Ezi-Wormer Duo 12.5mg/125 mg Chewable Tablets for Dogs

Milbemycin Oxime (A3 and A4), Praziquantel

Last verified

Veterinary medicinal product: chewable tablet. Distribution category: POM-V (Veterinary Medicines Regulations 2013, Schedule 3). Active substance: Milbemycin Oxime (A3 and A4), Praziquantel.1

In short: questions and answers

Does Ezi-Wormer Duo 12.5mg/125 mg Chewable Tablets for Dogs need a prescription?
Prescription only. As stated in the registration decision.1
Which animals is Ezi-Wormer Duo 12.5mg/125 mg Chewable Tablets for Dogs for?
Dogs.1
What is the active substance in Ezi-Wormer Duo 12.5mg/125 mg Chewable Tablets for Dogs?
Milbemycin Oxime (A3 and A4), Praziquantel. ATCvet code: QP54AB51.13
What is the withdrawal period of Ezi-Wormer Duo 12.5mg/125 mg Chewable Tablets for Dogs according to the leaflet?
No withdrawal period is set for this drug: it is not intended for food-producing animals.3
Dispensing
Prescription only1

POM-V: Prescription Only Medicine - Veterinarian. Supplied only on a prescription written by a veterinary surgeon who has assessed the animal.12

Supplied only on a veterinarian's prescription. As stated in the registration decision.

Animal species
Dogs1
Active substance
Milbemycin Oxime (A3 and A4), Praziquantel
ATCvet code
QP54AB513
Manufacturer
Marketing authorisation holder: C&H Generics Ltd

Withdrawal period

No withdrawal period is set for this drug: it is not intended for food-producing animals.3

Summary of product characteristics

Composition

Each tablets contains:

Active substances:

Milbemycin oxime 12.5 mg

Praziquantel 125 mg

Excipients:

Qualitative composition of excipients and other constituentsQuantitative composition if that information is essential for proper administration of the veterinary medicinal product
Propylene glycol (E 1520)4.54 mg
Iron Oxide, Brown (E 172)3.29 mg
Butylhydroxyanisole (E 320)1.32 mg
Propyl Gallate (E 310)0.46 mg
Glycerol (E 422)
Pre-gelatinised pea starch
Chicken flavour
Confectioner’s sugar
Purified water
Sodium Chloride
Citric acid monohydrate

Oval shaped, dark brown chewable tablet.

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Pharmacological properties

4.1 ATCvet code: QP54A B51

4.2 Pharmacodynamics

Milbemycin oxime belongs to the group of macrocyclic lactones, isolated from the fermentation of Streptomyces hygroscopicus var. aureolacrimosus. It is active against mites, against larval and adult stages of nematodes as well as against larvae of Dirofilaria immitis.

The activity of milbemycin is related to its action on invertebrate neurotransmission: Milbemycin oxime, like avermectins and other milbemycins, increases nematode and insect membrane permeability to chloride ions via glutamate-gated chloride ion channels (related to vertebrate GABAA and glycine receptors). This leads to hyperpolarisation of the neuromuscular membrane and flaccid paralysis and death of the parasite.

Praziquantel is an acylated pyrazino-isoquinoline derivative. Praziquantel is active against cestodes and trematodes. It modifies the permeability for calcium (influx of Ca2+) in the membranes of the parasite inducing an imbalance in the membrane structures, leading to membrane depolarisation and almost instantaneous contraction of the musculature (tetany), rapid vacuolization of the syncytial tegument and subsequent tegumental disintegration (blebbing), resulting in easier expulsion from the gastrointestinal tract or death of the parasite.

4.3 Pharmacokinetics

After oral administration of praziquantel in the dog, peak serum levels of parent are rapidly attained (Tmax approximately 0.5-4 hours) and decline quickly (t1/2 approximately 1.5 hours). There is a substantial hepatic first-pass effect, with very rapid and almost complete hepatic biotransformation, principally to monohydroxylated (also some di- and tri-hydroxylated) derivatives, which are mostly glucuronide and/or sulfate conjugated before excretion. Plasma binding is about 80%. Excretion is fast and complete (about 90% in 2 days); the principal route of elimination is renal.

After oral administration of milbemycin oxime in dogs, peak plasma levels occur at about 2-4 hours, and decline with a half-life of the unmetabolised milbemycin oxime of 1-4 days. Bioavailability is about 80%.

