Leptospirosis is a bacterial disease related to genus Leptospira which cause septicemia, It is rare in cats but more common in dogs, cattle

Leptospirosis is a zoonotic disease (human).

NB: In man: it causes Weil’s

disease

Septicemia septicemia leads to petechial septicemia leads to petechial

hemorrhages and edemahemorrhages and edema on serous membranes (on serous membranes (pleurapleura ) )::may be seen in other organs as may be seen in other organs as

myocardiummyocardium ,,adrenal glandsadrenal glands,,

pancreaspancreas , ,gallbladdergallbladder and and lunglung

Pulmonary hemorrhage

A-Canine Leptospirosis:Pathognomonic Lesions:Acute leptospirosis:

Liver:

Macroscopic Picture: 1-The liver is enlarged and yellow

in color.2-Yellow m.m. due to icterus.

3-Peticheal hemorrhages on the pleura, pericardium and peritoneum.

IcterusIcterus

.

Microscopic Picture:1 -coagulative necrosis in hepatic cells.

2-Dissociation of the hepatic cells (individualization).

3-hemolytic jaundice with dilation of the bile canaliculi with yellow bile pigments.

4-Hemosiderosis are seen in the kupffer cells.

Organ : Liver.Stain : H&E.Micro : Dissociation and individualization hepatic cells.

B- Bovine leptospirosisSubacute and Chronic leptospirosis:Macroscopic Picture:

1-The kidneys are enlarged & atrophied (chronic).

2-Grayish-white spots throughout the cortex (white spotted kidney) andthe capsule is not easily detached.

3-Smooth or pitted surface with hemorrhage at the corticomedullaryjunction.

.

Microscopic Picture:1-Agggregations of lymphocytes

2-Extenssive coagulative necrosis.3-Fibrosis and cystic dilation of

some renal tubules in chronic stage.

4-Cellular and hyaline casts