Page 795 - Problem-Based Feline Medicine

35 – THE CONSTIPATED OR STRAINING CAT 787

Antibiotics are only used in culture-proven cases of Differential diagnosis
infectious colitis.
Chronic colitis should be differentiated from more
If the cat is long-haired or over-grooms, consider acute causes of tenesmus, such as acute non-specific
clipping the coat if other causes of colitis cannot be colitis, and conditions causing small intestinal diar-
identified. rhea, because some causes of chronic colitis also
involve the small intestine, resulting in signs of both
Prognosis large and small bowel involvement.

The prognosis for full recovery is excellent in most
instances. Treatment
Treatment for this condition is based on treating
CHRONIC COLITIS** (INFECTIOUS, the primary cause. Lymphocytic-plasmacytic coli-
NEOPLASTIC, AND BENIGN INFILTRATIVE tis may require a food trial to investigate a dietary
MUCOSAL DISEASE) etiology, combined with oral prednisolone ther-
apy at immunosuppressive dose rates (2–4 mg/kg/
Classical signs day).

● Chronic large bowel diarrhea (tenesmus,
small-volume mucoid feces, DEHYDRATION AND HYPOKALEMIA*
hematochezia).
● +/- Systemic signs (lymphadenopathy, Classical signs
anorexia, weight loss, +/- fever) if
● Skin tenting, tacky mucus membranes,
infectious cause.
increased plasma protein and PCV.
● ± Muscular weakness, reluctance to jump,
See main reference on page 762 (The Cat With Signs of
ventroflexion of the neck associated with
Large Bowel Diarrhea) for details.
hypokalemia.
● Reduced, painful or absent defecation +/-
Clinical signs tenesmus.
● Feces are hard, dry with or without mucus.
Hematochezia, small-volume, high-frequency feces,
● +/- Anorexia, lethargy, weight loss and
and straining are observed.
vomiting depending on the cause.
Systemic signs (lymphadenopathy, anorexia, weight
loss, +/− fever) may be seen with infectious viral dis- See main reference on page 557 (The Polycythemic Cat
eases (FeLV and FIV) and systemic mycoses. (for dehydration)) and page 945 (The Cat With
Generalized Weakness) and page 893 (The Cat With
Cats with benign infiltrative mucosal disease (e.g. lym-
Neck Ventroflexion) for hypokalemia)) for details.
phocytic-plasmacytic colitis) rarely have systemic signs
except with concurrent small intestinal involvement.
Pathogenesis
Diagnosis Both dehydration and hypokalemia may be caused by
either reduced intake in anorexia, or by increased losses,
Laboratory testing detects evidence of infectious viral
or by a combination of both. This most commonly
diseases.
occurs in chronic renal failure in older cats. Other causes
Screen susceptible cats for FeLV antigenemia and of vomiting and/or diarrhea may also result in dehydra-
serum antibodies to FIV. tion and/or hypokalemia and constipation.
Mucosal biopsies are required for definitive diagnosis Dehydration exacerbates the already efficient reabsorption
of neoplastic, mycotic and benign infiltrative mucosal of water from the feline colon, and hypokalemia results in
diseases causing chronic colitis. weakness of the colonic smooth muscle, slowing the