Ruminant Multisystemic Disease Flashcards
1
Q
T/F: BVDV can be eliminated
A
True
2
Q
What is the prevalence of BVD
A
50-90% of cattle are serologically positive
<1 to 2% of general cattle population thta is persistently infected animals and individual herds may be higher
3
Q
What are the different Flaviviruses
A
RNA viruses
1) Pestiviruses
-Bovine Viral Diarrhea Virus (BVDV)
-Border Disease Virus (BDCV)
-Hog Cholera Virus (HCV)
2) Flaviviruses
-Louping III virus
-Japanese Encephalitis Virus
-Wesselsbron Virus
3) Human Hepatitis C Virus
4
Q
Why is BVDV really hard to get people to want to eradicate it
A
because it doesnt cause severe enough death, like other viruses do
5
Q
T/F: both cytopathic and noncytopathic BVDV can cause clinical disease
A
True
6
Q
What is the main difference between the cytopathic vs noncytopathic BVDV biotypes
A
In vitro designation
noncytopathic viruses are predominant biotype transmitted naturally
BOTH cause clinical disease
7
Q
What is the predominant BVDV biotype
A
Noncytopathic - because persistently infected animals can only be infected with the noncytopathic strain
8
Q
When vaccinating for BVDV, you need to vaccinate against what
A
BOTH BVDV Type 1 and Type 2
9
Q
How does BVDV Type 1 and Type 2 differ
A
antigenically and genetically different
both cause similar disease syndromes
10
Q
what BVDV type causes thrombocytopenic syndrome
A
BVDV Type 2
11
Q
T/F: BVDV has strong antigenic drift
A
True
12
Q
What serves as the primary reservoir for shedding of BVDV into the environment
A
Persistently infected animals
13
Q
What other species might maintain BVDV
A
Sheep
Deer
Pigs
14
Q
The infection outcomes of BVD depend on
A
-Pregnancy status
-Gestational age
-Immune status
-Strain of virus
15
Q
What are the 4 infection outcomes of animals with BVDV
A
1) Acute infection
2) Fetal Infection
3) Mucosal Disease
4) Persistent infection
16
Q
Animals with acute BVD infection likely are
A
NOT persistently infected
In fact, they havent seen virus or low levels of immunity
experiencing just a transient signs
17
Q
What are the clinical signs of acute BVD infection
A
Most are subclinical and just transient infection
Mild fever, maybe missed
Clinical: fever, diarrhea, depression, ocular/nasal discharge, ulcers platelet problems- bleeding
Mucosal disease (if PI and superinfected)
immine suppression- BRD, poor vaccine response
18
Q
If a cow is a persistently infected cow and gets acute infection / superinfected with different strain then what occurs
A
Mucosal disease
19
Q
PI cattle infected with endogenous noncytopathic BVDV
OR
animals become superinfected with cytopathic strain of BVDV
A
Mucosal Disease
20
Q
Why might you see Bovine Respiratroy disease and poor vaccine response with BVD
A
immunosuppression
causes thrombocytopenia
neutropenia
lymphopenia
21
Q
T/F: Acute BVDV infection causes severe fever, diarrhea, depression
A
False- often times subclinical or missed
22
Q
BVD fetal infection is dependent on
A
1) Viral strain
2) Stage of pregnancy
23
Q
Fetal infection with BVD might cause
A
1) Embryonic death
2) Abortion
3) Congenital defects
4) Persistent infection 30 to 125-150 days
5) Fetal immune response and seroconversion resulting in healthy live calf (>180 days of gestation) - NCP or CP
24
Q
What form of BVDV creates persistently infected individuals
A
Non-cytopathic
25
Calves with persistent infection to BVDV are infected within what time frame of gestation
30-125 days of gestation
26
How does the fetus become immunotolerant and have a persistent BVDV infection when infects days 30-125 days of gestation
Fetus becomes immunotolerant when the non-cytopathic virus strain infects them
No antibodies to the particular viral strain (before immune development of MHC)
the virus persists - clinically normal, weak, poor doer, immunosuppressed
27
With fetal infection of BVD,i f infected 30-125 days of gestation, the virus persist. what are the fates of the animal
Clinically normal
Weak, poor doer
