California Riding Magazine • February, 2013

Ask the Vet:
Digestive Disturbance

by Lydia F. Gray, DVM, MA

I bought a mare approx. 2 1/2 mos. ago. She came from a bad situation, basically a rescue. She was not starved but thinner than she should be; she was being fed sweet feed (I believe they said 4 quarts a day) Since I've had her, I had her teeth done (they were terrible), dewormed her (ivermectin), I give her as much free-choice hay as possible (I have no grass) along with her grain. I started her with a "complete feed" pellet, approx. 2 1/2 cups (measuring cup) twice a day/ (total=5 cups). Her weight did not change. I also had to wet her feed initially as she ate too fast & choked. I no longer do this. I (gradually) switched her to an extruded pellet that contained glucosamine (her joints "click) and seemed more rounded a feed type-plus she ate it slower. Same amount-5 cups total daily. Now her weight has slowly come up-but in the past week her manure is getting softer & looser--she is just short of actual diarrhea. I added probios to her feed for a week-no change. I don't know if it's the feed- (the bag is half gone) - or?? I'd hate to switch her again. Hope I covered everything. Any thoughts on this? thk you. Dee

Dear Dee,

My first thought is: thank you for giving this mare a chance! My second thought is: I am not surprised that when you switched from 5 cups of a complete feed to 5 cups of a fortified grain she gained weight. That's because "complete feed" is an all-in-one product (hay and grain in a bag), so that horses with poor teeth or areas of the country without quality forage can make sure their horses still get enough long-stem roughage in their diets. However, these products are very, very dilute when it comes to calories, protein, vitamins and minerals so you have to feed a lot of them—15, 18 even 20 pounds a day! I'm guessing here (but you need to get out your kitchen scale and actually weigh) but 5 cups of a complete feed is maybe 2 pounds? So she was getting way underfed this particular product. Five cups or two pounds of a fortified grain is closer to the recommend amount, but you still need to weigh the product and follow the instructions on the label for the proper amount to feed her given her age, weight and workload.

If you haven't had a veterinarian look at her recently, it's time again. A physical examination—along with bloodwork, a fecal exam or other diagnostic testing--may be able to rule out certain problems or even pinpoint the cause of the loose stool. Your veterinarian will also help you investigate all aspects of your mare's environment and possibly figure out if something else (a switch in hay, a new turnout buddy, other stress) could be responsible for her change in manure.

Adding a probiotic to her feed was a good idea; give this one a little bit longer then if you still don't see results, try another product. I've found that horses respond very differently to digestive supplements. That is, Brand A may work great in one horse but it does nothing for another horse yet that horse responds great to Brand B. I don't know if it's the different species of probiotics, the different amounts, the addition of prebiotics (food for the good bugs), active live yeast, enzymes or something else, but don't give up on supporting her GI system through her recovery just yet. Best of luck bringing her through this!

Article provided by SmartPak.
Dr. Lydia Gray is the Medical Director/Staff Veterinarian for SmartPak, where she guides research and new product development, answers questions on her Ask the Vet blog, and speaks around the country at various events such as Equine Affaire, Dressage at Devon, and the USHJA Trainers’ Symposiums.