Livestock Hematologic and lymphoreticular Flashcards
Anemia from blood loss can be
1) Chronic (parasites) - lice, flukes, haemonchus
2) Acute (hemorrhage)
3) Thrombocytopenia
4) Clotting defects
low PCV and total protein, the anemia is likely due to
blood loss
low PCV and normal to increased TP is likely due to
Hemolysis
How do you distinguish extravascular hemolysis from intravascular hemolysis
Both have low PCV and normal to increased TP
Extravascular = no hemoglobinuria (develops jaundice)
Intravascular = hemoglobinemia and hemoglobinuria
What might cause acute blood in cattle
1) abomasal ulcer (dont see active hemorrhage)
2) pulmonary hemorrhage
3) uterine artery rupture (dont see active hemorrhage)
4) mammary vein rupture
Does extravascular or intravascular hemolysis produce jaundice
extravascular
What are the clinical signs of acute blood loss in cattle
1) Blood loss- epistaxis, melena, hematuria, hematochezia
2) Pale to white mucous membranes
3) Increased CRT
4) Tachycardia
5) Weak pulse
6) Hypovolemic shock
7) Death
What might cause chronic blood loss in cattle
Losses over time - days to weeks
1) Parasitism- lice, flukes, haemonchus
2) Gastrointestinal ulceration
3) other sites of chronic hemorrhage- bladder
What should you do if you see cattle with severe blood loss and no change in PCV or TP
need to do something soon (ie blood transfusion)
What are signs of chronic blood loss in cattle
1) Ill thrift
2) poor body condition, rough hair coat
3) Pale mucous membranes
4) Weak, lethargic
5) Edema with concurrent protein loss
In cattle, blood loss due to thrombocytopenia might be secondary due to
1) BVDV- type 2
2) Bracken fern- pancytopenia
In cattle, blood loss due to clotting defects might be due to
1) Liver disease
2) Moldy sweet clover- dicoimarol
3) Ingestion of rat poisons - warfarin
What does the bracken fern cause in cattle
thrombocytopenia and subsequent blood loss
What does the dicoumarol in moldy sweet clover cause in cattle?
clotting defects and subsequent blood loss
What is the mechanism of action of warfarin /dicoumarol
rapid utilization of vitamin k, decreases its ability for clotting
How does DIC cause blood loss
all clotting cofactors used up and then blood loss occurs
What might cause extravascular hemolysis (no hemoglobinuria) in cattle
1) Anaplasmosis
2) Mycoplasmosis (Eperythrozoonosis)
What might cause intravascular hemolysis (hemoglobinuria) in cattle
1) Babesia
2) Copper toxicity
3) Plant toxicity - onion, rape, kale
4) Bacillary hemoglobinuria
5) Leptospirosis
6) Postparturient hemoglobinuria
7) Water toxicity
Babesia in cattle cause what type of hemolysis
Intravascular hemolysis
Copper toxicity in cattle cause what type of hemolysis
Intravascular hemolysis
Anaplasmosis in cattle cause what type of hemolysis
Extravascular hemolysis
Onion, rape, and kale in cattle cause what type of hemolysis
Intravascular hemolysis
Water intoxication in cattle cause what type of hemolysis
Intravascular hemolysis
Mycoplasmosis (Eperythrozoonosis) in cattle cause what type of hemolysis
Extravascular hemolysis
Leptospirosis in cattle cause what type of hemolysis
Intravascular hemolysis
Bacillary hemoglobinuria in cattle cause what type of hemolysis
Intravascular hemolysis
What causes Anaplasmosis in livestock
Rickettsia
1) Cattle (Anaplasma marginale, centrale)
2) Sheep and Goat: (A. ovis)
How is Anaplasmosis transmitted in livestock
1) Tick (West and intermountain area) - Dermacentor
2) Flies (Southeast) - Tabanids
3) Iatrogenic
anyway through blood, we can control spread with these things
The acute and severe infections of anaplasmosis in cattle are due to
Adults (3+ years) without previous exposure to it
Mild infections of anaplasmosis are typically seen in
Calves
-become persistently infected after the initial infection and severe as reservoirs of infections
What serves as a reservoir for Anaplasmosis
Cows that became persistently infected when they were calves
How do you distinguish cows that are persistently infected with Anaplasmosis
Serology (smear not as effective bc they have accommodated it)
How can you detect cattle with acute anemia, and you suspect Anaplasmosis infection
blood smear
The incubation of anaplasmosis in cattle is typically
3 to 8 weeks
What are the clinical signs of anaplasmosis in cattle
Fever
Lethargy/Weakness
Jaundice/Icterus
Anemia
Dyspnea
CNS disease- hypoxemia?
