Canine Leishmaniasis

Taxobox
color = khaki
name = "Leishmania"


image_width = 240px
image_caption = "Canine Leishmaniasis" positive dog.

genus = "Leishmania"
subdivision_ranks = Species
subdivision = "L. aethiopica"
"L. amazonensis"
"L. arabica"
"L. archibaldi" (disputed species)
"L. aristedesi"
"L. (Viannia) braziliensis"
"L. chagasi" (syn. "L. infantum")
"L. (Viannia) colombiensis"
"L. deanei"
"L. donovani"
"L. enriettii"
"L. equatorensis"
"L. forattinii"
"L. garnhami"
"L. gerbili"
"L. (Viannia) guyanensis"
"L. herreri"
"L. hertigi"
"L. infantum"
"L. killicki"
"L. (Viannia) lainsoni"
"L. major"
"L. mexicana"
"L. (Viannia) naiffi"
"L. (Viannia) panamensis"
"L. (Viannia) peruviana"
"L. (Viannia) pifanoi"
"L. (Viannia) shawi"
"L. tarentolae"
"L. tropica"
"L. turanica"
"L. venezuelensis"

"Canine Leishmania" (LESH-ma-NIGH-ah-sis) is a zoonotic disease (see Human Leishmaniasis) most commonly caused by the bite of an infected Phlebotomus sandfly. Canine Leishmaniasis was first identified in Europe in 1903 and in 1940 it was determined that 40% of all dogs in Rome were positive for Leishmaniasis [Dereure, Jacques. Pratlong. Dedit, J.P (1999) "Geographical distribution and the identification of parasites causing canine leishmaniasis in the Mediterranean Basin. Canine Leishmaniasis: an update." Proceedings of the International Canine Leishmaniasis Forum. Barcelona, Spain] . Traditionally thought of as a disease only found near the Mediterrean basin, 2008 research claims new findings are evidence that canine leishmaniasis is currently expanding in continental climate areas of northwestern Italy, far from the recognized disease-endemic areas along the Mediterranean coasts [cite journal |author=Ferroglio E, Maroli M, Gastaldo S, Mignone W, Rossi L |title=Canine leishmaniasis, Italy |journal=Emerging Infect. Dis. |volume=11 |issue=10 |pages=1618–20 |year=2005 |month=Oct |pmid=16318709 |doi= |url=http://www.cdc.gov/ncidod/EID/vol11no10/04-0966.htm ] . Cases of Leishmaniasis began appearing in North America in 2000 [Monti, Dean. (2000, June). "Hunters hounded as leishmaniasis is diagnosed in Foxhounds." Journal of the American Veterinary Medical Association. Schaumburg, IL. Available online: http://www.avma.org/onlnews/javma/jun00/s061500a.asp] , Leishmania positive Foxhounds have been reported in 22 states and 2 provinces of Canada as of 2008 Rosypal, Alexa. (2005 April) "Characterization of Canine Leishmaniasis in the United States: Pathogenesis, Immunological Responses, and Transmission of an American Isolate of Leishmania infantum". Veterinary Clinics of North America Small Animal Practice Journal. Blacksburg, VA. Updated version available online: http://scholar.lib.vt.edu/theses/available/etd-04152005-104125/unrestricted/Rosypaldissertation.pdf] .

Forms and Symptoms of Canine Leishmaniasis

Cutaneous

*Skin Lesions
*Alopecia
*Ulcerative or Exfoliative dermatitis
Visceral

*Swollen Lymphnodes
*Ocular signs
*Progressive loss of weight with decreased appetite
*Epistaxis (nose bleeds)
*Kidney failure > increased urination and drinking

Known Strains

Numerous strains and subgenus strains of Leishmania exist with Sandfly genome projects [http://www.genome.gov/Pages/Research/Sequencing/SeqProposals/SandFliesSeq.pdf] still underway strains are still being discovered.

