Multiple Choice Questions (MCQ) on Veterinary Pathology (Part- 4)

d. Mycoplasmal infection

• Coagulative Necrosis of the myocardium in calves is seen in Mycoplasmal infection .
• Lesions seen in Mycoplasmal infections: (Contagious Bovine Pleuro Pneumonia)
• Sharply circumscribed nodules scattered throughout the affected lungs.
• Marbling of Lungs
• Haemorrhagic infarctions leading to necrosis in different organs like Lungs Liver, spleen, Kidney, Heart, Pericardium and Joints.
• Lesion seen in Rinderpest
• Zebra marking or tiger striping in large intestine
• Lesion seen in Foot rot ( Spherophorous necrophorus)
• Ulcerative changes in Interdigital space

c. Bacteria

• Ulcerative Lymphangitis (Caseous lymphadenitis) is infectious disease of Cattle and Horse characterized by formation of skin ulcers with involvement of lymph vessel of lower limbs.
• Caused by Corynebacterium pseudotuberculosis, ( spore forming, non - capsulated gram positive bacteria).

b. Bacteria

• Strangle ( Equine Distemper; Infectious Adenitis) is an acute infectious disease of Equine Characterized by catarrhal inflammation of the upper respiratory tract with suppuration and abscessation of the associated lymph nodes.
• Strangle is caused by Streptococcus equi, gram positive bacteria, affect young horse within age group of 6 month to 36 month.
• Lesions:
• Edema and congestion of nasal mucous membrane
• -Abscess formation in Pharyngeal and submaxillary lymph nodes
• Empyema of the guttural pouch
• Suppurative pneumonic changes
• Changes in Pleura and pericardium

a. Swine Fever

• Pathognomic lesions of Swine Fever:
• Button ulcer in Caecum and Colon
• Turkey’s egg appearance of Kidney
• Infarct Spleen
• Other facts of Swine Fever:
• Swine fever is acute, highly contagious viral disease affecting pigs of all ages, characterized by rapid and sudden onset, high morbidity and mortality with generalized hemorrhage.
• Swine fever is caused by an enveloped single stranded RNA virus (pestivirus of family Flaviviridae).

a. Autoimmunity

• Autoimmunity: Autoimmunity is the system of immune response of an organisms against it’s own healthy cells, tissues and other body normal constituents. Any disease resulting from this type of immune response is term as “ Autoimmune disease”. When the body produces antibody against it’s own body cells, unable to differentiate between their own and foreign antigen.
• Immunodeficiency: Lack of Immunity.
• Innate Immunity: Inborn Immunity. It remains last for whole life. Innate immunity are of three types: Species, Breed and Individuals etc.
• -Acquired Immunity: Immunity that person acquired during lifetime.

d. M. paratuberculosis

• Johne’s disease is chronic infectious fatal gastrointestinal disease of ruminant characterized by progressive emaciation and diarrhea.
• Caused by M. paratuberculosis or M. Johnei
• Thickened and Corrugated intestinal wall
• Diagnosis:
• Intradermal and Intravenous Johnin test

a. T. annulata

• Theileriosis ( East Coast Fever/ Red water/ Rhodesian tick fever) is protozoan disease of Exotic and cross bred cattle, characterized by high fever, anemia and swelling of lymph nodes.
• Causes of Theileriosis: Theileria annulata, Theileria parva, and Theileria mutans. Theileria annulata is most extensively distributed parasite and causes Tropical and Acute theileriosis.
• The parasites remains in two forms: Erythrocytic form and Schizont form ( Koch’s blue bodies).
• Punched necrotic Ulcer in the Abomasum is the Pathognomic lesion of Theileriosis.

c. Microglial

• -Babes nodules in the rabies is formed due to the collection of microglial cells.
• Microscopic lesion of Rabies:
• Presence of Negri’s Bodies: Negri bodies are the accumulation of large aggregate of dense granular viriplasm in cytoplasm of infected cells. Negri’s bodies are found in Hippocampus of Carnivores and Purkinjee cells of Herbivores.
• Presence of Babes’s Nodules: Babes’s nodules are discrete glial cells clusters resulting from cell proliferation.

