Animal register · DogIn the app
Rat Terrier
Rattie, Ratty, American Rat Terrier
The Rat Terrier is a small American terrier, bred in two sizes — miniature and standard — with a short, close-lying, smooth and shiny coat. The breed standard allows a height of up to 18 inches (46 cm) at the withers, and PetMD gives a weight of 10–25 pounds (about 4.5–11 kg) for both sizes; a dog of this size is fully grown at about 9–12 months (PetMD). VCA gives a lifespan of 12–16 years, PetMD 12–18 years.
The Rat Terrier Club of America says Rat Terriers are good with children, especially if raised with them, and do fine in an apartment but need at least 30 minutes of exercise a day. PetMD says they need plenty of physical and mental stimulation, don't enjoy being left alone for long periods and shed mildly all year; VCA recommends brushing once a week and warns they may not be good with small pets, especially rodents.
Available in the 12-week PetPrep Challenge (paid breed).
Updated:
At a glance
- Size
- small — PetMD S648
- Adult weight
- males 4.5–11.3 kg, females 4.5–11.3 kg — PetMD S648
- Daily exercise
- at least 30 minutes a day — Rat Terrier Club of America S650
- Brushing
- once a week — VCA Animal Hospitals S647
Key facts from the sources at the bottom of the page. Where sources differ, each value is listed.
Who it suits
Good for:
- families with childrenS650
The same tags as in the app. Each tag is backed by the sources listed at the bottom of the page.
What it needs
From breed standards, kennel clubs, veterinary charities and studies. Where sources differ, each one is shown.
Exercise
- Daily exercise: at least 30 minutes a day — Rat Terrier Club of America S650
Coat and grooming
Meals
- Strongly motivated by food — helpful in training, but watch the portions. — PetMD S648
General guidance for dogs (not breed-specific):
Lifespan
Life stages
- Reaches adult size at: about 9–12 months (guidance for its size class) — PetMD S10
General guidance for dogs (not breed-specific):
Size and weight
Questions and answers
Answered only from the sourced facts on this page; every answer names its sources.
How much exercise does a Rat Terrier need?
According to our sources, the Rat Terrier needs this much exercise: at least 30 minutes a day — Rat Terrier Club of America S650.
How long does a Rat Terrier live?
According to our sources, the lifespan of the Rat Terrier is: 12–16 years — VCA Animal Hospitals S647; 12–18 years — PetMD S648. The sources give different values, so each one is listed.
How big does a Rat Terrier get and how much does it weigh?
Size and adult weight of the Rat Terrier, according to our sources: Size: small — PetMD S648; Adult weight: males 4.5–11.3 kg, females 4.5–11.3 kg — PetMD S648.
How much grooming does a Rat Terrier need?
Coat and grooming of the Rat Terrier, according to our sources: Brushing: once a week — VCA Animal Hospitals S647; Coat: short — Rat Terrier Club of America S650.
Who is the Rat Terrier a good fit for?
Our sources describe the Rat Terrier as a good fit for: families with children — Rat Terrier Club of America S650. Keep in mind: needs mental challenges — PetMD S648; loves company — best with someone home most of the day — PetMD S648; sheds — PetMD S648; loves food — watch the weight — PetMD S648.
Game rules, not veterinary advice
How PetPrep simulates it
In PetPrep one real week is one month of the pet's life. These are the rules the game uses for this breed. PetPrep chose them from the sources on this page; they are not care instructions for a real animal.
| Life stage | Starts | Meals a day | Daily step goal |
|---|---|---|---|
| Puppy | arrives at 2 months | 4; from month 3: 3; from month 6: 2 | 1,000 steps per month of age (2,000 on arrival), up to 3,000 from month 3 |
| Young dog | month 9 | 2 | 3,000 steps |
| Adult | month 36 (3 years) | 2 | 3,000 steps |
| Senior | month 108 (9 years) | 2 | 2,300 steps |
- Step goal = minutes of daily exercise × 100 steps: an adult gets 30 minutes, so 3,000 steps a day.
- Learns commands as fast as the mixed breed of the free plan.
- Becomes a senior in month 108 (9 years) — the last quarter of the breed's expected lifespan.
- Walks count real steps from Apple Health or Health Connect (with permission, read-only) and the phone's motion sensor — no GPS.
- Combing once a week.
