Presentation for VMC 979 (Equine Medicine, senior clinical rotation) discussing basic details of hyperlipemia in equids. Includes signalment, risk factors, pathogenesis, clinical signs, diagnosis, treatment, and prognosis.

1. HYPERLIPEMIA IN EQUIDS
Omega Cantrell
VMC 979

2. THE BASICS
 Clinical manifestation of a severe imbalance between energy
intake and demand
 Similar to ketosis in dairy cattle, but with triglycerides (TGs) rather
than ketones as a consequence of this negative energy balance
 Definitions
 Hyperlipidemia
 Serum [TG] increased but <500ng/dL
 Hyperlipemia
 Serum [TG] >500ng/dL

3. SIGNALMENT, HISTORY, RISK FACTORS
 Breed predilection
 Ponies, pony crosses, mini horses, donkeys, mini donkeys
 Body condition
 Obese animals (greater fat stores)
 Risk factors
 Obesity, lactation/pregnancy, stress/transportation
 Concurrent disease/state of increased demand with decreased intake
(especially in high risk breeds)
 Chronic internal parasitism, colitis, colic, poor nutrition, etc.
  Anything that would cause an animal to go off -feed, thus resulting in
decreased energy intake compared to increased metabolic demands

4. PATHOPHYSIOLOGY
 Negative energy balance = fatty acids (FAs) mobilized from
adipose tissue
 Most animals = production of ketones from FAs
 Equids ≠ ketones  large amounts of mobilized lipids in circulation
 Problem is TG overproduction, not catabolic failure
 Hyperlipemic ponies = lipoprotein lipase (LPL) activity is 2x that of healthy
animals of the same breed
 May be precipitated by insulin resistance
 Insulin inhibits hormone sensitive lipase (HSL, responsible for mobilization
of fatty acids from adipose tissue)
 Resistance = increased HSL activity = more FA mobilization, increased TGs
 Exacerbated by risk factors (obesity, pregnancy, stress)
 High serum [TG] may prolong/complicate recovery

5. CLINICAL SIGNS
 Often referable to the primary disease
 Hyperlipemia is typically a secondary problem
 Can see severe depression, anorexia
 Non-specific signs  measure serum [TG] in depressed,
inappetant animals of at-risk breeds

6. DIAGNOSIS
 Serum [TG]
 May also diagnose with PCV/TS – will see cloudy/white (lipemic)
serum once hemocrit tube is centrifuged
 Hepatic/renal function, chemistry profile
 Assessing for an underlying cause; can also help prognostically
 Any diagnostics need for evaluation of the primary condition
 YOU MUST TREAT THE UNDERLYING DISEASE!

7. COMPLICATIONS
 Hepatic failure
 Renal failure
 Death
 If it can be identified, YOU MUST TREAT THE PRIMARY
DISEASE!
 = often ends up being an expensive treatment, due to need for
diagnostics and aggressive treatment in most cases

8. TREATMENT
 Nutritional support
 Reverses negative energy balance, increases serum [GLUC], promotes
endogenous insulin release, inhibits lipid mobilization from
peripheral stores
 “Smorgasbord” approach, enteral, parenteral (rarely)
 Resolve the primary disease!
 Insulin therapy
 May not be effective if insulin resistance is present
 Heparin therapy
 Enhances lipogenesis via stimulation of LPL, but no longer
recommended (LPL high in affected individuals)
 Contraindicated if coagulopathic due to liver dysfunction
 No longer recommended as a mainstay of therapy

9. PROGNOSIS
 Poor to grave
 Mortality 43-80%
 Survival in mini horses and donkeys (78%) vs. ponies (20 57%)
 Prognosis worsens if renal involvement is present
 Development or worsening of azotemia
 Renal failure can cause further anorexia, which will exacerbate
hyperlipemia; also results in build up of toxins in the body
 Death is more often from failure to treat the primary disease
 These animals are typically presented when signs are
advanced, thus rapid, aggressive treatment is often required
 Can become very expensive very quickly  combination of poor
prognosis with a large estimate for care often results in euthanasia

10. REFERENCES
 Boyce, M. (1999). Hyperlipemia in Ponies and Miniature
Horses. Available:
http://wwwchem.csustan.edu/chem4400/sjbr/99boyce.htm.
Last accessed 24 October 2013.
 Semrad, SD. (2012). Hyperlipemia and Hepatic Lipidosis in
Large Animals. In: Aiello, SE et al. The Merck Veterinar y
Manual. Whitehouse Station, NJ: Merck Sharp & Dome Corp.
 Watson, T et al. (2013). Hyperlipemia Syndrome. Available:
http://www.vetstream.com/equis/Content/Disease/dis0032
9. Last accessed 24 October 2013.