Introduction

Classification

Taxonomy

• Classically, the genus Leptospira was divided into 2 species based on genetic analysis: L. interrogans sensu latu (pathogenic strains) and L. biflexa sensu latu (saprophytic strains).
• L. interrogans is divided into more than 250 serovars on the basis of antigenic composition and further classified into antigenically related serogroups.
• Serovar spectrum and frequency differs according to countries and regions (depending on distribution of rodent hosts, import of dogs from abroad, use of vaccination).
• The main infecting serovars in dogs were Icterohaemorrhagiae and Canicola in Europe and America prior to 1960. Since the use of the bivalent vaccine against Canicola and Icterohaemorrhagiae, a shift to other serovars occurred.
• Besides L. Icterohaemorrhagiae and L. Canicola, Serovars of importance in dogs include: Grippotyphosa, Bratislava, Saxkoebing, Sejroe, Copenhagi, Australis, Bataviae, and Pomona, Autumnalis, and Hardjo.
• Icterohaemorrhagiae and Canicola infections in unvaccinated dogs still occur, indicating that these serovars are not fully eradicated.
• Leptospires are motile, obligate aerobe, gram-negative bacteria, which are not visible in routinely fixed smears.
• Dark field microscopy or phase contrast microscopy is necessary for visibility of unstained leptospires.

Etymology

• Gk: lepto - thin, narrow; spira - a coil; leptospira - a fine coil.

Active Forms

Clinical Effects

Epidemiology

Habitat

• Leptospires have been isolated from birds, reptiles, amphibians and invertebrates.
• Rodents and wild carnivores are the most frequent carriers.
• Reservoir hosts show few or no signs of disease.
• Leptospira spp. are commonly sequestered in the renal tubules of mammalian kidneys.
• Different serovars typically have different reservoir hosts.

Lifecycle

• Generation time in culture media or host is long.

Transmission

• Direct or indirect transmissions are possible.
• Indirect transmission through contaminated water or soil is more common.

Pathological effects

• Infection occurs through ingestion of infected rodents or penetration of mucosae or traumatized skin. Leptospiremia occurs within 1 week. Leptospires spread to other organ systems (kidneys, liver, spleen, endothelial cells, lungs, uvea/retina, skeletal and heart muscles, pancreas, and genital tract) and cause tissue damage, visceral and vascular inflammation.
• Leptospiral pulmonary hemorrhage syndrome (LPHS) Lung: pulmonary hemorrhage can occur as severe manifestation of acute leptospirosis Leptospirosis.
• Leptospires can persist in immune privileged site (eg, renal tubes, eye).
• In the presence of adequate antibody titers, leptospires are eliminated from most organs. In the presence of low antibody titers mild leptospiremia can continue with a subclinical course of disease.

Other Host Effects

• Individual host may show little or no clinical signs but may be source of infection in the same animal species.
• An animal that has recovered may become a long-term shedder of the organism.
• Mainly dogs show disease; rodents often the reservoir.
• Cat disease is uncommon but serology shows that asymptomatic infection occurs.

• Individual host can show little or no clinical signs but can be source of infection to other animals or humans.
• An animal that has recovered can become a long-term shedder of the organism.
• Rodents are often the reservoir.
• Dogs commonly succumb to disease if infected.
• In cats, disease is uncommon but asymptomatic infection and shedding in urine occurs.

Control

Control via animal

Antimicrobial therapy

• Dogs with gastrointestinal signs should initially be treated with intravenous penicillin derivates (eg, ampicillin Ampicillin or amoxicillin Amoxicillin 20-30 mg/kg q6-8h). These should be continued until gastrointestinal signs are under control and liver enzymes are normalized. A directly following antimicrobial therapy with 3 weeks of oral doxycycline Doxycycline (5 mg/kg q12h) is necessary for prevention of carrier states.
• Dogs without gastrointestinal signs should immediately be treated with doxycycline.
• Antibody testing of dogs living in the same household as infected dogs is recommended. Oral doxycycline 5 mg/kg q12h for 3 weeks) should be administered, if these dogs have antibodies.

Symptomatic treatment

• Treatment of dogs with gastrointestinal sings includes antiemetics, gastroprotectants, and nutritional support.
• Use of opioids in dogs with pain can be necessary.
• Treatment of dogs with acute kidney injury Kidney: acute kidney injury (AKI) includes correction of loss of fluid, electrolytes, acid-base imbalances and hypertension, and if necessary hemodialysis for patients with persistent oligoanuria, life-threatening hyperkalemia Hyperkalemia , or severe volume overload.
• Oxygen therapy or mechanical ventilation can be necessary in dogs with LPHS.
• Plasma transfusions can be necessary for patients with DIC Disseminated intravascular coagulation.
• Whole blood transfusion Blood: transfusion can be helpful, if bleeding occurs.

Hemodialysis

• Hemodialysis is necessary in dogs with acute renal failure (life-threatening hyperkalemia or severe volume overload) and in dogs with advanced uremia refractory to medical management.
• Early referral to facilities where hemodialysis is available is recommended.
• Renal recovery usually occurs after 2-7 days of dialytic support.
• Hemodialysis leads to favorable prognosis for renal recovery (in more than 80% of dogs).

