Benjamin SE, Drobatz KJ. Retrospective evaluation of risk factors and treatment outcome predictors in cats presenting to the emergency room for constipation. J Feline Med Surg. 2019 Mar 5;:1098612X19832663. doi: 10.1177/1098612X19832663.
Constipation is a common issue in cats that may be life-threatening if it progresses to complete obstruction. It is often diagnosed late in the course of disease, making emergent care necessary. Constipation rarely occurs in isolation, and is often due to underlying factors bother within and external to the GI tract. Identification and management of the most common predisposing factors can help to prevent constipation from occurring or allow its management earlier in the course of disease.
The purpose of this study was to determine risk factors that may be associated with the development of constipation in cats, as well as factors that may lead to enemas being successful. The study was designed as a retrospective case-control study of all cats presenting to a university teaching hospital over a 6 year period.
Cats were included in the analysis if they were discharged by the ER service with a diagnosis of constipation or obstipation. Diagnosis was based on owner-reported clinical signs, physical exam findings, and evidence of constipation on radiographs. 99 cats discharged for non-constipation issues in the same time span were selected as controls. Signalment, medical history, diet (canned vs dry), physical exam findings, venous blood gas, abdominal imaging, and in-hospital treatments were recorded for all cats.
251 cats were initially identified, of which 62 were eliminated due to incomplete records, leaving 189 case and 99 control cats. Time of year had no influence of risk of constipation.
There was no effect of sex, diet type, or breed on the risk of constipation. After stepwise multiple logistic regression, only increased age and increased BCS were found to have an effect on risk of constipation. A history of CKD or previous constipation was associated with an increased risk of constipation. Several other diseases (small cell lymphoma and diabetes mellitus) showed a non-significant trend to increased risk of constipation but had small samples sizes.
Constipated cats had a higher total solids and ionized calcium and a lower potassium on presentation. This may be associated with dehydration and inanition, and are not likely useful as specific makers of constipation. After regression analysis only ionized calcium retained significance. Whether this is causational or secondary to constipation remains to be investigated.
Cats with a history of previous constipation were more likely to defecate following an enema. Abdominal pain decreased the success of enemas. The use of buprenorphine or methadone was not found to affect the success of an enema. Oral lactulose, SQ, and IV fluids were not found to change the chance of defecation, however, cats were only analyzed if they received one of these, and not combinations (potentially a significant limitation to this study).
The retrospective nature of the study and relatively small sample size (especially when stratified into some conditions such as diabetes mellitus) are significant limitations to this study.
The authors of this study conclude that increased age, obesity, chronic kidney disease, and a history of previous constipation are all risk factors for constipation. Warm water and lubricant enemas were of minimal efficacy in resolving constipation, stressing the need for multimodal therapy and prevention.
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