The Major Canine Tick-Borne Diseases
Tick-borne diseases are increasingly important across the developed world — climate change has expanded tick habitats, and new pathogens continue to emerge (Ehrlichia canis in Australia 2020; expanded Lyme distribution; UK babesiosis since 2016). This calculator covers the major canine tick-borne diseases:
Ehrlichiosis
Most common globally. *Ehrlichia canis* (brown dog tick *Rhipicephalus sanguineus* vector) is the classic, also *E. chaffeensis*, *E. ewingii*. Three phases:
- Acute (1-3 weeks post-infection) — fever, thrombocytopenia, lymphadenopathy, lethargy
- Subclinical — may persist months to years; mild thrombocytopenia, hyperglobulinaemia
- Chronic — pancytopenia, severe hyperglobulinaemia, bleeding, weight loss, ocular signs
Anaplasmosis
*Anaplasma phagocytophilum* (*Ixodes scapularis* / *I. pacificus* in US; *I. ricinus* in Europe) and *A. platys* (causes cyclic thrombocytopenia). Classic presentation:
- Shifting polyarthritis with lameness
- Fever, lymphadenopathy
- Thrombocytopenia
- Often self-limiting but doxycycline shortens course
Lyme Disease (Borreliosis)
*Borrelia burgdorferi*. *Ixodes* tick vector. Most US northeast / upper midwest, increasingly UK / Northern Europe. Most exposed dogs seroconvert without illness (estimates 5-10% develop clinical disease):
- Polyarthritis with lameness, fever
- Lyme nephritis — the most serious manifestation; immune-complex glomerulonephritis; over-represented in Golden Retrievers, Labradors, Bernese Mountain Dogs
Rocky Mountain Spotted Fever (RMSF)
*Rickettsia rickettsii*. *Dermacentor variabilis* (US) and *Rhipicephalus sanguineus* (US southwest). Severe acute disease:
- Fever, vasculitis
- Petechiae, ecchymoses
- Ocular signs (retinal haemorrhage, uveitis)
- Neurological signs in severe cases
- Doxycycline-responsive but can be fatal without treatment
Babesiosis
*Babesia canis* (Europe, *Dermacentor* vector), *B. gibsoni* (worldwide, including UK Essex since 2016, *Rhipicephalus* vector). Haemolytic disease:
- Haemolytic anaemia (intravascular or extravascular)
- Splenomegaly
- Fever, lethargy, icterus
- Treatment varies by species — imidocarb (B. canis), atovaquone + azithromycin (B. gibsoni)
The SNAP 4Dx Plus Test – The Workhorse
The SNAP 4Dx Plus (IDEXX, in-clinic, 8-15 minutes) is the screening tool of choice in endemic regions. It detects:
- Heartworm (Dirofilaria immitis) antigen
- Lyme (Borrelia burgdorferi) antibody — using C6 peptide (more specific than whole-cell antigen)
- Anaplasma (A. phagocytophilum + A. platys) antibody
- Ehrlichia (E. canis + E. ewingii + E. chaffeensis) antibody
Sensitivity and specificity both >90% for most organisms. Used for:
- Annual screening in endemic regions (standard preventive care)
- Workup of clinical signs suggestive of tick-borne disease
- Pre-purchase / shelter screening
Equivalent tests: Accuplex (Antech), VetScan FLEX4 (Abaxis).