a. Brucella infection

c. Aspergillosis

• Mixed Granulomatous inflammation occurs in Actinobacillosis, Actinomycosis and Tuberculosis except Aspergillosis.
• Types of Granulomas:
• Epithelioid granuloma- ( TB , Fungal,
• Epithelioid with suppuration - ( TB, Fungal - Histiocytic ( Fungal, Parasitic infestation)
• Foreign body granuloma ( Foreign body)
• Mixed - ( TB, Parasitic infestation)

a. Salmonella

• Pullorum disease in poultry is caused by Salmonella pullorum.
• Pullorum disease ( BWD) is contagious, egg- transmitted disease characterized by white diarrhea in young chick. Chick below 3 weeks of age are highly susceptible.
• The most important method of spread of disease is from infected hen through egg to newly hatched chick.
• Older birds may appears depressed and have pale and shrunken combs with ruffled feathers.
• Both growing and older birds may show greenish brown diarrhea.

b. Bollinger

• Bollinger bodies are observed in infected tissues of birds with avian pox. Bollinger bodies are relatively large, granular, acidophilic intracytoplasmic inclusion bodies seen in Avian pox’s infected cells.

c. E.coli

• Hjarre’s disease in poultry is caused by E. coli.
• Colibacillosis ( E. coli infection) in poultry occurs in two forms:
• Systemic infection: Presence of E.coli in Blood circulation (Colisepticemia), Respiratory tract infection, Pericarditis, Osteoarthritis and synovitis, Coligranuloma etc. 2. Localized infections: In this infections, infection is restricted to specific or limited area. Localized infections of E.coli includes Omphalitis ( Yolk sac infections), Salpingitis and Peritonitis in Layers, Enteritis, Coliform Cellulitis, Swollen head Syndrome, Egg peritonitis etc.

c. Both above

• Favus or tinea favosa is a severe and chronic inflammatory dermatophyte infections, caused by both Trichophyton and Microsporum fungus.

a. Ranikhet

• Hemorrhage at the tip of Proventricular gland seen in Ranikhet.
• Hemorrhage at the junctions of Proventriculus and Gizzard seen in IBD ( Infectious Bursal disease)
• CRD : Cheese -like Inflammatory material deposited in Air sacs
• Fowl Typhoid: Liver is friable ( Breaking easily), Swollen, and has a dark red or almost black in color. It’s surface has a characteristics coppery Bronze Sheen.
• Rinderpest: Zebra - marking or tiger striping in large intestine ( Caecum and may continue to rectum).

c. Occluding thrombus

• If a thrombus is attached to the entire endothelial circumference of vessel, completely obstruct the flow of blood through vessel, it is known as Occluding thrombus. Tissue death due to this thrombus, known as infarct.
• Mural thrombus is an organizing blood clot attached to the wall of blood vessel or the endocardium of heart or wall of the ventricles.

b. Spirochetosis

• Avian Spirochetosis is an acute bacterial infection transmitted by tick to wide range of birds, causative organism is Borrelia anserina, i.e. spirochetes. The most common vector that transmit avian spirochetosis is Argus persicus, the cosmopolitan fowl tick.

a. Bone marrow

• Both Granulocyte and Agranulocyte are formed in Bone Marrow. Granulocyte includes ( Eosinophils, Basophils, Neutrophils) while Agranulocyte includes Monocyte and Lymphocyte.

a. Rubricyte

• Erythrocytic series is the succession of morphologically distinguishable cells that are stages in erythrocyte development. In order of maturity, the Proerythroblast, basophilic Erythroblast, polychromatophilic erythroblast, orthochromatic erythroblast, Reticulocyte and Erythrocyte.
• a. Proerythroblast or rubriblast or pronormoblast is the earliest cell of Erythrocytic series, arises from Colony forming unit- Erythroid cells and and give rise to basophilic erythroblast.

