1
BCS 1: Severely underweight
Ribs, spine, and pelvic bones easily visible from a distance. Severe muscle loss. Always vet investigated, rarely a feeding issue alone.
Is Your Dog at a Healthy Weight? Free AI Body Condition Checker
Take a side on photo, get a body condition reading in about 10 seconds. We score on the standard 9 point veterinary BCS scale and tell you whether your dog is lean, ideal, carrying a few extra pounds, or worth seeing a vet for.
Scan nowFree · Private · Instant · No signup needed
How Body Condition Inspector Works
-
1. Snap a side on photo
Photograph your dog standing square in good light. Get the full body in frame, nose to base of tail.
-
2. We assess
The AI applies the standard 9 point BCS scale. Reads ribs, waist, abdominal tuck, and overall proportions. Takes about 10 seconds.
-
3. Get your plan
You see the BCS score (1 to 9), tier, observations, and a plan you can start tomorrow.
Loading the body condition checker…
What We Look For
The same four signals a vet reads on first look. The combination matters more than any single one. A dog with visible ribs and a clear waist is a different read from one with neither.
Ribs
How easy are the ribs to see and feel. At ideal BCS, ribs are easy to feel under a thin fat layer. At BCS 8 plus, they cannot be felt without firm pressure.
Waist
The hourglass shape from above. Visible at ideal BCS, lost at BCS 7 or higher. We infer it from the side view when an above shot is not available.
Abdominal tuck
The line of the belly rising up toward the back legs when viewed from the side. Pronounced at lean, visible at ideal, gone at obese.
Spine and tail base
Fat deposits on the lower back and base of tail are a reliable signal of BCS 8 or 9. Absent at lower scores.
The 9 Point Body Condition Scale
The standard scale used by veterinarians worldwide, referenced by WSAVA, AAFCO, Purina, and the Royal Veterinary College. Lean dogs (BCS 4 to 5) live on average 1.8 years longer than dogs in the 6 to 7 range, so where your dog sits on this scale matters.
2
BCS 2: Underweight
Ribs, spine, and pelvic bones easily visible with little fat covering. Mild muscle loss may be starting. Vet visit comes first.
3
BCS 3: Lean
Ribs easy to feel with minimal fat covering. Waist obvious, pronounced tuck. Normal for sighthounds and working dogs. Worth a parasite check for other breeds.
4
BCS 4: Ideal (lean side)
Ribs easy to feel with minimal fat. Waist visible from above, clean tuck under the belly. The lean end of textbook healthy. Many vets prefer dogs to sit here long term.
5
BCS 5: Ideal
Ribs felt easily under a thin fat layer. Waist clearly visible from above, visible tuck from the side. Textbook healthy weight, associated with the longest healthy lifespan in dogs.
6
BCS 6: Slightly overweight
Ribs felt with a clear layer of fat. Waist visible but less pronounced. Common in middle aged UK dogs. Responds well to a 10 to 15 percent food cut and an extra walk a day.
7
BCS 7: Overweight
Ribs difficult to feel under a heavier fat layer. Waist barely visible, tuck reduced. Worth a focused 8 to 12 week plan. Vet weigh in is a good baseline.
8
BCS 8: Obese
Ribs cannot be felt without firm pressure. No waist, fat deposits on lower back and base of tail. Health risks become significant. A vet led plan is the safest route.
9
BCS 9: Severely obese
Heavy fat deposits across chest, spine, and base of tail. No waist, no tuck. Affects mobility and breathing. Always a structured vet led plan, often with a prescription weight management food.
Common Weight Issues in UK Dogs
Overweight is under recorded in UK clinical notes (RVC VetCompass clocks it at around 1 in 14 dogs in vet records), but observational studies put the real prevalence at roughly half of all adult dogs. Most owners simply do not see it on their own dog. Here are the patterns owners ask about most. If any sound familiar, the tool above gives a personalised read.
At a Healthy BCS (4 to 5)
What it looks like: Ribs are easy to feel under a thin layer of fat. The waist is visible from above and there is a clean tuck under the belly from the side. Whatever is going on in the bowl and on the lead is working.
What to keep doing: Note the current food, portion, and walk routine in the household calendar so you can spot drift later. Weigh fortnightly. Treats stay under 10 percent of daily calories. Most healthy weight dogs slip out of this band quietly over 6 to 18 months unless there is a written record to compare against.
Where supplementation helps: Lean dogs live longer on average (the Purina lifetime study put it at 1.8 years), and a daily nutritional foundation protects the joints, gut, and skin barrier so the score stays where it is. Super Everyday is built for this preventative case.
When to see a vet: Annual check up with body condition scored hands on once a year. No urgency.
