[Disseminated intravascular coagulation in eperythrozoonosis of swine]

Investigations were carried out on the influence of latent and clinically manifest Eperythrozoon suis infection upon haemostasis in swine. The study was carried out with 14 German Landrace pigs. Latent eperythrozoonosis was induced in 7 animals by experimental infection. Splenectomy of these 7 animals and 2 spontaneously infected pigs led to clinical manifestation of eperythrozoonosis. Five clinically healthy pigs were splenectomized and served as controls. In healthy pigs splenectomy was followed by a transient rise in fibrinogen and platelet count. Latent infection with Eperythrozoon suis did not cause an impairment of haemostasis. Acute eperythrozoonosis was associated with increased haemorrhagic tendency considered to be a consequence of intravascular coagulation and subsequent consumption coagulopathy. There was a prolongation of partial thromboplastin time and prothrombin time (Quick) and a decrease of platelet count. Thrombelastography showed prolongation of reaction and clot building time and a short-term decrease of maximum amplitude. Deviation from normal values was proportional to the number of red blood cells infected with Eperythrozoon suis. Anti-rickettsial therapy led to quick normalization of haemostasis. Various aspects of the cause and the consequences of the haemostatic defect are discussed with special regard to the underlying disease.

Evaluation of antithrombin-III activity as a coindicator of disseminated intravascular coagulation in cats with induced feline infectious peritonitis virus infection

Six adult specific-pathogen-free cats were inoculated intraperitoneally with a cell culture-adapted strain of feline infectious peritonitis virus. Plasma samples were evaluated for antithrombin-III (AT-III) activities at post-inoculation days (PID) 0, 4, and 11 and at termination on PID 16 (1 cat) or 21 (5 cats). Other hemostatic values evaluated were activated partial thromboplastin times, prothrombin times, thrombin times, fibrinogen, platelet counts, and fibrin/fibrinogen degradation products. Antithrombin-III activity remained within normal or above normal range (89 to 246%) in all cats, with the exception of one cat on PID 4 (AT-III, 70%). Mean baseline AT-III activity for 6 cats at PID 0 was 123%. Mean AT-III activity on PID 4, 11, and 16 or 21 was 98, 162, and 130%, respectively. On PID 4 and 16 or 21, results of coagulation screening tests indicated that all cats had disseminated intravascular coagulation. Histologically, cats also had severe fibrinonecrotizing thrombovasculitis.

Dyspnea in aging rats due to disseminated intravascular coagulation (DIC)

During an 18-month oncogenicity study using rats, approximately 10% of the animals developed a form of respiratory distress very similar to that seen in the terminal stages of chronic respiratory disease, commonly associated with Mycoplasma pulmonis infection. Investigation of the lungs of the affected rats revealed not only that they did not have the consolidation usually associated with chronic respiratory disease, but they also appeared macroscopically normal. Further investigation of a number of cases revealed systemic intravascular thrombus formation of the type usually referred to as disseminated intravascular coagulation. Using an antiserum to fibrin we have demonstrated the presence of intravascular fibrin deposits in the lungs of the affected rats and have shown them to be the same as experimentally induced intravascular fibrin deposits induced in rat lungs by the administration of thrombin after blocking the fibrinolytic system. This is the first example of such a phenomenon being recorded in aging rats.

Trypanosoma vivax: disseminated intravascular coagulation in cattle

Five crossbred cattle infected with Trypanosoma vivax (Likoni) by Glossina morsitans developed capillary haemorrhages at the onset of parasitaemia, followed by the presence of occult blood in faecal samples and eventually melena. Two animals required treatment to survive, on days 13 and 38 respectively. The other three animals cleared their parasitaemias without treatment. Packed cell volume (PCV) levels decreased in all animals to levels ranging from 7.5 to 17%. Relapse in a treated animal initiated marked haemorrhage and a loss of 14 PCV units during a six-day period. Thrombocytopenia was common to all animals, and thrombocytes decreased to levels of 4000/microliters of blood. All animals developed increased levels of fibrinogen and fibrin monomer. Prolonged prothrombin times were found in all animals, and activated partial thromboplastin times were also extended in the two animals with high parasitaemias.

