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Lyme and Other Borrelioses 597

• Lyme nephritis: dehydration (kidney failure), Differential Diagnosis appear; paired titers are not necessary. C6
ascites/edema (nephrotic syndrome), saddle Lyme arthritis versus other causes for lameness: > 30 proves natural exposure (not cause)
VetBooks.ir thromboembolism), retinal hemorrhage/ osis, RMSF, bartonellosis), immune-mediated nonclinical, nonproteinuric dogs. Magnitude Diseases and Disorders
and is not an indication for treatment in
• Tick-borne arthritides (anaplasmosis, ehrlichi-
thromboembolism, dyspnea (pulmonary
polyarthritis, systemic lupus erythematosus,
detachment (hypertension)
of titer is not predictive of or correlated with
illness.
Etiology and Pathophysiology rheumatoid arthritis, bacterial endocarditis, • Polymerase chain reaction (PCR) assay or
septic arthritis
• B. burgdorferi is a small, microaerophilic • Degenerative joint disease, intervertebral disc paired serologic titers for other infectious
spirochete. disease, trauma diseases: RMSF (if acute presentation),
• The agent in North America is B. burgdorferi • Panosteitis, osteomyelitis, polymyositis, anaplasmosis/ehrlichiosis, babesiosis, bar-
sensu stricto, with at least 30 strains. neoplasia tonellosis, leptospirosis
• The organism multiplies in the tick and • Cardiopulmonary, metabolic, neurologic • Renal biopsy: immune-complex glomeru-
enters the host at the end of the tick’s blood disease lonephritis, tubular necrosis/regeneration,
meal (as OspA is down-regulated and OspC Lyme nephritis: interstitial lymphoplasmacytic inflammation
becomes expressed) after 36-48 hours of • Proteinuria: leptospirosis, urinary tract • Relapsing fever Borrelia spp cause spirochet-
attachment. infection, neoplasia, calculi emia (submit pre-treatment blood for PCR
• Replication in the skin at the tick bite site ○ PLN: genetic, infectious, immune- assay); antibodies may react on whole-cell
is followed by interstitial tissue migration. mediated, amyloidosis, neoplasia IFA/ELISA Lyme tests.
• Clinical signs appear to be due to an • Other causes for hypertension, hyperco-
immune-mediated pathogenesis (e.g., Lyme- agulopathy, edema/effusions, and/or kidney TREATMENT
specific antigen-antibody complexes are in injury
glomeruli of dogs with Lyme nephritis). Treatment Overview
• A persistent carrier state is likely in healthy- Initial Database Goals of treatment:
appearing carriers and clinically ill patients. To confirm exposure and rule out other causes • Avoid treating patients that have positive
• Vectors are Ixodes scapularis (deer tick) in of lameness/fever or PLN: titers alone (exposure) in the absence of
the eastern United States and Ixodes pacificus • CBC and serum biochemistry profile: throm- compatible clinical abnormalities.
in the western United States. The white- bocytopenia possible; otherwise, no specific • Resolution of lameness and fever if present
footed deer mouse is the main reservoir and findings expected unless Lyme nephritis: • Palliative/supportive care for complications
preferred host of larval and nymphal ticks. hypoalbuminemia, hypercholesterolemia, of PLN
There is no transovarial transmission. Migra- ± azotemia, hyperphosphatemia, anemia
tory birds are also carriers and disseminate • SNAP 4Dx Plus test for heartworm antigen Acute General Treatment
infective ticks. and antibodies to C6 peptide (specific for • Doxycycline 10 mg/kg PO q 12-24h
• There are 29 TBRF species with spirochetemia natural exposure to B. burgdorferi), Ehrlichia preferred (for coinfections, antiarthritic/
and transovarial transmission. Ornithodoros canis/chaffeensis/ewingii, and Anaplasma antiinflammatory properties) or amoxicillin
ticks, which feed for only 15-90 minutes, phagocytophilum/platys. This test replaces 20 mg/kg PO q 8h.
transmit B. turicatae and B. hermsii, causing previous two-tier testing with Western blot • Treatment for clinical cases is continued for
illness in dogs (fever, lameness, uveitis, for differentiating natural exposure from 4 weeks to try to eliminate the carrier state.
thrombocytopenia). vaccine-induced antibodies because the C6 • Treatment is not recommended for nonclini-
• It is unknown whether other Borrelia spp peptide of the VlsE antigen is not found in cal, nonproteinuric carriers.
