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Lactulose Solution

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2. We verify your prescription and ship your order!
$35.14 $23.93 
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10 gm/15 ml 16 oz
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$35.14 $23.93 
Ships in one business day or less

Step 1. Select an Option:

10 gm/15 ml 16 oz
Price w/coupon SAVE20
You save $11

Step 2. Select a Quantity:

Please select all product options.

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Product Info
What is Lactulose Solution?

Lactulose is used in cats and dogs as a laxative. Lactulose requires a prescription from your veterinarian.


Cats and Dogs

  • Liquid is easy to administer
  • No restrictions on food, drink, or activity unless otherwise directed by the veterinarian.
How it Works:

Lactulose is a disaccharide sugar composed of galactose and fructose. Unlike other sugars, its not absorbed into the blood. It passes unchanged to the large intestine. In the large intestine, lactulose is broken down by bacteria, resulting in the production of various acids. These acids draw water into the colon, softening the stool and increasing the volume, resulting in a laxative effect.


Side effects of lactulose include symptoms of flatulence, bloated stomach, and cramping. Diarrhea and dehydration are symptoms of overdose. Tell your veterinarian if your pet is diabetic, or pregnant or lactating.

Brand Name:

Chronulac or Cephulac (Hoeschst-Marion Roussel), Constulose or Enulose (Alpharma)

Generic Name:

Lactulose (lak-chew-lows)

What should I discuss with my veterinarian before giving lactulose to my pet:

Tell your veterinarian if your pet is diabetic. Tell your veterinarian if your pet is pregnant or lactating.

What is the most important information I should know about Lactulose:

Lactulose is a prescription medication that is not FDA approved for use in animals; however, it is a commonly accepted practice for veterinarians to use lactulose in dogs and cats as a laxative. Lactulose is available as a 10 Gm/15ml liquid. The usual laxative dose in dogs and cats is 1 ml per 2 pounds of body weight given every 8 hours initially, then use as needed. Notify the veterinarian if the pet develops excessive diarrhea.

How should this medication be given:

Give this medication exactly as directed by your veterinarian. If you do not understand the directions ask the pharmacist or veterinarian to explain them to you. Lactulose may be mixed with fruit juice, water, or milk to improve the taste. It may take 24 to 48 hours before the effects of lactulose are seen. Lactulose may darken slightly in color. This change is harmless. However, if lactulose becomes very dark or uneven in consistency do not use the product. Store lactulose at room temperature, away from moisture and heat. Keep this medication away from children and pets.

What happens if I miss giving a dose:

Give the missed dose as soon as you remember. However, if is almost time for the next regularly scheduled dose, skip the missed dose and take the next one as directed. Do not give a double dose of the medication.

What should I avoid while giving Lactulose to my pet:

There are no restrictions on food, drink or activity unless otherwise directed by the veterinarian.

What are the possible side effects of Lactulose:

If any of the following serious side effects occur, stop giving lactulose and seek emergency veterinary medical attention; an allergic reaction (difficulty breathing; swelling of the lips; tongue or face; hives). Other less serious side effects may occur. Continue giving lactulose and talk to your veterinarian if your pet experiences flatulence, abdominal cramps, diarrhea or nausea and vomiting. Other side effects may also occur. Talk to your veterinarian about any side effect that seems unusual or bothersome to the animal.

What other drugs will affect Lactulose:

Tell your veterinarian if your pet is being given an antacid as this may decrease the effects of lactulose. Drugs other than those listed may also interact with Lactulose. Talk to your veterinarian before giving your pet any prescription or over the counter medicines.

How to Use
  • Lactulose Solution is a prescription medication used in dogs and cats as a laxative.
  • Lactulose is also used to reduce blood ammonia levels in the prevention and treatment of hepatic encephalopathy.
  • Lactulose Solution is not FDA approved for use in veterinary medicine; however, it is a commonly accepted practice for veterinarians to prescribe this medication for dogs and cats.
  • Because Lactulose is a type of sugar (disaccharide) tell your veterinarian if your pet is diabetic.
  • Antacids may decrease the effects of Lactulose.

