Tag Archives: Vetmeduni Vienna

Dogs can adopt the perspective of humans

Humans are able to interpret the behaviour of others by attributing mental states to them (and to themselves). By adopting the perspectives of other persons, they can assume their emotions, needs and intentions and react accordingly.

In the animal kingdom, the ability to attribute mental states (Theory of Mind) is a highly contentious issue. Cognitive biologists from the Messerli Research Institute of the University of Veterinary Medicine Vienna could prove with a new test procedure that dogs are not only able to identify whether a human has an eye on a food source and, therefore, knows where the food has been hidden. They can also apply this knowledge in order to correctly interpret cues by humans and find food they cannot see themselves.

This perspective taking ability is an important component of social intelligence. It helps dogs to cope with the human environment. The results have been published in the journal Animal Cognition.

 

The so-called Theory of Mind describes the ability in humans to understand mental states in conspecifics such as emotions, intentions, knowledge, beliefs and desires. This ability develops in humans within the first four or five years of life while it is usually denied in animals. Indications that animals can understand mental states or even states of knowledge of others have only been found in apes and corvids so far. Dogs have been tested several times, but the results were poor and contradictory.

With a new experimental approach, cognitive biologists from the Messerli Research Institute could now provide solid evidence for dogs being able to adopt our perspective. By adopting the position of a human and following their gaze, dogs understand what the human could see and, consequently, know.

This ability to ascribe knowledge is only a component of a full-blown Theory of Mind, but an important one.

Identifying the right informant

The so-called Guesser-Knower paradigm is a standard test in research into the attribution of knowledge to others. This experiment involves two persons: a “Knower” who hides food, invisibly for the dog, in one of several food containers or knows where somebody else has hided it, and a “Guesser”. The Guesser has either not been in the room or covered her eyes during the hiding of the food. A non-transparent wall blocks the animals’ view of the food being hidden. After that, the two humans become informants by pointing to different food containers.

The Knower always points to the baited container and the Guesser to another one. All containers smell of food. “To get the food, the dogs have to understand who knows the hiding place (Knower) and who does not and can, therefore, only guess (Guesser). They must identify the informant they can rely on if they have to decide for one food container,” said principal investigator Ludwig Huber. In approximately 70 per cent of the cases the dogs chose the container indicated by the Knower – and thus were able to successfully accomplish the test. This result was independent of the position of the food container, the person acting as the Knower and where the Guesser was looking.

Eye on hidden food source

Dogs are able to identify the human having an eye on a hidden food source. (Photo: Ludwig Huber/Vetmeduni Vienna)

Dogs can adopt human perspectives

The only aim of this test series, however, was to independently confirm a study carried out in New Zealand. Clear evidence of dogs being able to adopt our perspective and take advantage of it was provided in a new test developed by the team, the so-called “Guesser looking away” test.

In this new experiment, a third person in the middle hides the food. This person does not give cues later on. The potential informants were kneeing left and right of this hider and looked to the same side and slightly down. Thus, one of the two persons looked towards the baiter, the other person looked away. “This means that the tested dogs, in order to get the food, had to judge who is the Knower by adopting the informants’ perspectives and following their gazes,” explained Huber. Even in this test, which is very difficult for the animals, approximately 70 per cent of the trials had been mastered.

Adopting the human perspective leads to invisible food

Being able to adopt the perspective of a human does, however, not require the ability to understand intentions or wishes. “But the study showed that dogs can find out what humans or conspecifics can or cannot see,” explained Huber. “By adopting the positions of humans and following their gazes geometrically, they find out what humans see and, therefore, know – and consequently whom they can trust or not.”

In similar experiments, chimpanzees and few bird species such as scrub jays and ravens were able to understand the state of knowledge and also the intentions of conspecifics and modify their own behaviour accordingly. For dogs, there have only been specualtions and vague indications so far. But dogs understand our behaviour very well, for example our degree of attention. They can learn from directly visible cues such as gestures or gazes. Thus, they are able to find food even if their view of it has been blocked. “The ability to interpret our behaviour and anticipate our intentions, which has obviously developed through a combination of domestication and individual experience, seems to have supported the ability to adopt our perspective,” said Huber. “It still remains unclear which cognitive mechanisms contribute to this ability. But it helps dogs to find their way in our world very well.”