Old World Leishmaniasis strains spread by the Sandfly in the genus Lutzomyia documented in dogs are:
*L. infantum "(Began appearing dogs in the United States in 2000)"
*L. donovani

New World Leishmaniasis strains are spread by Phlebotomus however research speculates that the North American sandfly could be capable of spreading but this is to date un-confirmed. Dogs are known resorvoirs of L.infantum and the spread of disease from dog to dog has been confirmed in the United States.
* Suspected cause of Canine Visceral Leishmania are geographic variants of the Donovani Complex including [Duprey ZH, Steurer FJ, Rooney JA, Kirchhoff LV, Jackson JE, Rowton ED, et al. Canine visceral leishmaniasis, United States and Canada, 2000–2003. Emerg Infect Dis. 2006 Mar. Available from http://www.cdc.gov/ncidod/EID/vol12no03/05-0811.htm] :
**L. infantum and
**L. Chagasi
**L. donovani

The Mexicana and Viannia strains are not commonly found in dogs:
Mexicana Strains are
*L. mexicana,
*L. amazonensis,
*L. venezuelensis,
*L. pifanoi)
subgenus Viannia is found only in Central and South America. Most important species are:
*L. braziliensis,
*L. guyanensis,
*L. panamensis and
*L. peruviana all of which cause Leishmaniasis in humans. [ [http://www.cvbd.org/4090.0.html Pathogens ] ]

Transmission

Traditionally canine transmission is directly from Sandfly to Dog. Cases in the United States have proven Leishmania Infantum transmission from dog to dog by direct contamination with blood and secretions as well as transplacentally from an infected bitch to her pups [ [http://www.capcvet.org/?p=Guidelines_Leishmaniasis&h=0&s=0 Companion Animal Parasite Council ] ] .
This mode of transmission seems to be unique to the Leishmania Infantum Mon1 strain found in the United States, a Brazilian study of 63 puppies from 18 L Donovani infected parents found no evidence of congential or transplacental infection.

See Also http://en.wikipedia.org/wiki/Leishmania#Uptake_and_survival

Diagnosis / Testing

In the United States certain breed clubs are strongly recommending screening for Leishmania especially in imported breeding stock from endemic locations. For reasons yet unidentified The Foxhound and Neapolitan Mastiff seem to be predisposed or at higher risk for disease [Petersen CHF paper 2008 ] [ [http://www.avma.org/onlnews/javma/jun00/s061500a.asp Hunters hounded as leishmaniasis is diagnosed in Foxhounds - June 15, 2000 ] ] The Italian Spinone Club of America is also requesting that all breeders and owners submit samples for testing, the club reports that 150 Spinone Italiano have tested positive in the United States [ [http://www.spinone.com/frhealth.htm Spinone Club of America Health Information - Spinoni Italiani ] ] .

In the United States the following veterinary colleges & government bodies assist with testing and treatment of Leishmania positive dogs:
*Iowa State University Dept of Pathology [http://www.biotech.iastate.edu/Current_Research/faculty_by_department.html#vetpathology]
*North Carolina
*Center for Disease Control

The PCR method for the detection of Leishmania DNA, currently used by Dr. Christina Peterson [http://www.vetmed.iastate.edu/faculty_staff/profiles/kalicat.asp] is the most sensitive and accurate method for detecting Leishmania. A study completed on Foxhounds (link) whom were tested with PCR showed approximately 20% of the tested dogs positive, the same population tested with anti-body serology (the traditional testing method in the US) showed only 5% positive [Petersen paper find notes ] .

Diagnosis can be complicated by false positives caused by the Lepto vaccine and false negatives caused by testing methods which lack sufficient sensitivity.

Prevention & Vaccines

In areas where the known vector is a sandfly an deltamethrin collars worn by the dog has been proven to be 86% effective [ [http://www.cdc.gov/ncidod/eid/vol7no5/reithinger.htm CDC - Topical Insecticide Treatments to Protect Dogs from Sand Fly Vectors of Leishmaniasis ] ] . The sandfly is most active at dusk and dawn, keeping your dog indoors during those peak times will help minimize exposure.

Unfortunatley, there is no one answer for Leishmania prevention nor will one vaccine cover multiple species. "Different virulence factors have been identified for distinct Leishmania species, and there are profound differences in the immune mechanisms that mediate susceptibility/resistance to infection and in the pathology associated with disease." [cite journal |author=McMahon-Pratt D, Alexander J |title=Does the Leishmania major paradigm of pathogenesis and protection hold for New World cutaneous leishmaniases or the visceral disease? |journal=Immunol. Rev. |volume=201 |issue= |pages=206–24 |year=2004 |month=Oct |pmid=15361243 |doi=10.1111/j.0105-2896.2004.00190.x |url=]

