**7. Treatment**

*Bacterial Cattle Diseases*

*5.1.3 Serological tests*

The test is read by DFM.

*5.1.3.1 The microscopic agglutination test (MAT)*

*5.1.3.2 IgM enzyme-linked immunosorbent assay (ELISA)*

against *Leptospira* in serum samples [63].

**6. Necropsy findings**

For this, an effective and specific amplification is performed by DNA polymerase and six primers in 1 hour under isothermal conditions. Now the amplified DNA can be easily detected by eye observation of fluorescence without using gel electrophoresis [60]. Loop-mediated isothermal amplification (LAMP) methods are recently developed for the quick diagnosis of pathogenic leptospires, and lipL41 and rrs are the genes targeted by LAMP. The specificity of these methods is weak because these can detect the threshold between 2 and 100 leptospires/reactive mixture [61].

This microscopic agglutination test is developed in Pasteur Institute. Dark field microscopy is required to see agglutination of live leptospires cultures with patient's serum. This is the gold standard test for leptospirosis. It determines the anti-*Leptospira* immunoglobulin titers in human and animal serum at the serogroup level, so it is used for clinical and epidemiological investigations [62]. MAT is performed on micro titration plates, dilutions of serum which is collected from the patient is made and then equal volume of leptospiral culture is added to form agglutinations of distinctive patterns that consist of highly dense packs of partly intact leptospires.

Normal ELISA is commonly used to diagnose leptospirosis. Enzyme immunoassay of leptospirosis can be performed using a commercially available kit or antigen obtained internally. Which is commonly used to detect IgM, and sometimes to detect IgG antibodies against leptospiral antigens. The presence of IgM antibodies indicates current or recent leptospirosis. The commercially available *Leptospira* IgM ELISA is used for the serological detection of acute leptospirosis infection in a patient's serum sample. This ELISA is based on the principle that any *Leptospira* IgM antibody present in the patient's serum binds to the *Leptospira* antigen that adheres to the microporous surface of the microwell. Residual serum was removed from these wells by washing with 1% buffer (included in the kit). Peroxidase-conjugated anti-human IgM is presented after adding to the wells, and the plate is reincubated so that the bound antigen-antibody complex binds to the conjugate. The wells are washed again and a colorless substrate system, tetramethylbenzidine hydroperoxide, is added. The substrate is hydrolyzed, and the chromogen is blue. When the reaction is stopped with phosphoric acid, TMB turns yellow. The development of color indicates the presence of visual acuity IgM antibody

Cows with acute leptospirosis are characterized by anemia, jaundice, hemoglobinuria, and lower lobe hemorrhage. An ulcer and bleeding may be present on the mucous membrane of the peritoneum. Pulmonary edema and emphysema are also common in cattle. Histologically, there is a progressive and diffuse interstitial nephritis and liver necrosis in the centre of the lobules. Sometimes the vascular lesions of the meninges are transferred to chronic infections. *Leptospira* can be seen in the silvery spots of a part of tortuous tubules proximal to the kidneys. In acute infection, there is minimal inflammation, and in the middle of the leaflet, there are only tubes filled with hemoglobin and visible liver necrosis. At a later

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Treatment is based on severity of illness being presented by animal which in most of the cases is mild and self-limiting requiring no care. Other considerations, while treatment is considered, include differential diagnosis, cost, and availability of drugs. Treatment obtained based on in-vitro studies presented doxycycline, ampicillin, azithromycin or amoxicillin [64]. The double-blind randomized trials conducted on 29 patients produced promising results by reducing symptoms of malaise in 2 days preventing leptospiremia. The treatment, however, was not conclusive prevention from progression to severity [65]. Doxycycline or azithromycin is the drug of choice in endemic areas while contraindicated in pregnancy [64]. Sever cases are responsive to penicillin G sodium in studies conducted before 90s. The emerging resistance has narrowed spectrum of antibiotic use against infections [66]. Open randomized trial conducted with experiment involving 256 patients proved nonsignificant difference among penicillin G, cefotaxime, and doxycycline antibiotics [67]. Some of meta-analysis studies have reported nonsignificant difference between penicillin G and placebo on mortality [68]. Mortality is reported to increase up to 70% with pulmonary involvement which is due to immune-mediated inflammatory response. The therapeutic indicated for this complication is steroidal drugs. Early steroid administration was found responsive but methodologically flawed in various studies. Desmopressin was evaluated in various randomized studies as adjunct therapy with nonsignificant mortality benefits [69]. Therapy is considered beneficial with doxycycline or azithromycin along with steroid administration in mild and severe cases. Variations in studies are reported with nonsignificant benefits to mortality reduction.
