Emergence of Arthropod Transmitted infections in Kennel Dogs

Changing scenario of climate resulting from global warming and adversity of nature has also resulted in emergence and re-emergence of diseases transmitted by arthropods. Increasing trends of population growth of dogs has increased the chance of disease transmission due to readily available susceptible host. Babesiosis and Hepatozoonosis and Ehrlichiosis are the main arthropod borne diseases of dogs prevalent in India. The present article explains the importance of these arthropod transmitted infections in kennel dogs, research progress and reason for their emergence in the present scenario.


Introduction
use of highly sensitive diagnostic tools like serological tests, molecular tools like PCR etc. in order to Climatic conditions in India are quite favorable undertake therapeutic and control measures.for the growth and multiplication of arthropods which Studies of canine babesiosis in India are limited act as vector for many diseases of animals including to epidemiological studies with prevalence of canine species.Changing scenario of climate resulting infection ranging from 0.1 -22% in different parts of from global warming and adversity of nature has also India on the morphological criteria by microscopic resulted in emergence and re-emergence of diseases examination (Sundar et al., 2004;Chaudhari, 2006).transmitted by arthropods.The process of disease Most of the studies regarding babesia in India are transmission is augmented by the large population of lacking information at level of species and genotype stray dogs in our country which acts as a host for harbored by infected dogs.The pathogenicity of constant maintaining the transmission cycles of vector babesia is also known to differ in different parts of borne diseases like hemoprotozooa (Azaziah et al., India which might be due to strain and species 2010).Above all, the changing social structure, variation (Azaziah, et al., 2010).urbanization and industrialization, people are Very sparse reports are available regarding the increasingly keeping dogs as pets for security as well prevalence of canine Hepatozoonosis in India.It has as companion animal.Security concern resulting from been reported in Mumbai in dogs with characteristic terrorist outfits and insecurity at border areas of our clinical signs of anemia, thrombocytopenia, hepatitis, country has also forced security forces (military, elevated blood urea nitrogen and hyperglobulinemia paramilitary and police) to increase dog squads and (Pawar and Gatne, 2005).Subclinical hepatozoon strength of dogs in kennels for multi-purpose use.
infections with prevalence ranging from 3-9% have Thus increasing population of dogs has increased the been reported (Gupta et al., 1994;Sharma et al., 1997).

chance of disease transmission due to readily available
There are very few studies regarding the prevalence of susceptible host.These tests are generally employed for Babesia parasite multiplies by binary fission in seroepidemiological studies.Nucleic acid detection erythrocytes.Infected erythrocytes incorporates by genus specific screening of DNA extracted from parasite antigen (Ag) into their surface which induces blood is performed by Polymerase Chain Reaction of transmission of Hepatozoon infection is unique.(PCR).Semi nested PCR even used for definitive Unlike other vector borne protozoon infections, diagnosis and differentiation of B. gibsoni and all Hepatozoon infection in canines occurs by ingestion subspecies of B. canis with defined limit of detection of vector containing mature oocytes of Hepatozoon in which could improve diagnostic efficacy for babesia hemocoel.Two species of Hepatozoon are prevalent infections (Birkenheuer et al., 2003).Recently among dogs across the world, viz., Hepatozoon canis and Hepatozoon americanum both of which produce application of quantitative fluorescent resonance unique clinical syndrome in infected dogs.energy transfer (FRET)-PCR to amplify 18S rRNA Hepatozoon canis infection (HCI) was first gene fragments of babesia spp.shown high sensitivity described in India in 1905 (Craig, 2006).HCI is and specificity as well as species differentiation based unique infection in which tick vector acts as a on disassociation temperature of the fluorescent definitive host for parasite where as dogs are probes (Wang et  dividing merozoites in dog tissues by process of metronidazole @15 mg/kg every 12 hours orally and merogony.They are of two types' viz., macromierzoites doxycycline @ 5 mg/kg every 12 hours orally (Suzuki or micromerozoites.Merozoites released from mature et al., 2007) and azithromycin @ 10 mg/kg every 24 meronts invade neutrophils as well as monocytes and hours orally with atovaquone @13.3 mg/kg every 8 undergo gamontogony to produce gamonts hours orally for 10 days with good efficacy and safety (previously called as gametocytes).Ticks become (Birkenheuer et al., 2004).Clindamycin @ 25 mg/kg infected by ingestion of leukocytes containing these orally every 12 hours for 1-3 weeks can be effective if gamonts during blood meal on dog host.other antibabesial drugs are not available.Doxycycline has also been found effective in Gametogenesis in gut of tick produces distinct gamets preventing or reducing the severity of parasitemia in which after fertilization produce zygote.Sporogony dogs.In case of severe anemia and dehydration, occurs in tick hemocoel to produce oocysts containing supportive therapy in the form of blood transfusion, 100s of sporocysts containing sporozoites infective to hematinic, fluid therapy, etc. is required. dogs.