Immunosuppressed
50% die within the first year of life
28
What is the key to eradicating BVDV
Eradicating the persistently infected animals
29
What is the fate of persistently infected calves with BVDV
50% die within the first year of life
few survive beyond 2 years of age
may be born small, have slow growth rates, appear unthrifty, predisposed to infections
some appear clinically healthy
30
What is the primary source of BVDV infection spread
Persistently infected cows- shed phenomenal amounts of virus
31
PIs occur when the fetus is infected between
30-125 days of age
32
At what stage of gestation does BVDV cause early embryonic death and infertilty
within the first month of gestation - fetus just dies
33
Calves that come across BVDV after 180 days of gestation have
fetal immune response, seroconversion
born healthy live calf
34
Congenital effects from BVDV occur when infection happens
during 60-80 to 150-180 days of gestation
35
What is seen with BVDV causing reproductive failure
5-10% drop in 1st service conception
5-10% increase in early embryonic death
2-5% increase in sporadic abortion
36
What congenital defects do you see with BVD infections during 80-180 days of gestaton
Cerebellar hypoplasia *
Hydrocephalus
Hypomyelogenesis
Microphthalmia
Cataracts
Retinal atrophy/dysplasia
Brachygnathia
Thymic hypoplasia
Hypotrichosis
37
BVDV causing thrombocytopenia is from a
Type 2 Non-cytopathic strain of BVDV
38
Immunosuppression from BVDV is typically associated with what form of infection
Acute infection
39
What is seen with immunosuppression of BVDV
1) Humoral and cell mediated immunity is impaired
2) Leukopenia
3) Lymphoid depletion
4) Decreased responsiveness of lymphocytes
5) Inhibited bactericidal activity of neutrophils
6) Associated with BRD
40
Why is BVD commonly associated with bone respiratory disease complex
because it causes increased susceptibilty to disease and decreased vaccination response
41
What is seen with hemorrhagic syndrome from BVDV
Thrombocytopenia from NCP BVD type II
-Platelet destruction and altered function
-Hemorrhagic diathesis
-Bloody diarrhea, epistaxis, hyphema, bleeding from injection sites, petechiation, ecchymoses, uterine bleeding
42
What are the 3 ways cows might get mucosal disease BVD
1) Spontaneous mutation in PI animal -most common
2) Natural or iatrogenic (MLV vaccine) infection- currently rare
3) Recombination between a heterologous cytopathic virus (natural or iatrogenic) and the persistent non-cytopathic virus (extremely rare)
43
What is the most common way an animal might get mucosal disease
PI animal has spontaneous mutation of BVD
44
Mucosal disease from BVD has the exact same clinical signs as
Rinderpest
45
What are the clinical signs of mucosal disease from BVD
1) Persistently high fever
2) Severe epithelial erosions/ulcerations *
on GIT and interdigital space, teats, vulva
Case fatality rate - 100%
most die within 3-10 days
46
What is the case fatality rate of mucosal disease from BVD
100%
most die within 3-10 days
47
Where does the severe epithelial erosions / ulcerations seen with mucosal disease typically occur
GI tract: tongue, palate, buccal surfaces, palate > severe diarrhea leading to severe diarrhea / dysentery
Interdigital space, coronary band leading to lameness
Teats, Vuval
48
What does the BVD leukogram look like
1) Lymphopenia
2) Neutropenia
-Severe (<1000/ul)
-No left shift
3) Thrombocytopenia
-Less than 100,000/ul, sometimes as low as 10,000 uL
type II, non-cytopathic, acute BVD
49
What is the mode of BVD transmission
Most secretions
-in feces, aersols, saliva, urine, uterine fluids, blood
inhalation/ingestion
blood feeding insects
mechanical vectors- needles
horizontal/veneareal - semen
vertical- transplacental
50
Animals with BVD acute infects shed
lower levels with limited length of shedding
51
How is BVD most commonly spread to different farms
most farms buy the problem into the herd
with PI or cow pregnant with a PI
52
