Left photo is of Savvy on day 1 of her diet and the dog on the right is what her end goal looks like--she's not there yet but she's certainly on her way!

Alright, so you gave your dog a once over and have discovered he is not as lean as he could be….now what?  Well, that sort of depends just how much extra weight your dog is carrying.  If your dog packed on a pound or two of winter weight (for a medium sized dog), you can approach things differently than a dog who is 25lbs overweight.

Before starting any plan, you should consult your vet so they know what you are working on and can make sure your dog is healthy enough for the activities you are planning.
Becoming overweight (in an otherwise healthy dog) is a combination between overfeeding and under exercising.  To lose weight both of these things need to be addressed.
The first step is changing the way you feed–NOT necessarily what you feed.  I am not a fan of changing to a diet/weight control food because often times the quality of ingredients diminishes as they stuff it with filler instead of quality meat sources.  So instead of changing what your dog eats, we will change how much they eat.  I am a very strong believer that if you are choosing to feed kibble (the hard food sold in bags) you should be measuring out the food for each meal.  Many dogs are simply eating way too much because their food isn’t being measured out.  Each bag should have a suggested serving size.  This is just a starting point… once you start feeding the advised amount of food, if you notice your dog gaining weight you should cut back on the amount of food (or if your dog is getting too skinny, add food).  When the bag suggests 2 cups a day… it doesn’t mean two 32oz “sweet tea” cups from McDonalds–it is talking about standard measuring cups.  You’d be surprised the number of people who say “he only gets two cups a day” but through further discussion admit the cup is a large beverage cup, so in actuality they are getting closer to 6-8 cups a day.
When you are deciding how much to feed you should not be basing it on the current weight but the ideal weight.  So if your dog currently weighs 55lbs but he should weigh 45lbs, you should feed based on the 45lb ideal weight.  The second piece of the puzzle is to also cut out treats (oh sad face!!).  Many dogs are given a crazy amount of treats each day between the various family members.  If you are doing training  you can do a few things–1. use your dog’s measured out kibble meals for training treats 2. compensate… when you do training, reduce the amount of food given during meal times and 3. you can use things like cut up fruit, boiled chicken breasts, or other low-calorie treats.
If your dog is giving you the sad eyes, staring at the bowl, nudging the bowl… or otherwise looking like you are starving them, you can add green beans to their kibble.  This is a very low-calorie filler.  It will help your dog feel more satisfied without adding much in the way of calories.
Along with modifying the diet, increasing exercise is an important tool.  This is where you need to be very careful.  Depending on how overweight your dog is, adding exercise may have to wait until some weight loss has already been achieved.  If your dog is  moderately mobile (gets winded quickly or is a bit of a slow mover), adding just 5 minutes to a walk is a good place to start to make a difference.  If your dog is still pretty active, you can do a little more… add more time to the walk, make the walk faster, add some moderately strenuous games of fetch outside, maybe start teaching them out to trot next to a bike.  Like with humans, dogs risk some pretty debilitating injuries if they attempt too much too soon in terms of exercise.  When you start increasing exercise, you must do it pretty methodically and in a predictable manner.  Add a few minutes, gradually increase the pace, add some semi-strenuous games of tug/fetch–slowly adding more duration or increasing the speed/intensity of the game.
There are so many different ways to increase exercise and not all of them are high impact or overly strenuous.  Here are some activities to increase exercise–swimming, walking, tugging, fetch, nosework games, training work (hand target games can get your dog up and moving), recall practice, hiking, biking, flirtpole games, rally-o classes, or doggie-exercise activities (balance ball work, stretching, core strengthening, etc).  Like I’ve said before, you need to take it easy to start–don’t go from 0 to 100 in a day.  If your dog is currently going for 15 minute walks try adding 5 minutes to your walk OR up the pace for five 1-minute parts of the walk.
This is not an exhaustive look at canine dieting or weight loss.  You always need to keep your dog’s safety as your primary concern… if your dog is not capable of safely completing a 15 minute walk, don’t force it.  Take your time… no crash dieting or extreme exercise regimes.  It’s not safe for humans and it’s not safe for our canine partners!