Canine Hepatozoonosis infection. HCI infection shows variety of clinical It is an arthropod borne hemoprotozoon infection patterns. Most common clinical presentation is low of canines caused by Apicomplexan protozoa level parasitemia (less than 5% neutrophils) which
Hepatozoon.Infection is transmitted by various may go asymptomatic or show mild disease and is arthropod vectors like ticks, mites, mosquitoes, characterized by anemia, lowered platelet count.Rare sandflies, tsetse fly, flea, lice and reduviid bugs.Mode but very severe disease is characterized by high parasitemia (approaching infection of 100% 'onion skin cysts' in large muscles of infected dogs neutrophils with leukocytosis).Severe syndrome is (Panciera et al., 1999).Researchers at Oklahoma state characterized by fever, lethargy, weight loss, anemia university have developed indirect ELISA using and γ-hyperglobulinemia.In highly parasitemic dogs sporozoites as antigens to diagnose the ACH infection load of blood and tissue parasites take its toll by (Mathew et al., 2001).Compared to HCI, ACH is demanding nutrients and exerting tissue injury.
frustrating to treat.Infection responds poorly to HCI is diagnosed on the basis of clinical pattern treatment regimen.Management of intense pain is of syndrome and laboratory findings like leukocytosis, done with non-steroidal anti-inflammatory drugs and extreme neutrophilia (more than 10000/µl), anemia supportive care with provision of food and (normochromic, normocytic), serum biochemical maintaining hydration of dog (Vincent-Johnson et al., changes like increased levels of serum Creatinine 1997).A novel therapeutic approach with Potentiated kinase (CK) and Alkaline phosphatase (ALP) as well sulfonamide (Sulfonamide + Trimethoprim) @ 15 mg/kg orally every 12 hours for 14 days with 10 mg/kg as γ-hyperglobulinemia.Examination of Giemsa of Clindamycin orally every 8 hours for 14 days, stained blood smears reveals presence of ellipsoidal Pyrimethamine @ 0.25 mg/kg/day orally for 14 days gamonts (11 x 4 µm) in cytoplasm of neutrophils and followed by Decoquinate @ 10-20 mg/kg orally every occasionally in monocytes.Histopathology of tissue 12 hours for continuous 2 years have show promising sections or cytology also aids in detection of meronts.
response in infected dogs but relapses occurs if Serological tests like IFAT and ELISA by employing treatment is discontinued (Macintire et al., 2001).purified gamont antigens is generally used for epidemiological studies.Generally antibodies of IgM Ehrlichiosis and IgG are produced against parasite as early as 16 It is a set of syndromes produced by tick and 22 days post infection respectively, which peaks at transmitted gram negative obligate intracellular 7-9 weeks and persists for up to 7 months (Gonen et Rickettsia of Ehrlichia genus that primarily infects al., 2004).leukocytes (monocytes, macrophages, and granulocytes).Imidocarb dipropionate is a choice drug used @ Syndromes in canine ehrlichiosis include canine 5-6 mg/kg IM or subcutaneously (SC) every 14 days monocytotropic ehrlichiosis, and canine granulocytotropic until blood smears were negative for gamonts.
ehrilichiosis etc.But cross-reactivity and co-Doxycycline @ 10 mg/kg/day orally for 21 days with infections commonly observed in dogs (Waner et al., Imidocarb dipropionate is commonly used in practice 2001).Ehrlichiosis generally presents as non-specific to treat identified or potential co-infections (Craig, 2006).Also combination of Tetracycline hydrochloride multisystemic disorder with clinical signs of lethargy, @ 22 mg/kg every 8 hours and Imidocarb dipropionate depression, weight loss, vomiting, diarrhea and @ 6 mg/kg SQ every 14 days can successfully clear anorexia.Affected dogs may show bleeding tendency gametocytes from blood with disappearance of due to platelet defects or thrombocytopenia.Other clinical signs (Eliase and Homans, 1988; Baneth and pathologies include uveitis, polymyositis, polyarthritis, and signs of central nervous system affection (Neer et Weigler, 1997).Generally prognosis is good except al., 2002).Hematological abnormalities include non-guarded prognosis in cases of dogs with high regenerative anemia and thrombocytopenia while parasitemia.
