Page 558 - Small Animal Internal Medicine, 6th Edition

530 PART IV Hepatobiliary and Exocrine Pancreatic Disorders

disease is likely to have a serious effect on both longevity and yet many potentially deleterious effects on the immune
quality of life. There are no studies specifically addressing the system and gut wall will already be underway. There is no
VetBooks.ir effect of malnutrition on survival and infections of dogs with simple blood test that allows diagnosis of malnutrition. The
most effective means to do this is by taking a careful history
liver disease, but in other canine diseases it is known to
increase the risk of septic complications. This is true in
with chronic liver or pancreatic disease should be considered
humans with portal hypertension and also likely in dogs. In as well as performing a clinical examination. Any animal
humans with portal hypertension, malnutrition also predis- as being at risk of protein-calorie malnutrition, and in this
poses to gut ulceration. In addition, negative nitrogen context an older animal that was previously overweight and
balance and reduced muscle mass predispose to HE. Break- has recently lost weight should be considered seriously for
down of body protein results in more ammonia production, nutritional and (if appropriate) pancreatic enzyme support.
and also in a normal individual up to 50% of arterial ammonia A history of partial or complete anorexia for more than
is metabolized in skeletal muscle by conversion of glutamate 3 days or recent weight loss of >10% not associated with
to glutamine, so loss of muscle mass will reduce the ability fluid shifts should trigger rapid and aggressive nutritional
to detoxify ammonia. What gives the most cause for concern management.
regarding protein-calorie malnutrition in the small animal
patient is that it is often partly caused by well-meaning but Suggested Readings
unhelpful manipulations by the clinician or even by a lack of Brioschi V, et al. Imaging diagnosis–extrahepatic biliary tract
recognition and attention. For this reason, it is very impor- obstruction secondary to a biliary foreign body in a cat. Vet
tant that clinicians treating dogs with chronic liver disease Radiol Ultrasound. 2014;55:628.
or cats and dogs with chronic pancreatic disease remain alert Fry W, et al. Thromboelastography in dogs with chronic hepatopa-
to the possibility of protein-calorie malnutrition. thies. J Vet Intern Med. 2017;31:419.
Malnutrition can also be seen in dogs and cats with con- Gow AG, et al. Surgical attenuation of spontaneous congenital por-
genital PSS, either as a result of reduced liver synthetic tosystemic shunts in dogs resolves hepatic encephalopathy but
not hypermanganesemia. Metab Brain Dis. 2015;30:1285.
capability or as a result of inappropriately severe protein Kelley D, et al. Thromboelastographic evaluation of dogs with acute
restriction by the attending clinician. Cats with chronic liver liver disease. J Vet Intern Med. 2015;29:1053.
disease may have negative energy balance, often as a result Lester C, et al. Retrospective evaluation of acute liver failure in dogs
of the effects of concurrent intestinal and pancreatic disease (1995–2012): 49 cases. J Vet Emerg Crit Care (San Antonio).
reducing digestion and absorption of food. In addition, cats 2016;26:559.
in negative nitrogen balance are at a particular risk of devel- Lidbury JA, et al. Hepatic encephalopathy in dogs and cats. J Vet
oping acute hepatic lipidosis (see Chapter 35), so protein- Emerg Crit Care (San Antonio). 2016;26:471.
calorie malnutrition in this species requires particularly Or M, et al. Ammonia concentrations in arterial blood, venous
aggressive management. blood, and cerebrospinal fluid of dogs with and without con-
genital extrahepatic portosystemic shunts. Am J Vet Res.
Clinical Signs and Diagnosis 2017;78:1313.
Or M, et al. Short communication: regional cerebral blood flow
When suffering from severe malnutrition, dogs and cats assessed by single photon emission computed tomography
appear cachectic, with reduced muscle mass (see Fig. 33.11). (SPECT) in dogs with congenital portosystemic shunt and
However, loss of muscle mass occurs relatively late in the hepatic encephalopathy. Vet J. 2017;220:40.
process, and in the earlier stages of protein-calorie malnutri- Tivers MS, et al. Attenuation of congenital portosystemic shunt
tion the animal’s body condition score may be normal and reduces inflammation in dogs. PLoS ONE. 2015;10(2):e0117557.