SNAP 4Dx Test Clinical Reference Guide

The SNAP ® 4Dx ® Test Clinical Reference GuideWellness Screeningfor Vector-borne Disease

Every dog, every year.For healthier pets and so much more.The benefits of vector-borne disease screening go far beyond the well-being of an individualpet. And adopting regular screening protocols at your practice can lead to a greaterawareness and understanding of vector-borne disease in your community, while buildingthe value of your practice with pet owners.Your PatientsBy educating pet owners about therisk of vector-borne disease, youhave the opportunity to stress theimportance of screening in terms ofpet health and disease prevention.Also, pet owners who understandthat a disease is often treatablewhen diagnosed early are morelikely to take preventative measuresincluding vaccination, screening andcomprehensive testing.Your CommunityComprehensive annual screeningsgive you a snapshot of howwidespread a certain disease is inyour area. With pets and peopleincreasingly on the move—andtick habitats expanding into newareas—vector-borne diseases arealso migrating to parts of the countrywe wouldn’t necessarily expect.Screening is an accurate way to staycurrent with incidence in your area.Your PracticeWhen you know more about vectorbornedisease, you open the door tothe possibilities of better medicine,healthier patients and a smarter, strongerpractice. Screenings are the foundationof preventative medicine programs inyour practice and let you know what yourpatients are being exposed to over time.This knowledge allows you to practicebetter medicine for those patientspresenting with clinical disease.

LYME DISEASETransmitted by the deer tick or black-legged tick, Lyme disease is caused by thebacterium Borrelia burgdorferi. Clinical signs may not appear until several monthsafter infection. Lyme disease has been found throughout North America withcases ranging from mild to severe.?12Did you know?The C 6 peptide used in the IDEXX SNAP ® 3Dx ® , SNAP ® 4Dx ® andLyme Quant C 6®tests have NOT been known to cross-react with antibodyresponse to commercially available Lyme vaccines. 2Ixodes ticks are known to be vectors for both Lyme disease and anaplasmosis.Dogs with seroreactivity to both B. burgdorferi and Anaplasma phagocytophilummay have two times the risk of developing clinical illness than singularlyinfected dogs. 3What to do with your resultWhat todo next?Diagnose*TreatClinical signs and/orlaboratory findings DOsupport Lyme disease(C 6 antibody level ≥30 U/mL)Doxycycline/tetracyclinePositive resultInfection is likelyDetermine antibody level with the Lyme Quant C 6 Testand evaluate for proteinuria (UPC)Clinical signs and/orlaboratory findings DO NOTsupport Lyme disease(C 6 antibody level

Canine anaplasmosisCanine granulocytic anaplasmosis is caused by the bacterium Anaplasmaphagocytophilum and is transmitted by the deer tick or black-legged tick.A. phagocytophilum is an obligate intracellular pathogen of neutrophils.Many mammalian species, including humans, are susceptible to infection.?Did you know?Coinfection of Anaplasma species with other vector-transmitted pathogensmay lead to more complex disease presentations and a slower responseto therapyAnaplasma platys is the cause of infectious cyclic thrombocytopenia in dogs,and antibodies to this pathogen cross-react with the A. phagocytophilum spoton the SNAP 4Dx TestA. platys infects canine platelets and is frequently seen as a coinfection with Erhlichia canisWhat to do with your resultWhat todo next?Positive resultThe dog has been exposed and may be infectedCheck for hematologic abnormalities (CBC and/or blood film)Negative resultExposure is unlikelyReview benefitsof tick preventionMedical backgroundPrimary vectorIxodes spp. (deer tick or black-legged tick)Transmission

