Page 435 - Problem-Based Feline Medicine

21 – THE YELLOW CAT OR CAT WITH ELEVATED LIVER ENZYMES 427

● Gastrostomy or jejunostomy tube alimentation with Thiamine supplementation (100 mg of thiamine
high-energy commercial enteral diets is necessary if hydrochloride, q 12 h by oral, subcutaneous or IM
vomiting is frequent. routes) is generally advised.
● Esophagostomy tubes can be used when vomiting is
The potential value of carnitine (1250 mg L-carnitine/cat
not frequent, and may be simpler and safer to place
q 24 h) and taurine (250–500 mg q 24 h) supplementa-
than gastrostomy tubes.
tion has not been critically assessed but is unlikely to be
● Nasoesophageal tubes are indicated in cats too ill
harmful.
for a gastrostomy tube.
● They are often used for short-term support until
placement of gastrostomy tube. Prognosis
● Nasoesophageal and some esophageal tubes require
Survival rates are up to 60% with aggressive therapy.
liquified commercial diets (Iams Nutritional
Recovery Formula, Clinicare, or Hill’s A/d mixed Evaluate closely for concomitant diseases (pancreatitis)
with water). as they warrant a more guarded prognosis.
● It takes several days before the caloric requirements
can be fed in 3–4 meals per day without inducing
Prevention
vomiting. Initially small volumes, e.g., 5 ml, should
be fed every 2 hours, and the volume is increased It is important to use sensible restriction diets for obese
while reducing the frequency over several days. cats. Feed 60–75% of maintenance requirements (60
Alternatively, feeding can begin with a constant rate kcal/kg) to promote slow but steady weight loss. Food
infusion over 24 hours using a syringe infusion intake should be adjusted monthly for the individual cat
pump with the volume increased gradually until the to produce a weight loss of 1–2% per week.
daily caloric requirements are met. Cats can then be ● A variety of commercial, nutritionally balanced but
transitioned to bolus feeding four times daily. Tubes reduced caloric rations are available.
should be left in place until the cat is voluntarily
eating its full caloric requirements for 2 weeks and
has a stable and increasing weight.
FELINE CHOLANGITIS (CHOLANGITIS/
Avoid benzodiazipines as they are inadequate to stimu- CHOLANGIOHEPATITIS SYNDROME)***
late appetite and may aggravate CNS signs.
Classical signs
Vomiting is controlled with metoclopramide
(0.2–0.5 mg/kg q 8 h or using a constant rate infu- ● Anorexia, weight loss, and vomiting.
sion 1–2 mg/cat/24 h). Two periods of exercise total- ● Jaundice, +/- fever, +/- ascites.
ing 45–60 min/day help reduce vomiting and high ● Often palpable hepatomegaly.
gastric residual volumes. This can be accomplished
by letting the cat free in a consulting room, prefer-
Pathogenesis
ably with a window.
Cholangitis is the cause of jaundice in 30% of cats.
Correct dehydration and electrolyte imbalances with
fluid therapy. Etiology is unknown but may involve causative factors
● Monitor serum potassium and phosphorous and such as bacterial infection. The different forms of
supplement with KCl and potassium dihydrophos- cholangitis may represent different stages of the same
phate as needed to combat hypokalemia and disease process. One hypothesis suggests that the
hypophosphatemia. unique anatomic relationship in which the bile duct and
major pancreatic duct form a short common duct enter-
Ursodeoxycholic acid (10–15 mg PO q 24 h) for intra-
ing the duodenum may predispose cats to inflammatory
hepatic cholestasis.
hepatic disease. This connection might favor the ascen-
Vitamin K is often given (3–5 mg per cat q 12 h ini- sion of luminal bacteria or the entrance of pancreatic
1
tially) due to the frequency of coagulation disturbances. enzymes into the biliary tract. Supporting this theory is