Infectious Equine Resp 1

Question 1

Whats the main difference between asthma and IAD horse signalments

Answer 1

Age- IAD will be younger racehorses while asthma will be middle aged-older horses

Question 2

Describe the transmission of diseases that affect the equine lung and pleura

Answer 2

Equine respiratory viruses may be transmitted by horse to horse transmission, contact with recently expelled secretions or recrudescence of a latent viral infection.

Question 3

Describe the pathogenesis of diseases that affect the equine lung and pleura

Answer 3

1.Virus enters the track and attaches to the respiratory epithelium
2. Virus enters the epithelial cells and uses cell apparatus to replicate
3. Virus is released from epithelial cells, killing cells
4. Viral shedding within 48 hours of infection
5. Damages the epithelium and mucociliary clearance mechanism
6. Virus can spread systematically: Viremia
7. Epithelium can take a month or more to fully recover

Question 4

Equine immune response to viral infection

Answer 4

1. Innate response (secretion of soluble factors into mucus)
2. Humoral immunity (URT: IgA local and LRI: IgG local and hematogenous)
3. Cell mediated immunity

Question 5

Clinical signs of ACUTE Equine Respiratory Viruses

Answer 5

typically it affects young horses with acute signs of a high fever, general malaise, cough that persists for weeks, clear or mucoid nasal discharge and MAYBE lymph nose swelling or limb and ventral edema

Question 6

Clinical signs of CHRONIC equine respiratory viruses

Answer 6

Young horses will have dismissed performance, chronic discharge, chronic pharyngitis, cough

Question 7

Secondary syndromes of equine respiratory viruses

Answer 7

Predisposition to bacterial infections, pleural pneumonia, generalized vaculitis, purpura type response

Question 8

What would bloodwork of a horse with a viral respiratory infection look like?

Answer 8

CBC: mild, Normacytic, normachromic anemia
Acute signs will have a lymphopenia followed by a neutrophilia after few days and then monocytosis and fibrinogen

Chem: +/- elevated CK, AST, LDH

Question 9

__ and __ can be used to treat fever while __ and __ can be used to treat the cough

Answer 9

Flunixin meglumine and Phenylbutazone can be used to treat fever while clenbuterol (B2 agonist) and ipatropium can be used to treat the cough

Question 10

If a horse with respiratory disease starts to exhibit neuro signs then __ and __ may be used as an antiviral

Answer 10

If a horse with respiratory disease starts to exhibit neuro signs then acyclovir and oseltamivir(EHV1 ) may be used as an antiviral

Question 11

How long should horses rest after resolution of a fever from equine respiratory disease?

Answer 11

3 weeks

Question 12

Equine viral respiratory disease may be specifically diagnosed by __

Answer 12

PCR

Question 13

Vaccines for equine respiratory disease

Answer 13

Killed vaccines mainly stimulate the humoral response through IgG(IM) or IgA (IN)

Modified live vaccines stimulate cell mediated response which is how infectious cells are eliminated

Question 14

___ is the best method for identifying viral strains, collect a nasopharyngeal swab

Answer 14

Virus isolation

Question 15

__ is the most common virus horses get in their respiratory system

Answer 15

Equine influenza

Question 16

Equine rhinovirus

Answer 16

Foals >3-4 weeks

Question 17

Equine adenovirus 1

Answer 17

Foals, severe if immunocompromised

Question 18

Equine herpes virus 2

Answer 18

Immunosuppression in weanlings

Question 19

Equine herpes 5

Answer 19

equine multinodular pulmonary fibrosis -> new strain of herpes that has a slower onset and will show blotches on imaging, BAL for dx but not treatable

Question 20

Equine Influenza viral characteristics

Answer 20

1. The most common URT infection what is a single strangled rna virus from the orthomyxoviridae family
2. Type A influenza virus classified based on hemagglutinin and neuraminidase surface antigens
3. Antigenic drift (change of antigenicity) and antigenic shift (new viral subtype H3N8 and H7N7)

Question 21

__ is the most common and more severe strain of equine influenza

Answer 21

H3N8

Question 22

How often should you vaccinate your horses to prevent equine influenza?

Answer 22

• Foals at 9 to 11 months
• Young performance horses every 2 to 4 months
• Adult pleasure horses every 6 to 12 months
• Pregnant mares 8 weeks prior to foaling

intranasal is effective and commonly used

Question 23

How long should new horses be isolated to prevent equine influenza

Answer 23

3 weeks

Question 24

Equine Herpes Virus 1 and 4 Viral characteristics

Answer 24

• Equine herpes viruses are double stranded DNA viruses
• They affect horses by the age of 2 typically by vertical transmission
• Incubation period of 2-10 days
• may become latent and resides in the respiratory lympho-reticular system or the Trigeminal ganglion

Question 25

Common clinical signs of a horse with EHV

Answer 25

1. Upper respiratory tract infection
2. Pulmonary vasculotropic infection
3. Late term abortion
4. Neonatal foal death
5. Myeloencephalopathy

Or neuro pathogenic disease with mutation of EHV1

Question 26

What is the most common form of EHV 1 and 4

Answer 26

URT - similar to influenza

Question 27

Abortion due to EHV is late term at least __ months into gestation, the fetus is minimally __, the fetus and placenta contain __ viral loads and typically follows respiratory signs

Answer 27

Abortion due to EHV is late term at least 5 months into gestation, the fetus is minimally autolysis, the fetus and placenta contain high viral loads and typically follows respiratory signs

Question 28

When should you vaccinate to prevent EHV 1 and 4?

Answer 28

1. First vaccine at 6 months, then 2 doses at 3 to 4 week intervals, third dose at 8-12 weeks then vaccinate every 4 to 6 months
2. Broodmares should be vaccinated a months 5,7,9,11 of gestation to prevent abortion

Question 29

T/F: the EHV vaccine prevent abortion but is not completely protective for other forms of disease

Answer 29

T

Question 30

Equine Viral Arteritis characteristics

Answer 30

EVA is a single stranded RNA virus in the family arteriviridae that is transmitted by aerosolized, contact with other horses, and venereal transmission that results in cell associated viremia and replication

Question 31

Equine viral arteritis will have a normal respiratory infection but horses may also develop ___ and __ of the mid ventrum, limbs, prepuce, scrotum and mammary gland. Young foals can develop fatal ___

Answer 31

Equine viral arteritis will have a normal respiratory infection but horses may also develop conjunctivitis and edema of the mid ventrum, limbs, prepuce, scrotum and mammary gland. Young foals can develop fatal interstitial pneumonia

Question 32

Equine viral arteritis will have a normal respiratory infection but horses may also develop ___ and __ of the mid ventrum, limbs, prepuce, scrotum and mammary gland. Young foals can develop fatal ___

Answer 32

Equine viral arteritis will have a normal respiratory infection but horses may also develop conjunctivitis and edema of the mid ventrum, limbs, prepuce, scrotum and mammary gland. Young foals can develop fatal ___

Question 33

How do EAV abortions differ from abortions caused by herpes?

Answer 33

EAV abortions can occur from 3 to 10 months of testimony , occurs while the mare has respiratory signs and the fetus is autolyzed (looks like its been rotting).

Herpes will happen after 5 months and the fetus will not be autolyzed

Question 34

Whats unique about the EVA vaccine and what animals should be vaccinated?

Answer 34

Once an animal is vaccinated for EVA they will be seropostive so not all animals should be vaccinated (esp if exporting). The modified live vaccine can be given to:
1. breeding colts 6 to 12 months of age
2. seronegative mares (for stallion carrier breeding, also need to isolate for 21 days bc they may shed)