Hepatozoon americanum hyperglobulinemia, hypoalbuminemia and low species of parasite was discovered in South America on the basis of albumin-globulin ratio are the biochemical phylogenetic analysis, geographic distribution, abnormalities reported in canine Ehrlichiosis (Neer vectors and pathogenesis (Baneth, et al., 2000).H. and Harrus, 2006).americanum infection also called as American Canine Canine Monocytic Ehrlichiosis (CME) : CME is Hepatozoonosis (ACH) which is transmitted by extensively studied ehrlichial disease of dogs caused Amblyomma maculatum ticks and reported across by infection with Ehrlichia canis and characterized by southern Gulf States of USA (Gavazza et al., 2003).thrombocytopenia and bleeding tendencies.Three ACH attacks skeletal muscles and myocardium which species of E. canis genogroup (I) viz., E. canis, E. is responsible for clinical syndrome that differs from chaffeensis, and E. ruminantium infect the monocytes HCI.It produces more severe infection characterized of dogs.Geographical distribution of each species by fever, lethargy, weight loss, stiffness, paralysis, varies as so vector tick.Rhipicephalus sanguineus is signs of pain, and mucopurulent ocular discharge.the vector for E. canis, also experimental transmission Infection is diagnosed by identifying organism as with Dermacentor variabilis has been reported (Johnson et al., 1998).E. chaffeensis is transmitted by may be beneficial.Immunosuppressive activity of Amblyoma americanum and also by Dermacentor Prednisolone might have role in to curtail immune variabilis while no reported evidence about the tick mediated mechanisms partially responsible for vector of E. ruminantium for transmission in canines is thrombocytopenia and decreased platelet functions available.Several factors affect the pathogenesis of (Frank and Breitschwerdt, 1999; Neer and Harrus, CME like size of inoculum, immunocompetence of 2006).Supportive therapy in the form of parenteral host etc. German shepherd breed of dog is more crystalloid or colloids or blood transfusion according susceptible to CME with more severe disease and poor to severity of disease has been indicated (Huxsoll et prognosis that could be due to depressed cell mediated al., 1970; Neer and Harrus, 2006).immunity in these dogs (Neer and Harrus, 2006).for the treatment of CGE is Tetracyclines @ 22 mg/kg CME diagnosed on the basis of combination of clinical signs, hematological deviations, thromboorally every 8 hours for 14-21 days or Doxycycline @ cytopenia, and serological tests.Definitive diagnosis 5-10 mg/kg orally every 12-24 hours for 10 days.is made on the basis of demonstration of morulae in Other drugs like Minocycline, chloramphenicol can leukocytes from blood smears or tissue aspirates of also used by weighing the benefit and adverse effects lung, spleen and lymph nodes.Serological diagnosis is on host body.There are no evidences suggesting performed with IFAT and ELISA.A sensitive tool for persistence of E. ewingii organism after undertaking ehrlichia detection is PCR method which detects DNA recommended treatment protocol (Greig et al., 2006). of organism.All diagnostics have their pros and cons Hemoprotozoon infections of canines are very in diagnosis, but effective and quick test should be dreadful to the health of canines as they affect several utilized for detecting infection that will help in body systems including blood and blood forming institution of treatment.Effective drugs against CME organs.Studies regarding prevalence of hemoprotozoon are tetracyclines, chloramphenicol, imidocarb diseases in India are partial despite climatic conditions dipropionate and amicarbalide.There are several that are frequently adorable for the transmission of controversies regarding effective drug, dose, duration vector borne hemoprotozoon diseases in canines of treatment, efficacy of therapy etc. Doxycycline @ (Azaziah et al., 2010).With advent of molecular tools 10 mg/kg/day orally for minimum 28 days is the it is now becoming necessary to encrypt the prevalence standard treatment commonly followed as per of these infections in order to take measures for American College of Veterinary Internal Medicine prevention and control of the same.(Neer and Harrus, 2006).Oxytetracycline @ 22 mg/kg Babesiosis and Hepatozoonosis and Ehrlichiosis in dogs in India.Conventional Ehrlichiosis are the main arthropod borne diseases of diagnostics of blood smear examination for parasite dogs prevalent in India.But till date our knowledge morphology has shown the prevalence ranging from regarding the epidemiology, diagnostics, treatment and management of these arthropod borne infections 0.35% in Punjab to 18.9% in Nagpur (Juyal et al., is quite limited.So these infections poses a great 1994; Samaradni et al., 2003).Lakshmanan et al., (2007) used nested PCR for detection of Ehrlichia challenge on veterinarians to improve knowledge as well as provide evidences regarding these infection by from blood of dogs and found 50% dogs positive by nested PCR for E. canis infection compared to only production of antibodies (Abs).Opsonization of 19% by blood smear examination.erythrocytes with Abs leads to removal of infected erythrocytes by mononuclear phagocyte system Southern Asia, Australia, prepared from peripheral blood.Examination of blood Europe and USA and transmitted by several species of smear under oil immersion lense used to identify Ixodid ticks.In addition to role of Ixodid ticks in morphology of parasite.B. canis appears as large, transmission of B. gibsoni, non-vector transmission piriform organisms which exist either as single or in by exchange of blood during fighting and biting has pairs in erythrocytes.Serological tests like indirect been reported in USA.Pit bull terrier dogs have more fluorescent antibody tests (IFAT), enzyme linked prevalence of B. gibsoni infections that might immunosorbent test (ELISA) have been developed, correlates to frequent use of these dogs for fighting sidetracked due to limited sensitivity and specificity.(Yeagley et al., 2009).
