Weight and Your Mastiff

Mastiff Information

When it comes to owning an English Mastiff, one of the many questions you will hear on a regular basis is how much does he way? With such an emphasis on this question, it is no wonder that so many owners worry about their Mastiff’s weight and how quickly, or not so quickly, their Mastiff is growing.

Before I look at the average growth chart of an English Mastiff, as well as what I have experienced firsthand, it is important to remember a few hard and fast rules.

  1. Weight is just a number. It isn’t important. There are 180lb English Mastiffs that are massive with proper bone, head, and size. Then there are 180lb English Mastiffs that are too fat at that weight and really need to lose a good 10 to 20lbs. Confirmation is not about weight but is about the actual way the dog carries the weight.
  2. A Mastiff is better lean than heavy. Although we want a nice big dog, with the key word being massive, it is better to keep your pups lean as they grow instead of fattening them up to please a growth range you see online.
  3. All Mastiffs grow at different rates. Some lines gain weight quickly and others gain height before they gain weight. Don’t compare your pup to others, even in the same litter. If the sire and dam are in the 200lb range, then your puppy will get to that weight at his or her own speed.
  4. You’re in for the long haul. Although a lot of breeds reach adult size around one to two years, English Mastiffs are slow growers. That means that you are looking at 3 years or even 4 years before your pup is his or her adult size. Be patient. Mastiff growth is a marathon and should never be forced to a sprint for health.
  5. Always discuss with your breeder about your puppy’s lines and growth. If anyone knows their dogs, it’s your breeder and they will give you advice on how to encourage the healthiest weight for your puppy.

Remember that your puppy’s maximum healthy weight is determined by genetics and while environment and feeding, can stunt that growth, it very rarely increases it. Feed so your puppy is healthy to prevent lifelong health and joint problems. Do not overfeed to get a high weight.

That being said, it is still interesting to chart the weights of a puppy. I chart all of my puppies to monitor their health while they are here and then I chart the dogs who live with me on a regular basis to chart their growth. I am not worried about the end number; so much as I am worried about seeing a steady weight and not a sudden loss, which could indicate a health problem.

With your own puppy, the best rule of thumb is to follow this generalized weight gain. It is important not to hold your pup to these weights as hard and fast. Some pups will start smaller and end larger, some will be in the weight range their entire growth, some will be heavier for some of it. What you want to focus on is healthy growth and the enjoyment of your Mastiff. But the weight ranges you should look at are:

  • 8 Weeks: 15-25 lbs
  • 6 Months: 65-85 lbs
  • 1 Year: 110-170 lbs
  • 18 Months: 140-185
  • 2 Years: 160-200
  • 3 Years: 170-220+

One of the more popular charts out there is one that I don’t overly recommend but I have posted it for you to see so you can see a steadier weight. Remember that this is not the average but simply looks at two individual dogs so it should not be considered the definitive numbers for your dog’s growth.

Another snapshot of growth is my Daisy from 4 weeks until 3 years of age.

3 weeks - 4 pounds 2 ounces

5 weeks - 15 pounds 6 ounces

6 and a half weeks - 18 pounds 8 ounces

8 weeks - 21 pound 8 ounces

11 weeks - 32 pounds even height 17 1/4 inches to the withers

13 weeks- 44.6 pounds, height 18.5 inches

15 weeks - 47.8 pounds

17 weeks - 52 pounds

19 weeks - 60.4 pounds, height 22 3/4 inches

20 weeks - 66.2 pounds

24 weeks - 74.6 pounds

27 weeks - 83.2 pounds, height 26.5 inches

6.5 months - 86.7 pounds

11 months - 113.4 pounds

13 months - 118.7 pounds

18 months

154 pounds

3 years

187 pounds

And finally, a growth chart for Einstein, our up and coming girl from birth. I will update it on a regular basis.

Day 1 AM (Birth): 4th

706g (1.55lbs)

Day 1 PM:

714g (1.57lbs)

Day 2 AM: 5th

724g (1.60lbs)

Day 2 PM:

752g (1.66lbs)

Day 3 AM: 6th

789g (1.73lbs)

Day 3 PM:

852g (1.88lbs)

Day 4 AM: 7th

920g (2.03lbs)

Day 4 PM:

988g (2.18lbs)

Day 5 AM: 8th

1067g (2.35lbs)

Day 5 PM:

1133 (2.50lbs)

Day 6 AM: 9th

1242g (2.74lbs)

Day 6 PM:

1265g (2.79lbs)

Day 7 AM: 10th

1380g (3.04lbs)

Day 7 PM:

1427g (3.19lbs) Dbld

Day 8: 11th

1504g (3.32lbs)

Day 9: 12th

1611g (3.55lbs)

Day 10: 13th

1804g (3.98lbs)

Day 11: 14th

1840g (4.06lbs)

Day 12: 15th

1992g (4.39lbs)

Day 13: 16th

2042g (4.50lbs)

Day 14: 17th

2181g (4.81lbs)

Day 15: 18th

2288g (5.04lbs)

Day 16: 19th

2314g (5.10lbs)

Day 17: 20th

2448g (5.40lbs)

Day 18: 21st

2559g (5.64lbs)

Day 19: 22nd

2689g (5.93lbs)

Day 20: 23rd

2757g (6.08lbs)

Week 3 Start: 25th

3041g (6.70lbs)

Week 3 Mid 29th

3697g (8.15lbs)

Week 4 Start Dec. 2

4209g (9.28lbs)