Term
| What three processes can contribute to the development of anemia? |
|
Definition
loss of RBC
increased RBC destruction
decreased RBC production |
|
|
Term
| What is the clinical consequence of anemia? |
|
Definition
| decreased oxygen carrying capacity of the blood |
|
|
Term
| What TP and PCV findings are consistent with acute hemorrhage? |
|
Definition
Low TP
Normal PCV (~12 hours post blood loss) |
|
|
Term
| Other than surgery or trauma, what other conditions/syndromes can result in acute blood loss? |
|
Definition
dicoumarol/warfarin poisoning
thrombocytopenia
vasculitis
DIC |
|
|
Term
| What TP and PCV findings are consistent with chronic hemorrhage? |
|
Definition
|
|
Term
| Which condition is associated with more severe clinical signs, acute or chronic blood loss? |
|
Definition
Acute
chronic hemorrhage is associated with MILDER clinical signs, even if blood loss is significant |
|
|
Term
| What are some toxins associated with increased RBC destruction? |
|
Definition
oxidants (onion, red maple leaf)
heavy metals (lead)
bacterial toxins (lepto, clostridium haemolyticum) |
|
|
Term
| What are three mechanisms for increased RBC destruction? |
|
Definition
Immune mediated (drug reactions/ infectious disease- EIA, babesia, anaplasma/ transfusion reactions)
mechanical damage (splenic or liver mass)
congenital disorders of RBC metabolism (rare) |
|
|
Term
| What RBC morphological abnormality is consistent with intravascular hemolysis? |
|
Definition
|
|
Term
| What protein is normally responsible for clearing free hemoglobin from circulation? |
|
Definition
haptoglobulin (hemoglobin-haptoglobulin complex is then cleared by heptatic MO -> biliary excretion),
when haptoglobulin is overwhelmed --> hemoglobinemia |
|
|
Term
| What diagnostic findings are consistent with intravascular hemolysis? |
|
Definition
hemoglobinemia (haptoglobulin is overwhelmed by the amount of free hemoglobin in circulation)
hemoglobinuria |
|
|
Term
| What RBC morphological abnormality is associated with extravascular hemolysis? |
|
Definition
|
|
Term
| How are RBC removed from circulation? |
|
Definition
| RBC are removed from circulation by splenic and hepatic macrophages |
|
|
Term
| What clinical signs and chemistry findings are consistent with extravascular hemolysis? |
|
Definition
| elevated serum bilirubin and icterus |
|
|
Term
| What is the most common cause of decreased RBC production in large animals? |
|
Definition
| chronic infections and inflammatory diseases |
|
|
Term
| What are some diseases/syndromes associated with decreased RBC production? |
|
Definition
nutritional deficiencies (Fe, Co, Cu)
chronic infectious/inflammatory disease
chronic renal failure
myelophthisis
viral infections
aplastic anemia (generalized peripheral cytopenias) |
|
|
Term
| In what species are signs associated with regenerative anemia impossible to identify? |
|
Definition
| horses (check for regeneration with serial CBC/PCV or bone marrow aspirate/biopsy) <-- caveat- be aware that splenic contraction (often secondary to adrenergic stimulation) in the horse can significantly affect PCV |
|
|
Term
| What RBC morphological feature can be seen in normal equine blood samples? |
|
Definition
| howell-jolly bodies (DNA remnants, NOT indicative of regenerative bone marrow response in horses) |
|
|
Term
| Heinz bodies are associated with ______ damage |
|
Definition
oxidative damage (ex. red maple leaf, onion)
Heinz bodies are denatured aggregates of hemoglobin in RBC |
|
|
Term
| What blood parasites infect RBC? |
|
Definition
|
|
Term
| Iron status is important for characterizing anemias, what findings are consistent with chronic blood loss? With chronic infection/inflammation? |
|
Definition
chronic blood loss is associated with low serum Fe and high TIBC (total iron binding capacity)
chronic infection/inflammation is associated with low Fe and normal TIBC (because the body wants to maintain low Fe to help curtail bacterial reproductive capacity) |
|
|
Term
| What are the indications for a blood transfusion as the treatment for anemia? |
|
Definition
| hypovolemic shock, rapidly falling PCV (below 20% in first 12 hours), PCV < 12% in 1-2 days, clotting factor deficiencies |
|
|
Term
|
Definition
| antigens that induce an immune response within individuals of the same species |
|
|
Term
| T/F There is no such thing as a universal blood donor in horses |
|
Definition
TRUE
Aa/Qa negative are considered the least antigenic horse donor blood type |
|
|
Term
| What blood types are considered the most antigenic in horses? |
|
Definition
| Aa and Qa prefer donor blood to be negative for these alloantigens |
|
|
Term
| Why is cross-matching so important before giving a horse a blood transfusion? |
|
Definition
| to prolong the lifespan of the transfused RBC (2-5 days) and to avoid life threatening hemolytic reactions |
|
|
Term
| What is does the term major cross match refer to? |
|
Definition
Donor RBC mixed with Recipient serum
checks patients alloantibodies against donor RBC |
|
|
Term
| What does the term minor cross match refer to? |
|
Definition
The Recipient's RBC with the Donor's serum
checks for donor alloantibodies against patient RBC |
|
|
Term
| What should you do if you have a horse that needs a transfusion and you don't have time to cross match 2-3 horses? |
|
Definition
| Choose a gelding of the same breed (not TB or Arabian), the first transfusion of whole blood in a recipient that has never previously been transfused is typically well tolerated. There is an increased risk of a transfusion reaction developing if patient receives another transfusion 3-4 days post this non cross matched transfusion |