Lactulose may be mixed with water or milk to improve the taste. It may take 24 to 48 hours before the effects of Lactulose are seen. Notify your veterinarian if your pet develops excessive diarrhea.

All weights
The usual does is 1 ml for every 2 lbs of pet's body weight every 8 hours to start, or as directed by your veterinarian, then use as needed
Do not use!

Store at room temperature, away from heat and moisture.

Lactulose Solution:
Active Ingredients (per 15 mL)
10 g
Less than 1.6 g
Other sugars
Less than 1.2 g
Customer Reviews
Lactulose Solution is rated 4.8 out of 5 by 70.
Rated 5 out of 5 by from Lactulose Solution My senior kitty has been suffering from major constipation over the past 6months that has led to costly vet visits to get her enemas. She was prescribed the lactulose and hasn’t had an issue since. I would recommend.
Date published: 2017-09-24
Rated 4 out of 5 by from Best price and service Our shih tzu is seriously ill with a liver issue. Our vet bills were in the thousands so we had to save where we could. This prescription medicine was 1/3 the cost of the vet's and when we had a prescription issue with the vet office petmed elevated shipping at no cost to us. Love them!
Date published: 2017-09-07
Rated 5 out of 5 by from Works Great! My cat suffers from constipation which in turn makes her throw up from straining. This medication works great. She likes the taste, so I just mix it in with her wet food. Happy cat...
Date published: 2017-09-05
Rated 5 out of 5 by from So far so good I have an older cat prone to dehydration and severe constipation. He is pretty healthy otherwise, no diabetes, etc. (because this IS a sugar solution). It has made a WORLD of difference. I give it by syringe. He is not wild about having to take it, but he knows it makes him feel better. The caveat is that there must be adequate intake of water for it to work. If not, it will exacerbate dehydration. If your animal will not drink, you may have to give Pedialyte (at home) or occasionally carry to vet to get fluids (which is what I do when necessary).
Date published: 2017-06-27
Rated 5 out of 5 by from My veterinarian recommended this medication Easy to administer via syringe. May not be appropriate for all cats. Always consult with your veterinarian since it needs an Rx.
Date published: 2017-05-13
Rated 5 out of 5 by from So happy I found this online! Our 20+ year old tabby was using lactulose and Cisapride thanks to my vet. It really helped him with his megacolon issues and I am grateful he found a solution. However the vet's office charges $48 for 2 oz of Lactulose. Now I get 16 oz of the same product for less than $30. Our cat cannot tell the difference. We mix it into his wet food with the Cisapride and Cosequine and he loves the taste. Thank you 1-800-PetMeds!
Date published: 2017-04-18
Rated 3 out of 5 by from Excellent ..but if You Add it to FOOD, READ this I gave this three stars to get your attention. It should be five stars but figured people are more likely to read the review if it has less and this is really important: according to my vet, if you add lactulose to food, you should only add it to a small amount (like a 1/4 can of fancy feast for example). Then an HOUR LATER you can go ahead and feed the rest of the can. This is because adding lactulose to the food makes a lot of the nutrients pass through your cats system. So you have to let the lactulose do it's thing and then an hour later, give your cat it's normal meal (like the other 3/4 of the can of Fancy Feast) so that the food will be absorbed properly. If you feed the whole can with the lactulose, it won't get absorbed properly. This product worked really well for my cat. It was recommended 1 ml in the a.m. and 1 ml at night. I did exactly as above - gave 1/4 can of Fancy Feast with the lactulose and then the remaining 3/4 can an hour later. At noon, he gets a whole can with no lactulose. Then at night he gets another 1/4 can with lactulose....and an hour later he gets the remaining 3/4 can. I also give him a single serving of Sheba cat food (pate) at bed time as a treat (these are sold in two-part plastic packages. He just gets one of the two) It's very, very liquid-y and I'm sure it helps push things through as well!
Date published: 2016-10-19
Rated 5 out of 5 by from Lactulose Solution Our cat has had issues with constipation for a long time! Finally we've found something that works great!! We do mix it with his soft food on a daily basis to keep him regular.
Date published: 2016-09-10
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I see from 3 years ago this product is not flavored. Is that still the case? I am looking for Lactulose that is green and banana flavored. Thank you.

