NAVLE STANDARD SET ANSWERS AND QUESTIONS
SET A+
✔✔A pig farm has several sick and dying adult pigs. Affected animals are febrile and
depressed.
Some seem constipated and others have diarrhea. A few are ataxic. A necropsy on one
of the dead pigs shows widespread petechial and ecchymotic hemorrhages in the
kidneys ("turkey egg kidneys"), bladder, spleen, and larynx. Which one of the following
choices is the most likely diagnosis?
A - Haemophilus parasuis
B - Hemagglutinating encephalomyelitis
C - Classical swine fever
D - Swine dysentery
E - Erysipelas - ✔✔C
Hemorrhages on the kidneys and other organs are characteristic of both classical swine
fever (CSF, also called "hog cholera") and African swine fever (ASF).
African swine fever cannot be differentiated from classical swine fever based on clinical
and postmortem symptoms alone. Confirmation is based on either PCR or ELISA
antigen testing. Both are reportable diseases. Classical swine fever was last reported in
North America in the 1970s.
Erysipelas is characterized by fever, painful joints, and diamond-shaped skin lesions.
Hemagglutinating encephalomyelitis (vomiting and wasting disease) and Haemophilus
parasuis (Glasser's disease) both occur mainly in young piglets.
✔✔A commercial pig farm experiences an explosive outbreak of respiratory disease
with high mortality, primarily in young pigs under 6 months of age.
Affected pigs show severe respiratory distress, fever up to 107°F (41.5°C), anorexia,
and reluctance to move. Some animals display open-mouth breathing with a blood-
stained, frothy nasal and oral discharge. On necropsy, the lungs are bilaterally dark and
,swollen and ooze bloody fluid from the cut surface. Which one of the following choices
is the most likely diagnosis?
A - Actinobacillus pleuropneumoniae
B - Fusobacterium necrophorum
C - Mycoplasma hyopneumoniae
D - Haemophilus parahaemolyticus
E - Swine influenza - ✔✔A
This is a classic scenario of an outbreak of pleuropneumonia, caused by Actinobacillus
pleuropneumoniae.
✔✔A group of chickens presents with scabby, proliferative, and ulcerative lesions on the
comb, wattles, eyelids, feet, and legs. Mortality is low. Which one of the following
choices is the most likely diagnosis?
A - Fowl cholera
B - Marek's disease
C - Infectious coryza
D - Avian pox
E - Fowl plague - ✔✔D
Avian pox, also known as Fowlpox. This disease is not contagious to humans. There
are two forms of the disease - 1) cutaneous or dry pox has low mortality, with
proliferative lesions on comb, wattles, etc, and 2) diphtheritic or wet pox that causes
yellow canker lesions on mucous membranes, tongue, esophagus, or trachea.
Fowl cholera causes swellings and abscesses in the comb and wattles, but also affects
the respiratory tract. The mortality can be high.
✔✔A foal born 12 hours ago is observed swishing its tail from side to side, straining with
an arched back and rolling on the stall floor. What test is indicated to rule in the
presumptive diagnosis?
A - Succussion of right caudal abdomen
B - Ultrasound of umbilicus/urachus
C - Digital exam of rectum
D - Cystocentesis
E - Endoscopy of gastric mucosa - ✔✔C
Digital exam of rectum. Foals with meconium impaction will swish their tail from side to
side, roll, and strain to defecate. A digital exam of the rectum will aid in rapid diagnosis.
,Meconium impaction is the most common cause of colic in the newborn foal, typically
seen within 24 hours of birth. More common in colts (males) than fillies because colts
have a smaller pelvis.
✔✔Which one of the following choices is the most common etiology of canine
cholangiohepatitis?
A - Neoplastic biliary obstruction
B - Idiopathic
C - Ascending infection
D - Liver fluke migration
E - Toxicity - ✔✔C
Enteric bacteria migrate up the bile duct from the intestines and create an infection in
the liver and biliary tract in most cases of canine cholangiohepatitis.
Feline cholangiohepatitis is more common than the canine form and has three main
etiologies.
1. Acute neutrophilic (suppurative)
2. Chronic (lymphoplasmacytic or mixed)
3. Lymphocytic (nonsuppurative)
✔✔Which one of the following choices is the best initial treatment in the patient with a
moderate elevation of calcium caused by idiopathic feline hypercalcemia?
A - Injectable fluids
B - Prednisolone
C - Diet change
D - Bisphosphonates
E - Furosemide - ✔✔C
Diet changes such as a high fiber food or food designed to treat renal disease may be
effective in restoring normocalcemia in the feline patient with Idiopathic hypercalcemia.