|
|
Term
| What type of material should you not use when collecting platelets? |
|
Definition
| Glass, platelets are activated by glass, use plastic instead |
|
|
Term
| What volume of blood can you take from a donor horse? |
|
Definition
| 20% of the horses blood volume (8% of the horse's body weight) every 3-4 weeks |
|
|
Term
| What is the formula used to calculate the volume of blood needed by a recipient? |
|
Definition
| [BW(kg) x blood volume (8% bw) x (PCV desired - PCV of patient)] / PCV donor *usually a moot point because limiting factor is the the volume that can be safely removed from the donor (20% blood volume) |
|
|
Term
| Why is it important to use filter screens in infusion sets when performing a blood transfusion? |
|
Definition
| To filter out fibrin or RBC clots (can even use a 2X2 gauze square as a filter) |
|
|
Term
| What are important parameters to monitor before initiating a blood transfusion? |
|
Definition
| baseline HR, RR, rectal temperature, and demeanor |
|
|
Term
| What clinical signs are suggestive of an adverse transfusion reaction? |
|
Definition
| increased HR, RR, and body temp agitation, muscle tremors, uticaria, colic Can occur with full cross match compatibility, during first transfusion and can range from mild to fatal |
|
|
Term
| What drip rate should be used for the first thirty minutes of a blood transfusion to limit the risk of an adverse reaction developing? |
|
Definition
|
|
Term
| What should you do in the case of a severe transfusion reaction? |
|
Definition
| stop transfusion the blood products; administer crytalloid solution IV (dilute out donor blood products); IV epinephrine and corticosteroids |
|
|
Term
| T/F PCV is a good test to measure transfusion efficacy? |
|
Definition
|
|
Term
| What are the best methods of monitoring transfusion efficacy? |
|
Definition
| decline in HR (by >20 bpm), decline in blood lactate, decline in RR |
|
|
Term
| What are some iatrogenic causes of intravascular hemolysis? |
|
Definition
| rapid administration of DMSO, hypotonic, or hypertonic saline (osmotic lysis --> rupture of RBC) |
|
|
Term
| What type of hemolysis is seen in conjunction with ingestion of oxidative toxins? |
|
Definition
intravascular (hemoglobinemia/uria) and extravascular (icterus) hemolysis
free radicals cause denaturation of hemoglobin --> formation of heinz bodies |
|
|
Term
| What is the pathogenesis of acute copper toxicity in sheep? |
|
Definition
copper salts are protein coagulants --> necrosis and irritation of GI, liver, and kidneys --> shock and hemolytic anemia
*** in cases of acute toxicity due to parentral overdose GI lesions are absent |
|
|
Term
| What is the pathogenesis of chronic copper toxicity in sheep? |
|
Definition
| excess dietary copper is stored in the liver -> hepatic injury, stress, or starvation causes stored copper to be released -> high serum levels of copper salts cause intravascular hemolysis (can lead to pigment nephropathy) or organ failure |
|
|
Term
| What is a good screening test for assessment of copper toxicity in a herd of sheep? |
|
Definition
Liver enzymes (elevated in pre-hemolytic phase of chronic copper toxicity)
(you can also dx in individual animals based on high copper levels in liver biopsys, but this procedure can insight a hemolytic crisis by traumatizing the liver) |
|
|
Term
| What is the treatment for acute copper toxicity in sheep? |
|
Definition
| remove source of copper; IV fluid (maintain renal function); GI protectants (if oral exposure); whole blood transfusions; oxygen therapy; minimize stress and activity |
|
|
Term
| What is the treatment for chronic copper toxicity in sheep? |
|
Definition
| remove source of copper, supportive care is progressed to hemolytic crisis (as for acute copper toxicity); IV chelator therapy can enhance excretion (costly); Oral sodium thiosulfate, ammonium, and sodium molybdate enhance fecal excretion; IV sodium tetrathiomolybdate protect RBC from coagulative nature of copper salts |
|
|
Term
| What mineral supplements can be used to bind excess copper in farms that have trouble with copper toxicity? |
|
Definition
|
|
Term
| Horses imported from southern USA/central and south america; or from Europe/Asia/Africa/Brazil can be asymptomatic carriers of which parasitic disease? |
|
Definition
| Babesia caballi and Babesia equi respectively |
|
|
Term
| What type of hemolysis is associated with equine babesiosis? |
|
Definition
| intravascular hemolysis --> pigment nephropathy |
|
|
Term
| T/F Horses that become infected with babesiosis remain carriers for life |
|
Definition
|
|
Term
| When are you most likely to see babesia inclusions within RBC? |
|
Definition
| in the early stages of the disease |
|
|
Term
| When is the earliest an ELISA will identify an infected animal post infection (babesia)? |
|
Definition
| seroconversion occurs within 14 days of infection, because the ELISA tests for babesia antibodies it will not be positive until 14 days post infection |
|
|
Term
| T/F treatment of babesiosis with Imidocard may resolve clinical signs but will not clear the carrier state |
|
Definition
True
**low doses of Imidocard are just as effective at minimizing clinical course of the disease and are therefore perferred to higher doses |
|
|
Term
| What is the pathogenesis of intravascular hemolysis associated with water intoxication in calves? |
