Obesity can be defined as an “increase in body weight to a level superior to that considered normal for a given size and build of an animal” (W. R. Fenner). A body weight that is 20% or more over the normal standard is generally considered an indication of obesity. Obesity can be secondary to concomitant organic diseases (Fig. 1) or related to an excessive intake of calories. The main causes of pathological obesity are lesions/dysfunction of the hypothalamus or pituitary glands and endocrine imbalances (hyperadrenocorticism, hypothyroidism, and insulinoma). There is also a form called pseudo-obesity, which is secondary to oedema, peritoneal effusion and marked hepatomegaly/splenomegaly.
Physiological obesity is caused by an intake of energy that is in excess of the amount used by an animal which is healthy in every other respect. The imbalance between the intake and the consumption of energy results in a persistent surplus of energy: the energy in excess is accumulated above all as lipids, resulting in weight gain and a modification of body composition. It is important to remember that some pathological conditions caused by behavioural diseases can be at the root of obesity. In fact, bulimia can occur during states of permanent anxiety and chronic depression.
Numerous studies have demonstrated that obesity can have harmful effects on the health and longevity of cats and dogs. Obese animals can develop orthopaedic disorders and cardiopulmonary problems. Obesity followed by prolonged anorexia can cause idiopathic hepatic lipidosis in cats and increase the probability of them developing diabetes mellitus. In obese dogs, the response to infection decreases, consequently increasing, for example, the incidence of pyoderma. Moreover, obesity not only increases the difficulty of performing surgery but also increases the risks of anaesthesia. Information about the possible risks to an animal’s health that an incorrect diet can have [9]are often ignored by the pet’s owner. The owner says that he loves his cat/dog so much that he can’t deny his love in the form of food. The lack of therapeutic team work between the veterinarian, the client and the pet is one of the most significant problems in the prevention and treatment of obesity in dogs and cats.
OBESITY: DOGS, CATS AND HUMAN BEINGS
A study conducted by Hill’s among Italian veterinarians in 2008 showed that cats have a greater predisposition than dogs to being overweight. Risk factors for excessive weight gain and obesity are castration/sterilisation and a domestic life style, which affects most of the animals examined, in particular cats. Industrially produced food given in a balanced way, rather than home-made food or a mixed diet, seems to be more effective at preventing excessive weight gain and obesity.
Between 20 and 40% of the world’s population over the age of 18 are either overweight or obese making this a major public health issue. Problems begin to be seen at school age and become steadily more serious in the adult population between 20 and 40 years of age. The prevalence of the disease progressively increases as people become older and finally stabilises around the age of 60. A sedentary life style, a dietary model based on foods with a high energy content and widespread availability of food are the main risk factors for the genesis of this condition. Individual risk factors for the development of obesity are premature excessive weight gain (in the first 5 years of life), obesity in a child’s first-degree relatives, the period in which a person starts working, pregnancy and menopause. With regards to what can be achieved through education, primary prevention strategies must be implemented as soon as possible in early childhood, regardless of the actual risk level at the time. The preventive interventions should promote increased physical activity and education about following a healthy, balanced diet. The aetiology of obesity is not only based on genetic factors, but also has social, cultural and psychological components and it is, therefore, understandable that life style and particularly eating habits can be considered important factors in a person’s well-being or ill health.
OBESITY AND BEHAVIOUR
Research conducted on mitochondrial DNA by C. Vilà et al. (1999) dated the beginning of the process of domestication of the dog to about 135,000 years ago while P. Savolainen et al. (2002) put the date around 40,000 years ago. The presence of a dog helped to increase family security: it stood guard during the night, it collaborated with hunting during the day and defended the group when they were on the move. The dog had such a significant influence on the human way of life in the Palaeolithic period that Allmann maintains that the presence of this animal contributed to the rise of Homo sapiens over Homo neanderthalensis. The effects of the co-evolution of humans and dogs included improved hunting techniques, a richer diet and increased reproduction which was followed by increased diffusion of both species.
