Anemia Flashcards
What are the 3 mechanisms of anemia?
Increased loss (hemorrhage)
Increased destruction (hemolysis)
Decreased production by marrow
Anemia is a reduction of red blood cell mass, resulting in _______ ______ of tissues.
decreased oxygenation
Since HCT can have calculation errors, what are more accurate ways to measure the red cell mass?
PCV HG concentration
A dog presents to your clinic for lethargy and exercise intolerance. On exam, you find that the dog is dyspneic, has pale mm, and an increased heart rate. There is no history of a heart murmur in the past, although you auscultated one today. What is likely the cause of the new murmur?
Anemia with PVC <20% (due to increased turbulence)
Non specific signs of anemia, such as weight loss, fever, lymphadenopathy, and PU/PD, can also be seen with kidney disease. How could you differentiate the two?
Kidney disease will show an increased BUN and creatinine, and very low urine SG (inability to concentrate urine)
A 2 year old dog is brought in for extreme lethargy and urinating blood. RR-68, T-103.4, P-220. The dog is icteric, and you are able to palpate the spleen, which is enlarged. PCV = 28 (35-45), TP = 7.5 (6.5-8). What is the likely mechanism of anemia in this dog?
Blood destruction
Signs will include splenomegaly, icterus, and hemoglobinuria. PCV will be low, indicating anemia, but the total protein will be within normal range.
In patients with a rapid onset anemia, clinical signs are (less/more) severe than with slow onset anemia.
more severe
What are the main aspects of the CBC needed for diagnosing anemia?
PCV (red blood cell mass)
MCV Reticulocyte count
Total protein
T/F: Total protein will be low in patients with acute and chronic anemia.
FALSE. Chronic anemias may show normal protein levels
Bixby is a 6 year old MN Golden Retriever with a PCV of 26. The owner has just informed you that over the past couple months, Bixby has had periodic episodes of weakness. What does this put on your differential?
Can indicate internal blood loss (hemangiosarcoma), or an insulinoma.
In acute anemia cases, erythrocyte morphology is usually normal. What is the exception to this and what changes would you expect to see?
Hemangiosarcoma
You would see acanthocytes, schistocytes, nRBCs and mesothelial cells.
What are some examples of acute blood loss?
Trauma/Surgery
Coagulation disorders (inherited or acquired)
Bleeding tumors
Thrombocytopenia (if PLT conc less than 10k)
T/F: Blood loss will cause thrombocytopenia.
FALSE - unusual to find PLT conc less than 100k from blood loss.
What is the most common route of blood loss in chronic anemia?
Via the intestine
What are some examples of chronic blood loss?
GI ulcer
Bleeding GI tumor
Blood consuming parasites
Inadequate intake in babies and chronic blood loss in adults can lead to __________ anemia.
Fe++ deficiency anemia
A lethargic 4 year old goat with pale mm has a PCV of 18% and a MCHC within normal range. The MCV histogram shows a left shift and the blood film shows keratocytes and increased central pallor of RBCs, with marked thrombocytosis. What could be the cause of anemia in this goat?
Fe++ deficient pastures or intestinal parasites (Iron deficiency anemia)
You suspect iron deficiency anemia in a cat. What changes would you expect to see in serum iron concentration, transferrin saturation, and ferritin or hemosiderin (storage iron) concentrations?
Serum iron: decreased
Transferrin: decreased
Ferritin/hemosiderin: decreased
In Fe++ deficiency anemia, what value will be normal in dogs and cats, but increased in other species?
Total iron binding capacity
Treating iron deficiency anemia in adults involves finding the source of blood loss. In neonates, iron is supplemented. What is the acceptable route of supplement administration?
Iron injections (oral supplements will not work!)
MCV histogram on an anemic shih-tzu with a portosystemic shunt shows a left shift. Is it safe to assume the anemia is from iron deficiency?
NO! Both portosystemic shunts and Chinese dog breeds are risk factors for microcytosis on their own.
T/F: Like in humans, anemia of inflammatory disease in dogs causes microcytosis.
FALSE
Anemia of inflammatory disease in dogs is usually normocytic and will have increased storage iron (ferritin/hemosiderin).
You prepare this blood sample on a dog with a PCV of 25%. What kind of anemia are you suspecting?
Iron deficiency
(thrombocytosis, keratocytes, increased central pallor, large platelets)
A 10 year old Labrador with periodic weakness and recent anemia has markedly increased reticulocytes and decreased HG. You suspect iron deficiency anemia. The blood film shows acanthocytes and schistocytes. You request a liver aspirate and discover these double-nucleated connective tissue cells with large nucleoli. What is the probable cause of anemia in this dog?
Hemangiosarcoma
A 1 year old dog presents to your clinic with microcytic anemia, vomiting, and abdominal pain. Past medications include steroids and antibiotics. What is a potential cause for iron deficiency anemia in this dog?