Prednisolone, fluid therapy, furosemide may be used in more severely affected patients
and when dietary therapy is ineffective.
Bisphosphonates may be utilized if increased osteoclastic activity is present.
✔✔Feline leukemia (FeLV) status has been shown to affect many aspects of disease
progression and treatment of lymphoma.
FeLV seropositive cats with lymphoma are similar to FeLV seronegative cats with
lymphoma in which one of the following aspects?
A - Remission rates
, B - Treatment response
C - Survival time
D - Prevalence of gastrointestinal lymphoma
E - Prevalence of mediastinal lymphoma - ✔✔B
Feline leukemia virus seropositive and seronegative cats share similar response rates
to initial treatment with chemotherapy for lymphoma.
Lymphoma remission rates are higher and survival times are shorter for cats with FeLV
compared with FeLV negative cats.
Most U.S. cats with mediastinal, multicentric, or spinal forms of lymphoma are FeLV-
positive.
✔✔This calf was aborted at 7.5 months pregnancy in early fall. The dam was a
primiparous beef animal housed on pasture in Northern California.
Necropsy revealed multiple petechial hemorrhages on the palate and scleral mucus
membranes of the fetus, and marked lymphadenopathy. The calf was not decomposed;
the cow retained the placenta.
image
Which one of the following choices is the most likely diagnosis of the abortion in this
case?
A - Leptospira pomona
B - Brucella abortus
C - Neospora caninun
D - Pine needles
E - Foothill abortion agent - ✔✔E
This is a typical case of foothill abortion, also called epizootic bovine abortion. The
condition is common in the coastal and Sierra Nevada foothills, and throughout much of
the western United States. It is the most common cause of abortion in California beef
cattle.
The etiologic agent has not been identified with certainty. Research suggests that it is a
delta protobacteria with DNA homology to bacteria of the vibrio genus. Pregnant cattle
exposed to thymic tissues from aborted fetuses can be protected from abortion by
feeding tetracycline through the early stages of pregnancy.
The agent is transmitted by the soft shelled Pajahuello tick (Ornithodorus coriaceus).
The disease occurs predominantly in heifers. Infection develops during the first trimester
of pregnancy while abortions occur later around the 5th to 9th month.
SET A+
✔✔A pig farm has several sick and dying adult pigs. Affected animals are febrile and
depressed.
Some seem constipated and others have diarrhea. A few are ataxic. A necropsy on one
of the dead pigs shows widespread petechial and ecchymotic hemorrhages in the
kidneys ("turkey egg kidneys"), bladder, spleen, and larynx. Which one of the following
choices is the most likely diagnosis?
A - Haemophilus parasuis
B - Hemagglutinating encephalomyelitis
C - Classical swine fever
D - Swine dysentery
E - Erysipelas - ✔✔C
Hemorrhages on the kidneys and other organs are characteristic of both classical swine
fever (CSF, also called "hog cholera") and African swine fever (ASF).
African swine fever cannot be differentiated from classical swine fever based on clinical
and postmortem symptoms alone. Confirmation is based on either PCR or ELISA
antigen testing. Both are reportable diseases. Classical swine fever was last reported in
North America in the 1970s.
Erysipelas is characterized by fever, painful joints, and diamond-shaped skin lesions.
Hemagglutinating encephalomyelitis (vomiting and wasting disease) and Haemophilus
parasuis (Glasser's disease) both occur mainly in young piglets.
✔✔A commercial pig farm experiences an explosive outbreak of respiratory disease
with high mortality, primarily in young pigs under 6 months of age.
Affected pigs show severe respiratory distress, fever up to 107°F (41.5°C), anorexia,
and reluctance to move. Some animals display open-mouth breathing with a blood-
stained, frothy nasal and oral discharge. On necropsy, the lungs are bilaterally dark and
,swollen and ooze bloody fluid from the cut surface. Which one of the following choices
is the most likely diagnosis?
A - Actinobacillus pleuropneumoniae
B - Fusobacterium necrophorum
C - Mycoplasma hyopneumoniae
D - Haemophilus parahaemolyticus
E - Swine influenza - ✔✔A
This is a classic scenario of an outbreak of pleuropneumonia, caused by Actinobacillus
pleuropneumoniae.
✔✔A group of chickens presents with scabby, proliferative, and ulcerative lesions on the
comb, wattles, eyelids, feet, and legs. Mortality is low. Which one of the following
choices is the most likely diagnosis?