Death
What is the general distribution of Anaplasmosis
“Southeast USA and mountain/California”
How do you treat Anaplasmosis in cattle
Oxytetracycline
Supportive
Carriers
How do you diagnose Anaplasmosis
Blood smears (acute)
PCR
Serology (chronic carriers)
When doing necropsy, what might a cow with Anaplasmosis look like
Hepatomegaly
Icterus
How do you control anaplasmosis in cattle
-Insect control
-Husbandry- avoid iatrogenic transfer
-Vaccine: conditional use
What can you do to control active Anaplasmosis infection
Veterinary feed directive (VFD): labeled for control of active infection- low level oxytetracyclines in feed in endemic areas
-do during tick/fly season??
aims to keep the disease from becoming a significant issue
For endemic areas of anaplasmosis, you should try to introduce what kind of cattle into endemic areas
YOUNG animals
introducing adults is risky
What are the different hemotropic mycoplasma in livestock
M. wenyonii: cattle
ovis: sheep
haemolamae: camelids
suis: pigs
Hemotropic Mycoplasma typically remains latent until
disease/ stressor
most of the time it is subclinical infection
Hemotropic mycoplasma, typically infects what kind of cow
heifer - young adult
Hemotropic mycoplasma causes
Edema
Anemia
Fever
typically subclinical infection and latent until disease/stressor
How can you diagnose Hemotropic mycoplasma in cattle
blood smear
How do you treat Hemotropic mycoplasma in cattle
Oxytetracyclines
What are other names of Babesiosis in cattle
Texas fever
Redwater fever
Cattle tick fever
prioplamsosis
What typically spreads Babesiosis in cattle
Rhipicephalus (formely Boophilus) tick
incubation for 2-3 weeks
T/F: babesiosis is reportable in the United States
True- exotic and reportable
typically in mexico but will occasionally get it in Southern Texas
What causes babesiosis in cattle
Babesia bovis and bigemina
What is the difference between Babesiosis and Anaplasmosis
both are tickborne diseases
but Babesia causes intravascular hemolysis/ hemoglobinuria
What causes bacillary hemoglobinuria
Cl. hemolyticum (Cl. novyi type D)
ubiquitous- in soil
Cl. hemolyticum (Cl. novyi type D) sits in the ______ until an insult occurs and then cause hemoglobinuria (Redwater disease)
Liver
-flukes can cause the insult
T/F: the Clostridium- 8 way vaccine in cattle is pretty effective
True- target toxins produced, animal always has clostridium present inside of them
7 way is done in places without liver flukes
What is the pathogenesis of bacillary hemoglobinuria
1) Spores of Cl. hemolyticum ingested or inhaled (persist in soil for > 1 year)
2) Liver damage occures, anaerobiasis and proliferation
3) Exototoxin causes tissue necrosis and IV hemolysis (fluke migration)
How do you treat bacillary hemoglobinuria
very hard to treat - try penicillin
How do you control bacillary hemoglobinuria
1) Liver flukes- anthelmintic (IvomecPlus (ivermectin + clorsulon)
2) Snail control
3) 8 way clostridial vaccine: give 2x year in endemic ares
4) Incinerate carcasses to destroy spores
What should you give as anthelmintic for liver flukes and bacillary hemoglobinuria control
Ivomec Plus (Ivermectin + Clorsulon)
What causes the intravascular hemolysis seen with postparturient hemoglobinuria
Low phosphorus <3mg/dl seen in high producing multiparous dairy cattle
causes hemoglinuria
What are the causes of postparturient hemoglobinuria in cattle
