Page 1174 - Small Animal Clinical Nutrition 5th Edition

1224 Small Animal Clinical Nutrition

fiber and high in carbohydrates predispose to GI hypomotility cases, metoclopramide stimulates gastric emptying and appar-
VetBooks.ir and retention of hair and food in the stomach (Harcourt- ently improves cecal activity. Fluid therapy to correct fluid and
electrolyte imbalances is a priority to counteract losses that
Brown, 2002; Jenkins, 2004). A definitive diagnosis can be dif-
accompany the diarrhea (Gentz et al, 1995). Other treatment
ficult. Occasionally, the stomach can be palpated in the cranial
abdomen as a large, doughy mass. Fecal pellet production is fre- recommendations have been previously reported (Gentz et al,
quently reduced or absent, and those that are passed are small- 1995; Jenkins, 2004).
er than normal. Survey radiography may reveal an enlarged
stomach with displaced intestines. Contrast radiography may Enterotoxemia
aid the diagnosis.A large,ingesta-filled stomach in a rabbit that Enterotoxemia is one of the most common diseases of rabbits
has been anorectic for four to seven days suggests gastric stasis. seen in clinical practice. Enterotoxemia is caused by the toxin
A definitive diagnosis requires exploratory laparotomy; howev- produced by Clostridium spiroforme (Jenkins, 2004). Rabbits,
er, given the risk of surgery in these compromised patients, a particularly those recently weaned, are sensitive to foods high in
presumptive diagnosis is often made based on response to treat- sugars and starches (Gentz et al, 1995). Feeding these foods has
ment (Jenkins, 2004). been associated with at least some cases of enterotoxemia.
Medical treatment strategies emphasizing rehydration of the Weanlings have an undeveloped population of normal GI flora
patient and stimulation of gastric motility have been developed and a high gastric pH, which allows proliferation of C. spiro-
with very good results (Hernandez-Divers, 2005). Force-feed- forme. Nutritional counseling, therefore, is an important part of
ing fluids, vegetable purees or commercial products (Critical rabbit medicine, especially because many rabbit owners think
c
Care for Herbivores ) is often indicated, as is administration of lettuce, carrots and sugary treats are an appropriate diet for their
subcutaneous fluids, or if the patient is hospitalized, intra- animals.
venous fluids (Jenkins, 2004). Additional treatments may in-
clude administration of an appropriate systemic antibiotic, gas- Obesity
tric motility stimulants and surgery if the rabbit fails to respond Many household rabbits have limited opportunities for exercise
to medical management. Although feeding fresh pineapple with almost unlimited access to palatable foods.Therefore,obe-
juice (10 ml/day) (which contains the enzyme bromelain), sity is common in pet rabbits.
papaya tablets (which contain papain) or proteolytic enzymes Because rabbits vary widely in body size, optimal body
have been reported to aid breakdown and passage of trichobe- weights are difficult to estimate. Frequent weighing of each
zoars, the response to such treatments is equivocal (Jenkins, rabbit and recording the results in the medical record are im-
2004) and no longer recommended as a treatment strategy. portant components of a preventive medicine program. Own-
Hairballs or gastric stasis in rabbits can generally be prevented ers can be shown gradual increases in their rabbit’s weight
by feeding foods with adequate fiber (>14% DM crude fiber), from medical records and the need for intervention. Systems
minimizing stress and boredom, frequent grooming and pro- for body condition scoring have not been published for rab-
viding adequate exercise (Carpenter et al, 1995). bits and would be a welcome addition to preventive medicine
programs.
Mucoid Enteropathy Because rabbits use fiber efficiently, obesity may occur even
Pet rabbits are also commonly presented with diarrhea, for when high-fiber foods are fed. However, weight control may be
which there are several differential diagnoses. Mucoid en- achieved by limiting the quantity of food offered. The amount
teropathy is a GI disorder that is paradoxically characterized by of food offered should be reduced gradually, perhaps 10% every
constipation and diarrhea (Gentz et al, 1995; Jenkins, 2004), two weeks, until the amount fed maintains the desired body
and by anorexia, lethargy, weight loss, cecal impaction and weight and condition.
excessive production of mucus in the digestive tract (Lelkes and
Chang, 1987). The cause of mucoid enteropathy is still under Vitamin Deficiency and Toxicosis
investigation, but the disease appears to be caused by changes Although cecal microbes synthesize B-complex vitamins and
in cecal pH that result from disruptions in the normal cecal vitamin K and the rabbit obtains them via cecotrophy, manu-
flora (Lelkes and Chang, 1987; Jenkins, 1993). It likely occurs facturers may add all of the essential vitamins to commercial
secondary to microbial alterations caused by hyperacidic cecal foods.The requirement for vitamin D may be low because rab-
pH (Lelkes and Chang, 1987). A food containing about 20% bits readily absorb calcium and phosphorus (Cheeke, 1995).
crude fiber seems to maintain an optimal cecal pH to prevent Signs of vitamin D toxicity include progressive emaciation
changes in the normal microbial flora. and weakness, loss of appetite, diarrhea and paralysis. Soft tis-
Mucoid enteropathy generally occurs in young rabbits, typi- sues (i.e., liver, kidneys, artery walls and muscle) may become
cally those just beyond weaning age (seven to 14 weeks) extensively calcified (Cheeke, 1995).
(Jenkins, 1993, 2004). It is rarely encountered in rabbitries that Vitamin A deficiency and excess may lead to reproductive dis-
feed a high-fiber ration and avoid grains, simple carbohydrates turbances. Low conception rates, fetal resorption, low survival of
and excesses of proteins or fats. Treatment includes feeding a newborn kits and hydrocephalus in fetuses occur with toxic lev-
high-fiber food (alfalfa hay) or syringe feeding a vegetable baby els. Toxicosis is generally associated with adding synthetic vita-
food (Jenkins, 1993) containing no additional sugars. In some min A to foods that contain high levels of good-quality alfalfa