FRIs my dog or cat a healthy weight?: check his shape with your hands, weigh him at home, and what to do next
Does your cat look round, your dog a little heavy? His ribs, his waist and a scale tell you more than any number you find online.
More than a portion problem? 514 223-1197 during our hours; outside them: a 24/7 emergency centre.
When weight is a symptom, not a portion problem
Go now, straight to a 24/7 emergency centre, at any hour: your dog keeps trying to vomit while bringing up almost nothing, especially if his belly is swelling or tightening (bloat, or gastric torsion).
Go now (to a 24/7 emergency centre; during our hours, call us on the way instead: we will tell you where to go):
- At rest, he is breathing hard or fast; in a cat, breathing with the mouth open is enough.
- His belly is hard or painful to the touch.
- She is an unspayed female who is lethargic or eating less, especially if she is vomiting, drinking more or her belly is getting bigger.
- He is drinking a lot and is vomiting, off his food or lethargic.
- Your cat is vomiting and not eating.
Call today (us during our hours, otherwise a 24/7 emergency centre):
- Your cat refuses a real meal or eats clearly less, especially if he is overweight or on a weight-loss plan: call at the first refused meal (why).
- His belly is getting bigger over a few days.
Book an appointment this week (if a sign above appears, follow its instruction):
- He is losing weight with no change in his food; in an older cat, even if he eats well or more than before (My cat is losing weight).
- He is hungrier or thirstier than before.
- He is gaining weight without eating more, and he is tired or feels the cold more easily (dogs).
Read his shape with your hands
Fur hides the outline: your hands tell you more than your eyes. Three steps, while he is relaxed:
- The ribs. Lay your hands flat on his sides and slide them backward. At a healthy weight you feel the ribs under a thin layer, a bit like the back of your hand. If you have to press to find them, there is too much fat; if every rib stands out sharply, he is too thin: show him to your veterinarian.
- The waist, from above. Behind the ribs, the outline narrows. A waist that has vanished, or sides that bulge: too much fat.
- The belly, from the side. It tucks up toward the hind legs, more so in dogs. A round, thick belly, with ribs that are hard to feel, signals too much fat.
In cats, the soft pouch of skin hanging between the hind legs does not, on its own, prove a cat is overweight: plenty of slim cats have one, and it can stay after weight loss. Judge by the ribs and the waist.
Body condition. Your veterinarian scores it on a scale of 1 to 9: 1 to 3, too thin; 4 and 5, the target range for most adults; 6 and 7, overweight; 8 and 9, obese. Your veterinarian will tell you which score to aim for, sometimes 6 for an older cat.
Muscle, scored separately. A pet can carry too much fat and still have lost muscle, especially with age: the team also feels the back, shoulders and hips, and records muscle on its own.
Many owners see their pet as slimmer than he is. At the exam, ask the team to show you what they feel under their fingers.
Weighing at home
A slow change is hard to see by eye; a scale shows it.
- The right tool. For a cat or a small dog, a baby scale or a pet scale picks up small changes. Failing that, weigh yourself holding him, then without him, and take the difference (if he struggles, weigh his carrier with him inside, then empty): it is a stopgap that misses small shifts.
- The method. Always the same scale, zeroed on a hard floor, at the same time of day; write down the number and the date.
- How often. For a healthy adult, about once a month is enough; more often if your veterinarian asks.
- Big dogs. We weigh your dog at every visit and the file keeps the numbers; in between, follow his shape with your hands.
______'s weight log
Same scale every time: ______
| Date | Weight | Body condition scored at the exam (1 to 9) | Notes (appetite, activity, food change, treats) |
|---|---|---|---|
No target weight here: your veterinarian sets it. Bring this log to every visit. A weight that changes quickly or for no reason: book an appointment this week. A cat who refuses a real meal, especially during a weight-loss plan: call at the first refused meal, us during our hours (514 223-1197), otherwise a 24/7 emergency centre.
montreal.vet · Client guides
Why a little extra weight matters
Excess weight, very common in dogs and cats, affects them in many ways:
- Joints. It keeps arthritis pain going, in dogs (osteoarthritis) and in cats (arthritis).
