Giardia species are found in mice, amphibians, and warm-blooded vertebrates.
Giardiasis is a chronic, intestinal, protozoal infection seen around the world in most mammals, many birds, and people too. As such it is a Zoonosis, infection is common in dogs, cats, ruminants, pigs, and the highest rates of infection are seen in young animals. Giardia species are found in mice, amphibians, and warm-blooded vertebrates. The species complexes infecting vertebrates include G Ardea and G Psitta from birds. G MicrotiI from muskrats and voles and G Duodenalis also known as G Intestinalis and G Lamblia which has a wide mammalian host range. As flageolet protozoan trophozoites Giardia attached to the brush border of the intestine, usually the proximal small intestine. Upon encystation in the smaller large intestine cysts then pass in the faces squared as infective and can survive for weeks in the environment. The pre-Payton period is generally 2 to 10 days, sis shedding may be continued over several days over a week, but is often intermittent, especially in the chronic phase of infection. Within this scheme obviously Giardia via injunction of materials contaminated by feces. Only smaller numbers of cysts are needed to initiate infection. High humidity facilitates the survival of cyst in the environment and animal overcrowding facilitates transmission. A not uncommon means by which humans become infected is through drinking untreated or unfiltered water, while hiking, camping, or even accidentally swallowing a bit of water while swimming. Giardia is present in many waterways and it should be assumed that all water is contaminated and needs to be treated. Coldwater from the mountain stream looks enticing but don’t fall for it. Symptoms may take 1 to 2 weeks to develop but may continue to 6 weeks leading to diarrhea, stomach cramps, nausea, or vomiting, flatulence, and greasy stools. Ensure that water is free of Giardia parasites by using one of these 3 methods
Gross intestinal lesions are seldom evident, Giardia causes an increase in the epithelial permeability and an increase in the number and activation of T lymphocytes in the gut. This leads to a shortening of the brush border microvilli and causes reduced absorption of water, electrolytes, and nutrients. Together with decreased activity of the small intestinal brush border enzyme, the host suffers from malabsorptive diarrhea and malnutrition. Reduced activity of lipase and increased production of mucin leads to steatorrhea and mucus diarrhea. Clinical signs are often normal, however, Giardia infections in small animals may manifest as chronic weight loss and chronic or intermittent diarrhea particularly in the young. Feces appear soft, pale, malodorous and contain mucus and fat. Watery diarrhea is unusual and fecal blood is usually not observed, however, an animal may vomit. Differential diagnosis includes virtually all other causes of malabsorption and maldigestion such as exocrine pancreatic insufficiency. Young remanence giardiasis can result in diarrhea, unresponsive to antibiotics, or coccidia stats. It should be suspected when feces are mucoid and pasty and animals less than 6 months of age show reduced weight gain. Giardia diagnosis involves a saline smear of feces that may show model oval trophozoites, unlike yeast or trichomoniasis they have a double nucleus. Fecal cysts 9 to 15 by 7 to 10 microns can be concentrated by the centrifugation floatation technique using zinc sulfate. Identification can be facilitated by iodine staining, because of intermittent excretion 3 fecal examinations should be performed over a period of 3 to 5 days. Specific detection can be enhanced immunofluorescence and commercially licensed techniques optimized for the species of interest. There are no FDA approved drugs for the treatment of giardiasis for dogs and cats. However, fenbendazole has been approved for use in Europe and is used off-label in the US. It has been shown to be safe in pregnant and lactating animals. A praziquantel parental and for battle, the combination has been used for 3 days. Extra label use of metronidazole for 5 days is effective in eliminating Giardia species from about 2 out of 3 infected dogs, but may be associated with the violation and neurological side effects. Combination or sequential strategies, be sure to bathe the animals to remove cysts have also been tried. Currently, no drug is FDA approved for the treatment of Giardia in ruminants. So off label users would consult with the food animal residue avoidance database for guidance on withdrawal time fenbendazole and albendazole significantly reduce cysts excretion and clinical improvement in calves. Paromomycin for 5 days is also found to be highly efficacious in calves. For production animals and group house domestic animal management is the key to the control of Giardia. Cysts can cause infection and reinfection particularly if housing is crowded. Giardia cysts get infected immediately when they are passed in the feces and survive in the environment. Cysts are said to be a source of infection and also reinfection in the case of animals particularly those in crowded conditions. Feces should be removed from the environment daily, dogs and cats should bathe to remove cysts from the hair coat. Disinfection with quaternary ammonium and steam or boiling water can inactivate cysts in the environment. To facilitate efficacy solutions should be left greater than 5 minutes before rinsing. Yards and animal runs cannot be disinfected and should be considered contaminated for at least a month after the removal of the last infected animal. Cysts may be inactivated by allowing the surface to dry thoroughly after cleaning. In summary, Giardia is a protozoan seen worldwide that causes chronic intestinal infection in most mammals, many birds, and people. Infection is common in dogs, cats, ruminants, and pigs. The highest rates of infection are seen in young animals. Affected domestic animals can be treated with antiprotozoal agents often in combination, but proper hygiene constitutes the best approach to animals in group housing. (Image to be added soon)
The cysts are said to be more resistant forms and are responsible for the transmission of giardiasis. Both cysts and trophozoites can be found in the feces at the diagnostic stages. The giardia life cycle is as follows
The clinical features of Giardia include the below
Giardia is a particular issue in developing countries and is the main cause of diarrhea like symptoms and abdominal pain. It is a major issue in developing countries because of overcrowding, the unhygienic environment, and poor quality of the water quality control in these areas. In the case of developing countries, the prevalence is said to be the highest in children, we can imagine how it will be a major issue.
Giardia intestinalis or lamblia protozoa has 2 forms, there is the Giardia cyst which is the infective form which is about 10 micrometers in diameter and is ovoid cell shape, it contains 4 nuclei in the cytoplasm. The Giardia cyst can become a giardia trophozoite, which is the mobile form that moves around. It is pear-shaped with 8 flagellants and thus it is known as protozoa flagellate. It contains 2 anterior suction disks that allow it to attach itself to the mucosal surface of the intestine and it contains 2 nuclei in the cytoplasm.
The parasite belonging to Giardia inhabits the intestinal tract of the vertebrates. There are various Giardia species which affect various animals including human beings, they are as follows
The systematic classification of Giardia is as given below
Giardia has 2 morphological forms trophozoites and cyst
Your email address will not be published. Required fields are marked *
Save my name, email, and website in this browser for the next time I comment.