In the rat, metabolism appears to be complete although slow, since unchanged milbemycin oxime has not been found in urine or faeces. Main metabolites in the rat are monohydroxylated derivatives, attributable to hepatic biotransformation. In addition to relatively high liver concentrations, there is some concentration in fat, reflecting its lipophilicity.

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Target species

Dogs (≥ 5kg).

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Indications

For dogs with, or at risk from mixed infections of cestodes, gastrointestinal nematodes, eyeworm, lungworms and/or heartworm. This veterinary medicinal product is only indicated when use against cestodes and nematodes or prevention of heartworm disease/angiostrongylosis is indicated at the same time.

Cestodes:

Treatment of tapeworms: Dipylidium caninum, Taenia spp., Echinococcus spp., Mesocestoides spp.

Gastrointestinal Nematodes:

Treatment of:

Hookworm: Ancylostoma caninum

Roundworms: Toxocara canis, Toxascaris leonina

Whipworm: Trichuris vulpis

Eyeworm

Treatment of Thelazia callipaeda (see specific treatment schedule under section 3.9 “Administration routes and dosage”).

Lungworms

Treatment of:

Angiostrongylus vasorum (Reduction of the level of infection by immature adult (L5) and adult parasite stages; see specific treatment and prevention disease schedules under section 3.9 “Administration routes and dosage”), Crenosoma vulpis (Reduction of the level of infection).

Heartworm

Prevention of heartworm disease (Dirofilaria immitis) if concomitant treatment against cestodes is indicated.

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Dosage

Oral use.

Underdosing could result in ineffective use and may favour resistance development.

To ensure a correct dosage, body weight should be determined as accurately as possible.

Minimum recommended dose rate: 0.5 mg milbemycin oxime and 5 mg praziquantel per kg are given as a single dose. The veterinary medicinal product should be administered with or after some food.

Depending on the bodyweight of the dog, the practical dosing is as follows:

WeightNumber of Tablets
5-25 kg1 tablet
> 25 - 50 kg2 tablets
> 50 - 75 kg3 tablets

In cases when heartworm disease prevention is used and at the same time treatment against tapeworm is required, the product can replace the monovalent product for the prevention of heartworm disease.

For treatment of Angiostrongylus vasorum infections, milbemycin oxime should be given four times at weekly intervals. It is recommended, where concomitant treatment against cestodes is indicated, to treat once with the product and continue with the monovalent product containing milbemycin oxime alone, for the remaining three weekly treatments.

In endemic areas administration of the product every four weeks will prevent angiostrongylosis by reducing immature adult (L5) and adult parasite burden, where concomitant treatment against cestodes is indicated.

For the treatment of Thelazia callipaeda, milbemycin oxime should be given in 2 treatments, seven days apart. Where concomitant treatment against cestodes is indicated, the product can replace the monovalent product containing milbemycin oxime alone.

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Contraindications

Do not use in dogs weighing less than 5 kg.

Do not use in case of hypersensitivity to the active substances or to any of excipients.

See also section 3.5 “Special precautions for use”.

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Adverse reactions

Dogs:

Very rare (<1 animal / 10,000 animals treated, including isolated reports):

Digestive tract disorders (such as Diarrhoea, Drooling, Emesis)

Hypersensitivity reaction

Neurological disorders (such as Ataxia, Convulsions, Muscle tremors)

Systemic disorders (such as Anorexia, Lethargy)

Reporting adverse events is important. It allows continuous safety monitoring of a veterinary medicinal product. Reports should be sent, preferably via a veterinarian, to either the marketing authorisation holder or its local representative or the national competent authority via the national reporting system. See the package leaflet for respective contact details.

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Warnings

Special precautions for safe use in the target species

Studies with milbemycin oxime indicate that the margin of safety in certain dogs of Collie or related breeds is less than in other breeds. In these dogs, the recommended dose should be strictly observed.

The tolerance of the veterinary medicinal product in young puppies from these breeds has not been investigated. Clinical signs in Collies are similar to those seen in the general dog population when overdosed (see section 3.10 “Symptoms of overdose (and where applicable, emergency procedures and antidotes)”).

Treatment of dogs with a high number of circulating microfilariae can sometimes lead to the appearance of hypersensitivity reactions, such as pale mucous membranes, vomiting, trembling, laboured breathing or excessive salivation. These reactions are associated with the release of proteins from dead or dying microfilariae and are not a direct toxic effect of the veterinary medicinal product. The use in dogs suffering from microfilaremia is thus not recommended.

