Five Components to a Successful Weight Management Strategy for Feline Obesity

7. Five Components to a Successful Weight Management Strategy for Feline Obesity

It is relatively easy to diagnose obesity and to prescribe a specific diet. The challenge lies in convincing the owner to introduce the necessary changes in the feeding and lifestyle of the animal in order to induce and maintain significant weight loss.

1. Initial assessment
2. Establishing pet owner understanding and commitment
3. Setting and managing owner expectations
4. Intervention
5. Maintenance

When a clinician is presented with an obese cat for the first time, it is essential to perform a thorough assessment of the patient. (© A. German).

Initial Assessment

The aims of the first examination are:

• To quantify the level of obesity. Whilst the language should be positive and constructive, the risk of allowing a cat to continue to be overweight should be firmly stressed. Owners are more likely to want to intervene if the perceived health benefits for their pet are clear;
• To identify predisposing factors for obesity in this cat
• To determine the current health status. This will enable weight loss to be instigated in the safest and most effective manner for the cat:

• Obesity-associated diseases
• Other, potentially unrelated diseases which may affect the way in which the case is investigated and treated.

The recommended components of the initial assessment follow several stages.

History - This should include details of environment, lifestyle, diet and exercise regimes, as well as a complete medical history including previous or current therapy.

Physical Examination - The goal is to identify signs of associated diseases (either causing or contributing to weight gain), and any concurrent diseases.

Weight Measurement - The use of a single set of electronic weigh scales is recommended which are, ideally, regulated validated for precision and accuracy.

Body Condition Score - Condition scoring the patient is not only a key diagnostic tool for establishing the degree of obesity but is also an invaluable tool for discussion with owners. Whilst the exact system used is not critical, clinicians should use the same one for all of their patients, since familiarity is likely to lead to more accurate scoring. The 5 or 9-point BCS (discussed earlier) have been validated against body fat measurements made by DEXA, and thus are known to correlate with the degree of adiposity if performed by a trained operator.

General Laboratory Investigations - Laboratory investigations may be necessary to verify the health status of the cat. These should include routine hematological examination, clinical chemistry, and urinalysis. Additional investigations may be required in some circumstances.

Additional Investigations - Additional investigations will depend on the presence or suspicion of any associated disease.

Examples include:

• Measurement of blood pressure if facilities are available
• Fructosamine measurement for diabetes mellitus
• Survey radiography for orthopedic and respiratory disease
• Hepatic ultrasonography, fine needle aspiration cytology and/or liver biopsy for suspected hepatic lipidosis
• Urine culture, ultrasonography, radiographic contrast studies for lower urinary tract diseases

Exactly what tests are recommended in each circumstance is beyond the scope of these guidelines and are at the discretion of the individual veterinarian. If other conditions are identified, specific therapy should be implemented at an appropriate time (before, during or after the weight management regime). Obviously, weight loss may be a major factor in the treatment of any obesity associated disease.

Establishing Owner Understanding and Commitment

Successful treatment of obesity depends above all on the motivation of the owner and their compliance with the weight loss program. Success is most likely when the client understands and accepts the reasons why weight loss is necessary. The clinician must be aware of the reason that the cat was presented for evaluation, as the level of client motivation will vary. There are three main scenarios: presentation for obesity itself, for an obesity-associated disease or for an unrelated reason.

Presentation for Obesity

The owner seeks advice about the weight problem. Client management will be easiest because these owners are already motivated and have accepted the need for intervention. Therefore, they should be most receptive to appropriate veterinary advice. This is the least common presentation.

Presentation for an Obesity-associated Disease

The cat presents with a condition that is due to obesity. The clinician can communicate to the client that the obesity is a medical, rather than cosmetic, problem. It is important to explain that the excess weight caused or contributed to the disease, and how it is an essential part of maximizing response. If such arguments are made in a convincing manner, client motivation should not be a problem.

Presentation for an Unrelated Reason

The obesity is an incidental observation during a consultation for an unrelated reason. This typically occurs during an annual vaccination or routine health check.

Initiating discussion in these cases is difficult because the reaction of the owner is not predictable. Some may refuse to believe that a problem exists, some may believe that the veterinarian’s recommendation is financially-motivated, whilst others believe that they are to be blamed for the problem. An additional problem arises with owners who have obesity or health problems of their own. The approach is to focus on the health of the cat, including any existing morbidity and the potential for future health problems as a result of continuing obesity. The veterinarian should use sensitive language, such that the owner can accept their pet is overweight without being made to feel guilty.

