Changes

==Introduction==

==Introduction==

[[Image:Giardia Cyst.jpg|thumb|right|150px| Giardia cyst from a dog. Source: Wikimedia Commons; Author: Joel Mills (2006)]]

[[Image:Giardia Cyst.jpg|thumb|right|150px| Giardia cyst from a dog. Source: Wikimedia Commons; Author: Joel Mills (2006)]]

''[[Giardia]]'' is a binucleate, flagellate protozoa that causes enteric infection giardiasis in dogs and occasionally cats. ''[[Giardia]]''  species have been reported to be found in 1-39% of faecal samples from dogs and cats, with a higher rate of infection in younger animals.Transmission is via cysts that are shed in the faeces, and may be direct or indirect. Indirect water-borne transmission is the most common modality and is favoured by cool, moist conditions that prolong cyst survival. Once cysts are ingested, motile trophozoites are released and attach to the cells of the small intestinal mucosa via an adhesive disc. Predilection sites in the dog are the duodenum and jejunum, whereas only the duodenum is favoured in cats. Multiplication by binary fission can then occur, and trophozoites encyst to a stage adapted for survival in the external environment. Cysts are seen in the faeces from day 3 post-infection in dogs (5-16 in cats), and can survive in the environment for several months. Animals that mount an immune response to ''[[Giardia]]'' can eliminate infection; however, the immunity acquired does not necessarily prevent re-infection after a short period.

''[[Giardia]]'' is a binucleate, flagellate protozoa that causes enteric infection giardiasis in dogs and occasionally cats and reptiles. ''[[Giardia]]''  species have been reported to be found in 1-39% of faecal samples from dogs and cats, with a higher rate of infection in younger animals. Transmission is via cysts that are shed in the faeces, and may be direct or indirect. Indirect water-borne transmission is the most common modality and is favoured by cool, moist conditions that prolong cyst survival. Once cysts are ingested, motile trophozoites are released and attach to the cells of the small intestinal mucosa via an adhesive disc. Predilection sites in the dog are the duodenum and jejunum, whereas only the duodenum is favoured in cats. Multiplication by binary fission can then occur, and trophozoites encyst to a stage adapted for survival in the external environment. Cysts are seen in the faeces from day 3 post-infection in dogs (5-16 in cats), and can survive in the environment for several months. Animals that mount an immune response to ''[[Giardia]]'' can eliminate infection; however, the immunity acquired does not necessarily prevent re-infection after a short period.

Giardiasis is a condition of significant zoonotic concern. Although the cat protozoa ''G. felis'' seems to be species-specific, dogs can host both the canine-specific ''G. canis'' and ''G. lamblia'', which has zoonotic genotypes. It is not known how important dogs are as a reservoir for human ''[[Giardia]]'' infection, or how frequently zoonotic transmission occurs. In man, ''[[Giardia]]'' may cause acute diarrhoea, particualrly in immunocompromised individuals. Subclinical infections also occur.

Giardiasis is a condition of significant zoonotic concern. Although the cat protozoa ''G. felis'' seems to be species-specific, dogs can host both the canine-specific ''G. canis'' and ''G. lamblia'' (characterised by twin eye-like anterior nuclei), which has zoonotic genotypes. It is not known how important dogs are as a reservoir for human ''[[Giardia]]'' infection, or how frequently zoonotic transmission occurs. ''G. lamblia'' is the protozoa most often involved in reptilian infections, so should be considered a zoonotic risk. In man, ''[[Giardia]]'' may cause acute diarrhoea, particularly in immunocompromised individuals. Subclinical infections also occur. Therefore strict hygiene should be employed to prevent faecal contamination.

==Signalment==

==Signalment==

[[Image:Giardia lamblia.jpg|thumb|right|150px| ''Giardia lamblia''. Source: Wikimedia Commons; Author: Janice Carr (2006)]]

[[Image:Giardia lamblia.jpg|thumb|right|150px| ''Giardia lamblia''. Source: Wikimedia Commons; Author: Janice Carr (2006)]]

Dogs are more commonly affected than cats. There are no age, breed or sex predispositions for ''[[Giardia]]'' infection, but puppies and kittens are more likely to contract clinical disease than adult animals.

Dogs are more commonly affected than cats. There are no age, breed or sex predispositions for ''[[Giardia]]'' infection, but puppies and kittens are more likely to contract clinical disease than adult animals. Disease may also be seen in immunocompromised or stressed individuals.

Many other pets, including small mammals, and livestock can be infected and a source of environmental contamination.

Many other pets, including small mammals, reptiles, and livestock can be infected and a source of environmental contamination.

==Diagnosis==

==Diagnosis==

===Clinical Signs===

===Clinical Signs===

Clinical signs are most likely to be seen in younger animals as older hosts are usually infected asymptomatically. Signs vary from acute, chronic or intermittent diarrhoea to chronic loose, fould-smelling faeces, and frequency of defaecation is usually increased. The stools are normally light coloured and mucoid and often contain fat. Blood is not normally present in the faeces. Vomiting, flatulence and weight loss/failure to gain weight may be seen in some cases, and the hair coat may be poor. Giardiasis may also cause malabsorption, and there are several proposed mechanisms for this. For example, the small intestinal villi may be grossly atrophied or damaged ultrastructurally, or giardiasis may lead to bacterial overgrowth. There is also evidence that ''[[Giardia]]'' consumes bile acids, preventing digestion of fats.

