Uninterruptedly the telephone rings, still at least 40 emails lie unanswered in the inbox. The fridge is empty and the supermarket closes in half an hour. And last but not least: Rex urgently needs to get out !!! – Translated in “hündisch”: “I do not know who she’s talking to again, not with me … Anything more important than the toy I’ve been offering her for hours … eating in peace? Wrong! Quick-fast, she still wants to go shopping … I have to go out long ago, at least for the essentials. A little bit outside, reading my ‘newspaper’? Maybe meet the dog lady next door? She smells so wonderful for a few days … No! No time! “- At least now we should look more closely, whether it builds up a chronic stress situation for Rex. When and how stress can make our dogs and cats ill, “my PETER” talked about it. Michael Leschnik from the University of Veterinary Medicine Vienna.
Question: “Just no stress” – Sometimes it seems that this good advice applies to the everyday life of our pets. Stress – what is that from a medical point of view?
Dr. Leschnik: Stress is first and foremost a reaction of the organism to external circumstances, in which there is a need for the body to be given an increased readiness to perform and respond and to be able to react at an increased speed. The triggers for this, the so-called stressors, are found everywhere in nature: in the hunter as well as in the prey, or as a result of hunger and thirst and thus as a drive for food and water. Stress occurs in connection with territorial behavior and accompanies the sexual behavior – both in the defense of a pack by the male and in the search of the respective partner animals. Stress is subsequently found in the dams when the body changes during pregnancy. And stress is ultimately the mechanism that triggers childbirth and determines behavior during rearing and lactation.
Dr. Leschnik: Yes, absolutely! Usually we understand stress as the state we are in or the factors that have led to it, but basically it is nothing but a necessary response of the body to survival.
What does this reaction of the organism look like? What happens in the body?
Dr. Leschnik: That’s a very close interaction between the nervous and endocrine systems. First, the perception of the external circumstances is processed by the nervous system and leads at the same moment to changes in the nervous function. The dilated pupils, wide-open eyes, increased heart rate and respiratory rate – these are reactions that are controlled directly via the nervous system and thus immediately and immediately function. At the same time, the hormone system is also activated via the nervous system: control hormones are released into the bloodstream via the pituitary gland and, for example, enter the adrenals, which now produce and release the stress hormone cortisol. The first reaction to a stress-inducing factor is therefore the pure nerve impulse that causes the changes in the body, the second reaction is the release of these stress hormones. These are normal physiological processes that lead to – adapted to the particular situation – increased willingness to perform. Today one often tries to differentiate between so-called good and bad stress, because we feel certain stress factors as pleasant, others unpleasant. That’s exactly the same with our pets. But even if the sensations are different, the processes in the body remain the same.
Dr. Leschnik: That’s exactly the second important factor! An example: A small cat is in an acute stress situation when a dog, perhaps not exactly a cat, passes by. The cat ducks, she hisses, she gets wide pupils. If the dog goes away, these reactions dissolve into complacency relatively quickly. But if the dog is lying down next to the cat, for example, it can be seen that the stress level reaches an extent that the cat can no longer handle normally. Either she tries to escape or attack. If both instinctively do not make sense, then suddenly there are so-called skip actions that serve as a valve. Some cats start to brush themselves in stressful situations, although that makes no sense at all at the moment. Often this behavior is misinterpreted by us, we think, the cat got used to the situation and no more stress. That’s wrong. The cat has just found a valve to relieve stress. In dogs, we can also observe these skipping actions, for example, when we give a command that the dog can not or will not follow. This often happens with unclear orders that do not consist of one word, but of a whole rush of speech that the dog does not understand, of course. First, he will sit there once, completely unaware of what we want from him. When the tone gets sharper, he still has no idea what he’s supposed to do, but all of a sudden he starts looking for his toy, lying on his back and offering his belly. With these behaviors that are now meaningless to our senses, he tries to reduce and soothe the stress he has given us. If we closely observe, we see these moments very often.
When is the point reached that makes stress sick?