Interpretation Of Positive Results
- Heartworm positive: confirm with second test + microfilaria check + ultrasound; treatment with melarsomine if confirmed
- Lyme positive: most dogs are clinically well; check CBC + UPC for clinical significance; treat if proteinuric or symptomatic; many dogs seropositive after vaccination
- Anaplasma positive: check CBC; treat if thrombocytopenic or symptomatic
- Ehrlichia positive: check CBC + globulins; treat if any abnormality
Cardinal Clinical Signs
| Sign | Suggests |
|---|---|
| Fever | All tick-borne diseases |
| Lameness (shifting polyarthritis) | Anaplasma, Lyme |
| Thrombocytopenia | Ehrlichia, Anaplasma, RMSF |
| Petechiae / bruising | Ehrlichia, RMSF (thrombocytopenia + vasculitis) |
| Epistaxis | Chronic ehrlichiosis classic |
| Hyperglobulinaemia | Chronic ehrlichiosis |
| Proteinuria | Lyme nephritis (retrievers) |
| Lymphadenopathy | Ehrlichia, Anaplasma |
| Haemolytic anaemia | Babesia |
| Ocular signs (uveitis, retinal haemorrhage) | Ehrlichia, RMSF |
Treatment – Doxycycline Is The Cornerstone
Doxycycline treats the major tick-borne diseases:
| Disease | Dose | Duration |
|---|---|---|
| Ehrlichiosis | 5-10 mg/kg PO q12h | 28 days |
| Anaplasmosis | 5-10 mg/kg PO q12h | 28 days |
| Lyme disease | 10 mg/kg PO q24h | 4 weeks (longer for nephritis) |
| Rocky Mountain spotted fever | 5-10 mg/kg PO q12h | 14-21 days |
Doxycycline is well-tolerated in dogs. Oesophageal stricture risk in cats (less in dogs) — give with food and follow with water or food bolus.
Alternatives
- Minocycline — similar spectrum
- Chloramphenicol — for chronic ehrlichiosis where doxycycline fails
For Babesiosis (Different Treatment)
- *B. canis* — imidocarb dipropionate (single dose, repeat in 2 weeks if needed)
- *B. gibsoni* — atovaquone + azithromycin combination (10 days)
The PuppaDogs Doxycycline Dosage Calculator gives weight-based dosing.
Lyme Nephritis – The Critical Retriever Issue
Lyme nephritis is immune-complex glomerulonephritis — the most serious manifestation of canine Lyme disease. Substantially over-represented in:
- Golden Retriever
- Labrador Retriever
- Bernese Mountain Dog
- Shetland Sheepdog
Presentation
- Proteinuria (UPC >0.5, often >2-3)
- Progresses to nephrotic syndrome — hypoalbuminaemia, oedema, hypercholesterolaemia
- Renal failure — azotaemia, hypertension
- Often fatal without aggressive management
Why Retrievers Are Predisposed
Mechanism not fully understood but likely immunological predisposition to forming pathogenic immune complexes against *Borrelia* antigens that deposit in glomeruli.
Screening Critical Component
For any Lyme-positive retriever (even if clinically well), UPC measurement is critical. UPC >0.5 prompts urgent workup for nephropathy.
Treatment
- Doxycycline — 10 mg/kg PO q24h for at least 4 weeks
- Immunosuppression for confirmed nephritis — mycophenolate, ciclosporin
- ACE inhibitor + telmisartan (antiproteinuric)
- Omega-3 at therapeutic dose
- Renal diet (Hill’s k/d, Royal Canin Renal)
- Aggressive monitoring of UPC, creatinine, blood pressure
- Prognosis guarded — substantial mortality despite treatment
See the PuppaDogs IRIS Kidney Disease Staging Calculator.
Tick Prevention – The Cornerstone
The single best way to avoid tick-borne disease is effective tick prevention.
Isoxazoline Class (Modern Gold Standard)
Oral or topical — kill ticks within 8-12 hours of attachment, before most pathogens transmit (Lyme transmission requires 24-48 hours of attachment):
- Bravecto (fluralaner) — 3-monthly oral; 3-monthly topical also available
- NexGard (afoxolaner) — monthly oral
- Simparica (sarolaner) — monthly oral; Simparica Trio adds heartworm + intestinal worms
- Credelio (lotilaner) — monthly oral
Fipronil
Older standard (Frontline). Less effective than isoxazolines but cheaper. Topical, monthly.
Amitraz Collar
Preventic, Scalibor — alternative for some dogs. Long-acting collar.
Permethrin (PEDOG, Vectra 3D)
Kills ticks on contact + acts as a repellent. Topical.
⚠️ NEVER use permethrin in cats — fatal toxicity. Households with cats: use canine-only permethrin formulations and separate the dog from the cat for the first 24-48 hours after application.