- Care: trimming the nails once a week — a task for the child.
- Care: a bath every 4 weeks — a reminder for the parent.
Each game number is a PetPrep decision recorded with its sources. — PetMD, AAHA, Dogs Trust, ASPCA, VCA Animal Hospitals, The Royal Kennel Club, Purdue University Canine Welfare Science, Wikipedia, British Journal of Sports Medicine, WebMD Pets, Rat Terrier Club of America S10S11S14S18S19S21S24S35S45S647S648S649S650
Common Rat Terrier owner mistakes
Small habits that cause bigger problems — each point comes from the sources of this breed.
- Too little daily exerciseExercise needed: at least 30 minutes a day. Plan it into every day, not only at weekends. — Rat Terrier Club of America S650
- Skipping coat careBrushing: once a week. — VCA Animal Hospitals S647
- Too many treats and too-big mealsPuts on weight easily — portions and treats need watching. Strongly motivated by food — helpful in training, but watch the portions. — PetMD S648
- Forgetting that the puppy is still growingAdult size reached at: about 9–12 months (guidance for its size class). Until then, plan exercise and food for a young animal that is still growing, and ask your vet what suits yours. — PetMD S10
- Overlooking the breed's known health issuesHip dysplasia, a poorly developed hip joint that can lead to arthritis, occurs in the breed; breeders are advised to have the parents' hips scored. Luxating patellas, where the kneecap temporarily slips out of place, occur in the breed. Legg-Perthes disease, a painful condition in which the hip joint dies and crumbles, can occur in the breed. Primary lens luxation, a painful inherited eye condition in which the lens slips out of place and which can cause blindness, occurs in the breed; a DNA test is available for breeding dogs. Skin allergies are a known concern in the breed; The Royal Kennel Club asks judges to look for signs of skin inflammation, and owners are advised to ask their vet before choosing a shampoo. — PetMD S648
In PetPrep a child practises exactly these habits — steps, meals, care — before the real pet comes home.
Health
For information only, not vet-reviewed. Ask your vet about your own animal.
- Hip dysplasia, a poorly developed hip joint that can lead to arthritis, occurs in the breed; breeders are advised to have the parents' hips scored. — PetMD S648
- Luxating patellas, where the kneecap temporarily slips out of place, occur in the breed. — PetMD S648
- Legg-Perthes disease, a painful condition in which the hip joint dies and crumbles, can occur in the breed. — PetMD S648
- Primary lens luxation, a painful inherited eye condition in which the lens slips out of place and which can cause blindness, occurs in the breed; a DNA test is available for breeding dogs. — PetMD S648
- Puts on weight easily — portions and treats need watching. — PetMD S648
- Skin allergies are a known concern in the breed; The Royal Kennel Club asks judges to look for signs of skin inflammation, and owners are advised to ask their vet before choosing a shampoo. — PetMD S648
Before you buy: what to check with the breeder
Questions to settle before you take a puppy home. The points are advice from vets, welfare charities and kennel clubs; each cites its source.
For every breed
- See the puppy with its mother, where it was born. — PDSA, RSPCA K1K2
- The puppy should not leave its mother before 8 weeks of age. — PDSA K1
- Ask for the pedigree. Under FCI rules a pedigree may be issued for correct parentage only. — FCI K7
- Ask to see the health-test results of both parents. Which tests matter depends on the breed. — PDSA, British Veterinary Association, FOUR PAWS UK K1K9K10
- National kennel clubs can set breeding rules that go beyond the FCI's — ask the breed club which tests the parents need. — FCI K7
- Ask for a written sale contract that records the puppy's background and health. — British Veterinary Association, FOUR PAWS UK K9K10
Laws on the minimum age, microchipping and vaccination differ by country — check the rules where you live.
Health tests of the parents for this breed
Other screening schemes for this breed
- Heart examination of the parents (breed club recommendation) — Rat Terrier Club of America K39
- Hip X-ray screening for hip dysplasia (UK: BVA/KC scheme) — Rat Terrier Club of America K39
- Kneecap check for luxating patella before breeding — Rat Terrier Club of America K39
- DNA test for primary lens luxation (PLL), an inherited eye disease in which the lens slips out of place — Rat Terrier Club of America K39
These lists come from the UK's Royal Kennel Club and are an orientation; national kennel clubs can set their own, stricter rules. Ask the breed club and the breeder which tests the parents have done.