The dog is a social animal and it is this trait above all others which explains why man has always used the code words wolf-dog when wanting to describe group identity and loyalty (R. Marchesini). Having an innate compulsion to be part of a social group means much more than simply saying that a dog likes having company. It is rather like dismissing a human being’s need to feel realized by saying “people like working” (R. Marchesini). The social nature of a dog is its life dimension: being a sociable and society-related animal means first of all building very close relationships and affinities. It is worth noting that the dog continuously looks for guidance and this is how it defines its position in the pack. The society-centred nature of a dog stimulates its interest in groups: the dog is interested in everything we do, it never loses sight of us, it is aware of every change in our mood or life style and it knows our habits and gestures. The dog learns from daily experience but in order to be able to do this it has to eliminate physical distance between itself and us: we will only be able to create a complete, multifaceted relationship if we spend as much time as possible with the dog. It is for this reason that even though owners try to give their dogs all possible comforts, they often find themselves failing to build a good relationship with their pet: for the dog the ideal situation is to do as many activities as possible together, to go everywhere together. There is no garden, no number of toys and no quantity of affectionate gestures that can compensate for a lack of time spent together (R. Marchesini).
As far as the cat is concerned, numerous authors agree that Felis silvestris lybica is the ancestor of the small domestic cat. Cats found in archaeological sites dating from the Ancient Egyptian Empire (4000 – 5000 BC) were large, and only subsequently became smaller. The tradition of cat mummification began during the Middle Empire (3000 – 2500 BC). In archaeological sites in Turkey dating from 10000 BC, cat skeletons were uncovered near the areas where people lived although no trace was found of a human-cat relationship with the exception of a small statue of a woman with an object in her arms which could be a cat. In 2004 a burial site in Cyprus dating back to 6000 BC was found to contain a man and a large cat. Both the cat and the man were shrouded in shells, plants and precious stones, bearing witness to the intimate nature of their relationship. When considering all the civilizations which had a close relationship with the cat the Egyptian one is particularly significant, although those cats probably came from more easterly regions, where Felis silvestris lybica was not present, but rather Felis silvestris ornata. Some authors believe that the cats were a mixture of the two subspecies.
Observations made over the last few years with regard to feline behaviour have emphasised that the image of the cat as a solitary animal does not correspond to reality. Coexistence with humans pushes the cat to create one or more social relationships with the family members, even though the primary relationship (which involves, for example, sharing the same sleeping place) is often with just one person. If we compare the way in which cats and dogs behave when facing a problem, we immediately note one very significant difference. A cat tends to look for a quick solution to the particular problem it is facing and then later tries to find a solution based on a comparison of the problem’s structural requirements. A dog, on the other hand, immediately and primarily looks for collaboration (R. Marchesini). While a cat's reasoning is based on how objects relate to each another and their mutual spatial and causal positions, a dog's reasoning is different, based on the nature of the relationships the subjects have with one another in reference to the possible dimensions of social relationships (R. Marchesini). The cat has a ‘hands on’ attitude to a problem, looking, as a soloist, for a strategy to put into action. In contrast, the first thing a dog does is to look at its owner. The dog’s cognition is concentrated on consultation and not on the solution of the problem. If the cat excels as a problem-solver, the dog is a "virtuoso" in social relations, talented in reasoning in terms of inter-subjective relationships. We, therefore, talk about enigmatic intelligence when we refer to cats and about social intelligence when we consider dogs (R. Marchesini).
OBESITY AND RELATIONSHIPS
Cohabitation with cats and dogs is necessarily founded on the creation of a correct relationship in which complete understanding of respective differences is essential. The veterinarian is fundamental to this process. Being aware of the fact that we belong to different species means recognising our companions’ needs. Food, water and shelter are considered physiological needs, essential for all living creatures (Fig. 2). Cats and dogs also have behavioural and safety needs given that they have a brain, abilities and emotions and are capable of building their own life experiences. Recognising an identity on the basis of the concept of similarities and diversities means giving an animal citizenship, that is, recognising that it has a role and a status in the relationship with man not based on the concept of sameness, but on that of otherness (R. Marchesini).