Gastric perforation secondary to ulcer (steroid treatment?)
IMHA, Heinz body anemia, RBC parasites, zinc toxicosis, inherited RBC enzyme deficiencies, and hypophosphatemia all cause:
blood destruction
IMHA is often secondary to:
infection
mod live virus vaccination
neoplasia (lymphoma)
drugs
Penicillin, cephalosporins, trimethoprim-sulfa, and levamisole are drugs implicated in causing _____.
IMHA
Factors linked to the onset of IMHA in equids:
Penicillin
Clostridial infections
Neoplasia
What can cause IMHA in cats?
Mycoplasma haemofelis
FeLV
neoplasia
What dogs are at a higher risk for developing IMHA?
Cocker Spaniels!
Poodles, Collies, Border Collies
Females
Middle aged - Old
A bone marrow aspirate on an dog with pale mm and enlarged spleen shows macrophages phagocytosing many RBCs. What is causing anemia in this dog?
IMHA
*extravascular hemolysis
You prepare a blood film on an icteric dog and see that the background of the slide looks more pink than usual, and that most of the RBCs are ghost cells. What kind of hemolysis is taking place?
Intravascular
*pink background is free HG and ghost cells are a result of HG loss
An icteric 7 year old female Cocker Spaniel in your care is urinating blood and has an enlarged spleen. The dog recently received a modified live vaccination, and you suspect IMHA, but the blood film isn’t showing spherocytes or agglutination. What test can you use to confirm IMHA in this case?
Coomb’s test.
*Contains Ab specifically against IgG to allow agglutination when there otherwise wouldn’t be any.
Disadvantages of the Coombs test:
Many false positives (cats especially)
Many false negatives
In cases of IMHA involving thrombocytopenia, a negative DIC test will suggest what other diease?
Evan’s Syndrome
Chemistry on a dog with suspected IMHA shows increased creatinine and BUN. What type of leukogram do you expect to see to confirm your diagnosis?
Inflammatory
Although spherocytosis can implicate IMHA, what other causes should be on you diffferential?
Previous mismatched blood transfusion
Rattlesnake evenomation
Heinz body anemia in horses
Zinc toxicosis
Bee stings
What is the most common cause of death with IMHA?
Thromboembolism
Why are glucocorticosteroids the preferred treatment option for IMHA?
They decrease Ab production, T-cell activity, and macrophage function without supressing erythropoiesis.
A Border Collie is hospitalized for IMHA with a PCV of 26. Which of the following should be included in the treatment plan?
A. IV fluids
B. Correction of acidosis
C. Glucocorticosteroids
D. Blood transfusion
E. Splenectomy
A, B, and C are correct.
A blood transfusion is only indicated when anemia is life threatening. This dog had a PCV of 26.
Splenectomy would not be indicated
A 5 year old Cocker Spaniel comes in on emergency for extreme lethargy. The dog is icteric and has a PCV of 12%. MCV is high at 114 (60-72) and Hgb is low at 3.6 (12-18). TP is within normal range. What treatments should you start on this dog?
BLOOD TRANSFUSION!
Fluids
Glucocorticosteroids
Treat acidosis
(IMHA with life threatening anemia)
What is a potential cause for a low arterial P02 in a dog with IMHA?
Pulmonary thromboembolism
In what species does a clostridial infection cause spherocytes and type 3 echinocytes, due to phospholipase hydrolyzing RBC membrane phospholipids and producing lysolecithin?
Horses
Why is Heinz body anemia a differential for IMHA in horses?
Heinz body formation results in band 3 clustering, with secondary Ab attachment (spherocyte formation)
What compound in bee venom promotes band 3 clustering and induces antibody attachment, resulting in spherocyte formation?
Mellitin
What protein increases the capacity of blood to carry O2 by exchanging HCO3- for Cl-?
Band 3
Band 3 is important in maintaining cell shape, and if absent, spherocytosis and hemolytic anemia result. This is seen in what animals?
Japanese black cattle and knockout mice
You are called out to look at a foal who became ill after nursing. You arrive to find the foal weak and anemic, with bloody urine. The farmer states that the mare had produced a healthy foal just last season. What’s the most likely diagnosis?
Neonatal isoerythrolysis
Most erythrocyte parasites cause immune mediated anemia with phagocytosis by macrophages (extravascular). How do Babesia and Theileria cause anemia?
Intravascular hemolysis
A MN 3 year old domestic shorthair cat presents with fever and lethargy. A blood film indicates severe anemia and shows erythrocytes with darkly stained spots at the periphery (as pictured). PCR is used to confirm your suspicion. What is the recommended treatment?
Blood transfusion
Prednisolone
Doxycycline x 3wks
The blood smear and symptoms indicate infection with Mycoplasma haemofelis. Enrofloxacin can be substituted if doxycycline is not well tolerated. Prednisone is used to suppress RBC destruction.