A - Fowl cholera
B - Marek's disease
C - Infectious coryza
D - Avian pox
E - Fowl plague - ✔✔D
Avian pox, also known as Fowlpox. This disease is not contagious to humans. There
are two forms of the disease - 1) cutaneous or dry pox has low mortality, with
proliferative lesions on comb, wattles, etc, and 2) diphtheritic or wet pox that causes
yellow canker lesions on mucous membranes, tongue, esophagus, or trachea.
Fowl cholera causes swellings and abscesses in the comb and wattles, but also affects
the respiratory tract. The mortality can be high.
✔✔A foal born 12 hours ago is observed swishing its tail from side to side, straining with
an arched back and rolling on the stall floor. What test is indicated to rule in the
presumptive diagnosis?
A - Succussion of right caudal abdomen
B - Ultrasound of umbilicus/urachus
C - Digital exam of rectum
D - Cystocentesis
E - Endoscopy of gastric mucosa - ✔✔C
Digital exam of rectum. Foals with meconium impaction will swish their tail from side to
side, roll, and strain to defecate. A digital exam of the rectum will aid in rapid diagnosis.
,Meconium impaction is the most common cause of colic in the newborn foal, typically
seen within 24 hours of birth. More common in colts (males) than fillies because colts
have a smaller pelvis.
✔✔Which one of the following choices is the most common etiology of canine
cholangiohepatitis?
A - Neoplastic biliary obstruction
B - Idiopathic
C - Ascending infection
D - Liver fluke migration
E - Toxicity - ✔✔C
Enteric bacteria migrate up the bile duct from the intestines and create an infection in
the liver and biliary tract in most cases of canine cholangiohepatitis.
Feline cholangiohepatitis is more common than the canine form and has three main
etiologies.
1. Acute neutrophilic (suppurative)
2. Chronic (lymphoplasmacytic or mixed)
3. Lymphocytic (nonsuppurative)
✔✔Which one of the following choices is the best initial treatment in the patient with a
moderate elevation of calcium caused by idiopathic feline hypercalcemia?
A - Injectable fluids
B - Prednisolone
C - Diet change
D - Bisphosphonates
E - Furosemide - ✔✔C
Diet changes such as a high fiber food or food designed to treat renal disease may be
effective in restoring normocalcemia in the feline patient with Idiopathic hypercalcemia.
Prednisolone, fluid therapy, furosemide may be used in more severely affected patients
and when dietary therapy is ineffective.
Bisphosphonates may be utilized if increased osteoclastic activity is present.
✔✔Feline leukemia (FeLV) status has been shown to affect many aspects of disease
progression and treatment of lymphoma.
FeLV seropositive cats with lymphoma are similar to FeLV seronegative cats with
lymphoma in which one of the following aspects?
A - Remission rates
, B - Treatment response
C - Survival time
D - Prevalence of gastrointestinal lymphoma
E - Prevalence of mediastinal lymphoma - ✔✔B
Feline leukemia virus seropositive and seronegative cats share similar response rates
to initial treatment with chemotherapy for lymphoma.
Lymphoma remission rates are higher and survival times are shorter for cats with FeLV
compared with FeLV negative cats.
Most U.S. cats with mediastinal, multicentric, or spinal forms of lymphoma are FeLV-
positive.
✔✔This calf was aborted at 7.5 months pregnancy in early fall. The dam was a
primiparous beef animal housed on pasture in Northern California.
Necropsy revealed multiple petechial hemorrhages on the palate and scleral mucus
membranes of the fetus, and marked lymphadenopathy. The calf was not decomposed;
the cow retained the placenta.
image
Which one of the following choices is the most likely diagnosis of the abortion in this
case?
A - Leptospira pomona
B - Brucella abortus
C - Neospora caninun
D - Pine needles
E - Foothill abortion agent - ✔✔E
This is a typical case of foothill abortion, also called epizootic bovine abortion. The
condition is common in the coastal and Sierra Nevada foothills, and throughout much of
the western United States. It is the most common cause of abortion in California beef
cattle.
The etiologic agent has not been identified with certainty. Research suggests that it is a
delta protobacteria with DNA homology to bacteria of the vibrio genus. Pregnant cattle
exposed to thymic tissues from aborted fetuses can be protected from abortion by
feeding tetracycline through the early stages of pregnancy.
The agent is transmitted by the soft shelled Pajahuello tick (Ornithodorus coriaceus).
The disease occurs predominantly in heifers. Infection develops during the first trimester
of pregnancy while abortions occur later around the 5th to 9th month.