(e.g., Borrelia miyamotoi) that cause illness any Lyme vaccines.
in people also do so in pets. ○ AccuPlex4, Multiplex, and Abaxis Lyme Chronic Treatment
test results may be confusing because • The length of time antibiotics are needed to
DIAGNOSIS OspA and OspC antibodies may occur clear the carrier state is unknown.
in vaccinated and naturally exposed dogs. • Treatment for Lyme nephritis often includes
Diagnostic Overview ○ Whole-cell IFA/ELISA/IgM/IgG titers long-term combination doxycycline, renin-
• A presumptive diagnosis of borreliosis are not helpful because of cross-reactions angiotensin-aldosterone inhibitors (enalapril,
includes 1) evidence of natural exposure and because experimentally infected dogs benazepril, or telmisartan), antithrombotics
antibodies, 2) clinical signs consistent do not show signs of Lyme disease until (low-dose aspirin or clopidogrel), omega-3
with borreliosis, 3) consideration of other 2-5 months after exposure, well after fatty acids, possibly additional antihyperten-
differentials, and 4) response to treatment, seroconversion. Paired acute/convalescent sives (amlodipine), colloids/crystalloids, and
although Lyme nephritis may not respond titers are unnecessary. treatments for renal failure. Immunosuppres-
well. • All Lyme-positive dogs should be screened for sive therapy protocols (e.g., mycophenolate)
• Overdiagnosis should be avoided; in endemic proteinuria by urinalysis, microalbuminuria, may be indicated (p. 390).
areas, many dogs with no clinical signs are or urine protein/creatinine ratio testing. Lyme • Supportive care of renal disease as appropriate
seropositive. Response to treatment does nephritis cases may also have glycosuria and/ (pp. 167 and 169)
not confirm diagnosis and may occur by or active sediment due to tubular damage • Avoid nonsteroidal antiinflammatories for
inadvertent treatment of co-infections (e.g., (rule out leptospirosis, pyelonephritis). pain relief (use opioids). Nonresponsive
anaplasmosis, Rocky Mountain spotted fever • If indicated, radiographs of limb(s) involved Lyme arthritis may be immune-mediated
[RMSF], ehrlichiosis, bartonellosis, leptospi- (nonerosive arthritis) polyarthritis, for which glucocorticoids are
rosis) or the antiinflammatory/antiarthritic • If indicated, arthrocentesis (p. 1059): added (e.g., prednisone 1 mg/kg PO q 12h,
properties of doxycycline. nonseptic suppurative inflammation tapering to 0.5 mg/kg PO q 48h) (p. 803).
• All seropositive (clinical and nonclinical) • Abdominal ultrasound and chest radiographs
dogs should be monitored for proteinuria. for dogs with PLN: rule out neoplasia Recommended Monitoring
Treatment for nonclinical, nonproteinuric, • Lyme nephritis is uncommon even in sero-
seropositive carrier dogs is controversial. The Advanced or Confirmatory Testing positive retrievers, but continue screening
dog’s sentinel status is an opportunity to • Specific quantitative serologic/antibody (duration/frequency unknown) all Lyme-
educate the owner about tick control and testing: C6 Quant. C6 antibody is detected positive dogs for proteinuria whether treated
public health aspects of Lyme disease. 3-5 weeks post exposure, before clinical signs or not.

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