Equine Liver and Weight Flashcards
mechanisms of bilirubin leading to icterus
decreased excretion (liver, biliary dx)
increased production (haemolytic anaemia)
impaired conjugation (liver dx)
which leads to more pronounced jaundice: conjugated or unconjugated bilirubin? acute vs chronic liver dx?
conjugated
acute
What are the 2 hepatocyte derived enzymes?
GLDH (liver specific)
AST (non-liver specific)
What are the 2 biliary trat derived enzymes?
GGT (liver specific)
AP (non-liver specific)
what does PCV and RBC tell you about liver status
haemolysis
most common cause of chronic liver dx in horses in UK
ragwort (cumulative effects)
pathology appearance for ragowrt
biliary hyperplasia
central vein occlusions
megalocytes
large RBC associated w ragwort
list some Ddx for liver dx
Ragwort
Cholangiohepatitis
Haemachromatosis
Abscess
Aflotoxicosis
Neoplasia
Fluke
pathogenesis of cholangiohepatitis?
intestinal reflux up bile ducts ==> inflammation & infection
BW signs for cholangioheptatits? tx?
increased bilirubin
increased GGT.
antimicrobial
what is Haemachromatosis
excessive iron accumulation in liver –> fibrosis, biliary hyperplasia
what can cause haemachromatosis
excessive iron supplements or sporadic
is liver cancer common in horses
no
tx for fluke
triclabendazole
Hyperlipaemia is often seen as a response to
stress or NEB
adipose tissue releases __ that infiltrate the organs and cause secondary liver damage
TGs
signs of hyperlipaemia
anorexia
depression
CNS (circling, seizure)
ventral edema
dx of hyperlipaemia
high TG in blood + fatty looking plasma
signs of liver dx show when ____% of hepatocytes are destroyed. It may have a history of what?
60-70
weight loss, low appetite
signs of liver dx
depression
anorexia
weight loss
abdominal pain
photosensitization, pruritis
HE (+/- bilateral laryngeal paralysis)
coagulopathy
will liver cases show hyper or hypo glycaemic
usually hyper
Liver enzymes indicate damage. Which values indicate function
bile acids
bilirubin
ammonia
why does acute liver dx have better prognosis than chronic
less fibrosis
diet for liver cases
high carb
which liver issues would antibiotic be needed
cholangitis
abscess
what condition would tracheostomy be needed
HE (bilateral laryngeal paralysis)
how to reduce GI absorption of potential toxins
liquid paraffin
lactulose
for EGS: which nervous system determines prognosis/severity of the dx
enteric
signs of EGS: ANS?
tachycardia
dysphagia
salivation
bilateral ptosis
sweating
rhinitis sicca (pathonumonic)
signs of EGS: ENS?
gastric reflux
firm, mucusy poo
risk factors for EGS
Young adult
Grazing, feed change
Frequent anthelmintics
which cases of EGS are not always fatal
chronic (50%)
short term measure tell horse for horse that may have EGS
take off grazing
does liver dx cause low albumin (–> edema) in the horse?
rarely
(protein loss through GIT is most common reason for low protein)
where on belly to do abdominocentesis
lowest point of midline
indication for rectal biopsy?
low albumin
non specific tx of weight loss
assess medications
prednisolone?
high E diet
anthelmintics
how can meds lead to weight loss? examples
phenylbutazone = colitis
AB = dysbiosis
what is laminitis
breakdown of hoof/lamellar bond
predisposition for laminitis?
obese
PPID
inflammation
PPID
triggers for laminitis?
insulin
change in blood flow
inflammation
mechanisms leading to laminitis?
lack of glucose/oxygen
protein breakdown
inflammation
what’re the 3 types of laminitis
Endocrinopathic (85%)
Inflammatory
Concussive
Endocrinopathic laminitis can be related to Insulin Resistence. What might cause this?
- Genetics (ponies)
- Obesity
- PPID
what is PPID?
Equine Cushing’s Disease (ECD):
excess cortisol (–> antagonizes insulin)
what age gets PPID
prevelence increases w age
is PPID pituitary, adrenal, or iatrogenic?
pituitary
signs of PPID
-Fluffy fur
-Prone to laminitis/infections
-Fat redistributions
-PUPD
-Sweating
what is hirsutism
hairiness, start w retained winter coat
where does fat deposit in re-distribution of PPID
above eyes
crest of neck
sheath/mammary region
how to dx PPID
resting ACTH
TRH response test (if still needed)
what would be an abnormal response to the glucose insulin test
glucose stays high, but jumps up and down
conservative tx for PPID?
-clip hair
-tx secondary infections
-monitor weight, teeth
-prevent laminitis
tx for PPID?
-dopamine agonist (Pergolide)
-serotonin antagonist
-trilostane
how does dopamine and 5HT (serotonin) affect ACTH
dopamine has negative feedback
5HT has positive feedback
poor prognostic indicators for PPID
laminitits
weight loss
secondary DM
not responding to tx
protocol for recurrent laminitis?
- rule out PPID/ exam
- resting metabolic bloods (assess insulin)
- dynamic tests
what factors can led to insulin dysregulation and hence endocrinopathic laminitis
genetics
PPID
obesity
iatrogenic steroids
stress
who gets Equine Cushing’s Disease (PPID)
older ponies
which cell type in the Pars Intermedia leads to overproduction of ACTH going to the adrenal gland
Melanotropes (no negative feedback)
clinical signs of poo
