Weight management is the single most important aspect of osteoarthritis (OA) treatment. In many cases, dogs with OA that “are on the skinny side of normal” and have sufficient muscle mass don’t need daily medications! But, it has been estimated that nearly 60% of dogs are overweight or have obesity, and being overweight predisposes dogs to many serious or life-threatening conditions such as:
- Osteoarthritis
- Diabetes
- High blood pressure
- Heart disease
- Respiratory disease (especially brachycephalic breeds!)
- Cranial Cruciate Ligament injury
- Higher risks with anesthesia
- Kidney disease
- Skin disorders
- Reduced immune function
- Many forms of cancer
Risk factors for obesity:
- Genetics/ breed:
- Labradors, Goldens, Rottweilers, Dachshunds, Bulldogs (French and English), Shelties, mix breeds (there are more…)
- Spay/ neuter status:
- Spayed and neutered dogs are 2x as likely to be overweight as intact female and male dogs. Metabolism decreases by 20-30% following gonadectomy while appetite increases.
- Age:
- With age comes the loss of lean muscle and increased deposition of fat; risk for increased body weight/ BCS increases with age.
- Activity:
- Reduced activity increases the risk of weight gain. This is especially relevant for dogs with OA that may be less active..
- Free choice feeding
- Keeping the food bowl full instead of meal feeding leads to weight gain. Dogs should be fed 90% of their daily calories in 1- 3 meals/ day. The bowl should be removed after 5-10 minutes even if they have not finished their meal.
- High-calorie treats and high-fat food:
- Fat has a higher caloric density per gram (compared to protein and carbohydrates). Feeding too many treats leads to excessive calorie intake. Treats should not be excluded, and it is OK for dogs to eat “people food.” But treats or table scraps should make up no more than 10% of the daily calories. You will be able to offer your dog more volume of low calorie treats than high fat/high calorie ones. See this article on low vs. high calorie treat options.
Many studies have shown the impact that weight loss or maintenance of a lean body condition can have on symptoms of OA in dogs. The majority of weight loss should come from reducing calories eaten; however, the addition of exercise does improve weight loss and maintenance of muscle (which dogs with OA need!).
Examples of studies looking at caloric restriction alone:
- Reduced symptoms of OA with as little as 6% weight loss. Dogs that were at least 20% overweight with hip or elbow OA were placed on a calorie-restricted diet for 18 weeks with the aim of 0.5-1% weight loss per week. No anti-inflammatory medications were given and no change in activity level. Lameness started to improve after 4 weeks, with about 50% improvement in lameness by 6 weeks and 80% improvement by the end of the study. (Marshall W et al. VCOT 2009)
- Significantly reduced lameness in client-owned dogs with hip OA that achieved 11-18% weight loss. These dogs were placed on a weight loss diet with caloric requirement calculated to 60% of current body weight. Dogs did not receive any medications or supplements and did not have any change in their exercise. (Impellizeri JA et al. JAVMA 2000)
- Dogs at risk of OA should maintain a BCS of ~4.5/9. Health risks increase at a BCS >6.5/9. Labrador retriever puppies with a genetic predisposition for arthritis were divided into 2 groups: one group fed to maintain BCS of ~4.5/9 (limit fed) while the other group was fed 25% more calories (control fed, BCS ~ 6.5/9). Dogs in the limit-fed group developed x-ray signs of OA at 12 years of age, while control fed dogs developed radiographic OA at 6 years. Limit-fed dogs took twice as long to develop radiographic OA in their hips! And…limit fed dogs lived on average 2 years longer! (Kealy RD et al. JAVMA 2000; Smith GK et al. JAVMA 2006; Lawler DF et al. JAVMA 2005.)