If they believe that their cat is currently healthy and an obvious co-morbidity does not exist, the owner may not be convinced by an argument structured around the potential future health problems that may arise. Instead, it may help to focus on detrimental effects on current quality of life e.g., fitness, physical activity and grooming. Before and after testimonials from previous clients, highlighting the health benefits of weight loss, may help in convincing these owners.

Some owners may still not be convinced of the need for intervention at the initial consultation, and may require several visits before the argument is accepted. Since owner motivation and compliance are essential pre-requisites for successful weight management, there may be little point in embarking upon a weight reduction program without them. However, providing information leaflets for owners to read may help to improve their understanding of the need to intervene.

Setting and Managing Owner Expectations

Once the veterinarian is happy that the owner is fully committed, treatment of obesity can be started.

There are two phases of the program:

• Intervention (when the weight loss occurs): this first phase can take many months
• Maintenance (when body weight is stabilized and then maintained): the second phase is lifelong.

Given that successful weight loss depends mainly on owner commitment, it is vital to ensure that the owner has realistic expectations from the outset.

The timescale of treatment, the level and rate of weight loss, cost of therapy, potential side-effects of treatment, behavioral changes in the pet, time commitment for lifestyle changes (e.g., exercise), behavior of other family members and any other potential pitfalls should be discussed. The aim should be to make sure that the owner is fully informed of all eventualities and has no unexpected surprises. The problems which are most likely to be encountered include:

• Difficulty in adapting to the new diet (palatability)
• Difficulty in adapting to a reduced amount of food
• Behavioral troubles due to permanent hunger with inopportune vocalizing, aggressiveness, stealing food
• Very slow loss of weight.

Every step of the way, the veterinarian should remind the owner of the goals of therapy, success so far, future expectations and how long-term success can be achieved. This should help to ensure that the client remains committed to each stage of therapy.

Intervention

When it comes to management of obesity in any species, there are four potential options:

• Surgery
• Pharmaceutical intervention
• Lifestyle alterations
• Dietary management

The usual methods generally lead to a reduction of adipose tissue mass either by reducing energy intake (e.g., dietary management, pharmaceuticals, bariatric surgery) or by increasing energy expenditure (e.g., increasing physical activity through lifestyle changes). In reality, whilst the latter may assist in weight loss, it is rarely successful if used as the sole component. Thus, some form of dietary caloric restriction is usually necessary, although a combination of strategies is likely to be most successful. Finally, for any intervention to be successful, close monitoring is vital. The approach chosen for any one case may vary and, as a result, the following guidelines are deliberately general.

Liposuction

This common cosmetic surgery technique in humans aims at reducing adipose tissue mass. However, only subcutaneous fat is removed, which carries little metabolic risk, and does not modify dietary behavior. A single canine case study reports the use of liposuction for the treatment of a large subcutaneous lipoma (Bottcher et al., 2007) but it is unlikely that this technique will be an ethically justifiable option in companion animals.

Bariatric Surgery

This term is used to describe surgery for the management of obesity through the control of food intake. One of the most successful treatment is the Roux-en-Y gastric bypass (Strader and Woods, 2005), which both reduces the stomach volume and allows a rapid delivery of the stomach contents to the small intestine. Compulsory restriction of meal size, decreased digestibility and changes in endocrine signals of the gut contribute to the weight loss.

Surgical Procedures

In addition to the ethical concerns, surgical procedures are unlikely to be a viable treatment option for obesity in pets because these procedures are complex, expensive and morbidity is likely to be high (e.g., 23% to 55% of patients have a short- or long-term complication) (Powers & Pappas, 1989). Gastric outlet obstruction, vomiting, dumping, gastric leaks and wound infections are common complications. Dietary deficiencies may also result from malabsorption.

Pharmacologic Treatment

For a number of years, pharmaceutical agents have been available for the treatment of obesity in humans. The drugs which are licensed in most countries are sibutramine and orlistat, although other drugs (e.g., rimonabant) are available in some countries. All available agents are successful in producing weight loss in the majority of patients, although the effect is modest at best (~5 - 10% weight loss). They can reduce obesity-associated diseases but side effects are common and can be problematic. In addition, a predictable rebound effect often occurs when the drug is discontinued.

With the ever-increasing global obesity epidemic, pharmaceutical management is a growth area, with many companies investing in the development of newer and more effective pharmaceuticals. Pharmaceutical agents have been recently licensed for treatment of canine obesity: the available agents are from a novel group of drugs, the microsomal triglyceride transfer protein inhibitors (MTPI). At the current time, these pharmaceutical agents are not suitable for use in cats. It is not known whether or not similar drugs will be developed for cats in the future.