According to the zooanthropological approach, a relationship is different from a simple interaction. A relationship is built from the meeting/confrontation between two subjects based on exchange processes able to create a bond, which in turn modifies the status of both the partners. The animal is recognized as a social partner, someone to talk to, as an individual, as being different. The animal takes part in relational situations because it is able to play a role and to provide new input: the pet must not to be transformed into an object or a machine (reification) and must not interpreted as if it is a human being (anthropomorphisation). If follows from this that a relationship with an animal should not be considered intuitive, that is to say, achievable through a simple process of projection. The relationship must be built with patience, humility, desire to learn, capacity for self-criticism as well as willingness to listen and to observe (R. Marchesini).
Humans and animals meet “on specific frequencies” called dimensions of the relationship. These dimensions include:
- The affective dimension (characterized by an exchange of affection, by the importance of protection and safety, by the feeling of being recognized and appreciated);
- The recreational dimension (characterized by a framework of exchange based on play, pretence, fluidity of roles, fun and entertainment);
- The epistemic dimension (characterized by giving priority to the guiding elements of consciousness, through interest, attention, reflection and sharing knowledge);
- The social dimension (regards the pleasure of sharing, of not being alone and of feeling sustained, of creating something as a couple, the capacity to react in a synchronous way and to collaborate)
One of the basic dimensions of the human-animal relationship is the affective dimension: this mutual exchange is based on protection, reassurance, offering/asking for help, and on sharing emotions. The affective sphere is expressed in different ways which change according to the role assumed by the beneficiary: epimeletic (the user offers protection, care, safety, food) or et-epimeletic (the user asks for protection, reassurance, safety, food). The human partner demonstrates a protective behaviour towards the animal taking on the role of parent and behaves like a typical parent. The aim of the relationship is a balance of the different components (relational equilibrium).
In order to assess the importance of the human-animal relationship with regards to the origin of obesity, a pilot study (A Comparison of the Feeding Behaviour and the Human-Animal Relationship in Owners of Normal and Obese Dogs; Ellen Kienzle, Reinhold Bergler and Anja Mandernach) recruited 60 owner/obese dog couples and the same number of owner/normal dog couples. Processing the data collected with the help of a questionnaire, it was found that the bond between owner and obese dog is closer than that between owner and normal dog: the owner of an obese dog is less worried about contracting illnesses from his pet, he talks to the animal about lots of different subjects, he often sleeps with the dog, he watches over his pet while it eats, he gives the dog numerous meals and snacks and considers physical exercise and mutual collaboration to be of little importance. These observations indicate that feeding is a gratifying form of communication and interaction with the dog: the owner of an obese dog interprets every one of his animal’s needs as a request for food. Moreover he does not seem to pay attention to his own health and transfers not only his own eating habits, but also his lack of interest in physical fitness to his pet.
E. Kienzle and R. Berglery also observed that only a small percentage of obese cats are able to lose weight by dieting. Nevertheless, controlled, clinical studies carried out in the laboratory showed that food restriction did enable cats involved in the study to lose weight. It is, therefore, possible to suppose a lack of compliance (therapeutic collaboration) by owners of obese cats. A recent study (Human-Animal Relationship of Owners of Normal and Overweight Cats; Ellen Kienzle and Reinhold Berglery) involved 120 cat owners, 60 normal animals and 60 obese ones. The study examined the human-animal relationship, some aspects of cat behaviour and some personal characteristics of the owners (for example, health and eating habits). The data, collected by questionnaire, showed that the relationship between owner and obese cat is closer than the one between owner and normal cat: the owner of an obese cat talks to the animal about lots of different subjects (job, family, friends and acquaintances), living with the cat reassures and consoles him and the animal is considered not only a member of the family, but also a baby to look after. The majority of the owners of obese cats watch their pet while they eat. Moreover, while the owners of normal cats use playtime as a prize, owners of obese cats offer their animals their favourite food. The risks of food ad libitum are open to debate. In fact only some of the studies undertaken found that free access to food and obesity are related. The majority of owners of obese cats perceive their animals to be thinner than they really are. One possible explanation for this could be that a pet cat almost never appears in public and consequently people only occasionally comment on the animal’s physical condition. In contrast to the data obtained from research on dog owners, the majority of owners of obese cats are female.
