Is it normal for my puppy to suddenly ignore commands she used to know?

Yes, and it has a name: the adolescent period, which in dogs typically spans roughly 6 to 18 months depending on breed size, with regression in trained behaviors like recall and "sit-stay" being one of the most commonly reported changes owners notice (American Kennel Club, 2023). This isn't defiance in the human sense; it reflects ongoing brain maturation, particularly in the prefrontal regions involved in impulse control, alongside rising sex hormones if the dog is still intact. Cornell Riney Canine Health Center research on canine adolescence has found that dogs showing more conflict behavior toward familiar caregivers during this window were also more likely to have that same friction persist into adulthood if training lapses (Cornell Riney Canine Health Center, 2020).

The practical fix is to go back to basics rather than assume the dog "already knows this." Short, high-value-reward sessions of 5 to 10 minutes, several times a day, tend to outperform long single sessions at this age, and reinforcing recall in low-distraction settings before adding distractions rebuilds reliability faster than repeating a command the dog is currently ignoring (American Veterinary Medical Association, 2023). Consistency between household members matters here too — if one person allows jumping on the couch and another doesn't, the mixed signals prolong the adolescent testing phase.

How much should a 6-month-old puppy weigh and is she done growing?

Growth trajectory at 6 months depends heavily on projected adult size. Small breeds (under 20 pounds adult weight) generally reach 75 to 80 percent of their adult weight by this age and may be nearly full height, while giant breeds like Great Danes or Mastiffs are typically only around 50 to 60 percent of adult weight and won't finish growing until 18 to 24 months (Merck Veterinary Manual, 2023). Growth plates in the long bones remain open longer in larger breeds, which is the biological reason veterinarians caution against high-impact exercise — repetitive jumping off furniture, forced long-distance running on hard pavement — until those plates close.

Body condition matters more than the number on the scale. A veterinarian or vet tech can teach owners to check body condition by feeling for ribs under a thin fat layer and looking for a visible waist from above; the World Small Animal Veterinary Association's body condition scoring system is the standard tool used in practice for this (World Small Animal Veterinary Association, 2023). Puppies fed to keep a lean body condition during growth have a documented lower lifetime risk of hip dysplasia and osteoarthritis compared to littermates allowed to grow heavier, based on long-term Labrador Retriever feeding studies referenced by veterinary nutrition specialists (Merck Veterinary Manual, 2023).

Should I spay or neuter my puppy at 6 months, or is that too early?

Six months has long been the traditional default age for spay/neuter, but current guidance has shifted toward breed- and size-specific timing. The American Veterinary Medical Association notes that for many large and giant breed dogs, delaying gonadectomy until after growth plate closure — sometimes 12 to 18 months or later — may reduce the risk of certain orthopedic conditions and some cancers, while early sterilization around 6 months remains appropriate and standard for most small and medium breed dogs (American Veterinary Medical Association, 2023). Research out of UC Davis specifically found breed-dependent differences in joint disorder risk tied to neuter timing, which is why a blanket "always neuter at 6 months" recommendation is no longer considered best practice across all breeds.

This decision should be made individually with your veterinarian, factoring in the dog's breed, size, sex, household situation (multiple intact dogs, risk of unplanned litters), and any orthopedic red flags already noted at exams. Six months remains a reasonable checkpoint to have this specific conversation even if the actual procedure is scheduled later.

Why is my puppy suddenly afraid of things that never bothered her before?

Many puppies go through a second fear period somewhere between 6 and 14 months, during which previously neutral or familiar stimuli — a vacuum, a stranger in a hat, a new location — can trigger disproportionate fear responses (American Kennel Club, 2023). This is a normal developmental stage tied to increased environmental awareness as the dog matures, not a sign that something is wrong with the dog or that earlier socialization failed.

The recommended approach is to avoid flooding the dog with the scary stimulus or forcing interaction, and instead let her retreat and observe at her own pace while pairing calm exposure with treats. Punishing fear responses at this stage can worsen and prolong them; a fear period that seems to intensify rather than resolve over several weeks, or that generalizes into fear of most new things, is a reasonable reason to consult a veterinary behaviorist (American Veterinary Medical Association, 2023).

What vaccines and parasite prevention does my puppy still need at this age?

By 6 months, most puppies have completed their initial core vaccine series (distemper, parvovirus, adenovirus, and rabies where legally required), typically finished between 14 and 16 weeks of age, with rabies often given as a single dose around 12 to 16 weeks depending on state law (American Animal Hospital Association, 2022). Six months is a common time for a booster check and for starting or confirming non-core vaccines like leptospirosis or Bordetella if the dog's lifestyle — boarding, dog parks, rural exposure — warrants it.

This is also the age when monthly heartworm prevention should already be well established, since the American Heartworm Society recommends starting preventives as early as label allows and testing puppies for heartworm at 6 months if prevention wasn't given consistently from the start (American Heartworm Society, 2023). Year-round flea and tick prevention, appropriate to the dog's weight, should continue uninterrupted through this stage regardless of season.

How much exercise and mental stimulation does a 6-month-old puppy actually need?

Physical exercise needs to be balanced against still-developing joints. A commonly cited guideline from veterinary rehabilitation specialists is roughly 5 minutes of structured exercise per month of age, twice daily, meaning a 6-month-old puppy would tolerate about 30 minutes of controlled walking per session — with free play in a securely fenced yard being lower-impact than repetitive forced activity like long runs or repeated stair climbing (American Kennel Club, 2023).

Mental stimulation matters just as much at this stage. Puzzle feeders, scent games, and continued obedience training tire out an adolescent brain in ways that plain physical exercise doesn't, and under-stimulated puppies in this age range are more prone to destructive chewing and excess barking as outlets for pent-up energy (American Veterinary Medical Association, 2023).

Why is my puppy chewing everything again after teething seemed to end?

Teething from baby to adult teeth is usually complete by around 6 months, but destructive chewing frequently continues or resurges afterward for behavioral rather than dental reasons — boredom, anxiety, or simple adolescent exploration of the environment through the mouth (American Veterinary Medical Association, 2023). At this checkup age, a veterinarian will also check for retained baby teeth, which can cause crowding and periodontal problems if the adult tooth erupted without the deciduous tooth falling out, and may need extraction.

Redirecting chewing onto appropriate chew toys, rotating toy novelty, and increasing overall enrichment tends to resolve most of this without needing to treat it as a dental problem. Persistent gum bleeding, visible retained baby teeth past 7 months, or a dog that won't close its mouth normally warrants a dental exam.