TV4101 - Bovine - Nervous 3 - Young Calves

Alpha-Mannosidosis

Signalment?

How does it work?

Control?

Affects Angus and Murray Grey

Autosomal, recessive deficiency of the

enzyme α-mannosidase is inherited → widespread storage of mannose-containing oligosaccharides

Large scale genetic screening programmes within pedigree nuclei

Alpha-Mannosidosis

CX?

Can be normal for several months b4 getting prog neuro signs

- a wide-based stance

- ataxia

- incoordination

- head nodding

- a tendency towards aggressiveness

BVD-ass. neuro dz in calves

How work? When?

Infection of a naïve dam around 90-130 days of gestation

• BVDV inf in pregnant cow → inf foetus

BVD-ass. neuro dz in calves

CX

Brain changes?

- cerebellar hypoplasia

- less commonly hydranencephaly, internal hydrocephalus,

microencephaly, porencephaly, or hypomyelinogenesis

BVD-ass. neuro dz in calves

CX

Eyes?

Eyes

• oscillating nystagmus

• No menace

• Micropthalamia

• Cataracts

• Retinal degen

BVD-ass. neuro dz in calves

CX

Movement issues?

Incoordination (characterised by a wide-based stance &

ataxia) is usually the most prominent sign

Dysmetria

BoHV - ass neuro dz

BoHV-1 usually causes?

Respiratory (IBR) or genital (IPV/IPB) diseases in cattle; less commonly it may be ass. with encephalitis

BoHV - ass neuro dz

BoHV-5 infection may cause?

Encephalomyelitis in young calves in Aus

BoHV - ass neuro dz

Disease is characterised by?

- incoordination

- occasional circling or licking of the flanks

- recumbency & death

BoHV - ass neuro dz

DX?

brain sample submitted for standard virus isolation procedures or virus identification by fluorescent

antibody techniques

BoHV

Diff types and dz they cause"?

 BoHV-1

IBR: Infectious bovine Rhinotracheitis

IPV: Infectious pustular vulvovaginitis

IBP: Infectious balinoposthitis

 BoHV-2

Bovine Herpes Mammillitis

Pseudo lumpy skin disease

 BoHV-5

Encephalomyelitis in young calves

Akabane Virus-asso dz

Prevalence?

Akabane virus is a major cause of epizootics of?

Transmission?

Endemic in N AUS

Congenital dz in calves → either hydranencephaly and/or arthrogryposis

• Present at birth → euth only option mostly

Spread by biting arthropods; major carrier is the biting

midge Culicoides brevitarsis

Akabane Virus-asso dz

In outbreaks occurring in herds with year-round or extended calving periods, what may we see?

First (early) cases seen are the result of viral infection in late gestation →Arthrogryposis

Towards the end of an outbreak are due to infection that

occurred when the foetus was in an early stage of development → Hydrancephaly

Akabane Virus-asso dz

In case of restricted seasonal breeding (or limited periods of exposure to infected vectors), abnormalities may be limited to?

Only one type

Akabane Virus-asso dz

The diff types of defect and when it happens?

 Arthrogryposis is usually seen in the early stage of an outbreak (it is the result of infection late in gestation – between 105 and 150 days)

 Hydranencephaly is usually seen towards the end of an outbreak (it is the result of infection early in gestation – between 30 and 105 days)

Calves showing both defects occur in the middle of an outbreak (it is the result of infection between 100 and 120 days of gestation)

What is this Dz?

Describe each photo

Akabane Virus-asso dz

Left - Severe arythrogryposis

Right - Small brain (microencephaly) surrounded by CSF

Clostridial (haemorragic) entertoxaemia

Agent? Features?

Affected calves age?

Clostridium perfringens

• 5 genotypes (A, B, C, D and E), but only Type D is important in cattle

• Ass with exotoxin prod in GIT lumen

1-2 wks old (but can be as old as 10 wks)

Otitis media (and vestibular Dz)

Commonly secondary to?

Neurological signs associated with otitis media include?

Most cases will?

TX?

Respiratory disease, (particularly bronchopneumonia) → bacteria reach middle ear via Eustachian tube

- head tilt

- drooping eyelids (ptosis)

- paralysis & drooping of the ear

Have discharge from affected ear

Treatment → broad-spectrum antibiotics & NSAID

Clostridial (haemorragic) entertoxaemia

CX?

- sudden death

- frothing at the mouth

- haemorrhagic diarrhoea

- abdominal discomfort

Neuro

• Stagger

• Appear blind

• Recumbent

• Some cases → opisthotonos, rigid muscles, convulse

Clostridial (haemorragic) entertoxaemia - DX

PM?

Definitive diagnosis requires identification of?

What else can we see?

Post-mortem examination → small intestine may be

haemorrhagic (associated with ischaemic necrosis)

β- or ε-toxin in small intestinal contents

Large numbers of Gram-positive rods in impression smears from duodenal or jejunal mucosa is strongly supportive (Clostridium spp are not normal inhabitants of upper SI)

Vertebral (spinal) abscess

Overview?

Why does it happen?

CX?

Abscessation or osteomyelitis of the spinal vertebrae is most

commonly seen in calves between 2 and 6 months of age

• Infection is usually the result of haematogenous spread

• Compressive lesion on the spinal cord → ataxia & paralysis

Vertebral (spinal) abscess

CX

Vary based on location of lesion

describe each

Lesion btw - T2 and L3

• Hindlimb ataxia and paresis

• W/O dysfunction of

  peripheral ns of hindlimbs and paralysis of rectum, bladder & tail

Cranial to T2

• Rigidity of forelimbs or tetraparesis

Lesion between C6 and T2

• Weak/para forelimbs with poor/absent reflexes

• HL less weak with normal/exaggerated reflexes

Where is lesion?

Lesion between T2 and L3

Where is lesion?

Lesion between C6 and T2

Many congenital diseases have been reported in cattle

May be ass with?

infectious, genetic, endogenous biochemical, and exogenous toxic causes

Congenital neuro dz in calves

cerebral disorders → primarily associated with changes in?

Mental status or behaviour, functional disturbances and abnormal postures

Congenital neuro dz in calves

cerebellar disorders → primarily characterised by?

incoordination

Congenital neuro dz in calves

Spinal defects ass with?

Affected peripheral control

Steps to follow when dealing with possible congenital neuro dz?

1. ID and confirm dz is neuro and ass. with changes b4 birth

2. Do good ante-mortem investigation to find lesion site

3. Submit animal for further PM exam and lab investigation

Citrullinaemia

How work?

Inherited as an autosomal, recessive disorder of HolsteinFriesian calves → def of urea cycle

enzyme argininosuccinate synthetase → Affected calves have greatly elevated concentrations of citrulline and ammonia in the blood

Citrullinaemia

Control?

Screening of heterozygous bulls that enter AB centres, using a DNA-based test

Citrullinaemia

CX?

Neuro?

Diagnosis is based on?

Calve normal at birth → 4 days shit goes down

Quick death

Neuro

• Stupor

• Wander aimlessly

• Head pressing

• Collapse

• Convulse

• Paddling

• Bellowing

Elevated levels of serum citrulline (1-3 mM) by Day 3