Deworming dogs and cats: how often and how
As a rule, internal deworming is repeated every 3 months and external deworming monthly during risk season. The exact schedule depends on the product, age and environment. Here is how to organise it without slip-ups.
Deworming dogs and cats combines internal antiparasitics (worms, giardia) and external ones (fleas, ticks). The frequency depends on the animal's age, environment and lifestyle: as a general guide, many adults are dewormed internally every 3 months, but the exact protocol is always set by the vet.
Key facts
- Internal (digestive) and external (fleas and ticks) treatments are different and complementary.
- As a guide, many adult dogs and cats are dewormed internally every 3 months.
- Puppies and kittens need more frequent protocols during their first weeks.
- Ticks can transmit serious diseases; prevention is more effective than treatment.
- Record each product and date so you never miss the next dose.
Internal vs external: what each covers
Who this guide is for
If you live with a dog or a cat, deworming and parasite control are part of their basic care throughout their whole life.
Families with a dog or cat
Both animals that go outdoors and those that live only indoors can have parasites. This guide helps you understand what your pet needs and when.
Households with children or older people
Some intestinal parasites can also affect people. Keeping parasite control up to date protects the whole family, not just the pet.
Those who have just adopted or already have several animals
Puppies, kittens and homes with several pets need specific schedules. Here you have a clear basis to discuss it afterwards with your vet.
When it will be useful
You have just adopted
Puppies and kittens often arrive with parasites from their surroundings or from the mother. The first deworming is one of the first health steps.
Flea and tick season arrives
In Spain, external parasites increase with the spring and summer heat. It is a good time to review external protection.
You are going to travel or change area
Areas with mosquitoes or particular ticks carry risks such as heartworm disease. It is wise to adjust prevention before setting off.
You can't remember when the next one was due
If you lose track of the last pipette or tablet, keeping a record in a digital health record avoids missed and double doses.
Why parasite control matters
Prevents digestive problems
Intestinal worms can cause diarrhoea, vomiting or weight loss. Internal deworming helps keep the digestive system healthy.
Protects against serious diseases
Ticks and mosquitoes can transmit serious diseases. Good external prevention greatly reduces that risk.
Also protects the family
Some parasites are zoonotic, meaning they can pass to people. Deworming your pet protects everyone at home.
Avoids flea problems
Fleas cause itching and skin allergies and can transmit other parasites. Keeping them at bay improves the animal's daily well-being.
Cheaper to prevent than to treat
Treating an infestation or a transmitted disease is usually more costly and harder than regular prevention.
Peace of mind and control
Knowing your pet is protected and having the history to hand gives reassurance, especially during vet visits or trips.
Practical cases
A dog that walks in the countryside
A dog that goes out to areas with tall grass has more exposure to ticks. Regular external protection is usually combined with periodic internal deworming, as the vet advises.
Indoor cat
Even if it never goes out, a cat can get parasites from insects that come into the home or from footwear. It is not wise to assume it is risk-free without checking.
A newly arrived puppy
Puppies usually need several consecutive internal dewormings in their first weeks. Your vet will set the exact schedule based on their age and weight.
How to organise parasite control
Consult your vet
They are the ones who define which product and what frequency your pet needs based on its age, weight, species and lifestyle. Every animal is different.
Choose the right format
There are pipettes, collars, tablets and chews. Some cover internal parasites, others external and some both. Your vet will help you choose.
Apply the correct dose
Follow the weight and the product instructions. Do not use dog products on cats or vice versa without confirming it, as some can be toxic.
Keep track and turn on reminders
Note every deworming in the free Cartilla Veterinaria digital record and set reminders so you don't skip the next dose or repeat one too soon.
Common mistakes
Deworming FAQ
Usually every 3 months, though it can be monthly in puppies or dogs with lots of contact with other animals.
Spot-ons and collars mainly tackle external parasites; tablets are often used for internal ones. Combined products exist; your vet will recommend the best option.
Internal deworming can start at 2 weeks of age, repeated frequently during the first weeks.
Heartworm disease, transmitted by mosquitoes, requires specific prevention that the usual products do not always cover. In at-risk areas of Spain it is important to discuss it with your vet.
Not always. Some dog antiparasitics contain substances that are toxic to cats. Always use the right product for each species and confirm it with your vet.
Most animals tolerate it well, but mild, temporary discomfort may appear. If you notice anything that worries you after applying it, contact your vet.
During pregnancy and nursing there are specific schedules and not all products are suitable. This is a case your vet should always assess before applying anything.
Some signs are itching, weight loss, diarrhoea or seeing parasites in the coat or faeces, but many show no symptoms. Whenever in doubt, the best thing is to see your vet.
You can note them in the free Cartilla Veterinaria digital record, alongside the rest of the history. That way you always have the dates and reminders to hand from your phone.
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