Page 712 - Problem-Based Feline Medicine

704 PART 9 CAT WITH SIGNS OF GASTROINTESTINAL TRACT DISEASE

Withhold food for 24–48 hours in cats with acute opment of food intolerance, as it is this tissue that
small bowel diarrhea, and only offer water or oral iso- is responsible for promoting tolerance and hyporespon-
tonic glucose, amino acid and electrolyte solutions. siveness to harmless dietary antigens.
Because most diarrheas in cats are osmotic rather Intolerance may develop as a result of abnormal
than secretory, feeding through an acute diarrhea will mucosal barrier function, disturbances in immuno-
worsen the signs and may exacerbate the condition. regulation (decreased tolerance) or simply an abnor-
This is in contrast to humans with secretory diarrhea, mal recognition or response to certain dietary
where feeding is advantageous. antigens.

Prognosis Clinical signs
In general, for the majority of cats with acute, non- Intermittent but persistent vomiting or diarrhea are
specific gastroenteritis, the prognosis is excellent. the most common signs.
The prognosis is guarded for cats with severe diarrhea Poor hair coat, pruritus, inappetence or failure to
or diarrhea occurring secondary to problems in other thrive may also be noted but these are less common.
body systems.
Presence of concurrent dermatologic and gastrointesti-
nal signs should prompt consideration of a food allergy.
Prevention
Reduce opportunities for ingestion of toxic or irritating
Diagnosis
substances.
There is no diagnostic test for this problem other than
to observe a beneficial response to an appropriate
FOOD INTOLERANCE***
dietary trial. This should be carried out for a minimum
of 3 weeks.
Classical signs
Use a highly digestible diet or an elimination diet,
● Intermittent vomiting or diarrhea.
either a commercial diet containing a single novel pro-
● Inappetence.
tein source, or a homemade diet of boiled white rice
and a novel meat source such as duck, venison, rabbit,
Pathogenesis kangaroo, tofu, horsemeat, etc.
Food intolerance is a non-immunologic, adverse reac-
tion to a substance(s) present in food. This reaction Differential diagnosis
may be to a food component such as the type of protein
or carbohydrate, a particular component (e.g. wheat Acute, intermittent diarrhea in an otherwise healthy
gluten) or it may be to food colorings, preservatives, cat suggests early inflammatory bowel disease, GI par-
flavorings, etc. asites, dietary indiscretion, or acute gastroenteritis due
to infectious causes.
Food intolerances may result from an inability to ade-
quately digest a dietary constituent (e.g. lactose) or In some cats, this may be a sign of early renal or liver
from metabolic, toxic or pharmacological responses disease, hyperthyroidism and other primary GI abnor-
to food components such as histamine in foods, lectins malities such as neoplasia.
or from the metabolism of dietary residues by the large
intestinal microflora.
Treatment
The precise mechanism associated with vomiting or
The diet should be changed so that it does not con-
diarrhea due to food intolerance is unknown.
tain the offending substance. This may be as simple
The mucosa (formerly gut) associated lymphoid tis- as changing from a grocery store brand to a premium
sue is believed to be a major component in the devel- brand food (or vice versa), but also may require changing