|
Definition
| sudden ingestion of large amounts of water --> osmotic lysis of RBC --> hemoglobinemia/uria |
|
|
Term
| What serum chemistry abnormalities are associated with water intoxication in calves? |
|
Definition
| hyponatremia, hypochloremia, and hypo-osmolarity <-- all due to dilution |
|
|
Term
| What is the treatment for water intoxication in calves? |
|
Definition
| restrict intake of free water, slow administration of IV saline (to restore blood osmolarity) |
|
|
Term
| What type of hemolysis is associated with equine neonatal isoerythrolysis? |
|
Definition
|
|
Term
| What is the pathogenesis of equine neonatal isoerythrolysis? |
|
Definition
| Major blood group incompatibility between dam and foal- usually Aa/Qa positive foals born from Aa/Qa negative dams that have had previous Aa/Qa positive foals. The mare is exposed to the Aa/Qa antigen in the foal's blood if placental disruption occurs during gestation and develops antibodies which are transmitted to the foal via colostrum (this process takes too long for the antibodies to be present when the first Aa/Qa positive foal nurses the dam's colostrum). |
|
|
Term
| What laboratory findings are consistent with neonatal isoerythrolysis in foals? |
|
Definition
| decreased PCV; excellent IgG; elevated serum bilirubin; +/- hemoglobinuria (if also has a component of intravascular hemolysis) |
|
|
Term
| How can you check foal and dam alloantigen compatibility in animal with suspected neonatal isoerythrolysis? |
|
Definition
dilute mare colostrum with saline and mix with foal RBC --> clumping indicated incompatibility
**can also use mare serum |
|
|
Term
| Why is blood transfusion risky in foal with neonatal isoerythrolysis? |
|
Definition
cross matching can be challenging, transfusion can exacerbate hemolysis and organ damage, large volume transfusion can result in fluid overload
**if absolutely necessary can use washed packed RBC (avoid excessive volume) |
|
|
Term
| What should be the cornerstone of treatment in a case of neonatal isoerythrolysis? |
|
Definition
| Focus of treatment should be in preventing further hemolysis (IV fluids, corticosteroids <-- remember these foals may be at increased risk of infection if concurrent failure of passive transfer) |
|
|
Term
| T/F pathogenesis of neonatal isoerythrolysis in calves is the same as in mares, but is almost always iatrogenic in etiology |
|
Definition
| True, affects calves of cows that were immunized with RBC containing vaccines (ex. Anaplasma) during pregnancy |
|
|
Term
| What is the pathogenesis of primary immune mediated hemolytic anemia? |
|
Definition
| self antigens on RBC are recognized as foreign by the body's own immune system |
|
|
Term
| What is the pathogenesis of secondary immune mediated hemolytic anemia? |
|
Definition
| Antibodies are directed against viral, bacterial, parasitic, neoplastic, or drug antigens on the body's own RBC's membrane |
|
|
Term
| Which is more commonly associated with IMHA, hemoglobinemia or icterus? |
|
Definition
icterus
**hemoglobinemia/uria may be absent (but NOT always) |
|
|
Term
| What clin path findings are commonly associated with IMHA? |
|
Definition
| regenerative anemia, leukocytosis, neutrophila with regenerative left shift, hyperbilirubinemia and spontaneous autoagglutination on blood smear |
|
|
Term
| Why is the direct Coomb's test of limited diagnostic value for patients with suspected IMHA? |
|
Definition
false negatives are common, false positives are also possible.
** If negative on direct Coombs rule out other causes of extravascular hemolysis (EIA, anaplasmosis, mycoplasma hemollama) and do a treatment trial <-- immunosuppressive doses of corticosteroids |
|
|
Term
| Why is the treatment for IMHA inherently risky in equine patients? |
|
Definition
| High doses of corticosteroids needed for immunosuppression increase the risk of laminitis in horses |
|
|
Term
| T/F horses infected with equine infectious anemia (EIA) can clear the virus after rigorous management |
|
Definition
| FALSE, horses infected with EIA (retrovirus- lentivirus) remain persistent carriers for life |
|
|
Term
| What is the major source and modes of transmission of equine infectious anemia (EIA)? |
|
Definition
| major source of infection is via blood either through natural transmission by blood-sucking insects, iatrogenically, or in utero transmission is also possible |
|
|
Term
| What is the pathogenesis of EIA? |
|
Definition
| virus replicates in macrophages -> viral proteins incite strong humoral and cell mediated immune responses -> immune mediated hepatitis, glomerulonephritis, vasculitis --> secondary thrombocytopenia and hemolytic anemia (circulation of immune complexes against lentivirus adsorb non-specifically to platelet/RBC surfaces) |
|
|
Term
| What is the most common presentation of equine infectious anemia in a horse? |
|
Definition
subclinical infection
**remember, although fulminant episodes of hemolytic anemia many not occur the horse remains a persistent carrier for life and recrudescence is possible at any time |
|
|
Term
| What time period is associated with hemolytic anemia in cases of equine infectious anemia? |
|
Definition
chronic (>30 days post-infection), requires time for plasma cells to develop antibodies against the lentivirus
**classic clinical signs include recurrent episodes of anemia, icterus, pyrexia, generalized edema (secondary to vasculitis), and weight loss) |
|
|
Term
| What test is used to diagnose equine infectious anemia? |
|
Definition