PI animals that get pregnant will always produce what offspring
produce PI infected offspring
53
How do you diagnose BVD
Suspicion: herd records, signalment and history, clinical signs and CBC, pathology/ histopathology
Definitive:
virus isolation (tissue, blood/serum)
PCR, ELISA
Serology
54
How do you get the definitive BVD diagnosis
virus isolation (tissue, blood/serum)
PCR, ELISA
Serology
55
How do you screen a herd for BVD
BVD Serology
1) 10 or more in-contact animals
2) Calves >6 months of age
3) Any titer >512 suggestive of circulating BVD
indicates the likely presence of a PI animal
56
Any BVD titer in a calve >6 months of age that is greater than ______ is suggestive of BVD
>512
57
Herd screening for BVD indicates the likely presence of
a PI animal
58
How old do cows need to be to screen for BVD
>6months of age
59
How do you definitively diagnose acute BVD infection
Virus isolation
PCR *
IHC
paired serology
60
What are the two tests to destinguish PIs of BVD *******
EAR NOTCH
1) Antigen capture ELISA (blood) - rarely for acute
2) IHC
others: antigen capture ELISA on serum >6mo (acute infections wont have high enough levels), or paired PCR (4 weeks apart), virus isolation-paired
61
T/F: PI animals will have high titers of virus that can be observed in hair follicles in epidermis
True
62
How do you make the distinction between BVD acute infections and PI animals
PI animals will have large amounts of virus that can be observed in fair follicles and epidermis
-Ear notch antigen capture ELISA or IHC
63
Antigen Capture ELISA for BVD
Rapid: 1-3 days
Inexpensive
Less sensitive (some false negatives)
Less specific (some false positives)
Maternal Antibody Interference: Calves > 6months
Use serum
good for PI screening
64
How do you submit a skin biopsy IHC for BVD
ear notch
formalin
*No maternal Ab inhibition
65
When testing for BVD, there is no concern of maternal Ab inhibition with
1) Skin Biopsy IHC
2) Skin Antigen Capture ELISA
66
Skin Antigen capture ELISA for BVD
Ear notch
Refrigerate or Freeze
No maternal Ab inhibition
Mix with saline for Ag capture ELISA
67
How do you control and manage BVD
1) Eliminate the source - PI carriers
2) Test all incoming cattle for PI carriers
3) Quarantine all incoming cattle for 1 month
4) Vaccinate all incoming cattle
5) Herd vaccination program
-Type I and Type II
67
What is the gold standard vaccine for BVD
Modified Live Virus
1) Induces best protection
2) Prevents viremia-reproductively protective
3) One dose required- quicker protection and less labor
4) Longer lasting >18 months
68
What are the pros to the modified live vaccine for BVD
1) Induces best protection
2) Prevents viremia-reproductively protective
3) One dose required- quicker protection and less labor
4) Longer lasting >18 months
69
What is a downside to the BVD modified live vaccine
abortifacient /teratogenic if vaccinating for the first time
70
First time BVD vaccination with a modified live in a pregnant animal will
abort the fetus
71
What BVD vaccination is not abortifacient
Killed
72
What BVD vaccination induces best protection
Modified Live
73
Is protection against BVD greater in modified live or killed
Modified Live: >18 months
Killed: 4 months
74
Does modifed live or killed BVD vaccine have less doses required
Modified Live- quicker protection and less labor associated
75
T/F: killed BVD vaccines prevent against viremia
False- can still get PI
modified live is better
76
What are common multisystemic diseases seen in cattle
Histophilus
Leptospirosis
Mycoplasma
Malignant catarrhal fever
Bluetongue
Rinderpest
Foot and Mouth Disease
77
a gram - rod
facultative anaerobe
capnophilic
requires special media
difficult to culture
feedlot > dairy
Histophilus somni
78
Histophilus somni causes what 5 syndromes
Respiratory *
CNS *
Reproductive
Musculoskeletal
Septicemia
becomes septicemic really commonly and moves to other tissues
79
Histophilus somni is more common in feedlots or dairies