The observations show that feeding is probably a gratifying way of communicating and interacting with the cat: the owner of an obese cat interprets every one of the animal’s need as a request for food. The authors have interpreted the differences shown in the relationship between owner/obese dog or cat as indicators of excessive humanisation of the animals.
The sensitivity of our species towards juvenile signals from puppies and kittens makes us want to adopt, protect and take care of these animals. The affective dimension, based on feeding and affection, not only predisposes the pet to gain weight, but is insufficient to satisfy all the animal’s needs. Food, petting, playing, collaboration, sharing experiences and meeting with other pets of the same species are some of the most important elements of exchange within a relationship. In order to achieve a balanced, satisfying bond, the affective dimension must be integrated with other relational dimensions (recreational, epistemic and social): the human companion must propose a large variety of activities so that he can be at the centre of the pet’s interests. (R. Marchesini).
OBESITY, PLAYING AND COLLABORATION
E. Kienzle and R. Berglery have emphasised that a psychological approach such as replacing a type of behaviour associated with food with a playful kind of behaviour can improve the compliance of owners of cats and dogs participating in weight loss programmes.
The human partner must engage both himself and the pet in games: the type of activity chosen must be fun and interesting to both participants. The emotions invoked must be positive (for example, joy) in order to encourage the pet’s participation, connecting the memory to a pleasant experience. The proposed games should stimulate the animal’s collaborative capacity (doing something together) and cognitive capacity (reflection and finding a solution) at the same time as improving the animal’s motor skills (movement and coordination).
The activity chosen should be that most appropriate for the age and abilities of the pet: each game must be easy to solve so that its correct execution increases the animal’s self-esteem and self-confidence. It is worth noting that neither the dog nor the cat knows what we want when we propose an activity or a game to them: it is important to proceed gradually, with patience, beginning with the simplest exercises in order to reach more complicated ones. A tasty treat is the best reward for the pet because it motivates and stimulates the learning process.
Games can be played at home and, as far as the dog is concerned, also while out on walks. The sessions should be brief (a few minutes) and finish with a successfully completed exercise. Objects around us can be transformed into obstacles to run around, to jump over or to explore: climbing over or passing under a chair or a bench, doing a slalom through lamp posts, jumping over a low wall, walking over a grating and so on. What is more our body can become a gymnasium where arms and legs become hurdles to run around and jump over for both the cat and the dog. The pet can be set simple puzzles to stimulate the acquisition of cognitive tools which the animal will then be able to apply in everyday situations to learn, for instance, how to manage their emotions without being overwhelmed, reducing arousal and promoting peace and tranquillity.
OBESITY AND THE VETERINARIAN
The veterinarian plays a fundamental role in the prevention and treatment of obesity. The veterinarian’s tools are nutritional tables, the Body Condition Score and the behavioural examination. Research done in the USA among veterinarians quantified compliance (therapeutic alliance) in six different areas: testing for and prevention of heartworm disease, preventive dental treatment, therapeutic diets, screening of elderly patients, essential vaccinations for cats and dogs and pre-anaesthetic screening. The results showed that the highest percentages of lack of compliance were related to therapeutic diets in cats (82%) and in dogs (81%).
