lymphoid system

What is combined immunodeficiency disorder and what are its clinical signs and affected species?

Combined immunodeficiency disorder is a condition involving defective B and T lymphocyte function, leading to severe immune deficiency. Clinical signs include recurrent infections and failure to thrive. Affects various species including Arabian foals and dogs.

What is equine combined immunodeficiency and what are its signs and host?

Equine combined immunodeficiency is an autosomal recessive disease in Arabian foals causing absence of functional B and T lymphocytes. Clinical signs include recurrent respiratory infections and death within 5 months. Affects Arabian horses.

What is thymitis and which organ does it affect?

Thymitis is inflammation of the thymus, usually due to infections. Clinical signs include swelling of the thymus and immune dysfunction. Affects the thymus in multiple species.

What is thymic hyperplasia and its clinical relevance?

Thymic hyperplasia is an enlargement of the thymus due to increased lymphoid tissue. It may be incidental or associated with autoimmune disease. Affects the thymus in several species.

What is thymic atrophy and what are its causes and signs?

Thymic atrophy is shrinkage of the thymus due to stress, malnutrition, or disease. Clinical signs include immunosuppression and susceptibility to infection. Affects the thymus in various animals.

What is a thymic cyst and how does it present clinically?

Thymic cysts are congenital or acquired fluid-filled sacs in the thymus. Usually asymptomatic but may cause mediastinal mass effects. Affects the thymus.

What is a thymic hematoma and what organ is involved?

Thymic hematoma is a blood-filled mass in the thymus, typically due to trauma. May cause respiratory distress due to mass effect. Affects the thymus.

What is thymic lymphosarcoma and what species and signs are associated?

Thymic lymphosarcoma is a malignant tumor of lymphoid origin in the thymus. Clinical signs include dyspnea and mediastinal mass. Affects cats, cattle, and dogs.

What is bovine thymic lymphosarcoma and its clinical presentation?

Bovine thymic lymphosarcoma is a sporadic form of lymphoma in young cattle affecting the thymus. Signs include dysphagia, bloat, and weight loss due to thoracic mass.

What is feline thymic lymphosarcoma and what are its signs?

Feline thymic lymphosarcoma is a lymphoid tumor in the thymus causing respiratory distress, coughing, and pleural effusion. Affects cats.

What is thymomas and which organ is involved?

Thymomas are epithelial tumors of the thymus, often associated with myasthenia gravis. Present as mediastinal masses. Affects dogs, cats, and goats.

What is asplenia and what are its effects?

Asplenia is the congenital absence of the spleen. Leads to increased susceptibility to infections due to impaired immune function. Affects all species.

What is splenic atrophy and its clinical significance?

Splenic atrophy is reduction in spleen size due to aging, cachexia, or disease. Leads to decreased immune surveillance. Affects the spleen.

What is hemosiderosis of the spleen and its presentation?

Hemosiderosis is iron accumulation in the spleen due to excessive RBC breakdown. Usually asymptomatic, identified histologically. Affects spleen in many species.

What are sidero-calcific plates and where are they found?

Sidero-calcific plates are mineralized areas in the splenic capsule due to old hemorrhages. Usually incidental findings in dogs.

What is splenic rupture and what are its signs?

Splenic rupture is a traumatic or pathological tear in the spleen, causing internal hemorrhage, hypovolemic shock, and sudden death. Affects dogs and other animals.

What is a splenic hematoma and how does it present?

Splenic hematoma is a localized blood-filled swelling due to trauma or rupture. Clinical signs include abdominal mass or shock. Common in dogs.

What is a subcapsular hematoma of the spleen and what does it cause?

Subcapsular hematoma is bleeding beneath the splenic capsule, potentially leading to rupture. Signs include abdominal pain and anemia. Affects the spleen.

What are splenic infarcts and what are their causes?

Splenic infarcts are areas of necrosis due to thrombosis or embolism. May be incidental or cause pain and fever. Seen in dogs and pigs.

What is splenomegaly and its types?

Splenomegaly is enlargement of the spleen. Can be congestive (e.g., due to heart failure) or non-congestive (e.g., neoplasia or inflammation). Affects spleen.

What is congestive splenomegaly and what causes it?

