How big will my puppy get?
Almost the first question anyone asks when thinking about adopting or buying a puppy is "How big will he get?" This is an important question to think about when you are considering adding any breed into your home. Looking up breed standards is a good place to start; books such as the Canadian Kennel Club's Book of Official Breed Standards or the American Kennel Club's Complete Dog Book have lots of valuable information about each breed, including average size.
Height ranges for the Havanese according to the breed standard of the American Kennel Club (AKC) is 8.5 to 11.5 inches and 21 to 29cm (8.3 to 11.4 inches) for the Canadian Kennel Club (CKC). Most people assume their puppy will grow to within these acceptable ranges. Though height does get asked about, when people ask "How big will my dog get?" for the most part what they really want to know is weight. The average mature Havanese weighs between about 8 and 13 pounds. Some weigh a bit less, some a bit more and some substantially more, a few weighing in a hefty 20+ pounds.
What about your puppy? Will your Havanese be 8 pounds or 18? How can you tell? You may get some idea by looking at the puppy's parents. You may also get clues by seeing several other dogs in your puppy's breedline and by talking to your breeder who knows their line best and how puppies in the past have matured. If that is not enough for you, here are a few insights to give you a handle on a puppy's growth potential; estimating a puppy's eventual size is not as tricky as it seems. Looking at weight at specific ages is one of the simplest methods.
The younger a puppy is, the harder it is to predict what size it will eventually be. Birth weights are the least value of all in predicting adult size. Actually, anything less than 8 weeks gives a pretty unreliable answer. Weight estimates before the age of 8 weeks give erratic results in large part because puppies are still nursing or being weaned. Nursing puppies may be heavier because of the high calorie/high fat content of mother's milk. Puppy weights in these early weeks also depend on the size of the litter. A singleton puppy that has all the milk to himself may have a much sharper weight gain than a puppy having to share the buffet with 6 littermates.
When predicting adult size, the two easiest formulas to remember are FOUR FOLD and DOUBLE UP. Four Fold: The weight of a healthy Havanese puppy at 8 weeks of age is approximately one quarter of adult weight. Double Up: The weight of a healthy Havanese puppy at 16 weeks is approximately one half of adult weight. The 16 week weight calculation is more reliable than the 8 week one. The 8 week calculation is reasonably accurate to within +/- 15% while the 16 week calculation is +/-10%.
Most breeders will have 8 week puppy weights and can give you an assessment as to what size to expect your puppy to mature. At that age, puppies are approximately one quarter of adult weight. The majority of puppies will see the Vet around 4 months of age as this is a typical age for a check up and Booster shot of puppy immunizations. At 16 weeks, a Havanese puppy is approximately one half of his adult weight. Whether this weight is measured closer to 15 weeks or 17 weeks may make the difference of up to 1 pound or so less or more than calculated which is a factor to keep in mind.
With the above factors taken into consideration, it is possible to make a reasonable guess of a puppy's weight at maturity using the Four Fold and Double Up formulas. These formulas work quite well for approximately 85% of Havanese. Many more are either a few ounces below or above. Very few are significantly off. The formulas are not 100% accurate but do provide pretty good ballpark estimates. Where they appear to not work, often you can find a simple reason like weights not taken on the right date, scale variation, not including margin of error, or not taking breedline maturing into consideration. Fast maturing lines may mature slightly lower than calculated and slow maturing lines may mature slightly higher. A preemie puppy or sickly puppy will have a larger margin of error in any calculations and adult weight is much harder to predict. Many things can also affect the mature weight of a puppy. Weight may vary depending on genetics and bloodline, diet and exercise. An adult dog with 2-3 extra pounds around his middle is not an exception. He needs a diet.
Here are a few examples.
Example # 1) Scamp at 8 weeks weighed exactly 3lbs. Using the Four Fold formula (8wk
weight x 4), we figure that his adult weight will be around 12 pounds. Factoring in the 15%
margin of error gives a projected range of 10lbs3oz to 13lbs13oz. As an adult, Scamp weighs
12lbs3oz which is right about where we calculated he would be.
Example # 2) Cricket weighed in at 2 lbs4oz at 8 weeks of age. A rough estimate using the
Four Fold formula (8wk weight x 4) told us to expect about a 9 pound adult. Her 16 week weight
was 4lbs4oz. An estimate using the Double Up formula (16wk weight x 2) gave us 8lbs8oz. So
we expected 8.5 to 9 pounds. At her first birthday, Cricket only weighed in at 7 pounds. What
happened? Even factoring the margin of error, 7 pounds is still well below expected range. A
closer look at her breedline and a chat with her breeder told us that she was from a very slow
maturing breedline and that we could expect a growth spurt around 18 months. So we waited.
At 2 years of age, Cricket weighed in at 8lbs9oz, which fits in nicely where we initially expected
her to be. At 6 years of age, she is at 8lbs11oz.
Example #3) Scruffy at 17 weeks weighed 9lbs5 oz. Using the Double Up formula (16wk weight x 2), we figure that his adult weight will be roughly18lbs10oz. We know he may be a little less than that as we are using a 17 week weight rather than a 16 week weight, but still can guess pretty definitively that he will be a big boy. Including the 10% margin of error, we calculate a range of 16lbs12oz -20lbs8 oz. As an adult Scruffy weighs 18lbs 5 oz., very close to what was expected.
Alhough not 100% accurate, the formulas Four Fold and Double Up can give a pretty good insight into answering the question "How big will my puppy get?". Take a peek at your Vet records and make note of your puppy's weight around 4 months of age. Try the formula out and see if it worked for you. I would love to hear back from you so that I can add your Havanese puppy into my breed statistics. Please include litter size, exact age at weight measure, and any special circumstances like any illness etc.
Note. Some breeders indicate their puppies are full grown at 6 months of age. Though this does happen quite frequently in regards to height, full weight at 6 months of age is not as common although it may be true of some very fast maturing breedlines. Similarly, those that continue to fill out weight till 18 - 24 months are less common but do occur in very slow maturing breedlines.
How Big Will My Puppy Get was published in Our Havanese Jan/Feb 2008 issue and received a Best Article nomination from DWAA (Dog Writers Association of America)