Source:  University of Veterinary Medicine, Vienna media release

Dogs give friends food (prosocial behavior in dogs)

A readiness to help and a positive attitude toward others are considered foundations of human relationships and human cooperation. But not only humans cooperate and support each other, animals do so, too. A group of ethologists from the Messerli Research Institute at the Vetmeduni Vienna have shown for the first time that dogs also behave prosocially toward others – provided that they know the other dog. The results were published in Nature’s Scientific Reports.

Compared to the rest of the animal kingdom, the human capacity for cooperation is something quite special. Cooperating with one another requires a certain amount of prosocial behaviour. This means helping others without any direct personal benefit.

“Dogs and their nearest relatives, the wolves, exhibit social and cooperative behaviour, so there are grounds to assume that these animals also behave prosocially toward conspecifics. Additionally, over thousands of years of domestication, dogs were selected for special social skills,” explains study director Range. For this reason, Range and her colleagues Mylene Quervel-Chaumette, Rachel Dale and Sarah Marshall-Pescini studied 16 dogs to test their readiness to benefit familiar versus unfamiliar partners.

The researchers studied the prosocial behaviour of the animals using a bar-pulling task in which the dogs had to pull trays and decide whether a second dog would receive a treat or not. In the test, the donor dogs used their mouths to pull a string to bring a tray toward a second dog. They could choose either an empty tray or a tray containing a treat on the partner’s side.

The donor dog (right) can pull a tray and donate food to the receiver-dog (left). (Photo: Mylène Quervel-Chaumette/Vetmeduni Vienna)

The donor dog (right) can pull a tray and donate food to the receiver-dog (left). (Photo: Mylène Quervel-Chaumette/Vetmeduni Vienna)

Dogs donate to familiar partners more often than to unfamiliar ones

Whether the donor dogs knew the recipient made a difference. Donor dogs pulled the giving tray more often for familiar dogs than for unfamiliar ones. “Dogs truly behave prosocially toward other dogs. That had never been experimentally demonstrated before. What we also found was that the degree of familiarity among the dogs further influenced this behaviour. Prosocial behaviour was exhibited less frequently toward unfamiliar dogs than toward familiar ones.

Prosocial behaviour put to the test

In the bar-pulling task, the donor dogs decided whether another dog would receive a treat or not. The donor dog itself did not get the treat. The only purpose of the task was to benefit the other dog. By conducting several control tests, the researchers excluded the possibility that the dogs were simply pulling the trays for the fun of it. Donor dogs were reserved in pulling the tray when an unfamiliar dog was in the next enclosure.

At the end of each test run, the researchers conducted another test to show that the donor dogs knew what pulling the tray meant. They allowed the donor dogs to pull on a tray to give themselves a treat, and all dogs did just that. “This control excludes the possibility that the dogs did not pull on the tray out of fear of the unfamiliar dogs. Given the same situation, the dogs gladly gave themselves a treat,” says Range.

“We were also able to disprove the argument that the dogs pulled the string less frequently because they were distracted by the unfamiliar partner during the test. Only rarely did a donor dog interact with the unfamiliar dog,” Range explains.

Source:   Vetmeduni Vienna media release

What are you looking at? (Dogs follow the human gaze)

Dogs are known to be excellent readers of human body language in multiple situations. Surprisingly, however, scientists have so far found that dogs do not follow human gaze into distant space. Scientists at the Messerli Research Institute at the Vetmeduni Vienna investigated how this skill of dogs is influenced by aging, habituation and formal training. The outcome: Gaze following to human gaze cues did not differ over the dogs’ lifespan, however, formal training was found to directly influence gaze following in dogs.


Gaze following to distant space has been documented in many species and is considered a basic response found in many taxa. Dogs may present a special case as the researchers found evidence that they are able to follow human gaze to objects such as food or toys, but not for the comparatively simpler task of following gaze into distant space.