Congestive splenomegaly is due to blood pooling from heart failure, portal hypertension, or torsion. Causes enlarged, dark spleen. Seen in dogs.

What is non-congestive splenomegaly and what are its causes?

Non-congestive splenomegaly occurs due to cellular infiltration from neoplasia or inflammation. Spleen is firm and enlarged. Affects various species.

What is a splenic hemangioma and its clinical signs?

Splenic hemangioma is a benign vascular tumor of the spleen. May cause splenomegaly or rupture. Common in dogs.

What is splenic hemangiosarcoma and what species is affected?

Splenic hemangiosarcoma is a malignant vascular tumor prone to rupture and metastasis. Signs include anemia and collapse. Common in dogs.

What is lymphoid hyperplasia and its significance?

Lymphoid hyperplasia is a reactive increase in lymphoid cells due to antigenic stimulation. Nodes are enlarged but non-painful. Common in all species.

What is lymphadenitis and how does it present?

Lymphadenitis is inflammation of lymph nodes due to infection. Nodes are enlarged, warm, and painful. Seen in all species.

What is caseous lymphadenitis and which species is affected?

Caseous lymphadenitis is a chronic bacterial infection (Corynebacterium pseudotuberculosis) in sheep and goats. Causes abscessed, caseous nodes.

What is suppurative lymphadenitis and how does it present?

Suppurative lymphadenitis is pus-forming bacterial infection of lymph nodes. Nodes are swollen and may rupture. Seen in many species.

What is granulomatous lymphadenitis and its causes?

Granulomatous lymphadenitis involves chronic inflammation with macrophage accumulation. Caused by TB, fungi, etc. Affects multiple species.

What is histoplasmosis and how does it affect lymph nodes?

Histoplasmosis is a fungal infection causing granulomatous lymphadenitis. Lymph nodes are enlarged and firm. Seen in dogs and cats.

What is exotic lymphangitis and what species are affected?

Exotic lymphangitis is a bacterial infection (e.g., Corynebacterium pseudotuberculosis) in horses, causing lymphangitis and lymphadenitis. Clinical signs include limb swelling.

What is leishmaniasis and how does it affect lymph nodes?

Leishmaniasis is a protozoal infection causing lymphadenopathy, skin lesions, and systemic illness. Affects dogs, foxes, and humans.

What is acute lymphocytic leukemia and which organs are involved?

Acute lymphocytic leukemia is neoplastic proliferation of lymphoid precursors in marrow and blood. Causes anemia, thrombocytopenia, and organ infiltration. Affects bone marrow and lymph nodes.

What is chronic lymphocytic leukemia and what are the signs?

Chronic lymphocytic leukemia involves mature lymphocyte proliferation. Often asymptomatic or causes lymphadenopathy and fatigue. Affects older dogs.

What is lymphosarcoma and which species are commonly affected?

Lymphosarcoma is malignant lymphocyte tumor in lymph nodes or organs. Causes weight loss, lymphadenopathy, and organ dysfunction. Common in dogs, cats, cattle, and horses.

What is canine lymphosarcoma and what are its clinical signs?

Canine lymphosarcoma is lymphoma in dogs affecting lymph nodes, spleen, liver. Signs include lymphadenopathy, lethargy, and anemia.

What is feline lymphosarcoma and what are the common forms?

Feline lymphosarcoma may be mediastinal, alimentary, or multicentric. Signs vary: respiratory distress, vomiting, or lymphadenopathy. Common in FeLV+ cats.

What is bovine lymphosarcoma and what are the associated signs?

Bovine lymphosarcoma is a BLV-associated or sporadic lymphoma. Signs include enlarged peripheral nodes, weight loss, and bloat.

What is equine lymphosarcoma and how does it present?

Equine lymphosarcoma affects lymph nodes, GI, or skin. Causes weight loss, swelling, and organ dysfunction.

What is Hodgkin’s disease and which organ system does it affect?

Hodgkin’s disease is a rare form of lymphoma with Reed-Sternberg cells. Affects lymph nodes and spleen. Rare in animals.

What are plasma cell neoplasms and where do they occur?

Plasma cell neoplasms, including multiple myeloma, affect bone marrow, lymph nodes, and organs. Signs include bone pain, anemia, and hyperglobulinemia. Affects dogs