1) Hemogloburia
2) Muscle weakness
3) Staggering
4) Inappetance
How do you treat postparturient hemoglobinuria in cattle
1) Oral phosphorus supplement
250-300 g NaH2PO4 as drench
2) Fleet enema diluted IV
3) NaH2PO4, 60g/300ml IV
3) Phosphaid Injection (Vedco)
*Control Diet
Intravascular hemolysis in cattle from leptospirosis is from what serovars
pomona, icterohaemorrhagiae
(non-host developed- from pigs or rodents)
(hardjo is just abortion because that is cattle host adapted)
How does water intoxication cause intravascular hemolysis
Osmotic shock to RBCs
1) Massive water intake = marked hypotnoicity of body fluids (often hypoNa, hypoCl, hypoproteinemic from dilution)
Cattle with intravascular hemolysis from water intoxication might have gotten it from
1) trailered cattle in summer- show
2) Calves raised exclusively on milk replacer- exposed to unlimited quantities of water for first time
How do you treat cattle with intravascular hemolysis from water intoxication
Restrict water and provide supportive care
What might cause watter toxicity in livestock
1) Feed rations to the wrong species (cow and horse rations to sheep)
2) Fungicides, Algicides, Footbaths, Injectables
What livestock species is more susceptible to water intoxication
Cows much more susceptible than llamas,sheeps, goats
Chronic copper toxicosiss results in
Liver parenchymal necrosis and oxidative damage to RBCs (intravascular hemolysis)
1) Copper stored in liver
intestine -> proteins -> liver
2) Accumulates in the hepatic lysosomes
3) Sudden Cu release from the liver spontaneously or following stressors
4) Liver damage and oxidative damage to RBCs from Cu
-Anemia, hemoglobinuria, increased enzymes
What species has the highest risk of copper toxicosis
Sheep»_space; goats > cows > horse
Copper levels by tissue
Serum: high in crisis
Liver: low after necrosis
Kidney: high if clinical
*do a feed analysis to evaluate copper
From copper toxicosis, what will the necropsy findings look like
Chronic: liver yellow and friable, gunmetal color
Acute: large swollen liver
easy diagnosis
What are the 2 very common neoplastic processes of cattle
1) Lymphosarcoma
2) Squamous Cell Carcinoma
What causes enzootic lymphosarcoma in cattle
Bovine Leukemia Virus
What are the 3 forms of sporadic lymphosarcoma in cattle
1) Juvenile
2) Thymic
3) Cutaneous
these are rare, non-infectious, not associated with BLV, young cattle
What are the characteristics of juvenile (calf) lymphosarcoma
-Rare
-Occur 2 weeks to 6 months
-Enlarged lymph nodes
-Bone marrow
-Weight loss
Death within 2-8 weeks
occur in utero
occasionally older animals (up to 2 years)
juvenile (calf) lymphosarcoma occurs in cattle of what age
occur in utero
affects 2 weeks - 6 months (up to 2 years)
death in 2-8 weeks
What are the clinical signs of juvenile (calf) lymphosarcoma
-Enlarged lymph nodes
-Bone marrow
-Weight loss
death within 2-8 weeks
Thymic lymphosarcoma in cattle clinical signs
1) Massive thymic infiltration
2) Jugular vein obstriction
3) Respiratory obstruction
4) Esophageal obstruction (bloat)
5) Metastasis
*Fatal
Thymic lymphosarcoma in cattle occur in what ages
3 months to 2 years old
very rare
Cutaneous lymphosarcoma in cattle clinical signs
Cutaneous plaques
1-5cm diameter
scab hairless
regression
relapse
What is the worst form of bovine lymphosarcoma