In heartworm risk-areas, or in the case it is known that a dog has been travelling to and from heartworm risk regions, before using the veterinary medicinal product, a veterinary consultation is advised to exclude the presence of any concurrent infestation of Dirofilaria immitis. In the case of a positive diagnosis, adulticidal therapy is indicated before administering the veterinary medicinal product.

No studies have been performed with severely debilitated dogs or individuals with seriously compromised kidney or liver function. The veterinary medicinal product is not recommended for such animals or only according to a benefit/risk assessment by the responsible veterinarian. In dogs less than 4 weeks old, tape worm infection is unusual. Treatment of animals less than 4 weeks old with a combination veterinary medicinal product may therefore not be necessary.

As the tablets are flavoured, they should be stored in a safe place out of the reach of animals.

Special precautions to be taken by the person administering the veterinary medicinal product to animals

This veterinary medicinal product may be harmful when ingested, particularly for children. To avoid accidental ingestion, the veterinary medicinal product should be stored out of sight and reach of children.

In case of accidental ingestion of the tablets, particularly by a child, seek medical advice immediately and show the package leaflet or the label to the physician.

This veterinary medicinal product may cause hypersensitivity reactions. People with known hypersensitivity to the active substances or to the excipients, butylhydroxyanisole (E320) and propyl gallate (E310), should avoid contact with the veterinary medicinal product. If contact occurs, wash hands and seek medical advice in case of hypersensitivity reactions.

Wash hands after use.

Special precautions for the protection of the environment

See section 5.5

Other precautions

Echinococcosis represents a hazard for humans. As Echinococcosis is a notifiable disease to the World Organisation for Animal Health (WOAH), specific guidelines on the treatment and follow up and on the safeguard of persons need to be obtained from the relevant competent authority (e.g. experts or institutes of parasitology).

3.11 Special restrictions for use and special conditions for use, including restrictions on the use of antimicrobial and antiparasitic veterinary medicinal products in order to limit the risk of development of resistance

Not applicable.

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Use during pregnancy, lactation or lay

The safety of the veterinary medicinal product has been established during pregnancy and lactation.

Pregnancy and lactation:

Can be used during pregnancy and lactation.

Fertility:

Can be used in breeding animals.

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Interactions

No interactions were observed when the recommended dose of the macrocyclic lactone selamectin was administered during treatment with an equivalent product of comparable composition at the recommended dose.

Although not recommended, the concomitant use of an equivalent product of comparable composition with a spot on containing moxidectin and imidacloprid at recommended dose rates following a single application was well tolerated in one experimental study in beagle dogs at the age 11 months or older. Transient neurological adverse reactions (poor proprioception, flaccid frontal and hind legs, incoordination, slight tremors and high stepping gait of the hind limbs only) were observed after concurrent administration of both products in another study conducted in puppies aged 8-12 weeks. Such signs were however not observed in this study after giving the equivalent product of comparable composition alone.

The safety and efficacy of this combination have not been investigated in field studies.

In the absence of further studies, caution should be taken in the case of concurrent use with any other macrocyclic lactone. Also, no such studies have been performed with breeding animals, Collies, related breeds and their crosses.

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Overdose

The adverse reactions observed are the same as those observed at the recommended dose (see section 3.6 “Adverse events”) but more pronounced.

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Special warnings

The possibility that other animals in the same household can be a source of re-infection should be considered, and these should be treated as necessary with an appropriate veterinary medicinal product.

It is recommended to treat all the animals living in the same household concomitantly.

When infection with the cestode D. caninum has been confirmed, concomitant treatment against intermediate hosts, such as fleas and lice, should be discussed with a veterinarian to prevent re-infection.

Parasite resistance to any particular class of anthelmintic may develop following frequent, repeated use of an anthelmintic of that class.

Unnecessary use of antiparasitics or use deviating from the instructions given in the SPC may increase the resistance selection pressure and lead to reduced efficacy. The decision to use the veterinary medicinal product should be based on confirmation of the parasitic species and burden, or of the risk of infection based on its epidemiological features, for each individual animal.

The use of the veterinary medicinal product should follow the implementation of appropriate diagnostic measures towards mixed infections by nematodes and cestodes with consideration of animal history and characteristics (e.g. age, health status), environment (e.g. kennelled dogs, hunting dogs), feeding (e.g. access to raw meat), geographical location and travel. Judgement of the administration of the veterinary medicinal product in dogs at risk from mixed re-infections or in specific at risk situations (such as zoonotic risks), should be made by the responsible veterinarian.