Daily Tick Checks
After outdoor activity in tick-endemic areas:
- Check between toes, in ears, around face, behind ears, neck, groin, armpits
- Remove ticks with tick remover tool or fine forceps grasping the head close to skin
- Don’t squeeze the body — increases pathogen transmission
- Don’t apply petroleum jelly, alcohol, or heat — outdated methods; can increase pathogen release
Lyme Vaccination
Available:
- Nobivac Lyme (whole-cell bacterin)
- RECOMBITEK Lyme (OspA subunit)
- Vanguard crLyme (chimeric OspA + OspC)
Use:
- Non-core vaccine
- Recommended for high-exposure dogs in endemic regions
- 2 doses 2-4 weeks apart, then annual booster
Controversy:
- Doesn’t replace tick prevention — vaccination + prevention is the combination
- Some controversy about efficacy and immune-complex disease in vaccinated dogs
- Discuss with vet for your specific dog and region
Region-Specific Risk
| Region | Major risks |
|---|---|
| US Southeast | Ehrlichia (canis, chaffeensis), RMSF |
| US Northeast | Lyme, Anaplasma |
| US Upper Midwest | Lyme, Anaplasma |
| US Southwest | RMSF, Babesia |
| UK | Lyme (increasing), Babesia (Essex since 2016) |
| Europe | Babesia, Ehrlichia (southern/Mediterranean), Lyme |
| Australia | Ehrlichia canis (emerged 2020, spreading from north) |
| Tropical | Year-round Ehrlichia, Anaplasma, Babesia, Hepatozoon |
Honest Caveats
- Seropositivity ≠ clinical disease — many dogs in endemic regions are seropositive without illness; CBC + UPC tells you if treatment is needed
- SNAP 4Dx false negatives can occur in early infection — repeat in 4-6 weeks if suspicion remains
- PCR testing for active infection in specific cases (recent exposure, immunocompromised, atypical signs)
- Treatment failure with chronic ehrlichiosis is recognised — alternative agents needed
- Lyme vaccination in seropositive dogs is controversial — vaccinate only documented seronegative
- This calculator helps you plan testing and discuss treatment — not replace examination
Conclusion
Canine tick-borne diseases — ehrlichiosis, anaplasmosis, Lyme, Rocky Mountain spotted fever, babesiosis — are common in endemic regions and spreading geographically. The SNAP 4Dx Plus (in-clinic, 8-15 minutes) is the workhorse screening tool, detecting heartworm + Lyme + Anaplasma + Ehrlichia. Doxycycline treats most tick-borne diseases (5-10 mg/kg q12h x 28 days for Ehrlichia/Anaplasma; 10 mg/kg q24h x 4 weeks for Lyme). Lyme nephritis in retrievers is the most serious manifestation — UPC screening is critical for any Lyme-positive Golden/Lab/Bernese. Tick prevention with isoxazoline-class products (Bravecto, NexGard, Simparica, Credelio) is the cornerstone — kill ticks before pathogens transmit. Annual screening in endemic regions is standard preventive care.
Frequently Asked Questions
What is the SNAP 4Dx test for dogs?
SNAP 4Dx Plus (IDEXX) is an in-clinic blood test (8-15 minutes) that detects four diseases: HEARTWORM (Dirofilaria immitis antigen) + LYME (Borrelia burgdorferi C6 peptide antibody – more specific than whole-cell antigen) + ANAPLASMA (A. phagocytophilum + A. platys antibody) + EHRLICHIA (E. canis + E. ewingii + E. chaffeensis antibody). Sensitivity and specificity both >90% for most organisms. Standard annual screening in endemic regions. Equivalent tests: Accuplex (Antech), VetScan FLEX4 (Abaxis).
What are the symptoms of tick-borne disease in dogs?
Vary by pathogen but common across many: FEVER, lethargy, anorexia, lameness (shifting polyarthritis classic for Lyme and Anaplasma), generalised lymphadenopathy, PETECHIAE / bruising (thrombocytopenia from ehrlichiosis/anaplasmosis/RMSF), epistaxis (chronic ehrlichiosis), uveitis/retinal haemorrhage (RMSF, severe ehrlichiosis), weight loss, peripheral/ventral oedema (Lyme nephritis), vomiting. Lab findings: thrombocytopenia (hallmark of ehrlichia/anaplasma), anaemia, hyperglobulinaemia (chronic ehrlichia), proteinuria (Lyme nephritis), positive 4Dx SNAP.
How is tick-borne disease treated in dogs?