Canine EhrlichiosisCanine ehrlichiosis is caused by the bacterium Ehrlichia canis and is transmittedby the brown dog tick. The infection may progress to a subclinical phase, whichcan last days, months or years. Chronic infections, if left untreated, can lead tobone marrow dysfunction or renal disease.Did you know?Dogs coinfected with E. canis and A. platys were found to have more severeanemia and thrombocytopenia than dogs with either single infection. 6E. canis, and likely A. platys, are transmitted by the same vector, the browndog tick.In a study of healthy dogs with antibodies to E. canis, 39% were thrombocytopenic. 7Medical BackgroundPrimary vectorRhipicephalus sanguineus (brown dog tick)TransmissionTime needed for transmission is unknown?12What to do with your resultWhat todo next?Diagnose*TreatPositive resultThe dog has been exposed and may be infectedCheck for hematologic abnormalities (CBC and/orblood film) and changes in serum proteinsClinical signs and/orlaboratory findingsDO supportehrlichiosisDoxycycline/tetracyclineClinical signs and/orlaboratory findingsDO NOT supportehrlichiosisNot generally recommendedNegative resultExposure is unlikelyReview benefitsof tick preventionPathogenEhrlichia canis infects canine monocytesClinical presentationCan present acutely:• Fever• Anorexia• Lethargy• Uveitis• Lymphadenomegaly• Bleeding disorders• CNS signsHas a chronic nature:• Weight loss• Bleeding disorders• Polyarthritis• Seizures• Multisystemic signs34MonitorPreventEvaluate plateletcount in 1 week; if noimprovement, pursueother diagnosesRecheck CBC atwellness examsDiscuss disease prevention strategies*Additional diagnostics mayinclude PCR or Ehrlichia IFAtiter. See the Diagnosticsfor Sick Patients sectionof this guide for moreinformation on serologicaland PCR testing.Laboratory abnormalities• Anemia• Thrombocytopenia• Hyperglobulinemia• Hypoalbuminemia• Pancytopenia• Proteinuria

HEARTWORMDirofilaria immitis, the causative agent of heartworm disease, is transmitted byinfected mosquitoes when D. immitis larvae are transferred to a healthy dog.Heartworm has no obvious clinical signs in the early stages, making preventativemeasures so much more important—especially as advanced infection may resultin death.Did you know?Despite availability of monthly preventatives, prevalence rates of canine heartwormhas remained consistent nationwide. 1The earliest heartworm antigen and microfilariae can be detected postinfection is5 months and 6.5 months, respectively.For more information and current recommendations on treating canineheartworm disease, go to heartwormsociety.org or capcvet.org.What to do with your resultHW Ag NEGATIVENo clinical signsCanine heartworm testingHW Ag POSITIVEClinical signsHW Ag NEGATIVEMedical backgroundPrimary vectorMosquitoesTransmissionPrepatent period approximately6 monthsPathogenDirofilaria immitisClinical presentationAsymptomatic at first, later developing:• Mild, persistent cough• Lethargy• Exercise intolerance• Reduced appetite• Weight lossNo action required• Confirm with retest• Radiographs (assesscardiopulmonary disease)• CBC, chemistry and/or otherappropriate tests• Modified Knott’s testingfor microfilariae*• Radiographs• CBC, chemistry and/orother appropriate tests• Consider otherdifferential diagnosesIf no definitive diagnosis,repeat in 1–3 monthsFollow-upRefer to the AmericanHeartworm Society(AHS)/CompanionAnimal Parasite Council(CAPC) guidelines onchemoprophylaxisTreatment/Follow-up• Treat according to the AmericanHeartworm Society guidelines• Retest 6 –12 months assessing for:- Conversion to Ag negative status- Improvement of cardiopulmonarydiseaseTreatment/Follow-upDependent uponsupplementary testresults*Less than 1% of infectionswill have microfilariae but notbe antigenemic (AmericanHeartworm Society)

Diagnostics forSick PatientsSerological and PCR Testing OptionsThe SNAP 4Dx Test helps you make the most of wellness screeningat your practice. But for a sick dog presenting with clinical signsconsistent with a vector-borne disease, it’s important to considerboth serological and PCR testing because they are complementary.Benefits and limitations of each diagnostic method:SerologyPolymerase chain reaction (PCR)Measures Antibody response of host Nucleic acid (DNA) from pathogenBenefitsLimitationsUseful for screening as wellas diagnosis of infectionClinical signs may precedea measurable antibodyresponseSpecifically identifies pathogensindicating active infectionA negative PCR result does notnecessarily rule out infectionDogs with ehrlichiosis and anaplasmosis may present with clinical signsat different times after infection. Which sick dog are you dealing with?When to use the IDEXX RealPCRvector-borne disease panels.• Sick patients with clinical signs and/orlaboratory abnormalities consistent witha vector-borne illness• Patients with subclinical infections basedon history, physical exam, serology andclinical laboratory findings• Monitoring response to therapy—the Lyme Quant C 6 Test can indicatewaning antibody levels, and for otherpathogens, a negative PCR resultindicates a reduction in pathogen load“No single test is sufficient fordiagnosing an infectious diseasein a sick patient.”Edward Breitschwerdt, DVM, DACVIMProfessor, Internal MedicineCollege of Veterinary MedicineNorth Carolina State UniversityPositive resultInfection orRecrudescencePCRDog ApresentsSerologyDog BpresentsTime postinfectionDog CpresentsUsing serology andPCR together improvesyour ability to make acomplete and accuratediagnosis.