- In cats. Obesity clearly raises the risk of diabetes and urinary problems, and it is linked to skin problems.
- Day to day. An overweight pet copes less well with heat and exercise, and anesthesia calls for extra precautions.
- Lifespan. In dogs, studies have linked excess weight to a shorter life.
The good news: in an overweight dog with arthritis, a modest loss, well before the target range, often helps him walk better. And preventing weight gain is still easier than slimming a pet down.
Prevention: the times to watch
- After spaying or neutering. Appetite can go up while energy needs go down: the same portions can make him gain. Measure his meals from the day he comes home and adjust them to his shape, with your veterinarian (Spaying and neutering).
- Middle age. Weight tends to creep up in middle-aged adults, dogs and cats alike.
- Indoor cats. They often move less: play with yours every day.
- When outings get shorter. Arthritis, deep cold: a pet who moves less may need less food. If he eats the same, his weight can rise slowly: the scale will show it. Review the amount with your veterinarian.
- The extras. Treats, table scraps, a bite that hides a pill, the other pet's food: it all adds up. How much room to leave for them: Everyday feeding for your dog or cat.
If he needs to slim down: a plan, never a fast
Weight loss is planned with your veterinarian: first they check that no illness explains the weight, then they choose the food, the amount and the pace with you.
- Cutting the portion is not a plan. Sharply reducing his usual food also cuts his vitamins and minerals, and does not fill him up. If a weight-loss food is part of the plan, your veterinarian chooses it with you and tells you how to introduce it gradually.
- Slowly. Weight loss is counted in months, and more of them for a very round cat. Recheck visits are there to weigh him again and adjust the plan, up to the target weight and beyond: lost weight often comes back.
- Moving and hunting for food. Walks for dogs, built up gradually, play for cats, food-dispensing toys for both; play can replace some of the treats. If he is in pain, your veterinarian eases it first.
- The whole household. Everyone follows the same plan, and each pet eats only his share.
No fasting for cats. Never fast a cat on your own initiative, and do not cut his food sharply: in a cat, not eating can quickly lead to serious liver disease, and an overweight cat is even more at risk. If your cat is on a diet and stops eating, that is not the diet working: that is an alarm, and we want to know. Call at the first refused meal: us during our hours, otherwise a 24/7 emergency centre. The same goes for a dog who stops eating during his plan.
No home medications
No pill to slim him down, nothing for a sore joint: nothing from the medicine cabinet without your veterinarian. And if a prescribed treatment boosts his appetite, do not stop it without talking to us first.
Acetaminophen (Tylenol)
Fatal to cats, even a single tablet. There is no safe dose. In dogs it is dangerous too, and it is not a painkiller for them. If your pet swallowed any, it is an immediate emergency.
Ibuprofen (Advil), naproxen (Aleve), aspirin
Toxic to dogs and cats alike: digestive ulcers, kidney damage. Cats are even more sensitive to them than dogs. Never a human anti-inflammatory, for any reason.
Appetite suppressants, "fat burners", weight-loss supplements
No over-the-counter product has been shown to slim down a dog or a cat, and some can harm him. Weight loss goes through your veterinarian's plan.
Leftover prescriptions and another animal's medication
Same apparent problem, same weight, same household: none of that is ever enough. What relieves a dog can kill a cat, and a dose calculated for another patient is not a dose.
Frequently asked questions
How can I tell if my cat is overweight?
How much should my dog or cat weigh?
After spaying or neutering, should I change my pet's food?
My cat always seems hungry and keeps begging. What can I do?
How fast can my pet safely lose weight?
My cat has a saggy belly. Does that mean he is overweight?
Also worth reading
This guide is a home-care support tool. It does not replace personalized advice from your veterinarian. For any questions, contact us at 514 223-1197.
Updated October 16, 2026
Does he look a little round?
Bring it up at his annual exam: we weigh him, assess his body condition with you and compare with his previous visits.