa one celled parasite. It undergoes  several stages of development. The isolated cell is called ’Giardia intestinalis’  It is a tear shaped bacteria with what looks  like two eyes at the anterior  end, These are the nuclei, which are in the part of the parasite which is the suction pad, this attaches to the small intestine of its hosts. Each Trophozite has five flagella, that aids motility. It is at this stage that the organism rapidly divides. As they detach they are swept down the intestine. At this stage they are very fragile. If peristalsis due to severe inflammation is rapid, the Trophozite would not survive very long. The more trophozite's one has the more inflammation occurs. The more inflammation in the bowel the quicker the trophozite's  divide. By the time the parasite is usually expelled it has undergone a massive change. It is now known as a cyst. The cyst is inactive,  but much more durable, whilst it lurks around in the litter pan, waiting to  be picked up on the next poor unexpected occupant. But unlike other organisms the cyst once more becomes active as soon as it is ingested. The acid in the stomach enables the outer part of the cyst to be broken down and releases two more Trophozite's.

It is also known as traveler’s diarrhoea in humans, usually because it is picked up in dirty water. [In fact the water could look clean and be as clear as spring water but if it has Giardia cysts in it, you can become infected. 

Clinical Signs and Symptoms. 

As few as one cyst can cause an acute onset of the infection. Once the Trophozite attaches itself to the intestinal wall, it can cause an acute foul smelling diarrhoea. The stool tends to be soft to watery, may be yellow and frothy. Normally the illness in humans will last one –two weeks, but due to a cats fastidiousness’, with constant washing of its own and companions rear end  it re- infects itself. Thank fully we humans do not do that, so it should be self eliminating. But chronic cases may last months to years. Mechanical obstruction of the absorption surface of the intestine may cause the kitten/cat to dehydrate,  lose weight , become anemic , due to the malabsorption of food and nutrients in the intestines. Until this problem came to my attention I was unaware how wide spread and serious this condition is. It can kill young kittens, elderly cats and those whose immune systems are already compromised.  

Clinical Diagnosis. 

Examination of the stools  for cysts, may give a positive diagnosis, but you may get negative tests, if no cysts are detected.  Blood tests can reveal a raised ESR, which indicates infection.

Without treatment the infection may continue, either intermittently or chronically.

It is more common in Multicat households. Catteries where there may even be  cats that do not display any symptoms but are infected and shedding Giardia cysts.  


Giardia organisms require a certain amount of moisture to survive  and are susceptible to drying out, therefore once litter pans are disinfected, [A diluted bleach solution will help control Giardia],  it is imperative to make sure they are dry before renewing litter. The Giardia organisms also die in excess heat, so sterilisation of food  and water bowls will help eliminate re-infestation.

For the general  environment a cup of bleach in a gallon of water should prove effective , but making sure surfaces can be safely treated with bleach first. Some homes are lucky enough to own steam cleaners, the heat should kill any lurking cysts.

Now I must admit, up until now,  to being one of those breeders, who because my cats do not go out, I have not been so vigilante with worming my older cats. Kittens are wormed as part of my contract  with new owners. Most people worm with Panacur [fenbendazole]  for 3 days, this is usually also a sufficient deterrent  against Giardia too, but please do not get a false sense of security. It only takes 1 cyst to be ingested for infection to occur. In a household where one or several cats have acute diarrhoea due to Giardia the best line of treatment is Metronidozole 50mgs twice daily for adults and 20mgs for kittens for 5 days. All cats/ kittens in same house hold need to be treated at the same time. Clip the hair around the anal area of long hair cats, to eliminate cysts attaching to hair and becoming ingested again. It has been suggested, by a vet trainee in Canada , that 1cc of Aloe Vera for 4 weeks be given until all strains of Giardia has gone. I could not find much on this, but can only think that it helps the cats immune system. I am not sure whether it was meant as a treatment . Treat any new cat entering your household, with Panacur, prior to socialisation with other cats.  


 Thank fully it is good.

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