In 2003 Fort Dodge [http://en.wikipedia.org/wiki/Wyeth] released the Leshmune Vaccine in Brazil for L.donovani (also referred to as kala-azar in Brazil). [cite journal |author=Nogueira FS, Moreira MA, Borja-Cabrera GP, "et al" |title=Leishmune vaccine blocks the transmission of canine visceral leishmaniasis: absence of Leishmania parasites in blood, skin and lymph nodes of vaccinated exposed dogs |journal=Vaccine |volume=23 |issue=40 |pages=4805–10 |year=2005 |month=Sep |pmid=16011864 |doi=10.1016/j.vaccine.2005.05.011 |url=] . Studies indicated up to 87% protectioncite journal |author=Parra LE, Borja-Cabrera GP, Santos FN, Souza LO, Palatnik-de-Sousa CB, Menz I |title=Safety trial using the Leishmune vaccine against canine visceral leishmaniasis in Brazil |journal=Vaccine |volume=25 |issue=12 |pages=2180–6 |year=2007 |month=Mar |pmid=17239495 |doi=10.1016/j.vaccine.2006.11.057 |url=] Most common side effects from the vaccine have been noted as anorexia and local swelling .The president of the Brazil Regional Council of Veterinary Medicine, Marcia Villa warns that since vaccinated dogs develop antibodies they can be difficult to distinguish vaccinated dogs from asymptomatic infected dogs [Moreno, Saulo. 2004, October. Brazzil Magazine. Authorized use of Leishmania Vaccine. Made in Brazil. Avail online: http://www.brazzilmag.com/content/view/579/41/] . Studies are also indicating that the Leshmune vaccine may be reliable in treating L. Chagasi and a possible treatment for already infected dogs with L.donovani [cite journal |author=de Andrade RA, Reis AB, Gontijo CM, "et al" |title=Clinical value of anti-Leishmania (Leishmania) chagasi IgG titers detected by flow cytometry to distinguish infected from vaccinated dogs |journal=Vet. Immunol. Immunopathol. |volume=116 |issue=1-2 |pages=85–97 |year=2007 |month=Mar |pmid=17287029 |doi=10.1016/j.vetimm.2007.01.002 |url=] . [cite journal |author=Santos FN, Borja-Cabrera GP, Miyashiro LM, "et al" |title=Immunotherapy against experimental canine visceral leishmaniasis with the saponin enriched-Leishmune vaccine |journal=Vaccine |volume=25 |issue=33 |pages=6176–90 |year=2007 |month=Aug |pmid=17630055 |doi=10.1016/j.vaccine.2007.06.005 |url=]

Treatment

Currently there exist no cure for Canine Leishmaniasis, there are various treatment options available in different countries. In the United States all drugs used to treat Canine Leishmaniasis are controlled and regulated by the Center for Disease Control (CDC). Treatment is best coordinated with veterinarian research hospitals and the CDC. Treatment does vary by geographic area, strain of infection and exhibited symptoms. Dogs can be asymptomatic for years. Most common treatments include:
L.infantum [http://asmcourse.ivic.ve/articulos/urbina/urbina3.pdf]
*Pentavalent antimonials
*Meglumine antimoniate
*Amphotericin B

L. Donovani
*Antimonial resistant
*Polyene antibiotic amphotericin B

Given the recent appearance of L.infantum in the United States and the absence of a known vector the CDC recommends euthanasia of infected dogs due to their concerns of spreading the disease and its zoonotic nature. To date no known cases of dog to human transmission have occurred in the United States.

Research Directions

In the United States, research examining the Foxhound and Neapolitan Mastiff is scheduled to continue into 2011 at the University of Iowa. The goals of this project are to screen for the presence of the Leishmania parasite DNA and to be a stepping stone to future research of T-Cell function with the hopes of understanding canine Leishmaniasis as a model for better understanding human Leishmaniasis.
* Neapolitan Mastiff Submission forms [http://www.everythingneo.com/index.php?option=com_content&view=article&id=126&Itemid=127]
* Foxhound Submissions forms [http://www.vetmed.iastate.edu/faculty_staff/profiles/kalicat.asp]

Also in the United States the CDC is monitoring Italian Spinones with no end date indicated on sample submissions.

References

External links

* [http://www.leishmaniasis.info/ The Canine Leishmaniasis Site by Vetstream]
* [http://www.cvbd.org/4095.0.html Video of Leishmaniasis positive dog]
* [http://www.atimana.it/news/lesmania.htm Treatment options (article in Italian)]
* [http://www.vet.uga.edu/VPP/clerk/joiner/ Overview of Canine Leishmaniasis]
* [http://www.vet.uga.edu/VPP/NSEP/Brazil2002/index.htm US & Brazil 2002 US Department of Defense funded Canine Leishmaniasis Project]