Cutaneous lymphosarcoma
Cutaneous lymphosarcoma in cattle occurs at what age
<3 years , rare
lymphosarcoma in cattle that is rare, non-infectiou, not associated with BLV
occur in young cattle
Sporadic form of bovine lymphosarcoma
1) Juvenile
2) Thymic
3) Cutaneous
lymphosarcoma in cattle that is common, infectious, and caused by bovine leukemia virus
occurs in adult cattle
Enzootic Bovine Lymphosarcoma
Enzootic Bovine Lymphosarcoma occurs in cattle of what ages
Adult cattle >2 years
Enzootic Bovine Lymphosarcoma is more common in beef or dairy cattle
Dairy > Beef
worldwide, caused by bovine leukemia virus
What is the estimated seroprevalence of Enzootic Bovine Lymphosarcoma
Herds:
Dairy: 89%
Beef: 40%
99% of dairies in the southeast
Individuals:
0-100% within herds
20% U.S diary populations
What is the #1 cause of whole carcass condemnations in mature (non-fed) cattle at slaughter
Lymphosarcoma
a retrovirus that causes lymposarcoma in cattle
Bovine Leukemia Virus (BLV) - has reverse transcriptase and incorporation of viral genome into the host cells
Why is it difficult for the cattle host to eliminate BLV
retrovirus - has reverse transcriptase and incorporation of viral genome into the host cells
can remain in non-reproducing covert state
once infection established, animals are infected and seropositive for life
T/F: once cattle are infected with BLV, they are seropositive for life
True
BLV infects only what cell type
B lymphocytes - natural transmission requires transfer of intact lymphocytes
ex: flies, close proximity, or sharing cells
What is the host range of BLV
Cattle primary natural host
one report of natural transmission in sheep
What are the clinical signs of Enzootic Bovine Leukosis
1) Asymptomatic (most animals)
2) Persistent lymphocytosis ( 30%)
3) Lymphosarcoma <5%
What are the primary organs infected with Enzootic Bovine Leukosis
1) Heart (right atrium): 50-65%
2) Uterus: 30-45%
3) Lymph nodes >90%
4) Abomasum: 60-75%
5) Spinal: 15-25% - neurological issues
6) Retrobulbar - 10% - bulging eyes
HULA is most common
Enzootic Bovine Leukosis affects what part of the heart
right atrium
What are the clinical signs of Enzootic Bovine Leukosis
depends on where the tumor is but common clinical signs are
-weight loss
-decreased milk
-external lymphadenopathy
-decreased appetite
-internal lymphadenopathy
-posterior paresis
-fever
-other: exophthalmos, heart failure, abomasal ulceration, and more
What is the typical incubation period of BLV
approx 4-5 years
disease is usually in cattle 4-8 years old
tumors uncommon but possible in animals <3 years
T/F: the tumors of Enzootic Bovine Leukosis always develop quickly
False- develop at variable rates
-may have tumors for weeks to months without signs
-rapid deterioration in late pregnancy
-stress/progesterone may lead to faster progression
-clinical coarse may range from peracute to chronic
How does BLV transmission occur
infected B lymphocutes
-almost any secretion can contain lymphocytes
virus in blood, colostrum/milk, nasal discharge, semen
physical contact, insect vectors (tabanid), colostrum, milk, in utero, venereal (very rare)
blood is most efficient- 2500 infected lymphocytes / 0.1 uL
How does age influence BLV seroprevalence
Age increases seroprevalence
-longer time to contract virus and seroconvert
BLV transmission is highest in what season?