Two possible reasons were offered to explain this phenomenon: One reason could be habituation. Dogs lose their innate gaze following response as they age, as they are frequently exposed to human gaze cues over their lifespan and slowly stop responding to them. Another reason could be formal training such as obedience, agility, and trick training may interfere with the dogs’ response to gaze cues, since dogs are usually trained to look at the owner, to wait for commands and ignore distractions.

What influences dogs’ gaze following response to human gaze cues?

Lead author Lisa Wallis and her colleagues at the Vetmeduni Vienna investigated 145 Border Collies aged 6 months to 14 years in the Clever Dog Lab in order to address the question of whether habituation, and/or training influences dogs’ gaze following response, and to determine, for the first time, how this ability changes over the course of a dog’s life by comparing groups of dogs of different ages. 

Dogs of all ages are able to follow human gaze

The scientists tested two groups of dogs with differing amounts of formal training over their lifespan. Both groups participated firstly in a test and control condition, where their initial gaze following performance was measured. The experimenter obtained the dogs’ attention using its name and the command “watch” after which the experimenter turned her head swiftly to look at the door of the testing room in the test condition, or looked down to the floor next to her feet in the control condition. If the dogs responded by looking at the door within two seconds in the test condition but did not look at the door in the control condition, a gaze following response was recorded.

Dogs’ tendency to follow human gaze is influenced by training for eye contact
Lisa Wallis with a Border Collie in the test room. (Photo: Clever Dog Lab / Vetmeduni Vienna)

Lisa Wallis with a Border Collie in the test room. (Photo: Clever Dog Lab / Vetmeduni Vienna)

The dog follows Wallis' gaze to the door. (Photo: Clever Dog Lab / Vetmeduni Vienna)

The dog follows Wallis’ gaze to the door. (Photo: Clever Dog Lab / Vetmeduni Vienna)

 

 

 

 

 

 

 

 

 

Dogs which had a higher amount of formal training over their lifespan showed a lower gaze following response compared to dogs with little or no training. Similarly, short-term training also decreased dogs’ gaze following response and increased gaze to the human face.

The authors conclude that formal training had a stronger influence than aging or habituation on dogs’ gaze following response. This may explain why previous studies have failed to find a gaze following response when cues to distant space are used, and why in comparison to other species dogs perform relatively poorly in this task. The fact that the experimenter used strong attention-getting cues and provided contextual relevance by looking at a door may have also contributed to the positive results found in this study.

“From a very young age dogs have experience with doors when they live in human homes. The dogs develop an understanding that at any time an individual may enter the room, and therefore doors hold special social relevance to dogs”. – says Lisa Wallis.

In her current project, together with her colleague Durga Chapagain, Wallis is investigating the effects of diet on cognitive aging in older dogs. The scientists are still looking for dog owners who would like to participate in that long-term study (food is provided for free).

This research has been published in the journal Animal Behaviour.

Source:  Vedmeduni Vienna media release

Behind the scenes in canine blood donation

Animals, including dogs, may need blood donations at critical points in their lives.

The University of Veterinary Medicine, Vienna has operated a blood bank for dogs for more than a decade. 

Reasons for a blood transfusion among dogs (and cats) are usually serious accidents, large operations, certain types of cancer, cases of intoxication with rodent poison, serious infectious diseases such as the tick-borne babesiosis, and blood illnesses including haemolytic or inherited bleeding disorders such as haemophilia.

At the University of Veterinary Medicine, Vienna dog owners can bring their animals to donate blood regularly or as needed. Blood donations two to four times a year per dog is the maximum. About 15 minutes are required for a donation. Dogs must have a minimum weight of 25 kilograms and usually donate about 450 millilitres of blood at each session.

Photo by Felizitas Steindl / Vetmeduni Vienna

Photo by Felizitas Steindl / Vetmeduni Vienna

Animal blood, as well as human blood, is divided into various groups based on different surface proteins found on the red blood cells. More than twelve different blood type systems have been described for dogs, although in practice dogs are only tested for DEA 1.1 positive or DEA 1.1 negative.