Feedlots - young and growing animals
80
What is seen in Histophilus somni respiratory syndrome
Bronchopenumonia
Pleuritis
Otitis media
Necrotizing laryngitis
81
What causes sleeper calves
Thrombo Meningoencephalitis (TME) from Histophilus somni
82
What is seen with Thrombotic Meningoencephalitis
-Fever, depression, ataxia
-Blindness
-Seizures
-Death
-High morbidity
-Respiratory disease and myocarditis increasing in prevalence vs TME
83
What are the two major components that Histophilus causes
1) Respiratory- bronchopneumonia, pleuritis, otitis media, necrotizing laryngitis
2) Thrombotic Meningoencephalitis (TME)
84
What reproductive issues is seen with Histophilus somni
EED and abortion
metritis
vaginitis
orchitis
85
What musculoskeletal abnormaltiies is seen with Histophilus somni
Septic arthritis *
Tenosynovitis
Tendonitis
86
Histophilus somni
septicemia leads to
Thrombotic Meningoencephalitis and myocarditis
also hepatitis, nephritis, retinitis/hemorrhage
87
What is the common source of Histophilus somni
Chronic carrier cattle
Secretions
Excretions
88
When doing necropsies, what is one of the most common ways to find Histophilus somni
Cut into the heart
Myocarditis
89
How do you diagnose Histophilus somni
Culture - swabs, tissue, exudate. no transport media, keep moist, check labratory
Serology- acute and convalescent
Pathology and Clinical signs
90
How do you treat Histophilus somni
Oxytetracycline
Florfenicol
Ceftiofur
Tilmicosin
Supportive
most of the time you cant save the cow but you need to be ready to prevent potential other cattle from developing further
91
How should you control for Histophilus somni
1) antimicrobials in outbreak
a) Tetracycline in feed
b) Mass medicate 1 time
2) Vaccination with Bacterin -decent efficacy and some reactions
3) Eliminate chronic carriers
92
What are the 2 major host adapted bacteria in cattle
1) Leptospirosis
2) Salmonella
93
Gram - spirochetes
Host adapted reservoir
transmitted through urine, aerosol, water
causes sporadic infections
Leptospirosis
94
How is leptospirosis transmitted?
urine
aerosol
water
95
What is the host adapted salmonella in cattle
Dublin - host adapted, most dont die
96
Non-host adapted Leptospirosis causes what in cattle
Acute, severe infection
1) Hemolytic Anemia- L. pomona, L. icterohaemorrhagiae
2) Hepatitis (canine)
3) Nephritis
4) Aortion
5) Mastitis
96
What Lepto strains cause hemolytic anemia in cattle
L. pomona
L. icterohaemorrhagiae
97
How does host-adapted disease differ from non-host adapted lepto disease in cattle
Host Adapted Diseases
-Chronic infections
-Mild to subclinical
-Transient malaise
-Agalactiae (Europe staine)
Non-Host Adapted:
Acute, severe infection
1) Hemolytic Anemia- L. pomona, L. icterohaemorrhagiae
2) Hepatitis (canine)
3) Nephritis
4) Aortion
5) Mastitis
98
What are the characteristics of host-adapted Lepto diseases
-Chronic infections
-Mild to subclinical
-Transient malaise
-Agalactiae (Europe staine)
99
What is the Leptospira serovar that is host adapted to cattle
hardjo-bovis
100
What is the Leptospira serovar that is host adapted to Swine and rodents
pomona
101
What is the Leptospira serovar that is host adapted to rodents and is zoonotic to humans *
Icterohaemorrhagiae
102
What is the Leptospira serovar that is host adapted to found in racoons, skunks, opassums
grippotyphosa
103
What is the Leptospira serovar that is host adapted to swine and horses
bratislava
104
In cattle, what is the most common outcome of Leptospira - serovar hardjo-bois
Abortion
6-12 weeks post infection
105
How does leptospira typically infect
1) Resides in renal tissues, shed in urine in high concentrations
2) Contact with urine contamination
3) Penetrates mucous membranes or compromised skin
4) Incubates for 3-7 days
5) Shed lepto before clinical signs appear
106
Animals shed lepto before
clinical signs occur
107
How do you diagnose Leptospira
1) Culture urine- cold enrichment
2) Fluorescent Antibody test on abortion tetal tissues