Pharmaceutical Agents Available for the Treatment of Obesity

Sibutramine

Sibutramine is the only centrally-acting anti-obesity drug approved for use in humans in most countries (Halford, 2006). It works as an inhibitor of the reuptake of serotonin, noradrenaline and dopamine. Sibutramine acts on both satiety and thermogenesis to induce weight loss.The efficacy of sibutramine has been demonstrated in rodents and humans. Numerous side effects may be seen on cardio-vascular function with studies showing increases in both heart rate and blood pressure.

Orlistat, or Tetrahydrolipstatin

Orlistat is the saturated derivative of lipstatin (potent inhibitor of pancreatic lipases isolated from Streptomyces toxytricini). Its primary function is to prevent intestinal absorption of fat. It is intended for use in conjunction with a supervised low fat calorie diet. Orlistat is minimally absorbed into the systemic circulation and its effect is local. The efficacy of Orlistat has been demonstrated in type 2 human diabetes patients. Orlistat induces a significant decrease in blood cholesterol and triglyceride concentrations, and it minimizes cardiovascular risk factors (Leung et al., 2003). Simultaneous administration of soluble dietary fiber (psyllium) significantly reduces the gastrointestinal side effects (steatorrhea and flatulence). Long-term orlistat use may reduce absorption of vitamins A, D, E and beta-carotene and supplementation is necessary.

Microsomal Triglyceride Transfer Protein Inhibitors (MTPI)

These drugs are only currently licensed for use in dogs, and block the assembly in the enterocytes and the release of lipoprotein particles into the bloodstream. Dirlotapide can be used as sole therapy for obesity for a maximum period of 12 months. It prevents lipid absorption and it reduces the appetite, the latter effect being the major contributor to weight loss (Li et al., 2007). The most common side effect is vomiting, which can occur in up to 20% of dogs using the drug.

Mitratapide

Mitratapide has recently been approved to aid in weight loss in dogs (Re, 2006). It is designed to be used short-term in conjunction with dietary management and behavioral modification. The drug is given for two 3 - week periods punctuated by a 14-day period off the medication. Predominant side effects reported are vomiting and diarrhea. Elevations in liver enzymes can also be seen, although there is no clear evidence of long-term hepatic dysfunction.

Lifestyle Alterations

These changes must be implemented during the intervention phase of the weight loss program but need to be maintained lifelong in order that there is permanent success e.g., a healthy lifestyle has been adopted.

The aim should be to increase the level of activity in gradual steps and to make it a regular feature of the pet’s life. In practice, exercise has many advantages:

• It increases energy expenditure during training and in the post-exercise period
• It stimulates fat oxidation
• It protects lean body mass
• It has the potential to reverse the decrease in BMR induced by a low calorie diet.

Methods to increase physical activity in cats include:

- Increasing play activity
- Encouraging the cat to exercise itself
- Icreasing movement through the use of food treats. (© C. Chataignier).

If possible, cats should be encouraged to spend time outdoors. Activity in cats can also be encouraged by using cat toys. For some cats, encouraging walking activity prior to meal times by moving the feeding bowl can also help. Many obese outdoor cats may voluntarily increase their activity levels once their fitness improves during weight loss. The exact exercise program recommended must be tailored to the individual and take into account medical concerns, existing capabilities, breed and age of the patient, as well as the age, and owner circumstances.

The benefits of exercise go beyond the fact that it burns calories: it builds muscle mass and thus increases the resting metabolic rate, improves mobility, is beneficial for the cardiovascular system in general, enhances the pet/owner bond, provides mental stimulation and generally improves welfare and quality of life. It also enhances compliance and improves the outcome.

In domestic cats, hunting and eating behaviors are independently motivated. Thus, cats have a physiological need to hunt (or perform some alternative to this such as play activity) even when their daily energy requirements are already fulfilled. Although play behavior may be more pronounced in juvenile cats, most owners do not realize that it is necessary throughout life.

Dangling toys are usually appreciated by cats. (© J. Newton).

When implementing regular play activity, it is best to start with short (~2 - 3 minutes) sessions each day. This will not overburden the owners, and allow the cat to become accustomed to the activity. Once a regular level of activity is established, and as weight loss progresses, it is possible to increase the duration and intensity of the exercise/play sessions.

A number of toys designed specifically for cats are now available; some features of good cat toys include:

• Ability to produce rapid and unpredictable movement
• Emission of a high-pitched sound
• Small "prey" size
• Ability to supply a food reward.

Some home-made objects can work equally well (e.g., rolled up paper, tin foil etc). Feline play stations are another means by which cats can both exercise and fulfill their natural behaviors. These incorporate the opportunity to climb, balance, scratch and hide.