Experimentally induced bluetongue virus infection in white-tailed deer: ultrastructural findings

White-tailed deer (Odocoileus virginianus) were inoculated with bluetongue virus serotype 17 and sequentially euthanatized during infection. Ultrastructural changes in the microvasculature of tongue, buccal mucosa, heart, and pulmonary artery, platelets, and bone marrow were evaluated. Bluetongue virus was found in endothelial cells of the microvasculature by postinoculation day 4. Viral replication was associated with the development of viral matrices, viral-associated macrotubules, and aggregates of mature viral particles in the cytoplasm of infected cells. Viral infection of pericytes and vascular smooth muscle cells developed subsequent to endothelial cell infection. Viral infection was associated with striking changes in the endothelial lining of the microvasculature by postinoculation day 4. Endothelial cell degeneration and necrosis, which resulted in denudation of the endothelial lining, and endothelial cell hypertrophy frequently were observed. Thrombosis, hemorrhage, and vessel rupture developed subsequent to endothelial damage. Bluetongue virus neither infected nor directly damaged platelets or bone marrow cells. It was concluded that viral-induced endothelial damage is the primary triggering mechanism for disseminated intravascular coagulation in bluetongue virus infection. Vascular damage coupled with the development of disseminated intravascular coagulation is responsible for the hemorrhagic diathesis, which is characteristic of bluetongue virus infection in white-tailed deer.

Experimentally induced bluetongue virus infection in white-tailed deer: coagulation, clinical pathologic, and gross pathologic changes

Ten yearling white-tailed deer (Odocoileus virginianus) were inoculated with bluetongue virus serotype 17. Two yearling white-tailed deer were inoculated with sonicated heparinized noninfected blood and served as controls. Clinical signs of bluetongue virus infection included increased rectal temperature, erythema, facial edema, coronitis, and stomatitis. By postinoculation day (PID) 8, excessive bleeding and hematoma formation at venipuncture sites, dehydration, and diarrhea developed. At necropsy, the most consistent findings were oral lesions and widespread hemorrhage, which ranged from petechia to massive hematoma formation. Bluetongue virus caused progressive prolongation of activated partial thromboplastin time and prothrombin time, and progressive reduction of Factors VIII and XII plasma activities beginning on PID 6. A progressive decrease in platelet numbers also developed on PID 6. Changes in platelet size were not detected. Mean thrombin time was shortened, but prolongation developed in 1 deer. Mean fibrinogen concentration and Factor V plasma activity initially increased and then decreased, but remained above preinoculation values. Factor V activity was low in a few deer. Results of screening tests for inhibitors of the intrinsic coagulation system were positive in 2 deer. High concentrations of fibrin(ogen) degradation products were first detected between PID 3 and 6. Hematologic changes included leukopenia, lymphopenia, neutrophilia, and low total plasma protein concentration. Differences in PCV, hemoglobin concentration, or RBC counts were not detected between infected and control deer. Serum total bilirubin concentration increased by PID 6, primarily because of increased unconjugated bilirubin concentration. Mild to severe increases in serum aspartate transaminase activity were accompanied by more marked increases in creatine kinase activity. Indirect Coombs test results were negative in all deer.(ABSTRACT TRUNCATED AT 250 WORDS)

Recognition and management of disseminated intravascular coagulation in horses

This article reviews normal hemostasis in order to provide the reader with the basis for understanding the pathogenesis and manifestations (both clinical and laboratory) of disseminated intravascular coagulation (DIC) in horses. DIC is subsequently discussed. The diagnosis and treatment of DIC in horses are also described.

Acute mastitis and disseminated intravascular coagulopathy caused by Pasteurella haemolytica in a cow

Pasteurella haemolytica was found to be the cause of acute mastitis, toxemia, and disseminated intravascular coagulopathy in a cow. Intensive treatment with antibiotics and fluid and heparin administration failed to reverse the progression of the disease, and death resulted. Necropsy revealed extensive evidence of consumptive coagulopathy, as well as mastitis. Pasteurella haemolytica rarely has been implicated as a cause of mastitis in cows.

Pathophysiology of antithrombin III deficiency

This article focuses on the pathophysiology of thrombosis in patients with acquired antithrombin III deficiency. Antithrombin III is an important natural inhibitor of the hemostatic mechanism, and a hypercoagulable state is often induced in diseases causing antithrombin III deficiency. Laboratory determination of antithrombin III activity is particularly useful in the clinical evaluation and therapeutic management of patients with disseminated intravascular coagulation, nephrotic syndrome, and severe hepatopathy.

Coagulation abnormalities associated with neoplasia

Subclinical abnormalities in hemostasis occur commonly in small animal patients with cancer, but the incidence of clinical thrombosis or hemorrhage is unknown. Malignancy can lead to abnormalities in both primary and secondary hemostasis, which in turn can lead to either thrombotic or hemorrhagic tendencies. These coagulation abnormalities can be associated with the tumor itself, with anticancer chemotherapy, or with secondary organ dysfunction. Thrombocytopenia and DIC are probably the most common defects associated with clinical bleeding in small animal patients.

Disseminated intravascular coagulation

Etiology, pathogenesis, clinical features, laboratory findings, and therapy of disseminated intravascular coagulation (DIC) in the dog and the cat are reviewed.