Coggins test (should be one of the first diagnostic tests performed in any anemia horse)
confirm positive results with AGID or ELISA (seroconversion occurs 10-14 days post infection and persists for life) |
|
|
Term
| What is the treatment for Equine Infectious Anemia? |
|
Definition
| confirmed cases must either be strictly quarentined for life; however, most animals are euthanized |
|
|
Term
| What is the pathogenesis of equine anaplasmosis? |
|
Definition
| tick borne parasite -> replication in granulocytes (inclusion bodies are visible in neutrophils and eosinophils before clinical signs appear or very early in the clinical course of the disease) |
|
|
Term
| T/F anemia due to anaplasmosis is an example of primary IMHA in a horse |
|
Definition
FALSE
anaplasmosis infection results in the development of antibodies targeted against parasitic antigens present on infected RBC membranes, that is SECONDARY IMHA |
|
|
Term
| How is equine anaplasmosis diagnosed? |
|
Definition
intracellular morulae on blood smear (btwn days 3-5 of fever)
IFA (takes a month to seroconvert)
PCR |
|
|
Term
| What CBC findings are consistent with equine anaplasmosis? |
|
Definition
|
|
Term
| What is the treatment for equine anaplasmosis? |
|
Definition
oxytetracycline
** prevent with good tick control, no vaccine is available |
|
|
Term
| What region of the united states is endemic for anaplasmosis? |
|
Definition
endemic in southern USA
sporatic cases occur in northern states |
|
|
Term
| What age group of cows have the highest mortality associated with anaplasmosis infection? |
|
Definition
severity and case fatality increase with age
**young animals are often a source of infection, animals that recover are carriers for life |
|
|
Term
| What clinical signs are associated with anaplasmosis in cattle? |
|
Definition
| transient fever followed by severe hemolytic anemia (direct damage to RBC, and secondary IMHA --> extravascular hemolysis (so NO hemoglobinemia/uria) |
|
|
Term
| What preventative measures can be used to control anaplasmosis in endemic regions? |
|
Definition
| vaccination, ectoparasite control, continuous feeding of tatracycline during seasons when vectors are active |
|
|
Term
| What species is affected by Mycoplasma hemollama? |
|
Definition
camelids
**rarely causes disease except in immunosuppressed or debilitated animals
dx- PCR; tx- tetracycline |
|
|
Term
| What is the pathogenesis of moldy sweet clover poisoning? |
|
Definition
mold converts plant coumarins to dicoumarol --> competes with vitamin k --> inhibition of hepatic synthesis of clotting factors (2, 7, 9, 10) --> secondary coagulopathy (SQ hematoma, bleed into body cavities + epistaxis/melena)
** dicoumarol can cross the placenta -> fetal hemorrhage and abortion |
|
|
Term
| what clin path findings are consistent with moldy sweet clover poisoning? |
|
Definition
increased PT, APTT, ACT
anemia on CBC with normal platelets
**you can test blood and feed for dicoumarol |
|
|
Term
| What fomulation of vitamin K should NEVER be used in horses? |
|
Definition
| Vit K3 (causes acute renal failure in horses and is much less effective in reestablishing levels of clotting factors than vit K1) |
|
|
Term
| What is the most common inherited coagulation disorder in horses? |
|
Definition
Hemophilia A (factor 8 deficiency --> intrinsic pathway is compromised --> prolonged APTT)
**sex linked recessive, avoid breeding carrier dams |
|
|
Term
| Profuse hemmorhage secondary to thrombocytopenia is rare and occurs when platelets are reduced to what levels? |
|
Definition
<10,000
more common to see petechiae with IMTP |
|
|
Term
| What clin path findings are consistent with immune mediated thrombocytopenia? |
|
Definition
platelets < 100,000/uL
anemia and hypoprotinemia on CBC
normal PT/APTT/fibrinogen (no effect on coagulation cascade)
bone marrow biopsy indicative of regeneration (erythroid and megakaryocytic hyperplasia) |
|
|
Term
| What is the treatment of choice for immune mediated thrombocytopenia? |
|
Definition
| immunosuppresive doses of dexamethasone (can also use prednisolon and azothioprine) |
|
|
Term
| What infectious agent is the main cause of IMTP in cattle and what severity of thrombocytopenia is associated with this disease? |
|
Definition
| type II BVD, thrombocytopenia may be severe enough to cause spontaneous hemmorhage ( <10,000/uL) |
|
|
Term
| T/F DIC is NEVER a primary disease entity |
|
Definition
TRUE
***in large animals DIC most commonly affects horses with severe underlying disease (ex. sepsis) and tends towards thrombosis rather than hemmorhage |
|
|
Term
| What is the major principle in management of DIC? |
|
Definition
Manage the underlying disease process
AND IV fluids +/- blood products, NSAIDs, heparin (inhibit microvascular thrombosis) |
|
|
Term
| T/F it is important to isolate animals that develop purpura hemorrhagica |
|
Definition
TRUE
purpura hemorrhagic is a sequela to strep. (strangles) or influenza infection |
|
|
Term
| What is the pathogenesis of purpura hemorrhagica? |
|
Definition
type III (immune complex) hypersensitivity rxn --> immune complexes are deposited in blood vessel walls --> mild anemia, edema, petechiation/ecchymoses
***tx w/immunosuppresive doses of steroids and penecillin |
|
|
Term
| What is the pathogenesis of bracken fern toxicosis in cattle and sheep? |
|
Definition
ingestion of large amounts (young plants, roots/stems most toxic) --> thiaminases present in the plant result in thiamine deficiency -> neurologic abnormalities