3) Serology- Microagglutination test (IgM)- timing vs seroconversion
acute- titer >100 + clinical signs
Chronic need to survery herd
4) PCR
108
How do you treat Leptospira in cattle
1) Oxytetracycline
2) Ceftioufur (Naxcel)
Dyhydrostreptomycin isnt available anymore
109
How do you control Leptospirosis in cattle
1) Eliminate carriers: host adapted and non-host adapted
2) Vaccination- bacterin (5 serovars)
3) Specific L. hardjo bacterin (enhanced effacacy)
110
What are the two vaccinations for leptospirosis in cattle
1) Bacterin - 5 serovars
2) Specific L. hardjo bacterin - has enhances efficacy
111
What Leptospirosis serovar is zoonotic
L. icterohaemorrhagiae
spread via rodents
112
Mycoplasma bovis causes what diseases in cattle
1) Mastitis
2) Respiratory Disease/ Pneumonia
3) Otitis media
4) Arthritis
5) Tendonitis
6) Tenosynovitis
113
What is a common differential for Mycoplasma bovis
Histophilosis
114
no cell wall
poor antibiotic response
chronic infection common
poor environmental survival
Mycoplasma bovis
115
How do you diagnose Mycoplasma bovis
-Clinical signs
-Suspicion
-Culture - diffuclt, need to request from lab the specific culture
-PCR
116
Why is maintaining hygiene really important for control of Mycoplasma bovis
it has poor environmental survival
almost host reliant
117
How do you treat Mycoplasma bovis
-Tulathromycin, florfenicol
-Oxytetracycline
-Enrofloxacin
-Danofloxacin
-Tilmicosin
NOT BETA lactams - mycoplasma does not have a cell wall
118
What antimicrobials are labeled for Mycoplasma bovis treatment
-Tulathromycin, -florfenicol
119
What antimicrobial should you use with caution in food animals
Enrofloxacin (Baytril) -beware resistance w humans
only use for mycoplasma if other drugs have failed
120
Malignant Catarrhal Fever is associated with what abunaks
Sheep (american)
Wildbeast (African)
121
T/F: sheep get significant Malignant Catarrhal Fever
false
122
What are the clinical signs of Malignant Catarrhal Fever in cattle
Enteritis- affects a lot of tissues
-Oral/nasal erosions
-Panopthalmitis
-Uveitis
-Ocular discharge
-Hematuria
-Lameness from coronary band breakdown
-Swollen lymph nodes
young to young mature (6 months to 3 years)
123
How do you treat Malignant Catarrhal Fever
not treatable - most euthanized
124
How do you diagnose Malignant Catarrhal Fever
OHV-2 PCR
-needs to be specific
-cell associated vs cell free virus
-detection limits
-latency
125
What are other differential diagnoses for Malignant Catarrhal Fever
-BVDV- mucosal form
-Salmonella
126
Blue tongue in sheep causes
-Vascultitis
-Enteritis
-Laminitis
-Coronitis
-myositis
-Conjunctivitis
-Abortion
-Congenital defects
127
How is blue tongue transmitted to sheep
Culicoides
128
How do you treat Bluetongue
Supportive care
Antimicrobial
129
T/F: blue tongue is extremely fatal
False- not much so
often times can go unnoticed and then you noticed congenital abnormalties in offspring
130
What are the clinical signs of bluetongue in cattle
often asymptomatic
-fever
-laminitis
-oral lesions
-reproductive
131
Bluetongue in wild ruminants is like
EHD
-occurs in white tailed deer
morbidity- 90%
mortality - 60%
132
exotic morbillivirus
causes
-lymphoid
-alimentary
-mucous membranes
-lungs
-marked leukopenia
Rinderpest
133
Rinderpest causes what syndromes
-lymphoid
-alimentary
-mucous membranes
-lungs
-marked leukopenia
looks very like malignant catarrhal fever and mucosal BVD
134
Small animal analogue to rinderprest
-lymphoid
-alimentary
-mucous membranes
-lungs
-marked leukopenia
Peste des petitis ruminants
135
T/F: foot and mouth disease isnt that stable in the environment
False - nonenveloped virus
VERY STABLE
136
How is foot and mouth disease transmitted
-direct contact
-aerosol
-secretions/ excretions / fomites
137
What kind of virus is foot and mouth disease
Aphthovirus (Picornavirus)
138
What are the clinical signs of foot and mouth disease
1) Epidermal Tissues
2) Viremia
3) Lesions- oral, feet, mammary
has carriers