One diagnostic partnergives you every advantageScreen with SNAP vector-borne testsand save on reference laboratory follow-up.Where serological tests, such as the SNAP 4Dx Test, measure the antibody responseto specific pathogens, vector-borne disease panels from IDEXX Reference Laboratoriescan complement serology to provide a greater level of diagnostic information.Now IDEXX Advantage saves you money while supporting you with the right diagnostictool at the right time. And it’s never been easier to take advantage of the savings.Simply enroll today to enjoy automatic discounted pricing on our most popularreference laboratory tests—up to 30%—when you start with SNAP ® testing. Nopaperwork or additional steps, just real savings on the diagnostics you use every day.IDEXX Advantage gives you the benefits of both serology and PCR testing with two new panels:Tick RealPCR Panel 4 with Lyme Quant C 6®Anaplasma spp. and Ehrlichia spp. RealPCR tests, and Lyme Quant C 6 TestSNAP ® 4Dx ® Tick/Vector Canine Comprehensive RealPCR Panel with Lyme Quant C 6®Anaplasma spp., Babesia spp., Bartonella spp., Ehrlichia spp., Hepatozoon spp.,Leishmania spp., Neorickettsia risticii and Rocky Mountain spotted fever RealPCR tests;Canine Hemotropic Mycoplasma RealPCR test, which includes Mycoplasma haemocanisand Candidatus Mycoplasma haematoparvum RealPCR tests; and Lyme Quant C 6 TestGet the complete picture of patient health and a healthier bottom line.For more information or to enroll in the IDEXX Advantage program today, call 1-888-433-9987.

1. Verdon DR. Heartworm infection continues its climb, survey reports. DVM Newsmagazine. February 1, 2006.2. O’Connor TP, Esty KJ, Hanscom JL, Shields P, Philipp MT. Dogs vaccinated with common Lyme disease vaccines do not respond to IR6, the conserved immunodominant region of the VlsE surface protein ofBorrelia burgdorferi. Clin Diagn Lab Immunol. 2004;11(3):458–462.3. Beall MJ, Chandrashekar R, Eberts MD, et al. Serological and molecular prevalence of Borrelia burgdorferi, Anaplasma phagocytophilum, and Ehrlichia species in dogs from Minnesota. Vector-Borne Zoonotic Dis.2008;8(4):455–464.4. Straubinger RK. PCR-based quantification of Borrelia burgdorferi organisms in canine tissues over a 500-day postinfection period. J Clin Microbiol. 2000;38(6):2191–2199.5. Egenvall A, Lilliehöök I, Bjöersdorff A, Engvall EO, Karlstam E, Artursson K, Heldtander M, Gunnarsson A. Detection of granulocytic Ehrlichia species DNA by PCR in persistently infected dogs. Vet Rec.2000;146(7):186–190.6. Gaunt SD, Ramaswamy C, Beall M, Caterina K, Breitschwerdt E. Potentiation of thrombocytopenia and anemia in dogs experimentally coinfected with Anaplasma platys and Ehrlichia canis. JVIM. 2007;21(3):576.7. Hegarty BC, Diniz PPVP, Bradley JM, Lorentzen L, Breitschwerdt EB. Clinical relevance of annual screening using a commercial enzyme-linked immunosorbent assay (SNAP 3Dx) for canine ehrlichiosis. JAAHA.2009;45(3):118–124.© 2010 IDEXX Laboratories, Inc. All rights reserved. • 09-69074-01 • All ®/TM marks are owned by IDEXX Laboratories, Inc. or its affiliates in the United States and/or other countries. The IDEXX Privacy Policy is available at idexx.com.