Dr. Leschnik: If many high stress levels are generated in short intervals, and the animal has no way to avoid this stress, then it comes again and again to short-term high physical stress responses and strains that can make you sick sooner or later. The other aspect is the chronic – perhaps not so high, but permanent – level of stress. Just think about the burnout syndrome in humans, which is nothing more than a constant overload, which is accompanied by a chronic increased stress level. Of course, we do not see any burnout in the animal, but many of our pets are also exposed to chronic stress – and whenever we do not adequately respond to them, they do not adequately satisfy their needs. In plain language: if we want too much of them and give too little for them. That makes stress! Likewise, in clinical work, we repeatedly find that hunting or athletic dogs in need of immobilization due to injury develop a high level of stress because they do not, or only for a short time, “work” or “work” should exercise restricted. These dogs can actually get sick. In the cat, these chronic stress factors mainly affect the gastrointestinal tract and the bladder, it can lead to bladder inflammation and urinary behavior. We also know that in addition to the nervous and hormonal systems, the immune system also plays a crucial role in all the stress reactions in the body. It is no coincidence that in medicine, we use cortisone in many clinical applications as a necessary drug that suppresses the immune system. This synthetically produced cortisone is in principle the same as the cortisol, which is released as a stress hormone in the body. So it comes in animals, in which a high stress-related high Cortisollevel is permanently given, to a limited function of the immune system.
Is the influence of stress on the immune system thus ultimately the reason that stress has an influence on the development of tumors?
Dr. Leschnik: Stress may not be the cause of tumor, but it may not be tumor-preventing. Potential tumors develop permanently in the body, and in most cases our immune system can cope with them and can eliminate the defective cells. However, if the immune system permanently works at a lower level because of an increased level of stress, it does not only affect the response to external agents, but also how to deal with changes that take place in the organism.
What causes adrenaline, which also plays a major role in the stress event?
Dr. Leschnik: The messenger adrenaline is also produced and distributed by the adrenals. But while the cortisol production is controlled by a hormone of the pituitary gland – this is a somewhat time-delayed, but longer-acting mechanism -, the adrenaline is released via a nerve impulse from the adrenal gland. Adrenalin and norepinephrine, while bypassing the blood system, also act directly between the nerve cells and the cardiovascular system. All this takes place in the millisecond range and is part of the immediate reaction of the nervous system.
Thus, stress also has a negative impact on diseases of the cardiovascular system?
Dr. Leschnik: On the one hand yes! The stress response is an activation and performance enhancement. When a cardiovascular system is chronically overwhelmed by stress, it changes: The elasticity of the vessel walls decreases, the heart muscle thickens. On the other hand, prolonged stress in old animals, which for other reasons already show changes in the heart muscle, can worsen existing problems, or the body may not be able to adequately respond to stress. Then we are dealing with an insufficient stress response. The organism is led in this situation to the limits of its efficiency. This situation we see less in cats and dogs, but certainly in house birds, which can suffer a cardiac death by very short-term extreme stressful moments. This is also the case with rabbits here and there.
What other negative effects can stress still have?
Dr. Leschnik: We know today that a chronic stress level leads to a shortened life expectancy and a faster breakdown of nerve cells. Of course, the normal aging process also plays a role. Similar to humans, brain mass also decreases in dogs and cats after the end of the growth phase, when the animal has reached its full maturity. However, stress hormones and all stress-related events accelerate this process: the capacity of the brain and nervous system decreases faster.
Which symptoms or illnesses can result?
Dr. Leschnik: When dogs and cats get very old, which is more and more the case, there is a phenomenon that we would call colloquial dementia, the term is cognitive dysfunction. These are z. For example, old dogs that simply stand in the room episodically and do not seem to be familiar anymore. They bark at the wall, suddenly wanting to go out the wrong side of the door, no longer recognize people, forget to eat, or become impure. In some animals you can already see in computer tomography that the brain mass actually has become smaller. When these animals die and we examine the brain more closely, the decrease in nerve cells can also be demonstrated histologically – to an extent for which we sometimes have no exact explanation. One possible cause, among many other chronic stress.
Dr. Leschnik: Yes, but you have to be careful. Environmental influences can cause exactly the same – but the constant contact with environmental toxins is also a form of stress for the body. We also do not always experience stress consciously, but process a lot without even being aware of it. Recognizing acute stress in our animals is not difficult, but when it comes to chronic stress, it’s easy to fail. It would be so important to recognize just this chronic stress and try to look at the life of the animal a little out of his eyes.