NP4D

Question 1

• there is actually very little inflammation in these lesions
• has an unusual tropism for vascular endothelial cells of spinal cord and brainstem white matter
• Disease presents as a sudden onset of ataxia in otherwise healthy horses
• Severe forms can present as paraparesis and animals are euthanized because of the irreversible nature of the change
• Gross post mortem examination shows multifocal hemorrhage in the white matter, and these are often triangular shaped foci with the base oriented to the meningeal surface

Answer 1

equine herpesvirus myeloencephalitis

Question 2

fatal generalized perinatal infection
abortion

Answer 2

Equine herpesvirus 1

Question 3

causes an airway infection, rhinopneumonitis

Answer 3

Equine herpesvirus 4

Question 4

coital exanthema (urogenital infection)

Answer 4

Equine herpesvirus 3

Question 5

Equine herpesvirus 3 and Equine herpesvirus 4 do not cause what?

Answer 5

equine herpesvirus myeloencephalitis, infarction of WM

Question 6

Clinical differentials for ataxia in a horse:

Answer 6

• Degenerative myeloencephalopathy (a neuroaxonal dystrophy), no gross changes
• Cervical vertebral instability, spinal cord compression
• Cervical static stenosis, measuring areas where the vertebral canal is narrowed

Question 7

Clinical signs are generally mild and include diarrhea. These viruses can persist, with animals developing a high antiviral antibody titer in serum.

Answer 7

feline enteric coronaviruses (FECV)

Question 8

___________ are commonly infected by feline enteric coronaviruses (FECV) that predominantly replicate in the epithelium of the distal small intestine and cecum.

Answer 8

Young cats

Question 9

The problem is when a variant of the FECV is encountered, and this variant is distinct in that it has a strong tropism for monocytes. This variant is known as FIPV and either arises directly from a persistent FECV or represents a new infection. Now we have circulating monocytes that are producing virus, generating complement, reacting to activated complement, and releasing inflammatory cytokines.

Question 10

There is a wet and dry form of the disease, although the distinction has little clinical value. Both are associated with a strong humoral (B cell) response that drives immune complex formation.

Answer 10

refer to the disease as FIP

Question 11

The ___________ is associated with a stronger cell-mediated (T cell response) with less vascular effusion and discrete nodules along blood vessels. These nodules are foci of pyogranulomatous inflammation - a focal response to immune complex deposition, complement activation, and the monocyte response.

Answer 11

dry form of FIP

Question 12

In the ____________, the change is characterized by diffuse leakage of fluid and fibrin in capillary beds of the pleura (with pleural effusion), peritoneum (peritoneal effusion), and the delicate capillary beds beneath the ependymal lining of the ventricles in the brain.

Answer 12

wet form of FIP

Question 13

Is a Retrovirus that causes arthritis in adult goats, being transmitted through body fluids and feces, and it causes encephalitis in the young, where the virus may be acquired through colostrum or milk.

Answer 13

Caprine arthritis encephalitis virus (CAEv) infection

Question 14

Caprine arthritis encephalitis virus (CAEv) infection:
A common cell target for infection is the _______________, and this includes microglia in the brain.

Answer 14

monocyte/macrophage

Question 15

Caprine arthritis encephalitis virus (CAEv) infection:
Persistent infection of these cells results in a heightened state of activation, which includes their antigen presentation functions. Priming of T cells to the virus has occurred in the periphery, and they respond to antigens presented by microglia, releasing __________ that can induce MHC I on oligodendrocytes and astrocytes

Answer 15

interferons

Question 16

Caprine arthritis encephalitis virus (CAEv) infection:
In the midst of this inflammatory response, an oligodendrocyte may die, be phagocytized, and the material trafficked to cervical lymph nodes where immune responses against privileged antigens (myelin-associated glycoprotein and myelin basic protein) may be primed. The autoreactive T cells not traffic into areas of inflammation and are stimulated by microglia expressing myelin-associated antigens, and attack oligodendrocytes expressing these epitopes via MHC I. The result is _____________

Answer 16

primary demyelination

Question 17

You are presented with an ataxic horse that is euthanized because of the poor prognosis for recovery. Which of the following differentials cannot be supported by gross examination alone?

Answer 17

degenerative myeloencephalopathy