Week 4- Equine Infectious Neurological Diseases

Question 1

What type of virus is West Nile virus

Answer 1

Flavivirus

Question 2

What insect vector transmits West Nile virus

Answer 2

Culex mosquito

Question 3

Do most horses infected with West Nile virus show clinical signs

Answer 3

No most horses remain asymptomatic

Question 4

What neurological symptom is commonly seen in West Nile virus infection

Answer 4

Muscle fasciculations

Question 5

What cranial nerve deficit can West Nile virus cause

Answer 5

Facial paralysis

Question 6

What is a primary test to diagnose West Nile virus in horses

Answer 6

IgM capture ELISA on serum

Question 7

What is a typical cerebrospinal fluid finding in West Nile encephalitis

Answer 7

Lymphocytic pleocytosis with elevated protein

Question 8

Is there a specific treatment for West Nile encephalitis in horses

Answer 8

No only supportive care

Question 9

Is a vaccine available for West Nile virus in horses

Answer 9

Yes an inactivated vaccine

Question 10

What should you do if you suspect a case of West Nile virus in the UK

Answer 10

Report it to DEFRA

Question 11

Is West Nile virus zoonotic

Answer 11

Yes it can infect humans

Question 12

What virus causes equine herpesvirus myeloencephalopathy

Answer 12

EHV1

Question 13

What is the mechanism of neurological damage in EHV1 myeloencephalopathy

Answer 13

Viral vasculitis and thrombosis causing ischaemic neuronal death

Question 14

In EHV1 myeloencephalopathy which limbs are usually more severely affected

Answer 14

The hindlimbs more than the forelimbs

Question 15

What urinary symptom is commonly seen in EHM

Answer 15

Urinary incontinence or bladder distension

Question 16

What clinical signs often precede the neurological signs of EHM

Answer 16

Fever dullness and inappetence

Question 17

What test is used to confirm EHV1 in a horse with neurological signs

Answer 17

PCR on a nasal or nasopharyngeal swab

Question 18

What colour may the cerebrospinal fluid be in EHM

Answer 18

Xanthochromic

Question 19

How are horses with EHM treated

Answer 19

Symptomatic and supportive care with NSAIDs nursing and antivirals

Question 20

What antiviral drug may be used in EHM

Answer 20

Valacyclovir

Question 21

What biosecurity action should be taken for EHM cases

Answer 21

Isolation of affected horses

Question 22

Can vaccination prevent EHM completely

Answer 22

No but it may reduce viral shedding

Question 23

What is the prognosis if a horse with EHM is recumbent for more than 24 hours

Answer 23

Grave

Question 24

What bacterium causes tetanus in horses

Answer 24

Clostridium tetani

Question 25

How does tetanus toxin affect the nervous system

Answer 25

It blocks inhibitory neurotransmitters like GABA causing spastic paralysis

Question 26

What are early clinical signs of tetanus in horses

Answer 26

Stiffness third eyelid prolapse nostril flaring

Question 27

What is the typical stance of a horse with tetanus

Answer 27

Sawhorse stance

Question 28

What autonomic signs may be seen in tetanus

Answer 28

Tachycardia and miosis

Question 29

How is tetanus treated in horses

Answer 29

Penicillin antitoxin wound care and muscle relaxants

Question 30

Why must antitoxin be given before wound debridement

Answer 30

To neutralise circulating toxin before it enters neurons

Question 31

What muscle relaxants are used to treat tetanus

Answer 31

Diazepam methocarbamol alpha2 agonists

Question 32

What environmental changes reduce stimulation in tetanus

Answer 32

Dark stable cotton wool in ears low noise

Question 33

When should tetanus vaccination start in foals

Answer 33

From 6 months of age

Question 34

What is the booster schedule for tetanus in adult horses

Answer 34

Every 2 years after primary course

Question 35

What is the prognosis for recumbent tetanus cases

Answer 35

Very poor to grave

Question 36

What bacterium causes botulism

Answer 36

Clostridium botulinum

Question 37

What are three routes of botulism exposure in horses

Answer 37

Ingestion of toxin ingestion of spores wound infection

Question 38

What is the pathophysiology of botulism

Answer 38

Toxin blocks acetylcholine release at the neuromuscular junction

Question 39

What type of paralysis does botulism cause

Answer 39

Flaccid paralysis

Question 40

What cranial nerve signs may be seen in botulism

Answer 40

Dysphagia ptosis reduced tongue tone

Question 41

How is botulism treated

Answer 41

Supportive care and botulinum antitoxin

Question 42

What improves prognosis in botulism

Answer 42

Nonrecumbency at presentation

Question 43

Is botulism common in the UK

Answer 43

No it is rare

Question 44

What is the suspected cause of Equine Grass Sickness

Answer 44

Ingestion of a neurotoxin possibly Clostridium botulinum related

Question 45

What part of the nervous system is most affected in EGS

Answer 45

The enteric nervous system

Question 46

What age group is most at risk of EGS

Answer 46

Horses aged 2 to 7 years

Question 47

Name two risk factors for EGS

Answer 47

Cool dry weather and recent movement to new pasture

Question 48

What are the three clinical forms of EGS

Answer 48

Acute subacute and chronic

Question 49

What is the prognosis for acute EGS

Answer 49

Fatal within 48 hours

Question 50

What are typical signs of chronic EGS

Answer 50

Weight loss dysphagia rhinitis sicca narrow stance

Question 51

Why is manual faecal evacuation needed in EGS

Answer 51

Because GI motility is impaired causing impactions

Question 52

What is rhinitis sicca in the context of EGS

Answer 52

Dry crusted nasal mucosa from autonomic dysfunction

Question 53

How is a definitive diagnosis of EGS made

Answer 53

Histopathology of enteric or autonomic neurons

Question 54

What topical test may temporarily reverse ptosis in EGS

Answer 54

Phenylephrine eye test

Question 55

What is the mainstay of chronic EGS treatment

Answer 55

Intensive nursing and nutritional support

Question 56

Why is owner commitment crucial in chronic EGS

Answer 56

Treatment is expensive prolonged and outcome is uncertain