CBC and blood film on a cat with M. haemofelis indicate a non regenerative anemia. In this case, what concurrent diseases would you test for?
FeLV or severe inflammatory diseases
A dog arrives at your clinic for weakness and lethargy. The owner states that the dog has been healthy since his splenectomy last year, other than this recent episode. You see dark, chain-like areas in the erythrocytes. What is the most likely diagnosis?
Mycoplasma haemocanis
A farmer calls you out to check on his cattle, who have recently been acting ill. The cattle in barn A seem to have edema and swollen lymph nodes, while the cattle in barns B and C appear unaffected. The farmer states that the cows were just vaccinated a few weeks ago, and when you ask about vaccination practices, you discover that all vaccines for one barn are given with the same needle and syringe to save money. You perform a blood film and find numerous parasites free in the plasma, with a few attached to the RBCs. What is the most likely diagnosis and mode of transmission?
Mycolpasma wenyonii
Most likely transmitted iatrogenically via vaccination needles.
What is this RBC parasite of sheep?
Mycoplasma ovis
This RBC parasite is opportunistic and causes mild anemia in camelids.
Mycoplasma haemolamae
RBC parasite that causes severe anemia in baby pigs and decreased weight gain in adults. Can be treated with single dose of long acting oxytetracycline.
Mycoplasma haemosuis
Multiple cattle in a local herd have fallen ill, and 2 of the older cows have died. You find that the cattle are infested with ticks and decide to prepare a blood film. How will you treat the cattle and what recommendation will you make to the farmer going forward?
Treat with tetracycline
Recommend vaccinating the herd for Anaplasma marginale and A. centrale
These RBC parasites cause severe disease and hemolytic anemia, and may be mistaken for IMHA. They are transmitted by ticks, blood transfusions, and vertically.
Babesia spp
A dog from the east coast is diagnosed with Babesia gibsoni. What can you treat him with?
imidocarb dipropionate
diminizine aceturate
A few cattle and goats on a farm in Virginia have become lethargic and have blood in their urine. You perform blood smears to find that the animals are anemic and have piroplasms in ther RBCs. The farmer is concerned about East Coast Fever. You perform PCR, which confirms the farmer’s suspicion. What is the pathogen?
Theileria parva
A 4 year old MN cat was brought in for PM after dying in an outdoor cattery in Missouri. A blood film showed piroplasms within the RBCs, and a tissue sample revealed schizonts within macrophages. What advice will you give to the owner of the cattery?
Tick prevention!
This is Cytuxzoonosis. Other cats may be tested and positives can be treated with dispropionate or diminazine aceturate, however, the infection is usually fatal.
A blood film on an anemic cat shows erythrocytes with Heinz bodies. You know that oxidative damage like this can be caused by ingestion of acetaminophen or propylene glycol, but the owner insists there’s no chance the cat ate anything it shouldn’t have. What diseases should you check for as the potential cause?
Lymphoma
Hyperthyroidism
Diabetes mellitus
What plants can cause Heinz body formation?
Allium (onions, garlic)
Brassica (kale, cabbage, rape)
Red maple leaves (Acer rubrum)
Zinc, Cu/Se deficiency, crude oil, methylene blue, and napthalene (moth balls) can all cause what type of anemia?
Heinz body anemia
Why are cats more susceptible to Heinz body anemia?
Sulfhydral groups are susceptible to oxidation and cats have 8 sulfhydral groups.
Why do we see spherocytes with Heinz body anemia?
Hemichromes form complexes with protein band 3, which causes them to cluster and creates a recognition site for auto-Ab.
How does spectrin-hemoglobin cross linking in Heinz body anemia make RBCs more susceptible to lysis or removal by macrophages?
Increases membrane rigidity and decreases deformability.
Nitrate poisoning causes what blood disorder in cows?
Methemoglobinemia
A cat presents to your clinic on emergency after ingesting acetaminophen. Upon placing an IV catheter, you note that the blood is chocolate brown. What treatment should you start?
Methylene blue
This is methemoglobinemia. Iron is in the ferric state, unable to carry oxygen. Blood will appear brown when 30% of hemoglobin is methemoglobin, and the animal will die at 90% methemoglobin. Methylene blue activates methemoglobin reductase.
A farmer calls you to come look at one of his sheep who has been urinating blood. You walk out to where the sheep are and notice a brown mineral block in the pasture. A blood sample shows Heinz bodies and hemoglobinemia on the film . What is the most likely diagnosis?
Copper toxicosis
Accumulates in the liver!! Causes hemoglobinuria, hemoglobinemia, hemolytic anemia, and Heinz body formation/oxidative damage.
Hemolysis due to hypophosphatemia can be found in what situations?
