Hello, I'm Dr. Deb.
I recently came online and see that your question about your cat hasn't been answered. I'm so sorry that you've had to wait for a response, but if you still need assistance, I'd like to help if I can.
Sometimes it's difficult to tell if how cats are straining to urinate versus straining to produce a stool (secondary to constipation). However, if you're fairly certain that it's the latter issue, I do have a few suggestions.
1. Hairball laxatives such as Laxatone or Laxaire which are brand names but every pet or grain store will carry these products. I usually suggest 1-2 inches 2-3 times a day.
2, Canned pumpkin (NOT the pie mix) at a dose of 1/4-1/2 tsp per day. You might be surprised how well many cats like the taste of it although obviously not all of them do. For those cats with chronic issues,there are some diets available which contain pumpkin.
3. Over the counter, human Miralax (polylethylene glycol 3350 aka macrogol 3350) at a dose of 1/8th-1/4th tsp daily which can be increased until soft stools are produced.
4.Raw bran flakes (wheat bran, not cereal) in canned food 1/4-1/2 tsp daily.
5. Pediatric glycerin suppositories for those patients who are badly constipated: http://pedia-lax.com/products/liquid-glycerin-suppositories You'll want to read the label closely and only purchase those with glycerin on the label; those with phosphate can kill cats.
I hope this helps although, again, my apologies for the delayed reply. Deb
Dulcolax® One 5 mg tablet PO; do not break tablets If using oral tablets, do not crush or allow animal to chew; intense cramping may occur.
Fiber supplemented diets are available commercially, or the pet owner may wish to add psyllium (1-4 tsp per meal), wheat bran (1-2 tblsp per meal), or pumpkin (1-4 tblsp per meal) to canned cat food. Cats should be well hydrated before commencing fiber supplementation to maximize the therapeutic effect and to minimize the impaction of fiber in the constipated colon.
Unlessotherwise directed by veterinarian, bisacodyl should be used on an"occasional" basis only. Chronic use can damage the nervesin the colon and has lead to laxative dependence in humans.