Slightly Overweight (BCS 6 to 7)
What it looks like: Ribs are still there but harder to feel under a layer of fat. Waist visible from above but less pronounced. The dog still looks fine to most owners, which is part of why it goes unnoticed.
Common causes: Slow calorie creep over years (food the same, activity dropping). Treats and table food. Neutering can cut metabolic rate by 20 to 30 percent. Some breeds (Labradors, Beagles, Pugs) are genetically predisposed.
What to do: Cut daily food by 10 to 15 percent. Swap treats for vegetables (carrot batons, cucumber, green beans). Add 15 to 20 minutes to the daily walk. Weigh fortnightly. Most BCS 6 to 7 dogs return to ideal in 8 to 12 weeks.
When to see a vet: If 8 weeks of measured changes have not moved the score. Hypothyroidism and Cushing's both drive weight gain and need ruling out via blood work.
Significantly Overweight (BCS 8 to 9)
What it looks like: Ribs cannot be felt without firm pressure. No waist visible. Fat deposits on the lower back, base of tail, and around the chest. Often accompanied by reduced mobility, faster fatigue on walks, and sometimes loud breathing at rest.
Health risks: Joint deterioration, diabetes, heart strain, reduced lifespan, increased cancer risk, complications under anaesthesia. The Purina lifetime study estimates obese dogs lose around 2 years of healthy life on average.
Why vet supervision matters: Owner led calorie cuts can backfire. Crash diets in obese dogs carry their own risks. A structured vet led programme, often with a prescription weight management food, is safer and more effective.
What to do: Book a vet appointment in the next 1 to 2 weeks. Many UK practices run free nurse led weight clinics. Take a photo of the standing dog with you. Be ready to discuss feeding history, treats, and any mobility limits.
Underweight Dogs
What it looks like: Ribs, spine, and pelvic bones easily visible. Pronounced tuck under the belly. Possible muscle loss across the back and hindquarters. The look comes on slowly enough that owners often spot it from a photo before the mirror.
Common causes: Internal parasites are the single most common reason healthy dogs cannot put weight on. Dental pain reducing intake. Chronic disease (kidney, liver, thyroid, malabsorption disorders). Anxiety or environmental stress. Recent illness or surgery.
When concerning: A BCS of 1 or 2, or any sudden drop in body condition over weeks rather than months, warrants a vet visit. Worming, dental check, and basic blood work usually find the cause.
What to do: If BCS 3, a 10 to 15 percent food increase plus a worming check usually moves the score. If BCS 1 or 2, vet first, food adjustments after.
Breed Specific Considerations
Sighthounds (Greyhound, Whippet, Saluki, Lurcher): Visible ribs and a pronounced waist are normal at ideal BCS. The body type evolved for sprinting, and a sighthound that looks lean by Labrador standards is usually right where it should be. The tool factors this in based on the breed you provide.
Brachycephalic breeds (Bulldog, French Bulldog, Pug): Loose skin and short coats can hide weight. A Pug at BCS 7 often looks like a Pug at BCS 5 from a casual glance. We compensate by reading rib coverage and proportions rather than silhouette alone.
Long coated breeds (Newfoundland, Bernese, Old English Sheepdog): Fur volume can hide both lean and overweight readings. A side on photo helps but a hands on rib check is the gold standard.
Small and toy breeds: Half a kilo of weight gain on a 5 kg dog is the equivalent of a 30 kg Labrador putting on 3 kg. Small breeds need a finer eye on body condition than larger dogs.
What Body Condition Inspector Isn't
Body Condition Inspector observes. It does not diagnose. The 9 point BCS scale is a structured way to read a dog's body shape, and we apply it consistently from a photo. A vet can do the same with their hands, which is more accurate.
For BCS 1, 2, 8, or 9, we always escalate to a vet visit. Severe under or overweight readings often have an underlying cause (parasites, dental issues, hypothyroidism, Cushing's, joint or breathing limits) that a vet can investigate. We are conservative on red tier and we do not show supplement content for those readings. For a broader read across skin, joints, energy, gut and more, take Super Score's full health audit.
By breed: weight guides
Breed-specific weight ranges by age and sex, alongside body-condition guidance. Use these as a starting point, then run a BCS check on your dog above.
Labrador Retriever
Adult range 25–36 kg · highest UK overweight rate
View weight guide →Cocker Spaniel
Adult range 12–16 kg · working vs show-line variation
View weight guide →French Bulldog
Adult range 8–14 kg · weight critical for BOAS
View weight guide →Golden Retriever
Adult range 27–38 kg · cancer-risk-linked weight
View weight guide →Border Collie
Adult range 14–22 kg · lean working build
View weight guide →Frequently Asked Questions
Get the Full Picture: Take Super Score
Body Condition Inspector reads weight in a single moment. Super Score gives the full picture across skin, joints, energy, gut, cognition and more in 5 minutes.
Take Super Score