In fact, during the establishment of the therapeutic process, food restriction may be at the base of the opposition to change by the client, the dog or the cat. The doctor and client should negotiate the desired goal and what the pet likes: for example, a diet in exchange for walks in places where the dog likes to go (dog areas, parks, city centre) or, in the case of a cat, environmental enrichment (a little water fountain, climbing games, a scratch pole, a tunnel). What is more it is fundamental to create new relationship dimensions in order to put the affective dimension back into perspective and, thereby, balance the different components of the relationship. When planning a food restriction programme, the ethological characteristics of the species under consideration should be remembered. For example, the cat’s feeding behaviour is very different from the dog’s. Many authors define the cat as a nibbling animal because it has from 8 to 16 small meals in 24 hours. This animal is, in fact, a solitary hunter which captures many types of small prey. Giving the animal food at fixed times could risk causing the onset of behavioural problems such as indoor anxiety (characterized by the appearance of aggressive predatory behaviour and irritation towards the owner), the tiger syndrome (characterized by the appearance of aggressive predatory behaviour towards the owner when it is time to eat), cohabitation anxiety (characterized by aggressive behaviour, caused by the animal’s irritation, towards other cohabitant cats) and for elderly cats some forms of senile dementia. Moreover the unease caused by the diet can make pre-existing behavioural problems worse.
The dog is a predator which hunts for larger prey in a pack. Furthermore, feeding has a social significance for this species. Food restriction can cause a worsening of pre-existing behavioural problems because of an increase in anxiety caused by the discomfort of being hungry. For example, a dog affected by hierarchical imbalance (modification of the role and rank within the human-dog/dog-dog group) could develop a stage 1 sociopathy (a disease characterized by numerous symptoms including aggressive behaviour caused by irritability and dominating behaviour towards the owner or other dogs it lives with). It is, therefore, important to carry out a careful behavioural assessment in order to prevent the onset of behavioural problems or the worsening of those already present.
CONCLUSIONS
As in human medicine, the concept of dimensions of a relationship is becoming ever more important. In the past, mothers were educated to concentrate above all on the dietary dimension (the quality and quantity of food) to the detriment of the relational dimension. Nowadays the trend seems to be quite the opposite, in that it is based on feeding on demand, with the aim of protecting the mother-child relationship, neglected for so long. When planning a food restriction programme, the veterinarian must take into account numerous factors: the presence of behavioural problems, the pet’s ethological needs and the predominant dimension in the human-animal relationship. If this is done the therapeutic process will be successful.
Suggested readings
- B. Alessio, “Setting e dintorni: il significato del primo colloquio nella terapia comportamentale”, Veterinaria, monografia SISCA.
- O. Chambon, M. Marie – Cardine, “Les bases de la psychothérapie”, Dunod, Paris 1999.
- R. Colangeli, S. Giussani, “Medicina del comportamento del cane e del gatto”, Poletto Editore, Gaggiano, 2005.
- U. Galimberti, “Dizionario di psicologia”, UTET, Torino 2000;
- E. Kienzle, R. Berglery, “Human-Animal Relationship of Owners of Normal and Overweight Cats”, American Society for Nutrition. J. Nutr. 136: 1947S–1950S, 2006;-
- Kienzle, R. Bergler, A. Mandernach, “A Comparison of the Feeding Behavior and the Human–Animal Relationship in Owners of Normal and Obese Dogs”, American Society for Nutritional Sciences. J. Nutr. 128: 2779S–2782S, 1998.
- R. Marchesini, “Canone di zooantropologia applicata”, Apèiron Editoria e Comunicazione S. r. l., Bologna 2004.
- R. Marchesini, “L’identità del cane”, Apèiron Editoria e Comunicazione S. r. l., Bologna 2004.
- R. Marchesini, “Fondamenti di zooantropologia”, Alberto Perdisa Editore, Bologna 2005.
- W. B. Saunders, “Managing a veterinary practice”, 2° ed. Elsevier, Ltd 2008.
- W. R. Fenner, “Manuale pratico di medicina veterinaria”, UTET, Torino, 1996.