Examples of studies looking at caloric restriction plus exercise:
- Exercise helps achieve weight loss, but accountability helps even more. Dogs with OA that were overweight or obese were put on a weight loss diet and given a home exercise program that included walking 20 minutes, 3x/day as well as massage and passive range of motion. Half of the dogs also came into the clinic twice a week for the first 2 months for weigh-ins, review of the home program, and TENS treatment to the affected joint (this is a passive therapy and does not burn calories). After 6 months, all dogs lost weight, but dogs that came into the clinic in the first 2 months lost significantly more weight (13.6 vs 9.3%). All dogs had reduced pain and lameness throughout the study, with the dogs that lost more weight showing less lameness. Increased owner compliance may have resulted in the difference between groups. (Mlacnik E et al JAVMA 2006)
- Underwater treadmill therapy may help with weight loss. Dogs with obesity were placed on a reduced-calorie diet and exercise program that included leash walking at least once a day, obedience class, and underwater treadmill (no set schedule or protocol, but an average of 13 sessions). After 3 months, the average amount of weight loss was 18.9% of starting body weight (1.5%/ week). Body condition as measured by thoracic and abdominal girth also declined. (Chauvet A et al. Can Vet J 2011)
- Exercise preserves lean body mass with calorie restriction weight loss. Dogs that were overweight and considered sedentary were placed on a reduced-calorie diet. One group did not change their exercise level, while the other group participated in a clinic-based fitness training (UWTM plus land treadmill) for 1 hour, 3x/ week. After 12 weeks, dogs in both groups lost weight; dogs in the fitness training group lost a larger amount of weight (13.9 vs. 12.9%) and importantly, maintained a lean body mass (i.e. muscle) compared to the calorie restriction only group which lost muscle mass. (Vitger AD et al. JAVMA 2016)
Barriers to Weight Loss
According to a 2019 report from Banfield, 80% of veterinarians view pet caregiver compliance as the largest barrier to weight loss in animals with OA. Other barriers included the cost of a veterinary diet and caregivers denial that their pet is overweight (one study found that about 40% of clients with overweight dogs thought their dog was an ideal body weight).
Of note, 50% of responding veterinarians indicated that a primary barrier was that they did not have enough time to spend educating their clients on the importance of weight loss. This is why we created CARE! CARE is here to help continue the education provided in the veterinary clinic and provide tools that can help caregivers stay compliant with weight-loss plans.
3 Steps to Caregiver Compliance for Weight Loss
Step 1: Clear plan
Just being told “Your dog needs to lose weight, you should cut back on the amount you feed” is not generally helpful. Pet caregivers need a plan that is Clear, Customized, and Realistic.
The plan must include a diet recommendation (i.e. specific brand and type of food).
What food should dogs eat to lose weight?
Most of the studies on weight loss and nutritional requirements for dogs have been done using products from Royal Canin, Hills or Purina.
We are very fortunate to have the data that has come out of these studies. However, a lack of research does not equate to lack of efficacy. So, would a home-cooked or commercially available cooked or freeze-dried diet also help achieve weight loss? Most likely yes, so long as the diet is complete and balanced and meets the nutritional needs of the individual dog.
There is not a single right or best food out there. Veterinary teams must work with clients to find the right food that fits their dog’s medical needs, their budget and lifestyle.
CARE guidelines for making diet recommendation:
1. Figure out the dog’s current daily caloric intake and where all of the calories are coming from.
2. Figure out the dog’s daily caloric requirement or caloric deficit required. Use this tool (Calorie Calculator and Worksheet) to help calculate the caloric requirements.
Here is how the daily calorie requirement is calculated (the calorie calculator linked above will do this for you). The formulas used to calculate the recommended daily caloric intake are based on the dog’s ideal body weight, not their current body weight.
Figure out ideal body weight by finding % overweight using BCS:
• Each point above 5 on 1-9 scale = 10% overweight
Using the ideal BW, figure out the Resting Energy Requirement:
• RER = BW(in kg)0.75 x 70
• For weight loss, multiply RER by 0.8 (feed 80% of RER)
• Once the target weight is achieved, then the dog can be fed full RER.
3. Determine how many calories are in the food that is being fed. This information should be available on the packaging or product website. If it is very calorie-dense (typically high in fat), then the dog will need a smaller volume, and this runs into the problem of “I only feed my dog ½ a cup and they still look starving.”
- Seek out higher protein foods with lower fat content.
- Calories are often expressed as kcal per cup or can… There is no conversion needed for kcal, just use the number provided as calories per cup or per can.
4. Give an allowance for treats! 10% of daily calories can come from treats or “people food” that is not part of the primary diet.