Similar breeds
Other dogs in the register with similar needs — each with sourced facts.
Sources
Every fact on this page cites one of these sources.
- S10PetMD — S. C. Mitchell, DVM, DABVP, 2025-05-20 — When Do Dogs Stop Growing?https://www.petmd.com/dog/general-health/when-do-dogs-stop-growing
- S11AAHA — 2019 AAHA Canine Life Stage Guidelines — Canine life stage definitionshttps://www.aaha.org/resources/life-stage-canine-2019/canine-life-stage-definitions/
- S14Dogs Trust (UK) — Caring for an older doghttps://www.dogstrust.org.uk/dog-advice/life-with-your-dog/at-home/looking-after-an-older-dog
- S18ASPCA — General Dog Carehttps://www.aspca.org/pet-care/dog-care/general-dog-care
- S19VCA Animal Hospitals (2025-02-21) — Feeding Times and Frequency for Your Doghttps://vcahospitals.com/pets-first/know-your-pet/feeding-times-and-frequency-for-your-dog
- S21The Royal Kennel Club (UK) — Puppy feeding tipshttps://www.royalkennelclub.com/health-and-dog-care/health-dog-care/health/health-and-care/a-z-of-health-and-care-issues/puppy-feeding-tips
- S24Purdue University Canine Welfare Science (content: Pet Leadership Council 2019, bedogsmart.com) — Dog Fitness and Exercise (PDF)https://caninewelfare.centers.purdue.edu/wp-content/uploads/2022/12/Dog-Fitness-and-Exercise.pdf
- S35Wikipedia — The Intelligence of Dogshttps://en.wikipedia.org/wiki/The_Intelligence_of_Dogs
- S45British Journal of Sports Medicine (2018) — Tudor-Locke C. et al. How fast is fast enough? Walking cadence (steps/min) as a practical estimate of intensity in adults. doi:10.1136/bjsports-2017-097628https://pmc.ncbi.nlm.nih.gov/articles/PMC6029645
- S647VCA Animal Hospitals (LifeLearn; no author / date shown) — Rat Terrier — dog breed pagehttps://vcahospitals.com/know-your-pet/dog-breeds/rat-terrier
- S648PetMD — Kristen Seymour, reviewed by Barri J. Morrison, DVM (updated 2023-03-06) — Rat Terrier Dog Breed Health and Carehttps://www.petmd.com/dog/breeds/rat-terrier
- S649WebMD Pets — medically reviewed by Amy Flowers, DVM (2022-05-09) — Rat Terriers: What You Should Knowhttps://www.webmd.com/pets/dogs/what-to-know-about-rat-terriers
- S650Rat Terrier Club of America (AKC judges' education, hosted by AKC) — The Rat Terrier Breed Presented by Rat Terrier Club of America (RTCA) (PDF)https://images.akc.org/judges/Rat_Terrier.pdf
- K1PDSA — Getting a puppyhttps://www.pdsa.org.uk/pet-help-and-advice/looking-after-your-pet/puppies-dogs/getting-a-puppy
- K2RSPCA — Buying a puppyhttps://www.rspca.org.uk/adviceandwelfare/pets/dogs/puppy
- K7FCI (copy hosted by Norsk Kennel Klub) — International Breeding Rules of the FCIhttps://nkk2023.stage22.coretrek.no/getfile.php/131987377-1520848467/Dokumenter/Registrering/FCIs%20avlsregler%202013.pdf
- K9British Veterinary Association — What should you consider when buying a puppy?https://www.bva.co.uk/news-and-blog/blog-article/what-should-you-consider-when-buying-a-puppy/
- K10FOUR PAWS UK — Questions to ask when buying a puppyhttps://www.four-paws.org.uk/our-stories/publications-guides/questions-to-ask-when-buying-a-puppy
- K39Rat Terrier Club of America (hosted by AKC) — Rat Terrier Health Statement (June 2025) (PDF)https://s3.amazonaws.com/cdn-origin-etr.akc.org/wp-content/uploads/2025/09/24155713/Rat-Terrier-Health-Statement.pdf
PetPrep is a simulation for families. This page is not veterinary advice — for a real animal, ask a vet or the breed club.
Ready for a pet?
Be among the first families to try PetPrep. We will email you when it is ready — nothing else.