Summer months- flies and bugs can also transfer the disease
What are ways of natural BLV transmission
Physical contact
Insect vectors (tabanid)
Colostrum
Milk
In Utero (10%)
Venereal (very rare)
How might iatrogenic transmission of BLV occur
-Ear tagging
-dehorning
-tattoo
-supernumerary teat removal
-common injection needles
-rectal palpation (common sleeve)
-Common surgical/obstetrical equipment
How do you diagnose Enzootic Bovine Leukosis
1) Clinical signs- tumors
2) Serology- BLV status via AGID or ELISA
3) CBC- lymphocytosis
4) Cytology/ Histopathology- lymphosarcoma
5) PCR- blood cells, tissues
can evaluate proviral load in seropositive animal to assess level of threat for spreading
Why do we commonly do serology (AGID and ELISA) for BLV diagnosis
because most of the time, they will seroconvert within a couple months
very sensitive and specific
detect antibodies to gp51 or p24
Utilizing PCR for BLV diagnosis is valuable in
evaluating proviral load in seropositive animal to assess the level of threat for spreading
can quantitate the most infectious levels and cull them
dont want to cull all the seropositive animals
Serology (ELISA, AGID, RIA) for BLV detects what
gp51 or p25 antigen
very specific and sensitive
seroconversion 2-4 months post infection
Colostrum is seropositive for BLV for how long
6 months
If an animal is seropositive for BLV before given colostrum then they likely have
likely have had an in utero infection
If an animal is seropositive for BLV then
they have BLV infection (unless young)
Why might an animal be transiently seronegative periparturiently even if infected with BLV
Because of the colostral drain of IgG
How do you control Enzootic Bovine Leukosis
1) manage iatrogenic spread of BLV
2) Manage natural spread of BLV- insects, physical contact, milk
3) Test- incoming cattle, and herd
4) Cull
How do you treat bovine lymphosarcoma
eventually fatal
no treatments are effective except for reducing clinical signs
gram + rod that causes anthrax
Bacillus anthracis
Where is bacillus anthracis commonly found
bacillus and spore form
form spores in contact with air
spores can survive for decades
Tropical climate > Temperate
Soil
primary case- sporadic
secondary case- epizootic
What climate is more common for Anthrax
Tropical > Temperate
common in old US cattle trails
Outbreaks of anthrax occur after
flooding, excavation
-soil disturbance
-alkaline soils
often confined to a particular area
How might zoonotic exposure of anthrax ococur
Exposure to hides, undercooked meat
Contaiminated cuts and abrasions
What is the pathogensis of anthrax
1) Entry
2) Local proliferation in LN
3) Septicemia and spread
4) Toxin causes edema and necrosis
5) Incubation of 1-2 weeks
What are the clinical signs of Anthrax
Peracute: Sudden death (1-2 hours), causes fever, tremor, dysnpea, congestion, terminal convulsions
Acute: depression, lethargy, weakness, anorexia, fever up to 107, tachypnea, tachycardia, congestion and hemorrhages, death (48 hours)
What should you do when you suspect Anthrax in cattle
Avoid opening carcass
take a blood sample and send to diagnostic lab- culture and cytology (12 hours)
close and protect remains - prevent spore formation and distribution
call state/federal vet
quarantine
incinerate the remains
How do you diagnose Anthrax
1) Blood smear
2) dark hemorrhage from body orifices
3) Failure of blood to clot
4) Absence of rigor mortis
5) Splenomegaly
avoid opening carcass and do carcass putrefaction
close and protect remains, prevent spore formation
How should you treat/ control Anthrax
1) Antibiotic - Oxytetracycline and Penicillin
2) Prophylactic Antibiotic
3) Vaccination- attenuated live spore- not commonly used in US
What causes caseous lymphadentitis
Cornyebacterium pseudotuberculosis
facultuative intracellualr
occurs in sheeps and goats
caseous lymphadentitis prevalence increases with
age
chronic infection that occurs from environmental exposure- survives in soil 8 months
What are risk factors for caseous lymphadentitis
1) Shearing
2) Draining abscesses
3) Close physical contact
4) Nasal and oral secretions
5) Sheep dip
6) Head wounds
7) Fomites
What are the clinical signs of caseous lymphadentitis
1) Abscessesl- internal and external
2) Enlarged lymph nodes
3) Respiratory disease
4) Weight loss- internal form
5) CBC
6) Culture/Gram stain- not all asbcesses are CL
7) Serology (ELISA) - better for herd an individual dx
8) Can be zoonotic
T/F: caseous lymphadentitis is zoonitic
true
Serology (ELISA) for caseous lymphadentitis is better for what
better for herd diagnosis rather than individual dx
The internal form of caseous lymphadentitis might present as
weight loss