Know exactly how much to feed and use a calibrated measuring cup to ensure the right amount is being fed (rather than just a plastic cup).
Step 2: Accountability
There is a reason why Weight Watchers and other human diets have meetings and support groups—going on a diet is hard and everyone needs help and accountability!
The best way to do this is to schedule weekly or bi-weekly weigh-ins at your veterinary clinic. This should be a quick an easy visit where your dog learns to step on the scale (and should be rewarded with a treat!) and reinforces that vet visits don’t have to be stressful. The receptionist should be able to enter your dog’s weight into their record for the veterinary team to track, and you may want to keep track yourself.
Step 3: Adjust the Plan When Indicated
Weight loss is not meant to happen quickly (in order to be safe and lasting), which means it can be frustrating not seeing immediate results. Be sure to celebrate each week of weight loss, but understand life happens and there may be plateaus. This is where weekly weigh-ins and weight loss tracking can really help everyone see the big picture. If weight loss plateaus or is just not happening, revisit with your veterinary team to ensure the plan is correct for your dog. A different diet may be indicated.
The yo-yo diet is a real thing. For pets too. The plan does not stop once the target weight/ BCS is reached, your vet should provide a plan for maintaining the dog’s new body condition. Should they stay on the same food? Can the calories be increased?
In theory, the calories can be increased to a maintenance level once the caloric deficit is no longer needed. But this is a time that weekly weigh-ins must continue! If the dog can maintain their ideal weight with the increased amount of food for 4 weeks, then you can start backing off the frequency of weigh-ins. But make sure that you know how to monitor your dog’s body condition and adjust the amount you feed each day based on the dog’s activity level.
-
In summary, weight loss is THE most important aspect of managing OA and keeping dogs healthy throughout their life.
References
Brooks D, Churchill J, Fein K, et al. 2014 AAHA Weight Management Guidelines for Dogs and Cats. J Am Anim Hosp Assoc 2014; 50:1-11.
Felson DT, Chaisson CE: Understanding the relationship between body weight and osteoarthritis. Ballieres clin Rheumatol 11: 671-681, 1997.
Marshall WG, Hazewinkel HAW, Mullen D, et al. The effect of weight loss on lameness in obese dogs with osteoarthritis. Vet Res Commun 2010;34:241-253.
Marshall WG, Bockstahler BA, Hulse DA and Carmichael S. A review of osteoarthritis and obesity: current understanding of the relationship and benefit of obesity treatment and prevention in the dog. Vet Comp Orthop Trauamatol 2009;22:339-345.
Impellizeri JA, Tetrick MA, Muir P: Effect of weight reduction on clinical signs of lameness in dogs with hip osteoarthritis. J Am Vet Med Assoc 216: 1089-1091, 2000.
Lawler DF, Evans RH, Larson BT, et al. Influence of lifetime food restriction on causes, time, and predictors of death in dogs. J Am Vet Med Assoc 2005;226:225-231.
Kealy RD, Lawler DF, Ballam JM, et al. Evaluation of the effect of limited food consumption on radiographic evidence of osteoarthritis in dogs. JAVMA 2000.
Smith GK, Paster ER, Powers MY, et al. Lifelong diet restriction and radiographic evidence of osteoarthritis of the hip joint in dogs. JAVMA 2006
Mlacnik E, Bockstahler BA, Muller M, et al. Effects of caloric restriction and a moderate or intense physiotherapy program for treatment of lameness in overweight dogs with osteoarthritis. J Am Vet Med Assoc 2006;229:1756-1760.
Chauvet A, Laclair J, Elliott DA, German AJ. Incorporation of exercise, using an underwater treadmill, and active client education into a weight management program for obese dogs. 52(5):491-496, 2011.
Vitger AD, Stallknecht BM, Nielsen DH, Bjornvad CR. Integration of a physical training program in a weight loss plan for overweight pet dogs. J Am Vet Med Assoc 2016;248:174-182.
German AJ. Weight management in obese pets: the tailoring concept and how it can improve results. Acta Vet Scand 2016;58:57.
Glanagan J, Bissot T, Hours MA, et al. Success of a weight loss plan for overweight dogs: The results of an international weight loss study. PLOS One 2017 https://doi.org/10.1371/journal.pone.0184199