Clinical signs are most likely to be seen in younger or immunocompromised animals, as healthy, older hosts are usually infected asymptomatically. Signs vary from acute, chronic or intermittent diarrhoea to chronic loose, fould-smelling faeces, and frequency of defaecation is usually increased. The stools are normally light coloured and mucoid and often contain fat. Blood is not normally present in the faeces. Vomiting, flatulence and weight loss/failure to gain weight may be seen in some cases, and the hair coat may be poor. Giardiasis may also cause malabsorption, and there are several proposed mechanisms for this. For example, the small intestinal villi may be grossly atrophied or damaged ultrastructurally, or giardiasis may lead to bacterial overgrowth. There is also evidence that ''[[Giardia]]'' consumes bile acids, preventing digestion of fats.

===Laboratory Tests===

===Laboratory Tests===

==Treatment==

==Treatment==

It is particularly important to treat giardiasis in animals owing to its zoonotic potential. In the UK, '''fenbendazole''' is licensed for use against ''[[Giardia]]''. '''Metronidazole''' may also be used in dogs and cats but it is important to confirm the respective doses. However, metronidazole is only 67% effective in dogs and has a bitter taste. A combination of febantel, praziquantel and febantel (Drontal Plus) can be used in dogs. Following treatment, it is advisable to repeat faecal examinations to confirm the efficacy of treatment and to detect re-infection. As well as drug therapy, thorough cleaning and disinfection of the environment and the animal's belongings is essential. Shedding of cysts can be difficult to detect and so in contact animals may be treated concurrently.

It is particularly important to treat giardiasis in animals owing to its zoonotic potential. In the UK, '''fenbendazole''' is licensed for use against ''[[Giardia]]''. '''Metronidazole''' may also be used in dogs and cats but it is important to confirm the respective doses. However, metronidazole is only 67% effective in dogs and has a bitter taste. A combination of febantel, praziquantel and febantel (Drontal Plus) can be used in dogs. Metronidazole is the recommended treatment for reptiles. Following treatment, it is advisable to repeat faecal examinations to confirm the efficacy of treatment and to detect re-infection. As well as drug therapy, thorough cleaning and disinfection of the environment and the animal's belongings is essential. Shedding of cysts can be difficult to detect and so in contact animals may be treated concurrently.

A vaccine comprising killed trophozoites has been developed and is available in the USA for use in dogs and cats. The vaccine decreases the excretion and viability of ''[[Giardia]]'' cysts, thus reducing the environmental burden.

A vaccine comprising killed trophozoites has been developed and is available in the USA for use in dogs and cats. The vaccine decreases the excretion and viability of ''[[Giardia]]'' cysts, thus reducing the environmental burden.

|literature search = [http://www.cabdirect.org/search.html?q=%28%28title%3A%28Giardiasis%29+OR+title%3A%28Giardiosis+%29+OR+title%3A%28Giardosis+%29+OR+title%3A%28%22Giardia+Infection+%22%29%29%29+OR+%28%28title%3A%28%22Lambliasis+%22%29+OR+title%3A%28lambliosis%29%29%29 Giardiasis publications]

|literature search = [http://www.cabdirect.org/search.html?q=%28%28title%3A%28Giardiasis%29+OR+title%3A%28Giardiosis+%29+OR+title%3A%28Giardosis+%29+OR+title%3A%28%22Giardia+Infection+%22%29%29%29+OR+%28%28title%3A%28%22Lambliasis+%22%29+OR+title%3A%28lambliosis%29%29%29 Giardiasis publications]

|full text = [http://www.cabi.org/cabdirect/FullTextPDF/2010/20103310400.pdf '''Giardia and giardiasis.''' Ivanov, A. I.; Faculty of Veterinary Medicine, Trakia University, Stara Zagora, Bulgaria, Bulgarian Journal of Veterinary Medicine, 2010, 13, 2, pp 65-80, many ref.]

|full text = [http://www.cabi.org/cabdirect/FullTextPDF/2010/20103310400.pdf '''Giardia and giardiasis.''' Ivanov, A. I.; Faculty of Veterinary Medicine, Trakia University, Stara Zagora, Bulgaria, Bulgarian Journal of Veterinary Medicine, 2010, 13, 2, pp 65-80, many ref.]

|flashcards = [[Small Mammals Q&A 11]]

|flashcards = [[Small Mammals Q&A 11]]<br>[[Reptiles and Amphibians Q&A 23]]

}}

}}

==References==

==References==

*Fisher, M (2002) Endoparasites in the dog and cat: 2. Protozoa. ''In Practice'', '''24(3)''', 146-153.

*Fisher, M (2002) Endoparasites in the dog and cat: 2. Protozoa. ''In Practice'', '''24(3)''', 146-153.

*Taylor, M A and Webster, K A (1998) Recent advances in the diagnosis of Cryptosporidium, Toxoplasma, Giardia and other protozoa of veterinary importance. ''Research in Veterinary Science'', '''65''', 183-193.

*Taylor, M A and Webster, K A (1998) Recent advances in the diagnosis of Cryptosporidium, Toxoplasma, Giardia and other protozoa of veterinary importance. ''Research in Veterinary Science'', '''65''', 183-193.

*Papasouliotis, K and Gruffydd-Jones, T (1996) Practical Approach to Diarrhoes in the Cat. ''In Practice'', '''18(5)''', 206-214.

*Papasouliotis, K and Gruffydd-Jones, T (1996) Practical Approach to Diarrhoes in the Cat. ''In Practice'', '''18(5)''', 206-214.

[[Category:Intestinal Diseases - Cat]]

[[Category:Intestinal Diseases - Cat]]

[[Category:Zoonoses]]

[[Category:Zoonoses]]