short term high level exposure -> severe aplastic anemia
long term low level exposure -> hemorrhagic cystitis and transitional cell carcinoma (development of neoplasia associated with concurrent BPV-2 infection) |
|
|
Term
| What clin path findings are associated with acute high level exposure of ruminants to bracken fern? |
|
Definition
pancytopenia on CBC
aplastic anemia (generalized hypoplasia) on bone marrow biopsy |
|
|
Term
| What form of polycythemia is common? |
|
Definition
| relative polycythemia secondary to dehydration (PCV and TP increased) |
|
|
Term
| How can absolute polycythemia be distinguished from relative polycythemia? |
|
Definition
in cases of relative polycythemia (ie. dehydration) both TP and PCV are increased
in cases of absolute polycythemia (ex. neoplasia, high altitudes/chronic pulmonary dz) PCV is increased but TP is normal |
|
|
Term
| What is the epidemiology associated with sporatic lymphosarcoma in cattle? |
|
Definition
| occurs sporatically (ie. individual isolated cases) in young cattle |
|
|
Term
| What is the most common clinical sign associated with sporatic lymphosarcoma in cattle? |
|
Definition
| generalized lymphadenopathy in cattle <1 year of age |
|
|
Term
| What clinical signs are associated with thymic lymphosarcoma? |
|
Definition
young cattle (6-24 months)
large space occupying mass at base of neck -> esophageal compression (dysphagia, weight loss, bloat); tracheal compression (dyspnea/cough); and vascular compression (cardiovascular insufficiency) |
|
|
Term
| What clinical signs are associated with cutaneous lymphosarcoma in cattle? |
|
Definition
young cattle (1-3 yrs)
multiple raised, circular, ulcerated skin massess --> dermal lesions occasionally regress but tumor invariably spreads to other organ systems |
|
|
Term
| What is the etiologic agent of enzootic lymphosarcoma in cattle? |
|
Definition
| Bovine Leukemia Virus (BLV) is an oncogenic retrovirus --> persistent viremia and active sheddding of virus for the life of the animal |
|
|
Term
| T/F animals infected with BLV invariably develop lymphosarcoma |
|
Definition
FALSE
<5% of BLV infected animals develop lymphosarcoma |
|
|
Term
| T/F adult cattle that develop lymphosarcoma are almost always infected with BLV |
|
Definition
TRUE
only 1-3% of adult onset lymphosarcoma occurs without concurrent BLV infection (ie. sporatic form), the vast majority of cases are asymptomatic with no effect on milk production |
|
|
Term
| What is the most effective way BLV can be transmitted between animals? |
|
Definition
| horizontal transmission via blood sucking insects, direct contact with bodily secretions (ie. urine, vaginal), and iatrogenic (contaminated instruments) is most effective; however, vertical transmission is possible (transplacental (10% of calves born to infected cows) and mammary secretions) |
|
|
Term
| lesions associated with enzootic (BLV associated) lymphosarcoma in cattle occur most commonly at which two anatomic sites? |
|
Definition
peripheral lymph nodes
Right atrium (signs of right sided heart failure- jugular distention, hepatomegally, edema/ascites) |
|
|
Term
| What are the most common clinical signs associated with enzootic (BLV) lymphosarcoma in cattle? |
|
Definition
| decreased milk production, weight loss, external lymphadenopathy |
|
|
Term
| What is the most accurate method of diagnosing enzootic (BLV) lymphosarcoma in cattle? |
|
Definition
| histopathology of LN or tumor biopsy |
|
|
Term
| What test is used to identify animals infected with BLV? |
|
Definition
Agar gel immunodiffusion test (AGID)
***remember, while a positive test confirms BLV infection it does NOT constitute a diagnosis of enzootic lymphosarcoma (<5% of BLV infected animals develop lymphosarcoma) |
|
|
Term
| What are the strategies used to control BLV in cattle? |
|
Definition
| No vaccine or tx once infected, can cull or segregate seropositive animals |
|
|
Term
| What is the most common type of neoplasia in the horse? |
|
Definition
| lymphoma (T, B, and mixed cell populations have been reported) |
|
|
Term
| What are the two most common forms of lymphosarcoma in horses? |
|
Definition
Cutaneous: most common form, dermal lesions may regress temporarily with seasons, pregnancy, and corticosteroids
Alimentary: <5 yrs, weightloss despite good appetite
**also possible to have thymic and multicentric presentations, however, much less common than cutaneous and alimentary |
|
|
Term
| How do you diagnose lymphoma in a horse? |
|
Definition
CBC is often normal
Bone marrow aspirate, cytology of cavitary effusions, or histopath of tumor biopsy can be used however non-diagnostic samples are often obtained
paraneoplastic hypercalcemia has been identified |
|
|
Term
| What type of IMHA is most common in dogs? In cats? |
|
Definition
Primary (idiopathic) IMHA is more common in dogs
Secondary IMHA is more common in cats |
|
|
Term
| What three tests are used to demonstrate immune mediated destruction of erythrocytes? |
|
Definition
| autoagglutionation, direct coombs, spherocytosis (not in cats) |
|
|
Term
| T/F in patients with IMHA, strength of reaction of direct coombs correlates with severity of disease |
|
Definition
|
|
Term
| Why does IMHA significantly increase the risk of patients developing thromboembolic disease? |
|
Definition
| IV catheters cause endothelial damage; cage confinement and recumbency result in blood stasis; erythrocyte membrane exposure, defective fibrinolysis, and increased prothrombotic factors secondary to immunosuppressive therapy all contribute to hypercoagulable state |
