Defense & Barriers 2: LA Immunodeficiency

Question 1

4 types of infections most common in IMMUNODEFICIENT animals?

Answer 1

1. NON-RESPONSIVE infection
2. RECURRENT infections
3. Often non-pathogenic/OPPORTUNISTIC organisms
4. Typically at a YOUNG AGE

Question 2

RISK factors for failure of passive transfer? (4, include subs for first and last)

Answer 2

1. Foaling EARLY in the YEAR
   –> Days are SHORTER so COLOSTRUM ISN’T AS GOOD
2. Adverse health events to mare or foal during periparturient period can prevent INGESTION of colostrum by foal or PRODUCTION of colostrum by dam
3. Age of dam (OLDER is worse)
4. Colostral immunoglobulin content is NOT GOOD QUALITY
   –> GOOD QUALITY = 2500  5000 mg/dL IgG

Question 3

how do we get POOR QUALITY COLOSTRUM that then causes ___ ____ ____ ____?
start with fill in the blank
4 reasons, but include 3 subs for FIRST and THIRD points

Answer 3

causes FAILURE of PASSIVE TRANSFER

1. PREMATURE lactation
   –> Twin pregnancies
   –> Placentitis
   –> Premature placental separation
2. Premature foaling = MARE HASN’T DEVELOPED THE COLOSTRUM AS WELL
3. FAILURE for mare to concentrate IgGs
   –> STANDARDBREDS more likely to have this happen
   –> Shorter day length
   –> Older mares
4. Ingestion of FESCUE GRASS by dam

Question 4

when do PRIMARY IMMUNODEFICIENT foals show SIGNS OF INFECTION if FPT is adequate?

Answer 4

1-2 months! WHEN MOM’S IgG is GONE

Question 5

4 common bacterial infections SECONDARY TO FPT?

Answer 5

1. Septicemia
2. Septic arthritis
3. Pneumonia
4. Enteritis

Question 6

what should we NOT do to measure HOW MUCH COLOSTRUM a FOAL has ingested? what organism CAN we do this in?
what 2 tests CAN we do in foals? (2 types/2 subs for bottom)
when is the best time to take this measurement in foals/why?

Answer 6

we should NOT do TOTAL SERUM PROTEIN to determine COLOSTRUM INGESTION in FOALS, but CAN IN CALVES!

what 2 tests?
1. QUANTITATIVE = RADIAL IMMUNODIFFUSION ASSAY
2. SEMIQUANTITATIVE = ELISA (stall-side)
–> compare result to INSERT
–> gives RANGE

best time?
–> BETWEEN 12-24 hours of age!
–> Absorption of colostrum DECLINES RAPIDLY in the FIRST FEW HOURS

Question 7

colostrum PARAMETERS in foals? (4)

Answer 7

<800 mg/dL = FAILURE TO INGEST or ABSORB IgG

<400 mg/dL at 24 hours = COMPLETE FAILURE

400-800 mg/dL = PARTIAL failure

> 1000 mg/dL = HEALTHY foals with adequate ingestion/absorption

Question 8

how can a DIRTY ENVIRONMENT affect amount of COLOSTRUM a foal needs?

Answer 8

if in DIRTY ENVIRONMENT, more likely to be EXPOSED TO PATHOGENS and have to USE UP IgG FENDING THEM OFF

will need MORE COLOSTRUM

Question 9

TREATMENT of FPT in foals depends on what 4 things?

Answer 9

1. Degree of FPT
2. Environment cleanliness
3. Foal’s age at diagnosis
   –> If foals is 24 hours and IgG LOW, CANNOT ABSORB COLOSTRUM ANYMORE
4. Presence of secondary infection, at higher risk of catabolizing IgG

Question 10

who should we give EXTRA colostrum to? (2, foals)

Answer 10

babies that are SEPTIC/NOT ACTING RIGHT and BEFORE 24 HOURS

Question 11

colostrum administration in FOALS
what should we give in NORMAL and COMPLETE FAILURE foal? (include weight)

what should we do if COLOSTRUM is not available in normal and complete failure foals??