Postparturient hemoglobinuria in cattle
Diabetes mellitus in cats
Enteral alimentation in cats (refeeding syndrome)
What bacterial species produce a lecithinase and cause hemolytic anemia?
Clostridium spp
This bacterium causes hemolytic anemia in lambs and calves. “Yellow Lamb Disease”.
Clostridium perfringens Type A
You are performing a necropsy on a cow who died after an episode with bloody diarrhea and urine, dyspnea, and suspected pain, as she was arching her back. Inspection of the liver reveals severe fluke infection, and you decide to take microbiological samples. What causative agent are you expecting to find on the culture?
Clostridium haemolyticum
Causes “Red Water Disease” and “Bacilliary Hemoglobinuria”
What issues can we anticipate in calves that gain unlimited access to water after its unavailability?
Water intoxication. Hemolysis due to decreased osmolality of plasma.
*more severe in Fe++ deficient calves
Swamp Fever is a hemolytic disease caused by which virus?
Equine Infectious Anemia virus
You are performing a necropsy on a 4 year old Basenji who died after a recent illness. Medical records indicate that the dog had moderate anemia and reticulocytosis. You note myelofibrosis and sclerosis during the necropsy. What is your diagnosis?
Hemolytic anemia due to pyruvate kinase deficiency
You diagnose an Abyssininan cat with hemolytic anemia due to pyruvate kinase deficiency. You know that in dogs, the prognosis is very poor, with death by 4 years old. Should you prepare the owner for the worst?
No. Cats don’t get osteosclerosis and can live into old age.
Mechanism of hemolytic anemia that results in poor energy metabolism (decreased glu utilization and ATP formation) and leads to increased RBC destruction.
Pyruvate Kinase deficiency
What inherited enzyme deficiency in English Springer Spaniels causes hemolytic crisis when alkalemic?
Phosphofructokinase deficiency
*decreased synthesis of 2,3-diphosphoglycerate
You arrive at a farm to check on some anemic calves with pink teeth and photosensitivity rashes. What is the disease mechanism?
Deficiency of uroporphyrinogen III co-synthase, leaving the calves unable to synthesize hemoglobin. Accumulation of uroporphyrin in teeth and bones.
What symptoms of porphyria would you not expect to see in pigs and cats?
Pigs: no photosensitivity
Cats: no anemia
In non-regenerative anemia, cells are usually normal size. What is the exception to this rule?
FeLV induced macrocytosis
What are the 3 ways estrogen causes bone marrow suppression in dogs and ferrets?
Granulosa cell tumors
Sertoli cell tumors
Unspayed ferrets
(Estrogen induced)
What infectious agents can cause aplastic anemia?
FeLV
Ehrlichia canis
EIA (Equine Infectious Anemia: lentivirus)
Trimethoprim-sulfadiazine, cephalosporin, and phenobarbital can cause what bone marrow disorder in dogs?
Immune mediated aplastic anemia
What are 3 ways to get erythroid aplasia?
Immune mediated destruction of RBC precursors
FeLV
(RARE)
Myelodysplasia, leukemia, and immune-med destruction of RBC precursors are _______ mechanisms of erythroid hypoplasia.
intrinsic
Chronic renal disease, endocrine disorders, and inflammatory disease are _______ mechanisms for erythroid hypoplasia.
extrinsic
A dog with non-regenerative anemia has decreased erythropoietin, uremic toxins, high PTH, and hypocalcemia. What is the underlying disease?
Renal disease
A dog with a PCV of 30% has low serum iron, but increased storage iron (ferritin). What is causing non-regenerative anemia in this dog?
Inflammatory disease
(erythroid suppression from unavailability of iron or from inflammatory cytokines)
In anemia of inflammatory disease, LPS and IL6 induce hepatic production of what hormone that binds to ferroportin, inhibiting cellular efflux of iron?
Hepcidin
How does LPS affect iron metabolism in anemia of inflammatory disease?
Inhibition of duodenal iron absorption (down regulates DMT1)
Down regulation of ferroportin (decreased iron release from stores in macrophages and hepatocytes)
Induces production of Hepcidin (binds to ferroportin)
What’s the deal with iron metabolism in anemia of inflammatory disease?
Basically, LPS prevents release of storage iron, and cytokines induce more storage of iron, so all this iron is being put into storage and none is coming out. Decreased iron in transport and functional pools limits iron for erythropoiesis.
In people, AID is microcytic. In animals, most of the time AID is (microcytic/normocytic/macrocytic).
Normocytic
Dogs with hypothyroidism can have high cholesterol and _____ anemia.
Mild (PCV 30%)
What endocrine disorder features mild anemia, often masked by dehydration?
hypoadrenocorticism
How does diabetes in a cat cause hemolytic anemia?
Fats are being used for energy, which produces ketones. Ketone products cause Heinz bodies.