|
|
Term
| Which drugs can induce IMHA in small animals? |
|
Definition
| cephalosporins, penicillin, sulfonamide antibiotics and methimazol |
|
|
Term
| What is the treatment of choice for primary (idiopathic) IMHA? |
|
Definition
| immunosuppressive doses of prednisone +/- azathioprine (to reduce necessary dose of pred and therefore adverse side effects, do NOT use in cats --> destroys bone marrow) Low molecular weight heparin with antifactor Xa assay monitoring is also an important treatment used to minimize hypercoagulable state |
|
|
Term
| What are the indications for blood component therapy in IMHA patients? What complications do these patients present? |
|
Definition
| patients with adverse signs associated with anemia (PCV <12-16) may benefit from blood products; however, given the presence of autoagluttination or hemolysis interpretation of cross match reactivity is complicated. DEA 1 negative RBC are generally an acceptable option for dogs with IMHA |
|
|
Term
| What is the mechanism of action of glucocorticoids in relation to the treatment of IMHA? |
|
Definition
| glucocorticoids at immunosuppressive doses decrease Fc receptor function and expression, reduce antibody production, and decrease circulating levels of lymphocytes |
|
|
Term
| Why and how does heparin work to improve the treatment of IMHA? |
|
Definition
| thromboembolic disease is a significant complication in patients with IMHA. Heparin binds to antithrombin to enhance the function of this molecule, heparin also blocks the common coagulation pathway at factor 10 and thrombin |
|
|
Term
| What is the most common cause of thrombocytopenia in dogs? In cats? |
|
Definition
Immune mediated thrombocytopenia is the most common cause of thrombocytopenia in dogs.
Bone marrow disorders are the most common cause of thrombocytopenia in cats |
|
|
Term
| What is the most common type of immune mediated polyarthropathy? |
|
Definition
| Idiopathic (type 1) 65% of cases |
|
|
Term
| T/F physical exam findings are not sufficient to distinguish types of immune mediated polyarthropathies (ex. idiopathic, infection associated, hepatic/GI associated, distant neoplasia) |
|
Definition
TRUE
regardless of type most present with lameness and gait abnormalities affecting multiple limbs, joint swelling, and fever |
|
|
Term
| Which joints are most commonly affected by immune mediated polyarthropathies? |
|
Definition
| stifle, and distal limb joints |
|
|
Term
| What CBC findings are consistent with primary (idiopathic) immune mediated polyarthropathies? |
|
Definition
may be normal or may have non-specific leukocytosis and/or mild anemia
look at blood smear!!! for parasitic inclusions |
|
|
Term
| Which joints are easiest to tap when performing arthrocentesis? |
|
Definition
| carpus and stifle <-- however the tarsal and hock joints yield a higher diagnostic sample (always include one sample from the hock) |
|
|
Term
| Which joints yield the highest diagnostic samples following joint tap? |
|
Definition
| trasus and the hock <-- always include at least one sample from the hock |
|
|
Term
| Why is analysis of synovial fluid crucial in the work up of a patient with suspected joint disease? |
|
Definition
| critical to differentiate between inflammatory and non-inflammatory conditions |
|
|
Term
| What cell counts and types are present in the synovial fluid of dogs with non-septic inflammatory joint disease? |
|
Definition
nucleated cells increased (normal is <3,000/uL)
predominant nucleated cell type are non-degenerate neutrophils avg. of 80% (normal < 12%)
**these results do not determine the cause of inflammation |
|
|
Term
| What is the treatment for primary (idiopathic) immune mediated polyarthritis? |
|
Definition
Immunosuppresive doses of prednisone, cytologic confirmation of normal synovial fluid (repeat joint taps every 2-3 weeks to guide therapy)
<--- if inadequate response to pred can add azathioprine, cyclosporine etc. |
|
|
Term
| What is the prognosis for primary immune mediated polyarthritis? |
|
Definition
GOOD!! >55% recover completely
20% managed with long term meds
15% refractory to initial treatment
10% recurrence |
|
|
Term
| What is the treatment for secondary immune mediated polyarthritis? |
|
Definition
| doxycycline if rickettsial origin, drug/vaccine induced resolve shortly after detection; NSAIDs can be used to relieve pain during resolution |
|
|
Term
| Which joints are most commonly affected by erosive/rheumatoid arthritis in small animals? |
|
Definition
| carpal, tarsal, and interphalangeal joints |
|
|
Term
| What is the difference in synovial fluid cytology of patients with erosive/rheumatoid arthritis vs. patients with immune mediated polyarthritis? |
|
Definition
| in errosive(RA) predominant cells are DEGENERATE neutrophils similar to IMPA also have increased volume, discoloration, decreased viscosity, and elevated nucleated cell counts |
|
|
Term
| How does the clinical presentation of erosive/rheumatoid arthritis differ from that of IMPA? |
|
Definition
| often patients have a history of episodic occurence with increasing frequency and duration with each relapse |
|
|
Term
| T/F positive RF serology is not specific to patients with erosive/rheumatoid arthritis |
|
Definition
TRUE
positive titers have been identified in dogs with chronic infections as well as 5% of normal dogs |
|
|
Term
| how are radiographic findings associated with erosive/RA different from those associated with IMPA? |
|
Definition