Answer 11

NORMAL foal?
1. Giving oral colostrum within 6-12 hours allows for GOOD ABSORPTION
2. Give 1-3 L over MULTIPLE FEEDINGS if COMPLETE FAILURE (45 kg foal)

if COLOSTRUM not available?
–> IV plasma after 12 hours (2-4 L for complete failure)

Question 12

what if CALVES don’t receive colostrum?
3 ways this can physically manifest?
what OTHER kind of immunity can colostrum provide?

Answer 12

NO COLOSTRUM = still capable of mounting INNATE immune response, but GREATER RISK OF DISEASE during NEONATAL PERIOD and BEYOND

manifests as…
1. OMPHALITIS (umbilical infections)
2. Pneumonia
3. D+

colostrum also provides ENTERIC IMMUNITY for 3-4 days

Question 13

when to feed colostrum in CALVES?
2 methods to feed it? (+how much to administer in second option)
can we give colostrum from MULTIPLE COWS/why?

Answer 13

when?
= feed APPROPRIATE VOLUME within FIRST 2 HOURS OF LIFE

2 methods?
1. BOTTLE FED = helps close ESOPHAGEAL GROOVE
2. ESOPHAGEAL FEEDER = MORE EFFICIENT
–> need to give 4 L in FIRST 4 HOURS

DO NOT give colostrum from multiple cows because BACTERIAL OVERLOAD

Question 14

2 ways to test QUALITY of colostrum in cows & values?

Answer 14

1. Brix refractometer
   –> Should be >22%
2. Colostrometer (specific gravity)
   –> 50 g/L IgG is adequate

Question 15

what should we do to test COLOSTRUM ABSORPTION/INGESTION in calves?
what tool should we use to measure this?
3 parameters/their meaning?

Answer 15

= TOTAL SERUM PROTEIN levels should be DRAWN AFER 24 HOURS

we should use a COLOSTROMETER (specific gravity) TO MEASURE

3 parameters?
1. FAILURE = <5.5 g/dL
2. ADEQUATE = 5.5-6 g/dL
3. EXCELLENT = >6 g/dL

Question 16

Severe Combined ImmunoDeficiency (SCID)…
what is it? (2)
how is it inherited in HORSES?
what 5 species is it prevalent in? (include breed for last one)

Answer 16

what is it?
1. a GROUP of disorders where T- and B-cell functions are ABSENT due to STEM CELL DEFECT that PREVENTS MATURATION of T and B cells
2. causes ABSENCE of ANTIGEN-SPECIFIC immune responses, including HUMORAL or CELLULAR immunity

inherited horses? = AUTOSOMAL RECESSIVE trait

species?
1. Humans
2. Mice
3. Dogs
4. Pigs
5. Horses –> More commonly ARABIANS & PART-ARABIANS

Question 17

Severe Combined ImmunoDeficiency (SCID)…
when do infections tend to occur? (2)
which disease is most COMMON? what 2 pathogens can cause it?
lifespan?
additional 2 clinical signs? (1 is a sign, 1 is a test result)

Answer 17

when do infections tend to occur?
1. Tends to be normal at birth but develop infections as COLOSTRAL ANTIBODIES WANE
2. Infectious disease occurs between birth and 2 months of age

COMMON disease?
= PNEUMONIA particularly common, caused by…
1. Pneumocystis carnii
2. adenovirus

lifespan? = die by 5 months of age

2 clinical signs?
1. Thymic hypoplasia
2. NEGATIVE for intradermal phytohemagglutinin (PHA)
= NO INCREASE IN SKIN THICKNESS

Question 18

Severe Combined ImmunoDeficiency (SCID)…
2 hematological results?
diagnosis? (3)

Answer 18

2 hematological results?
1. PERSISTENT ABSOLUTE LYMPHOPENIA
2. Absence of serum IgM in PRESUCKLE (before colostrum) SAMPLES

diagnosis?
1. via GENETIC TESTING via pulling HAIRS
2. must be HOMOZYGOUS for DEFECTIVE SCID GENE
3. Make sure to get HAIR ROOTS

Question 19

what is the MOST COMMON DIAGNOSTIC route for SCID?