The best-designed stations are those that provide many and varied levels and climbing options (thus making full use of 3-dimensional space), include dangling toys and scratch posts. Scratching is an additional means by which cats can expend energy; posts which allow the cat to stretch at full stretch are best.

Food can also be a useful motivator for physical activity. Hollow toys can be purchased or constructed, which contain small amounts of kibbles (Figure 15). The cat must then play with the toy (thereby expending energy) to receive the reward. This solution diverts the cat, decreases its boredom when living exclusively indoors, and helps to reduce overall food consumption.

Figure 15. Examples of good cat toys include devices that encourage the cat to play with the toy to receive its food. (© C.Arpaillange).

Modifying Feeding Behavior

Long-term modification of the owners approach to feeding the cat is the second component to a successful program. The following points should be considered.

• Always weigh out food on weigh scales; measuring cups are unreliable.
• Record the amount fed and eaten throughout the weight program.
• Offer the daily food ration in divided meals (2 - 4 per day) rather than as a single meal.
• Consider methods of slowing food intake at meal times. This can include the use of feeding toys, diets with a larger kibble size (that require more chewing before swallowing), relocating the feed bowl before or during meal times, and activity related rewards e.g., food ration only given after an activity has been performed.
• Avoid feeding additional food in the form of treats or table scraps. Occasional (ideally nutritionally- balanced) treats are acceptable as long as they are factored into the feeding strategy e.g., count towards total daily intake.
• Make certain that all members of the family, friends and neighbors are aware of and are committed to the program.
• If scavenging and begging behavior is seen, do not offer a food reward but encourage another form of positive owner-pet interaction e.g., play session. This will distract the cat from the behavior at the same time as increasing energy expenditure.

Overview of Dietary Management

In theory, dietary management can be achieved in three ways:

• Using a standard maintenance diet, but reducing the amount of food offered daily
• Using a diet which has a lower energy density
• Using a food which has low palatability.

It is inadvisable to use a standard maintenance ration and simply restrict the amount of food given. Most nutrients are balanced to the energy content of the ration and, when this is restricted, malnutrition states may develop. For similar reasons, using diets with low palatability are also not an answer; cats will remain hungry, can develop behavioral problems and may become malnourished. Therefore, using diets with a reduced energy density is the key strategy during dietary intervention and additional dietary modifications can help to produce optimal weight reduction with minimal loss of the body fat free mass.

A variety of diets are available, all of which work through caloric energy restriction. Detailed information on the formulation of weight loss diets for cats can be found in future sections. The current information is a summary.

Maintenance

Although the main medical benefit of a weight reduction program is a long-term reduction in adipose tissue mass, of greater importance is the permanent switch to a healthy lifestyle. As such, success ultimately depends not only on reaching the target, but in avoiding any rebound. In short, a permanent change in the attitude and behavior of the owner is required to ensure so that any weight loss is maintained long term.

The first challenge is to change the cat from a protocol designed for weight loss, to one designed to maintain body weight. The passage to the stabilization diet should be gradual, e.g., the hypoenergetic food should be substituted with a maintenance ration in a step-wise fashion, without provoking any weight gain.

The energy level required can be determined in various ways:

• One method is to increase the food intake by 10% every two weeks until no further weight loss occurs. This will enable the veterinarian to set the exactly daily caloric requirement to prevent a rebound;
• Alternatively, if food intake was recorded throughout the period of weight loss and, at some point, no weight was lost between consecutive visits, the caloric consumption at this stage may be a suitable estimate of maintenance requirements.

Once target weight has been achieved, regular check-ups should be continued, as well as the support and encouragement for the owner: there should be revisits every 2 - 4 weeks until the veterinarian is satisfied that weight is being maintained. Thereafter, the interval can gradually be extended but should not be less frequent than once every 3 - 6 months.

The choice of diet for the maintenance phase is less critical than that used for weight loss. There should be no need to feed a diet specifically formulated for weight loss, long term. However, it may be necessary for the cat to continue on a hypoenergetic diet, albeit consuming larger (i.e., maintenance) quantities. Purpose-formulated diets are available for use in the post-weight loss phase, and contain many desirable characteristics, including reduced energy content and increased fiber level (to promote satiety).

Any strategy that is implemented must aim to put in place a healthier relationship between the cat and the owner. The weight loss program is doomed to failure if no such change is made. For long-term effectiveness, it is essential that the patient does not return to the former situation. The owners should be counseled to the fact that modification of lifestyle is a lifelong (but difficult) process, and that they will need to continue to manage dietary intake for life.