Puppy vaccines, deworming and neutering: the complete guide

The three preventive-care essentials of a puppy’s first year are vaccines, deworming and, later on, neutering. None of them is optional if you want to protect your puppy properly: vaccines and deworming prevent serious diseases (some fatal, like parvovirus) from the first weeks of life, and neutering is a decision worth planning ahead, not leaving for “whenever it happens.” Here’s the general schedule for each one, explained without unnecessary jargon.

Vaccines: the first-year schedule

A puppy’s vaccination schedule broadly follows this structure:

• Initial vaccination (6-8 weeks): the first dose of the combined vaccine, covering the most serious diseases: parvovirus, distemper, infectious canine hepatitis and parainfluenza.
• Boosters (every 3-4 weeks until ~16 weeks): a puppy’s immune system needs several doses to build full protection; skipping a booster leaves gaps in that protection.
• Rabies: mandatory in most autonomous regions of Spain, though the exact schedule varies depending on local regulations and the vaccine manufacturer.
• Adult boosters: annual or every 3 years depending on the vaccine and your vet’s judgement.

One important nuance: the exact schedule (ages, combinations, brands) is set by your vet based on your puppy’s history, local disease prevalence and each vaccine’s manufacturer. This guide is a general reference, not a fixed protocol.

Until your puppy has completed the initial course, avoid contact with dogs of unknown health status and with areas heavily used by other dogs (parks, dog-friendly terraces): the risk of parvovirus is real, and the first few weeks are the most vulnerable.

Deworming: internal and external

Deworming has two distinct fronts, and both are necessary:

Internal deworming (roundworms and other digestive parasites)

• From 2 weeks old, repeating every 2 weeks until 3 months.
• From 3 to 6 months, a monthly schedule.
• From 6 months on, the usual adult schedule is quarterly, although your vet may adjust it based on your dog’s lifestyle (access to hunting/wildlife, living with children, travel).

Some of a dog’s internal parasites (such as certain roundworms) are zoonotic: they can be transmitted to people, with a higher risk for young children. That’s a good reason not to skip the schedule, beyond the dog’s own health.

External deworming (fleas and ticks)

Usually applied monthly from whenever the puppy reaches the minimum age and weight stated on the product (spot-ons, collars and oral tablets each have different minimum ages). Ticks, besides being a nuisance, can transmit serious diseases such as ehrlichiosis or babesiosis, so keeping up the schedule all year round — not just in summer — is what most vets in Spain recommend, given the climate.

Neutering: what it is and when it makes sense

Neutering is the surgery that removes a dog’s ability to reproduce. Its most commonly cited benefits include controlling the dog population, reducing the risk of certain tumours (mammary in females if done early, testicular in males) and of serious uterine infections (pyometra), as well as potentially softening some behaviours linked to sex hormones.

• There’s no single correct age. As a general guideline, many vets place the window between 6 and 12 months, but for large and giant breeds it’s sometimes recommended to wait until bone growth is complete. It’s a decision your vet should make case by case, not a generic date off the internet.
• Males (orchiectomy): removal of the testicles. Simpler surgery, generally quick recovery (a few days).
• Females (ovariohysterectomy): removal of the ovaries (and often the uterus). Somewhat more invasive, with a somewhat longer recovery and stricter after-care (avoiding strain, watching the wound).
• What it doesn’t do: neutering isn’t a shortcut to “fix” a dog with general behaviour problems. It can reduce specific hormone-driven behaviours (marking, roaming, mounting), but anxiety, fear or a lack of training need to be addressed separately.

How to plan the first year: a general timeline

1. Weeks 6-8: first vaccine + start of internal deworming (if not already started).
2. Weeks 9-16: vaccine boosters every 3-4 weeks + fortnightly/monthly internal deworming + start of external deworming.
3. Months 4-6: end of the booster schedule + monthly deworming + first vet assessment on neutering.
4. From 6 months on: annual check-ups, vaccine boosters as scheduled, quarterly deworming, and neutering if appropriate.

This timeline is a general guide: your vet should confirm each step based on your puppy’s breed, weight and specific health.

Even with good prevention, no puppy is completely free from the occasional digestive upset. If that happens, we have specific guides on why dogs vomit and on what to do if your dog has diarrhoea, including the warning signs that mean it’s time to see the vet without waiting.

Preventive health care is only part of these early weeks — behavioural groundwork matters just as much. We have a full guide on how to train a puppy, covering socialisation, first commands and house training.

Frequently asked questions

What vaccines does a puppy need, and when?

The usual schedule starts between 6 and 8 weeks with the initial vaccination (parvovirus, distemper, hepatitis and parainfluenza), with boosters every 3-4 weeks until around 16 weeks, plus the rabies vaccine as required by regional regulations in Spain. Your vet sets the exact schedule based on the vaccine brand and your puppy’s situation.

How often do you need to deworm a puppy?

Internal deworming usually starts at 2 weeks old and repeats every 2 weeks until 3 months, then monthly until 6 months, and after that on whatever schedule your vet sets (often quarterly in adults). External deworming (fleas and ticks) is usually monthly from whenever the puppy meets the product’s minimum age and weight.

When is the best time to neuter a dog?

There’s no single age that works for every case: it depends on sex, breed and expected adult size. As a general guideline, many vets recommend somewhere between 6 and 12 months, but for large breeds it can be worth waiting a bit longer. It’s your vet who should set the timing based on your dog’s specific development.

What’s the difference between neutering a male dog and spaying a female?

In males it’s an orchiectomy (removal of the testicles), a simpler surgery with a generally faster recovery. In females it’s an ovariohysterectomy (removal of the ovaries and, depending on technique, the uterus too), somewhat more invasive with a somewhat longer recovery and stricter after-care. Both are done under general anaesthesia, and your vet will give you the specific post-op instructions.

Does neutering my dog fix behaviour problems?

Only partly. It can reduce behaviours linked to sex hormones (marking, mounting, roaming to find a mate, some male-on-male aggression), but it doesn’t correct the rest of a dog’s behaviour: that takes training and, if needed, a behaviour professional. Neutering is not a substitute for training.