In the absence of risk of co-infection with nematodes or cestodes, a narrow spectrum veterinary medicinal product should be used.

Resistance of Dipylidium caninum to praziquantel as well as cases of multi-drug resistance of Ancylostoma caninum to milbemycin oxime and resistance of Dirofilaria immitis to macrocyclic lactones have been reported.

It is recommended to further investigate cases of suspected resistance, using an appropriate diagnostic method. Confirmed resistance should be reported to the marketing authorisation holder or to the competent authorities.

The use of this veterinary medicinal product should take into account local information about susceptibility of the target parasites, where available.

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Withdrawal period

Not applicable.

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Incompatibilities

Not applicable.

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Immediate packaging

Blister packs made up of a cold form laminate of OPA/ALU/PVC of thickness 25µm/47µm/60µm with a 20μm hard tempered aluminium foil.

Available pack sizes:

Cardboard box containing 2 tablets. (1 blister strip of 2)

Cardboard box containing 4 tablets. (2 blister strips of 2 or 1 blister strip of 4)

Cardboard box containing 8 tablets. (4 blister strips of 2 or 2 blister strips of 4)

Cardboard box containing 10 tablets. (5 blister strips of 2 or 1 blisters strips of 10)

Cardboard box containing 16 tablets. (4 blister strips of 4 or 2 blisters strips of 8)

Cardboard box containing 20 tablets. (10 blisters strips of 2, 5 blister strips of 4 or 2 blister strips of 10)

Cardboard box containing 24 tablets. (6 blister strips of 4 or 3 blisters strips of 8)

Cardboard box containing 30 tablets. (3 blister strips of 10 or 15 blisters strips of 2)

Cardboard box containing 32 tablets. (8 blister strips of 4 or 4 blisters strips of 8)

Cardboard box containing 40 tablets. (10 blister strips of 4, 5 blisters strips of 8 or 4 blister strips of 10)

Cardboard box containing 48 tablets. (24 blisters strips of 2, 12 blister strips of 4 or 6 blister strips of 8)

Cardboard box containing 50 tablets. (5 blister strips of 10)

Cardboard box containing 96 tablets. (12 blister strips of 8)

Cardboard box containing 100 tablets. (10 blister strips of 10)

Cardboard box containing 192 tablets. (24 blister strips of 8)

Cardboard box containing 200 tablets. (20 blister strips of 10)

Cardboard box containing 480 tablets. (48 blister strips of 8)

Cardboard box containing 500 tablets. (50 blister strips of 10)

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Storage

Do not store above 25°C.

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Shelf life

Shelf life of the veterinary medicinal product as packaged for sale: 18 months

Shelf life after first opening the immediate packaging: use immediately

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Disposal of unused product

Special precautions for the disposal of unused veterinary medicinal product or waste materials derived from the use of such products

Medicines should not be disposed of via wastewater.

The veterinary medicinal product should not enter water courses as it may be dangerous for fish and other aquatic organisms.

Use take-back schemes for the disposal of any unused veterinary medicinal product or waste materials derived thereof in accordance with local requirements and with any national collection systems applicable to the veterinary medicinal product concerned.

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Additional information

Vm 40162/3011 (NI)

Vm 40162/5011 (GB)

8 DATE OF FIRST AUTHORISATION

25 September 2025

9 DATE OF THE LAST REVISION OF THE SUMMARY OF THE PRODUCT CHARACTERISTICS

September 2025

10 CLASSIFICATION OF VETERINARY MEDICINAL PRODUCT

Veterinary medicinal product subject to prescription.

Find more product information by searching for the ‘Product Information Database’ on www.gov.uk.

Approved: 23 October 2025

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Registration holder

C&H Generics Ltd

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Regulations

Sources

  1. VMD Product Information Database: Ezi-Wormer Duo 12.5mg/125 mg Chewable Tablets for Dogs, 40162/5011 UK Veterinary Medicines Directorate (OGL v3.0), checked 2026-10-04 archived copy from 2026-10-04
  2. The Veterinary Medicines Regulations 2013, Schedule 3 (categories of veterinary medicinal products) UK Government, legislation.gov.uk, checked 2026-10-04 archived copy from 2026-10-04
  3. Summary of Product Characteristics: Ezi-Wormer Duo 12.5mg/125 mg Chewable Tablets for Dogs UK Veterinary Medicines Directorate, SPC of the marketing authorisation holder, checked 2026-10-04 archived copy from 2026-10-04

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