b. Myelophthisic anemia

• Anemia resulting from the displacement of bone marrow by abnormal cells - Myelophthisic anemia
• Pernicious anemia is anemia occurs due to deficiency of Vitamin B12, which leads to failure of maturation of RBC.
• Aplastic Anemia is a condition that occurs when body stops producing enough new blood cells due to defect in Bone marrow.

d. Leukocytosis

• Myeloid: Erythroid ratio is increased in Leukocytosis . Since, Myeloid leads to production of leucocytes while Erythroid leads to give Erythrocyte.
• Leucopenia: Decrease in number of leucocyte
• Erythrocytic hypoplasia is the decrease in the number of erythrocyte
• Erythrocytic hyperplasia is the increase in the number of Erythrocyte.

d. T cells and macrophages

• The cellular reactions in transplant rejections comprises T cells and macrophages.
• The ability of recipient T cells to recognize Donor - derived antigens, called allorecognition, initiates allograft rejection. Once recipient T - cell becomes activated, they undergo clonal expansion, differentiate into effector cells and migrates into the graft where they promotes tissue destruction.

c. CD8

• The Surface marker present on Helper T cell - CD4 while the surface marker present on Killer or Cytotoxic T cells is CD8.

b. Polychromasia

• Basophilic erythrocytic cytoplasm is typically seen in Polychromasia. Polychromasia occurs on a lab test when some of red blood cells shows up as bluish- grey when they are stained with a particular types of dye.
• Hypochromasia means that the red blood cells have less color than normal when examined under microscope. This usually occurs when there is not enough of pigment that carries hemoglobin in RBC.
• Hyperchromasia : Hyperchromasia condition suggest malignancy.

b. Sub- leukaemic leukaemias

• Normal or below normal leucocytes count occurs in Sub - Leukaemic Leukaemias while in Leukocytosis and leukaemic Leukaemias. leucocytes counts increases.

c. Ovalocyte

• Elliptical erythrocyte is called Ovalocyte
• Spherical erythrocyte is called Spherocyte
• Flat erythrocyte is called leptocytes
• Myelocyte are the precursors of the neutrophils, the largest class of white blood cells.

a. Erythrocytosis

• Erythrocytosis- Increased Erythrocyte count
• Reticulocytosis- An elevation in the number of reticulocytes ( young red blood cells) in blood, a sign of unusually rapid red blood cell production. The number of reticulocytes is normally less than 1 %of total number of Red blood cells.
• Poikilocytosis: An increase in abnormal red blood cells of any shape that makes up to 10% or more of total population. Poikilocytes can be flat, elongated, teardrop- shape, crescent shape, sickle shape or having thorns likes projections etc.
• Anisocytosis: Anisocytosis is the medical term for having Red blood cells that are unequal in size.

c. Howell Jolly bodies

• Howell Jolly bodies are the little fragments of the red cell nucleus, commonly seen in Splenectomy while Heinz bodies are denatured globin chains, seen in G6PD deficiency. When there is no enough G6PD ( Glucose 6 phosphate Dehydrogenase) around, the bonds between heme and globin are attacked. Heme is just recycled, but the globin chains becomes denatured, forming a little ball that sticks to the inside of the red cell membrane. This is Heinz body.

d. All

• All cytokines ( IL-2,3,4 ) all are produced by Activated T -cells
• T- cell differentiation and role of cytokines
• T - cell formed in bone marrow and immature T-cell migrates to Thymus. After thymic selection, T-cell differentiate into 2 types: i.e. CD4+ helper T cell( able to recognize peptide that bound to MHC -2) and CD8+ Cytotoxic T cell ( able to recognize peptide that bound to MHC-1).
• When Antigen presenting cell ( Dendritic cell) holding peptide sequence of class -2 MHC molecules, activated Helper T- cell, Activated Helper T-cell on returns produces large numbers of interleukins which in turns produces large number of activated T-cell.
• Activated Helper T -cell secretes cytokines that acts on the bone marrow to increase the production of monocytes.

c. Cytokines

• Messenger molecules of the immune system is Cytokines
• Lymphokines are the cytokines produced by Lymphocytes while Monokines are the cytokines produced by Monocytes.