Dogs can be registered as blood donors at the Clinical Unit of Internal Medicine Small Animals of the Vetmeduni Vienna. The donors receive a donor card and undergo a thorough examination before each donation. This mandatory health check includes a complete blood count, a test for blood parasites, and a check-up for viral infections.

“Donating blood does not harm the animals. The donated amount can be quickly regenerated by the animal’s organism,” says  specialist for small animal internal medicine and blood bank coordinator Nicole Luckschander-Zeller. “We pay special attention to making sure that donor animals feel good during donation. That’s why, after every donation, we give the animals a little snack.”

Dog blood is not only used as a whole. Individual blood components, such as plasma or erythrocyte concentrates, are stored and used when needed.

Source:  Vetmeduni Vienna media release

 

Immunotherapy hope

There is a form of cancer treatment called immunotherapy, where antibodies inhibit tumor growth.  Until now, such therapy wasn’t available for dogs.  A research team at Messerli Research Institute of the Vetmeduni Vienna, the Medical University of Vienna and the University of Vienna have now developed antibodies to treat cancer in dogs.

The newly developed antibody brings hope for dogs. (Photo by:  Michael Bernkopf / Vetmeduni Vienna)

The newly developed antibody brings hope for dogs. (Photo by: Michael Bernkopf / Vetmeduni Vienna)

Since cancer cells bear very specific antigens on the surface, the corresponding antibodies bind to these molecules and inhibit tumor growth.  A destructive signal sent by the antibody to the inside of the cancer cell initiates its death. In a second mechanism, the immune system of the patient also destroys the “marked” tumor in a more efficient way.

Josef Singer and Judith Fazekas, both lead authors of the study, discovered that a receptor frequently found on human tumor cells (epidermal growth factor receptor or EGFR) is nearly 100 percent identical with the EGF receptor in dogs. In human medicine EGFR is frequently used as the target of cancer immunotherapy because many cancer cells bear this receptor on their surface. The so-called anti-EGFR antibody binds to cancer cells and thus triggers the destruction of the cells. “Due to the high similarity of the receptor in humans and dogs, this type of therapy should work well in dogs too,” the scientists say. The binding site of the antibody to EGFR in man and dogs differs only in respect of four amino acids.

The head of the study, Professor Erika Jensen-Jarolim, explains as follows: “We expect dogs to tolerate these anti-cancer antibodies well. This will be investigated in clinical studies in the future and is expected to greatly improve the treatment as well as the diagnosis of cancer in dogs.”

The newly developed antibody provides an additional benefit for dogs. As in human medicine, antibodies can be coupled with signal molecules. When the antibody binds to a cancer cell in the organism, the coupled antibody – in this case a radioactive isotope – can be rendered visible and is thus able to show where tumors and even metastases are located. When the selected isotope also contributes to the decay of cancer cells, the approach is known as “theranostics” (therapy and diagnostics).

In veterinary medicine, immunotherapy will be employed for the treatment of mammary ridge cancer (milk line cancer) in dogs. It may also be used as part of a combination therapy.

The team have published their study results in the journal Molecular Cancer Therapeutics.

Source: Vetmeduni Vienna media release

Attentiveness in dogs

Photo by Angela Gaigg

Photo by Angela Gaigg

Researchers at the Messerli Research Institute at the Vetmeduni in Vienna have researched dogs’ attentiveness and how it changes over their lives – and the patterns shown are similar to humans!  The results have been published in the journal Frontiers in Psychology.

Dogs are individual personalities, possess awareness, and are particularly known for their trainability. To learn successfully, they must display a sufficient quantity of attention and concentration.

The study’s lead author, Lisa Wallis, and her colleagues investigated 145 Border Collies aged 6 months to 14 years in the Clever Dog Lab at the Vetmeduni Vienna and determined, for the first time, how attentiveness changes in the entire course of a dog’s life using a cross-sectional study design.