Hematuria in rabbits

A nine year retrospective study of hematuria in 14 New Zealand White rabbits was conducted to classify possible etiologies of this clinical finding. Physical examination, laboratory tests, radiography and postmortem examination were utilized in most cases to verify the presence of hematuria and to determine its etiology. Uterine adenocarcinoma was diagnosed in two rabbits. Three rabbits had uterine polyps with hemorrhage. Renal infarction with hemorrhage was diagnosed in three rabbits. Urolithiasis with secondary urethral obstruction and hemorrhagic cystitis was identified as the cause of hematuria in four rabbits. Other causes of hematuria included chronic cystitis, disseminated intravascular coagulation, bladder polyps and pyelonephritis. Hematuria of undetermined origin was observed in one rabbit. This last [corrected] case was negative for both blood and porphyrin in the urine, but positive for excess levels of urobilin, the oxidative product of urobilinogen. This case illustrates that hyperpigmented urine should be a rule out in all cases of suspected hematuria in rabbits.

[Disseminated intravascular coagulation in the horse: a report of six cases]

Six cases of disseminated intravascular coagulation in the horse are reported. They were characterised clinically by severe subcutaneous oedema of the head and neck, and clinocopathologically by abnormal partial thromboplastin and prothrombin times, a thrombocytopaenia and an increase in fibrin degradation product concentrations. Various aetiologies played a role in the pathogenesis of the condition including African horsesickness, babesiosis, lymphosarcoma and verminosis.

Disseminated intravascular coagulation in "Hitra disease" (hemorrhagic syndrome) in farmed Atlantic salmon

Necropsy findings in adult salmon with subclinical "Hitra disease" (hemorrhagic syndrome) varied from negligible to hemorrhagic diathesis with generalized edema. By light microscopy, minute vessels were dilated, arterioles had mural necrosis, and thrombi were present. Occlusions consisted of fused erythrocytes and fibrin. Ultrastructurally, endothelial nuclei were pyknotic with condensed chromatin. The cytoplasm contained numerous laminar structures and electron-dense particles. Damaged erythrocytes adhered to the degenerated endothelium, and coalesced erythrocytes had formed mural thrombi or filled the vascular lumen. Microthrombi were frequently seen. There were no thrombocytes in the thrombi, which consisted of erythrocytes or reticulocytes. Clinically healthy farmed salmon parr showed the same disorders as did adults, but to a far lesser degree. Wild salmon parr had normal microvasculature. Results indicate that disseminated intravascular coagulation (DIC) occurs in "Hitra disease" in farmed Atlantic salmon.

Histopathologic and electron microscopic studies on the acute toxicity of ochratoxin A in rats

Ochratoxin A was given by gavage to male rats. Moribund and dead animals were necropsied, and the surviving rats, including the controls, were killed 48 hours after dosing. Many of the principal rats were moribund, or began dying, within 12 to 24 hours after dosing. Lesions suggestive of disseminated intravascular coagulation were seen by light microscopy as early as 12 hours after dosing; fibrin deposits were in the spleen, brain choroid plexus, glomerular capillaries, liver, and heart. Renal tubular nephrosis, hepatic and lymphoid necrosis, and necrotic enteritis with villous atrophy were also seen. Electron microscopy demonstrated fibrin strands mixed with degranulated platelets, necrotic leukocytes, and swollen endothelial cells in glomerular capillaries. Myocardial changes included focal supercontracted sarcomeres adjacent to intercalated disks. Swollen sarcolemma, lysed myofibrils and fragmented Z-bands with interstitial edema, vascular thrombosis, and endothelial damage were also seen. The acute pathologic changes induced by ochratoxin A in the intestine, liver, and lymphoid tissues were more obvious than the tubular nephrosis, and the development of a disseminated intravascular coagulation-like syndrome with myocardial changes was a complicating factor.

Secondary myelofibrosis in three dogs

Myelofibrosis was diagnosed in 3 dogs. In each dog, there was evidence of concurrent bone marrow necrosis, suggesting that the myelofibrosis was a secondary change. This suggestion was supported by a lack of dysplastic changes in hematopoietic cells. Bone marrow necrosis in 2 of the dogs may have been the result of widespread malignancy. Reversal of the myelofibrosis in 1 dog suggested that myelofibrosis is not always a terminal disorder.

Plasma fibronectin concentrations in dogs with disseminated intravascular coagulation

Plasma fibronectin concentrations were significantly (P less than 0.001) below the reference range in dogs with disseminated intravascular coagulation (DIC) secondary to nonlymphomatous neoplasia, acute necrotizing pancreatitis, sepsis, chronic active hepatitis, and heat stroke. There was no statistical evidence of a group effect. Decrease in fibronectin concentration was associated with severe DIC, although no attempt was made to correlate fibronectin concentration with prognosis. These findings parallel those reported for severely ill human beings with diseases associated with DIC. They exemplify the potential of spontaneous diseases in animals as models for the study of human disease.