transmitted by Dermacentor ticks.Third species, B. haemolysis, fever, anorexia, depression, lethargy, canis rossi is most pathogenic among three, which is pale mucus membranes, splenomegaly, and prevalent in South Africa and transmitted by lymphadenomegaly.While complicated babesiosis is Haemophysalis leachi ticks.With advent of molecular characterized by simultaneous pathology in various methods, newer species that infect dogs have been organ systems like, acute renal failure, cerebral identified like, B. conradae (Kjemtrup and Conrad, babesiosis, coagulopathy, icterus, hepatopathy, 2006), B. microti like (Camacho-Garcia, 2006) and immune mediated hemolytic anemia, acute unnamed large Babesia spp.(Birkenheuer et al., respiratory distress syndrome, hemoconcentration, 2004).hypotension, cardiac changes, acute pancreatitis, acid-Small babesia constitutes B. gibsoni which is a base disturbances etc. (Taboada and Lobetti, 2006).small (1-3.2 µm), pleomorphic organism usually Diagnosis is done conventionally by Wright, observed singly within erythrocyte.It is distributed Giemsa or Diff-Quick staining of blood smear over Northern America, al., 2010).intermediate hosts from which ticks acquire infection Line of treatment for canine babesiosis varies of gamonts through ingestion of infected leukocytes.with the severity of infection and accompanying HCI is prevalent among dogs in tropical, subtropical complications.Diminazene aceturate is the widely as well as temperate climates.There is no gender and practiced drug across the world (Irwin, 2009).It is breed predilection and disease is reported in dogs of all effective when given intramuscularly (IM) but age groups.Dogs acquire infection by ingestion of clearance of parasite in not consistent.On the other ticks infected with Hepatozoon canis.Brown dog tick hand drug exerts some toxic effects in predisposed (Rhipicephalus sanguineus) acts as a primary vector.canines.Imidocarb dipropionate is an effective Transtadial transmission has been reported.therapeutic agent against B. canis infection in dogs.A Horizontal transmission through uterus from dam to single dose of 6-7.5 mg/kg the day following a regular offspring may also occur.dose of diminazene at 3.5 mg/kg has shown efficacy in After ingestion of vector tick by dog, sporozoites clearing the infection.But all these drugs are not are released in to intestine which invades mononuclear extensively studied as Diminazene aceturate.Other cells after penetration of gut wall and disseminate drugs that have been exploited for managing clinical hematogenously or via lymph to hemolymphatic signs for many years include Quinuronium sulphate, target organs.Target organs include bone marrow, trypan blue, pentamidine, phenamidine and spleen, lymphnodes and liver, kidneys and lung.It parvaquone (Irwin, 2009).
Canine Granulocytic Ehrlichiosis (CGE): CGE is a disease of neutrophils caused by Ehrlichia ewingii and In infected ticks ehrlichae organisms are reported only in USA.Organism of CGE is transmitted distributed by hemocytes from the gut to the salivary by several ticks like Ixodes pacificus, Dermacentor gland.During feeding, ticks inject salivary secretions variabilis, Rhipicephalus sanguineus, Amblyomma containing organisms into feeding sites which causes americanum and Ixodes scapularis (Goldman et al., transmission in dogs.Ticks are able to overwinter and 1998).Disease is characterized by fever, lethargy, transmit infection for 155 days from infection.anorexia, weight loss, vomiting, diarrhea, transient Organisms multiply in macrophages of MNS by thrombocytopenia which tend to be severe, and non-binary fission and spread throughout body leading to regenerative anemia.It also produces acute polyarthritis acute, subclinical or chronic syndrome.CME is syndrome as well as neurological disturbances characterized by development of leucopenia, anemia (Maretzki et al., 1994).Clinical and hematological and thrombocytopenia.Clinically it is a multisystemic abnormalities of E. ewingii infection are similar to disorder characterized by depression, lethargy, weight those produced by E. canis but appear to be milder loss, and anorexia with or without bleeding tendencies.than later.Diagnosis of CGE is based on the complete Dogs also exhibit ocular signs (anterior uveitis), history, clinical findings, hematological findings, neuromuscular signs, and polyarthritis.Concurrent or demonstration of morulae in granulocytes or synovial secondary infections may aggravate the condition of fluid, serology and PCR.The recommended protocol dogs.