IMPA --> joint effusions
RA --> bony erosions, loss of trabecular bone density at epiphyses **caveat- these changes are not present early in the course of RA, at this point in the disease rads may be impossible to distinguish from IMPA |
|
|
Term
| What is the prognosis for erosive/RA? |
|
Definition
POOR
lesions are progressive and lead to secondary degenerative joint disease, most animals eventually become refractory to pain management and anti-inflammatory doses of steroids --> euthanized due to chronic pain |
|
|
Term
| How many blood types do dogs have? |
|
Definition
|
|
Term
| What canine blood type is the universal donor? |
|
Definition
DEA 4
(and negative for all other DEAs <- dog erythrocyte antigens) |
|
|
Term
| T/F there is no universal blood donor in cats |
|
Definition
|
|
Term
| severe/fatal transfusion reactions in cats are due to which type of antibodies? |
|
Definition
| high levels of anti-A antibodies present in cats with type B blood (however most cats in the US are type A, so this minimizes the risk a little) <-- crossmatch is mandatory in cats!!! |
|
|
Term
| Which bovine blood groups have the greatest clinical significance? |
|
Definition
groups B and J
**presence of alloantibodies are rare in cattle |
|
|
Term
| What are two clinical syndromes where blood/plasma transfusions will not be adequate therapy? |
|
Definition
hypoalbuminemia (would require tremendous volumes, can be used in conjunction with colloids)
thrombocytopenia (small number and short half life of transfused platelets) |
|
|
Term
| which dog erythroid antigens (DEAs) should canine blood donors be negative for? |
|
Definition
should be negative for DEA 1.1, 1.2 and 7
***remember DEA 4 is the universal donor |
|
|
Term
| In what species is cross matching before blood transfusion mandatory? |
|
Definition
FELINE
**severe to fatal reaction to anti-A antibodies |
|
|
Term
| What is the procedure and purpose associated with the MAJOR crossmatch? |
|
Definition
recipients serum (contains antibodies)
mixed with donor's RBC (antigen)
checks to see if the recipient has antibodies against donor RBCs |
|
|
Term
| what is the procedure and purpose associated with the MINOR crossmatch? |
|
Definition
donor serum mixed with recipient's RBC
check to see if the donor has antibodies against the recipient's RBC (if this is positive but the major crossmatch is negative then can wash RBC and give as packed RBC rather than whole blood) |
|
|
Term
| What are some indications for plasma transfusion? |
|
Definition
| invasive procedure (surgery, biopsy) planned on a coagulopathic patient; subclinical DIC; +/- pancreatitis |
|
|
Term
| T/F the goal of a transfusion is to restore PCV to normal ranges |
|
Definition
FALSE
**goal is to ameliorate clinical signs associated with anemia (PCV ~20-25%), care must be taken not to volume overload the patient |
|
|
Term
How can you estimate the volume of blood needed by a patient without using the
[blood vol recipient x (PCV desired - PCV patient)]/ PCV donor |
|
Definition
| 1ml of fresh whole blood per pound raises the PCV by 1% |
|
|
Term
| What are two indications for autotransfusion? What are two contraindications? |
|
Definition
indications: preop donation, salvage in cases of cavitary bleeding (ex. rodenticide toxicity)
contraindications: bacterial contamination +/- neoplasia |
|
|
Term
| In what species is crossmatch NOT necessary? |
|
Definition
| Ferrets (no discernable blood types) |
|
|
Term
| What historical or clinical observations suggest the presence of an immunodeficiency disorder? |
|
Definition
| infections in the first weeks of life, recurrent infections with poor response to tx, suceptibility to organisms that are not normally pathogenic, illness following modified-live vaccines, lack of serological response to vaccines, persistant lymphopenia or leukocytosis |
|
|
Term
| T/F B and T lymphocytes cannot be distinguished from one another on CBC |
|
Definition
TRUE
phenotyping studies are necessary to measure the number of B and T lymphocytes in peripheral blood |
|
|
Term
| How are numbers and distribution of B and T lymphocytes evaluated in the lymphoid organs (LN, spleen, thymus)? |
|
Definition
| phenotyping studies can also be performed on lymphoid tissue biopsies to quantify amount and distribution of B and T lymphocytes |
|
|
Term
| What in vitro tests can be used to evaluate the function of B and T lymphocytes |
|
Definition
B and T lymphocyte proliferation tests
additionally radial immunodiffusion test can be used to quantify serum immunoglobulin levels in vitro (assess B cell function/humoral immunity) |
|
|
Term
| What in vivo test can be used to quantify either humoral or cell mediated immunity respectively? |
|
Definition
humoral immunity can be quantified in vivo via evaluation of serological responses to vaccines (ie. titers)
cell mediated immunity can be quantified in vivo using intradermal PHA injection (PHA is a T cell mitogen that should stimulate an inflammatory response given normal T cell function) |
|
|
Term
| compare and contrast the use of radial immunodiffusion and ELISA based tests in the diagnosis on monitoring of foals with suspected failure of passive transfer. |
|
Definition
radial immunodiffusion is the most accurate assay for measuring IgG, IgM and IgA, but it is expensive and time consuming
ELISA tests measure IgG, they are rapid, but only semi-quantitative (ie. compare color change, don't get a value)- however; these are more practical for routine use that radial immunodiffusion |