DOXYCYCLINE is the cornerstone treatment. EHRLICHIOSIS: 5-10 mg/kg PO q12h for 28 days. ANAPLASMOSIS: 5-10 mg/kg PO q12h for 28 days. LYME DISEASE: 10 mg/kg PO q24h for 4 weeks (longer for nephritis). ROCKY MOUNTAIN SPOTTED FEVER: 5-10 mg/kg q12h for 14-21 days. Well-tolerated; oesophageal stricture risk minimal in dogs – give with food. BABESIOSIS treated differently: imidocarb dipropionate for B. canis; atovaquone + azithromycin for B. gibsoni. Lyme nephritis requires additional immunosuppression + ACE inhibitor + telmisartan + renal diet.
What is Lyme nephritis in dogs?
Lyme nephritis is IMMUNE-COMPLEX GLOMERULONEPHRITIS – the most serious manifestation of canine Lyme disease. Substantially OVER-REPRESENTED in GOLDEN RETRIEVERS, LABRADOR RETRIEVERS, BERNESE MOUNTAIN DOGS, SHETLAND SHEEPDOGS. Presents as PROTEINURIA (UPC often >2-3) progressing to NEPHROTIC SYNDROME (hypoalbuminaemia, oedema, hypercholesterolaemia) and renal failure. Often fatal without aggressive treatment – doxycycline + immunosuppression (mycophenolate/ciclosporin) + ACE inhibitor + telmisartan + omega-3 + renal diet. UPC screening is critical for any Lyme-positive retriever even when clinically well.
How can I prevent tick-borne disease in my dog?
EFFECTIVE TICK PREVENTION is the cornerstone. ISOXAZOLINE CLASS (modern gold standard – kill ticks within 8-12 hours of attachment, before most pathogens transmit; Lyme transmission requires 24-48 hours of attachment): Bravecto (fluralaner) 3-monthly, NexGard (afoxolaner) monthly, Simparica (sarolaner) monthly, Credelio (lotilaner) monthly. Older standard: Fipronil (Frontline). Amitraz collars (Preventic, Scalibor). Permethrin (Vectra 3D) – kills + repels but NEVER use in cats (fatal). DAILY TICK CHECKS after outdoor activity. Annual SNAP 4Dx screening in endemic regions.
Should my dog get the Lyme vaccine?
Lyme vaccination is a NON-CORE vaccine. Available products: Nobivac Lyme (whole-cell bacterin), RECOMBITEK Lyme (OspA subunit), Vanguard crLyme (chimeric OspA + OspC). Two doses 2-4 weeks apart then annual booster. RECOMMENDED for high-exposure dogs in endemic regions. DOES NOT REPLACE tick prevention – vaccination + prevention is the combination. Some controversy about efficacy and immune-complex disease in vaccinated dogs. Vaccinate only documented seronegative dogs (SNAP 4Dx negative). Discuss with your vet based on local epidemiology and your dog’s specific risk.
Related PuppaDogs Calculators
Continue building your dog’s personalised care plan with these related PuppaDogs calculators:
- Dog Pregnancy / Whelping Due-Date Calculator
- Puppy Weight Predictor (Adult Weight Calculator)
- Heatstroke Risk Calculator for Dogs
- Bloat (GDV) Risk Calculator for Dogs
- Dog Life Expectancy Calculator (Breed, Body Condition, Lifestyle)
- Spay/Neuter Timing Calculator for Dogs (Breed-Specific)
References & Further Reading
The dosing ranges and safety information on this page are drawn from the following veterinary references. Always defer to your own veterinarian and the manufacturer’s label for your specific product.
- ACVIM consensus statement on Ehrlichiosis, Anaplasmosis, and Lyme Disease.
- Greene CE (ed). Infectious Diseases of the Dog and Cat, 4th ed. Elsevier Saunders.
- Companion Animal Parasite Council (CAPC). Tick-borne disease guidelines. capcvet.org.
- Littman MP, Goldstein RE, Labato MA, et al. ACVIM consensus statement on Lyme nephritis. JVIM.
- Cohn LA. Ehrlichiosis and related infections. Veterinary Clinics of North America: Small Animal Practice.
- Plumb’s Veterinary Drug Handbook – doxycycline, imidocarb, atovaquone.
- PuppaDogs. Doxycycline Dosage Calculator and IRIS Kidney Disease Staging Calculator. puppadogs.com.