Mechanical ventilation

• Ventilation Anesthetic ventilators: overview can be necessary in dogs with severe pulmonary hemorrhage due to LPHS.

Vaccination

• Vaccination protects against clinical disease and carrier status with shedding.
• Protection is serogroup-specific and temporary.
• Annual boosters are required.

Diagnosis

Further Reading

Publications

Refereed papers

• Recent references from PubMed and VetMedResource.
• Fraune C K, Schweighauser A & Francey T (2013) Evaluation of the diagnostic value of serologic microagglutination testing and a polymerase chain reaction assay for diagnosis of acute leptospirosis in dogs in a referral center. J Am Vet Med Assoc 242 (10), 1373-1380 PubMed.
• Hartmann K, Egberink H, Pennisi M G et al (2013) Leptospira species infection in cats: ABCD guidelines on prevention and management. J Feline Med Surg 15 (7), 576-581 PubMed.
• Abdoel T H, Houwers D J, van Dongen A M et al (2011) Rapid test for the serodiagnosis of acute canine leptospirosis. Vet Microbiol 150 (1-2), 211-213 PubMed.
• Sykes J E, Hartmann K, Lunn K F et al (2011) 2010 ACVIM small animal consensus statement on leptospirosis: diagnosis, epidemiology, treatment, and prevention. J Vet Intern Med 25 (1), 1-13 PubMed.
• Kohn B, Steinicke K, Arndt G et al (2010) Pulmonary abnormalities in dogs with leptospirosis. J Vet Intern Med 24 (6), 1277-1282 PubMed.
• Burr P, Lunn K, Yam P (2009) Current perspectives on canine leptospirosis. In Practice 31 (3), 98-102 VetMedResource.
• Geisen V, Stengel C, Brem S et al (2007) Canine leptospirosis infections - clinical signs and outcome with different suspected Leptospira serogroups (42 cases). J Small Anim Pract 48 (6), 324-328 PubMed.
• Ghneim G S, Viers J H, Chomel B B et al (2007) Use of a case-control study and geographic information systems to determine environmental and demographic risk factors for canine leptospirosis. Vet Res 38 (1), 37-50 PubMed.
• André-Fontaine G (2006) Canine leptospirosis--do we have a problem? Vet Microbiol 117 (1), 19-24 PubMed.
• Goldstein R E, Lin R C, Langston C E et al (2006) Influence of infecting serogroup on clinical features of leptospirosis in dogs. J Vet Intern Med 20 (3), 489-494 PubMed.
• Meeyam T, Tablerk P, Petchanok B et al (2006) Seroprevalence and risk factors associated with leptospirosis in dogs. Southeast Asian J Trop Med Public Health 37 (1), 148-153 PubMed.
• Moore G E, Guptill L F, Glickman L W et al (2006) Canine leptospirosis, United States, 2002-2004. Emerg Infect Dise 12 (3), 501-503 PubMed.
• Ward M P, Guptill L F & Wu C C (2004) Evaluation of environmental risk factors for leptospirosis in dogs: 36 cases (1997-2002). JAVMA 225 (1), 72-77 PubMed.
• Boutilier P, Carr A & Schulman R L (2003) Leptospirosis in dogs: a serologic survey and case series 1996-2001. Vet Ther 4 (4), 387-396 PubMed.
• Burriel A R, Dalley C, Woodward M J (2003) Prevalence of leptospira species among farmed and domestic animals in Greece. Vet Rec 153 (5), 146-148 PubMed.
• Ebani V V, Cerri D, Poli A et al (2003) Prevalence of Leptospira and Brucella antibodies in wild boars (Sus scrofa) in Tuscany, Italy. J Wildl Dis 39 (3), 718-722 PubMed.
• Harkin K R, Roshto Y M & Sullivan J T (2003) Clinical application of a polymerase chain reaction assay for diagnosis for leptospirosis in dogs. JAVMA 222 (9), 1224-1229 PubMed.
• Adin C A & Cowgill L D (2000) Treatment and outcome of dogs with leptospirosis - 36 cases (1990-1998). JAVMA 216 (3), 371-375 PubMed.
• Steger-Lieb A, Gerber B, Nicolet J et al (1999) [An old disease with a new face: canine leptospirosis does not lose its relevance]. Schweiz Arch Tierheilkd 141 (11), 499-507 PubMed.
• Brown C A, Roberts A W, Miller M A et al (1996) Leptospira interrogans serovar grippotyphosa infection in dogs. JAVMA 209 (7), 1265-1267 PubMed.
• Harkin K R & Gartrell C L (1996) Canine leptospirosis in New Jersey and Michigan - 17 cases (1990-1995). JAAHA 32 (6), 495-501 PubMed.
• Anderson J F, Miller D A, Post J E et al (1993) Isolation of Leptospira interrogans serovar grippotyphosa from the skin of a dog. JAVMA 203 (11), 1550-1551 PubMed.