Asked by: ADLKS
The lactulose that we currently have in stock is Actavis Brand Fresenius Kabi MFTR. It is a natural colored unflavored solution.
Answered by: Lisa M
Date published: 2017-10-26

I am from Canada  my vet will not write a scrip for clavaseptin. He wants to sell it to us.  Dog meds in Canada are expensive. I have an invoice to show the dog is on these med   is there anyway I can get them through your company? 

Asked by: Richard barket
Hello Richard, thank you for your question. I am very sorry to hear about your situation. Unfortunately, Lactulose solution requires a prescription from your veterinarian.
Answered by: Roseanna Pharmacy Intern
Date published: 2017-03-29

Ok mydog doctor gave my dog lactulose but he said every 12 hours but my timeming to give him the lactulose is at 4 in the morning and i have to give it to him with food but he dont wanna eat at that time to give him the lactulose what should i do.

Asked by: Erica
Erica, I would recommend changing the timing can be a bit lenient with every 12 hours. Just twice a day at least and spaced out as well as you can is ideal. You could try doing like an 8am, 8pm sort of schedule. It does not have to be perfect. It is important for the dog to eat when taking the medication, so try to give the medication when the pet will eat. As always, consult with your Vet if you anything serious happens or you have further concern. Hope this helps.
Answered by: Trey W
Date published: 2017-03-13

How long is this medicine good for? I've had it since may and my cat is constipated again and wasn't sure if it was still good or not.

Asked by: Amyw
The bottle does have an expiration date on it that should not be exceeded and prescriptions drugs also have a year expiration date placed on their label which is required by law in many jurisdictions. Generally with prescription medication it is important to check with the veterinarian prior to administering them for a condition other then the original condition that the medication was prescribed for. Either way please make certain that the date printed on the bottle is not exceeded. Some medications lose potency or actually become toxic if the date which was used for testing the product by the pharmaceutical company is passed.
Answered by: 1800Petmeds Pharmacist
Date published: 2017-09-18

is this product comparable to: Generlac Solution 10g/15ml Lactulose Solution (Duphalac) - (mfg.: Morton Grove Pharmaceuticals // distributed by Workhardt, USA, LLC) prescribed by my vet?.. looking to save a little expense

Asked by: watreehugger
Yes, Generlac is the brand, and lactulose is the generic. They both contain the same active ingredient (lactulose) and should be equally effective.
Answered by: Christine
Date published: 2017-01-31

My dog took lactulose and then ate. Ate too much and then threw I redose at next dose time?

Asked by: ltp1950
Yes, you can wait until your dog is scheduled for their next dose to give lactulose.
Answered by: Christine
Date published: 2016-10-05

Can giving a cat Lactalose make her diabetic?

My 10 year old cat has had chronic constipation for about two years. I have found that by giving her Lactulose, it has somewhat helped. My vet said that the only side effects would be diarrhea, if I gave her too much. I currently give her lactulose along with Vetasyl, which is a fiber pill and it is finally working. Recently she has been diagnosed to have diabetes. I can't help thinking that the lactulose I gave her is the reason that she became diabetic. Could I have unknowingly done this to her? My vet said no, but I keep having this nagging feeling.
Asked by: Deb
What does your vet say? We've used it for several years, and our cat has not developed diabetes.
Answered by: Sunny's mom
Date published: 2015-09-01

Can lactulose be used in cats with diabetes?

Asked by: Puff
This medication should be used with caution in diabetic patients.
Answered by: S Duesler PharmD MBA
Date published: 2016-12-31
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