Answer 19

GENETIC TESTING via PULLING HAIRS

Question 20

foal immunodeficiency syndrome…
“old name?”
3 predisposed breeds?
etiology? (3)
clinical signs? (5)

Answer 20

“FELL PONY SYNDROME”

3 breeds?
1. fell ponies
2. dale ponies
3. gypsy vanners

etiology?
1. GENETIC and INHERITABLE fatal condition
2. caused by SINGLE NUCLEOTIDE POLYMORPHISM
3. Inherited via AUTOSOMAL RECESSIVE

clinical signs?
1. Born HEALTHY but RAPIDLY FAILS TO THRIVE by 1 MONTH
2. Weight loss
3. Dullness
4. Pale mucous membranes
5. Infection (pneumonia, entercolitis)

Question 21

what 2 diseases can we genetically test for in horses?

Answer 21

severe combined immunodeficiency & foal immunodeficiency syndrome

Question 22

selective IgM deficiency
commonality?
what defines it?
etiology?
2 breeds common?
MOST COMMON presentation? (clinical signs & survival)
RARE presentation? (clinical signs & survival)
additional presentation? (** hint = age range)
prognosis?

Answer 22

commonality? = RARE

what defines it?
= ABSENT or MARKEDLY DECREASED serum IgM concentrations with normal or ELEVATED levels of other Ig isotypes

etiology? = CAN be hereditary

breeds?
1. ARABIANS
2. AMERICAN QUARTER HORSES

MOST COMMON presentation…
1. Foal with SEVERE INFECTIONS (pneumonia, arthritis, enteritis)
2. Die by 10 mos of age

RARE presentation…
1. REPEATED infections that respond to antibiotics but tend to recur
2. Survive 1-2 years

additional presentation?
2-5 year olds will DEVELOP LYMPHOSARCOMA

prognosis? = GUARDED

Question 23

COMMON VARIABLE IMMUNODEFICIENCY…
commonality?
what is it/what does it result in?
age?
history?
what disease should we RULE OUT?
when INFECTIONS occur, what causes them?
weird vaccine response?

Answer 23

RARE

= LATE-ONSET immunological disorder of the HORSE where IMPAIRED B CELL DIFFERENTIATION causes INADEQUATE Ab PRODUCTION in the BONE MARROW
–> Results in B-cell DEPLETION from lymphoid tissues & blood

age?
= tends to occur in 10 years or older, but 2-23 range
** OLDER MORE COMMON

history? = HEALTHY until late-onset RECURRENT BACTERIAL INFECTIONS and FEVERS

what disease should we RULE OUT? = PPID, much more common!

INFECTIONS often caused by ENCAPSULATED bacteria

hematology?
1. Serum IgG LOW (<800 mg/dL)
2. IgM reduced
3. IgA starts out NORMAL then REDUCES

**HAS NO RESPONSE TO TETANUS TOXOID (vaccine)

Prognosis? = GUARDED, hard to manage!

Question 24

Bovine Leukocyte Adhesion Deficiency (BLAD)
= what is it/what single thing causes it?
etiology? (2)
what breed?
4 clinical signs?
hematological finding?

Answer 24

= LACK of expression of ADHESION MOLECULES (CD11/CD18) on LEUKOCYTE SURFACE from a SINGLE POINT MUTATION

etiology?
1. AUTOSOMAL RECESSIVE
2. CONGENITAL disease

breed = HOLSTEIN CALVES

clinical signs?
1. CHRONIC, RECURRENT bacterial infections within a couple weeks of birth
2 Severe oral ulcerations
3. Loss of teeth
4. Death

hematological finding?
= marked and PERSISTENT neutrophilia due to LACK OF EMIGRATION OUT OF VESSEL

Question 25

failure of passive transfer in FOALS…
why does it happen? (2)
how long do maternal Abs provide protection?
what’s it called when Abs transition from mom to neonate IgG/should we worry about the levels dipping below healthy?

Answer 25

why does it happen?
1. Normal foals are IMMUNOCOMPETENT AT BIRTH and capable of mounting immune response
2. BUT, they’re IMMUNOLOGICALLY NAÏVE, so because they’ve had no exposure to pathogens and no transfer of IgGs from mom –> neonate (diffuse epitheliochorial placenta) until COLOSTRUM ingestion

maternal Abs protection?
–> once ingested, lasts 1-2 months

Abs transition?
MATERNAL –> AUTOLOGOUS IgG
TOTAL ANTIBODY LEVELS, whether maternal or autologous, WILL NOT DIP BELOW HEALTHY