|
|
Term
| which branch(es) of the immune system are affected by failure of passive transfer? What is the pathogenesis? |
|
Definition
humoral immunodeficiency
dam factors: poor quality colostrum, leakage of colostrum prior to partuition, rejection of the foal, death following partuition
foal factors: unable to nurse (congenital abnormalities, weakness, traumatic injury), decreased absorptive capacity of the gut (>6hours of age) |
|
|
Term
| which branch(es) of the immune system are affected by equine combined immunodeficiency? What is the pathogenesis? |
|
Definition
complete deficiency in both cell mediated and humoral immunity
inherited autosomal recessive in Arabians --> mutation (DNA protein kinase) inhibits differentiation of lymphoid stem cells |
|
|
Term
| which branch(es) of the immune system are affected by equine selective IgM deficiency? What is the pathogenesis? |
|
Definition
humoral immunodeficiency
Pathogenesis is unknown, in young foals most likely genetic basis, in older animals most likely secondary to lymphoma/other disease |
|
|
Term
| which branch(es) of the immune system are affected by equine transient hypogammaglobulinemia? What is the pathogenesis? |
|
Definition
humoral immunodeficiency (delayed onset of immunoglobulin synthesis)
pathogenesis is unknown |
|
|
Term
| which branch(es) of the immune system are affected by equine agammaglobulinemia? What is the pathogenesis? |
|
Definition
humoral immunodeficiency (absence of B cells and therefore absence of immunoglobulins)
Pathogenesis is unknown but most likely inherited x-linked recessive as ONLY occurs in male foals |
|
|
Term
| which branch(es) of the immune system are affected by equine common variable immunodeficiency? What is the pathogenesis? |
|
Definition
humoral immunodeficiency (progressive B lymphocyte depletion in adult horses)
pathogenesis is unknown |
|
|
Term
| which branch(es) of the immune system are affected by bovine leukocyte adhesion deficiency? What is the pathogenesis? |
|
Definition
innate immunity
inherited autosomal recessive -> mutation in gene endoding CD18 (cell surface adhesion molecule) --> homozygous animals have marked neutrophilia because neutrophils cannot extravasate out of the vasculature |
|
|
Term
| Are most of the antibodies in colostrum manufactured in the udder or concentrated from the damʼs blood? |
|
Definition
| Most of the antibodies in colostrum are concentrated from the dam's blood, only IgA is manufactured in the udder (and therefore present in milk) |
|
|
Term
| What is the dominant type or class of immunoglobulin present in equine and bovine colostrum? |
|
Definition
|
|
Term
In normal healthy full-term neonatal foals and calves, during what approximate time frame is intestinal absorption of colostral antibodies most efficient? During what time frame does absorption decline significantly? At approximately what time is gut closure
complete? |
|
Definition
| gut absorption of colostral antibodies is most efficient during the first 6 hours of life. Absorptive capacity declines significantly after the first 6 hours of life, and complete gut closure occurs by 24 hours of life. |
|
|
Term
| Diagnosis of failure of passive transfer in foals is based on measurement of blood IgG concentrations. What is the specific concentration generally considered to reflect an adequate degree of passive transfer, and below which some degree of failure of passive transfer is said to exist? |
|
Definition
IgG > 800mg/dL indicates adequate passive transfer
IgG < 400 mg/dL indicates complete failure of passive transfer
in between 800 and 400 mg/dL partial failure of passive transfer is evident, specific treatment may or may not be indicated |
|
|
Term
| Colostrum from different dams is highly variable in Ig content, and therefore quality. Describe 2 different ways to assess colostrum quality. |
|
Definition
| assess specific gravity (colostrometer or sugar refractometer), measure amount of IgG using colostrum specific ELISA test |
|
|
Term
You examine a neonatal foal whose dam has not produced any milk or colostrum, so you diagnose complete failure of passive transfer. The foal is otherwise clinically healthy.
What approach to achieving adequate IgG levels would you recommend if the foal is:
a. 4 hours old
b. 36 hours old |
|
Definition
a. NG administration of good quality colostrum if available (not usually), or 2-3 bottles of seramune (commercial IgG supplement)
b. Plasma transfusion (1-2 L) <-- administer very slowly and pretreat with NSAIDs to reduce risk of adverse reaction |
|
|
Term
| Which of the test can be used for direct or indirect evaluation of passive transfer in calves? |
|
Definition
Radial immunodiffusion (generally cost prohibitive)
ELISA tests
total plasma protein (> 5.5 g/dL suggests adequate transfer, assess hydration status (dehydration will elevate TPP) <-- NOT reliable in FOALS, because of individual variability
serum GGT (very high levels of GGT in cow colostrum) <-- NOT reliable in FOALS, which have high endogenous levels of GGT in their blood |
|
|
Term
| Neonatal calves should receive 100 g of IgG as soon as possible after birth. What is the minimum volume of quality colostrum that dairy calves should receive within the first 6 - 12 hours of life in order to ensure this? |
|
Definition
beef calves (2-3 Liters)
dairy calves (4 Liters) <-- dairy cows produce much higher volumes of milk and colostrum which results in dilution of immunoglobulins |
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