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Logic Firm (previously Diar-Stop) for Dogs & Cats

  • Diar-Stop Cats & Dogs 2 - 7kg » 10ml Syringe £8.50
  • Diar-Stop Dogs 7 - 30kg » 24ml Syringe £9.49
  • Diar-Stop Dogs 30 - 60kg » 60ml Syringe £11.99
  • Diarsanyl Foals » 60ml Syringe £14.49

Selection of 4 products from

£8.50 to £14.49

Digestive upsets in dogs and cats occur when the intestines become irritated. This can be caused by a sudden change in diet or by eating inappropriate food, e.g. scavenging on a walk or eating from the rubbish bin.

Logic® Firm is a pharmaceutical grade formulation which helps support a dog or cat’s digestion.


  • Montmorillonite - Coats and protects the intestinal lining and absorbs toxins
  • Sodium, Magnesium & Potassium - Help to restore electrolytes lost through diarrhoea
  • Dextrose - Provides an energy source for the small intestine
  • Prebiotics (FOS – fructo-oligosaccharides) - Help to restore the normal bacterial flora



Fructo-oligosaccharides, Dextrose, Glycerol, Sodium chloride, Magnesium salts of organic acid.


Bentonite - montmorillonite (E558) 40%, Potassium sorbate.

Analytical constituents

  • Crude ash - 35%
  • Total sugars - 30%
  • Moisture - 22%
  • Sodium - 2.5%
  • Crude protein - 0%
  • Crude fibre - 0%
  • Crude oils & fats - 0%

Feeding guidelines

Pet Weight

Syringe Size
Syringe Size
Syringe Size
0 – 7 For Cats and Dogs
7 – 30 For Dogs only
> 30 For Dogs only
Body Weight Number of Graduations
Morning Evening
2kg - 7kg 1 1
8kg - 30kg 1 1
> 30kg 1 1

Need help or advice? Contact us:

  • Landline: 01582 842096
  • Mon - Fri: 8:30am - 5:00pm
  • Sat: 9:00am - 1:00pm
  • Email:

All prices include VAT where applicable.

Reviews of Logic Firm (previously Diar-Stop) for Dogs & Cats

Read our customers' reviews of Logic Firm (previously Diar-Stop) for Dogs & Cats

Questions & Answers for Logic Firm (previously Diar-Stop) for Dogs & Cats

Below are some recent questions we've received regarding Logic Firm (previously Diar-Stop) for Dogs & Cats, including answers from our team.

Ask Your Own Question


14th Feb 2018

What size in mare the graduations on the 24ml size and the 10 ml size ?

  • Customer Service Advisor

Hi Richy

Thanks for your questions. The graduations are 1ml on the 10ml size and 2ml on the 24ml size.

Hope this helps.

Kind regards


Suitable for kittens?

11th Oct 2017

I have two 14 week old kittens who have been suffering diarrhoea. Is this product suitable for them?

  • Veterinary Advisor

Yes you can give this product to kittens once they have been weaned from their mother. It is a good idea to reduce the amount of food they are getting and give several small meals a day. They will recover much better if their digestion is not overloaded. You should see your vet though if the diarrhoea lasts for some time or the kittens look unwell.