To determine how rapidly dogs of various age groups pay attention to objects or humans, the scientists performed two tests. In the first situation the dogs were confronted with a child’s toy suspended suddenly from the ceiling. The scientists measured how rapidly each dog reacted to this occurrence and how quickly the dogs became accustomed to it. Initially all dogs reacted with similar speed to the stimulus, but older dogs lost interest in the toy more rapidly than younger ones did.

In the second test situation, a person known to the dog entered the room and pretended to paint the wall. All dogs reacted by watching the person and the paint roller in the person’s hands for a longer duration than the toy hanging from the ceiling.

The dogs generally tended to react by watching the person with the object for longer than an object on its own. The team found that older dogs – like older human beings – demonstrated a certain calmness. They were less affected by new items in the environment and thus showed less interest than younger dogs.

In a further test the scientists investigated so-called selective attention. The dogs participated in an alternating attention task, where they had to perform two tasks consecutively. First, they needed  to find a food reward thrown onto the floor by the experimenter, then after eating the food, the experimenter waited for the dog to establish eye contact with her.  These tasks were repeated for a further twenty trials. The establishment of eye contact was marked by a clicking sound produced by a  “clicker” and small pieces of hot dog were used as a reward. The time spans to find the food and look up into the face were measured. With respect to both time spans, middle-aged dogs (3 to 6 years) reacted most rapidly.

“Under these test conditions, sensorimotor abilities were highest among dogs of middle age. Younger dogs fared more poorly probably because of their general lack of experience. Motor abilities in dogs as in humans deteriorate with age. Humans between the age of 20 and 39 years experience a similar peak in sensorimotor abilities,” says Wallis.   

Dogs also go through a difficult phase during adolescence (1-2 years) which affects their ability to pay attention. This phase of hormonal change may be compared to puberty in Man. Therefore, young dogs occasionally reacted with some delay to the clicker test. However, Wallis found that adolescent dogs improved their performance more rapidly than other age groups after several repetitions of the clicker test. In other words, the learning curve was found to be steepest in puberty. “Thus, dogs in puberty have great potential for learning and therefore trainability” says Wallis.

Source: Vetmeduni media release

Harness fit in guide dogs

A research team at the University of Veterinary Medicine in Vienna (Vetmeduni Vienna) have studied the forces that guide dogs are exposed to during their work to ascertain what types of harness are most suitable.

Guide dogs walk under constant tension. A well-fitting harness is extremely important for the animals (Photo: Michael Bernkopf/Vetmeduni Vienna)

Guide dogs walk under constant tension. A well-fitting harness is extremely important for the animals (Photo: Michael Bernkopf/Vetmeduni Vienna)

A proper harness that enables good communication between the blind person and the dog is an important factor to support the dog’s well-being, while a poorly fitting harness may result in health problems and impaired communication between dog and owner.

The team members, movement analysts and physiotherapists, examined the distribution of pressure in working guide dogs by placing pressure sensors beneath their harnesses. Eight guide dogs were filmed with a trainer while climbing steps, avoiding obstacles, turning left and right and walking straight ahead. To visualize the movements, the animals, the trainers and the harnesses were equipped with reflective markers. The positions of the markers were recorded by a total of ten cameras.

The results showed that the bottom right of the animals’ chests is particularly stressed. As Barbara Bockstahler explains, “Guide dogs walk under constant tension. They are usually on their owners’ right and in front of them.” The scientists found that the pressure on the right side of a dog’s chest may equate to up to 10 per cent of the animal’s weight. In contrast, the dog’s back experiences far less pressure. “It is important for guide dogs to exercise regularly without a harness to compensate for the lopsided pressure they experience in their work”, says Bockstahler.

Very rigid harnesses enable quick and finely tuned communication between dogs and owners but cause stress to the animals. The more stiffly the harness is anchored to the handle, the more pressure the animal experiences. The most comfortable harness relies on a hook-and-loop connection, which provides the least pressure on the dog, although for long-haired dogs a plastic clip version is favourable.

The researchers want to study guide dogs for a longer period of time to find out whether any of the harnesses are associated with long-term problems in the animals.   They require partners and sponsors for this work.

The results of this study have been published in the Veterinary Journal.

Source:  Vetmeduni Vienna press release