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Cluj Vet J 2022, 27, 3 http://clujveterinaryjournal.ro 

Short Communication 

Study on aggression in dogs in a public shelter 
Sorin Marian MÂRZA1*; Orsolya KASA1; Mariana TĂTARU1; Radu LĂCĂTUŞ1; Felix Daniel LUCACI1 and Ionel 
PAPUC1 

1 Faculty of Veterinary Medicine, University of Agricultural Sciences and Veterinary Medicine Cluj-Napoca; 
e-mail: sorinmarza@yahoo.com; orsolya_kasa@yahoo.com; mariana.tataru@usamvcluj.ro; 
radu.lacatus@usamvcluj.ro; lucacifelix@yahoo.com; ionel.papuc@usamvcluj.ro;  

* Correspondence: M.S.M. sorinmarza@yahoo.com;   

Abstract: Assessing the behavior of a dog in a shelter is extremely important because the type of behavior can tell us if the animal 
can be given up for adoption, to whom it can be given up for adoption, if it cannot be given up for adoption and in which direction 
improvements in behavior need to be made to get it safely given up for adoption. This study aimed to assess the behavior of dogs in 
a public dog shelter by how a dog behaves towards a person (examiner) in a sequence of situations and to determine the number of 
individuals who responded with aggression. The behavior test was developed by The Rottweiler Rescue Society (Ontario, Canada) 
and John Rogerson, Blue Cross, Britain. Following minor modifications, has been used to examine dogs in public shelters. The test 
contains two additional assessment items from the article "An Evaluation of a Behavior Assessment to Determine the Suitability of 
Shelter Dogs for Rehoming" [1]. A total of 187 adult dogs were examined, of which 24 were identified with aggressive behavior and 
the types of aggression identified were dominance, interspecific, or territorial aggression.  No behavioral test can show specifically 
how a dog will behave in a new environment, but the information obtained from the examination can indicate extreme manifesta-
tions of canine behavior, such as dominance aggression, possessive aggression, territorial aggression, and separation anxiety. 

Keywords: dogs; aggression; behavior 
 

 

1. Introduction 
 Evaluating behavior in dogs is an important part of responsible pet ownership and 

training. It involves observing and analyzing a dog's actions and reactions to various 
stimuli to understand their behavior and determine any potential problems or areas for 
improvement [2, 3]. Many different methods and approaches can be used to evaluate 
behavior in dogs, including observation, assessment tools, and training techniques. 
Common behaviors that may be evaluated include aggression, separation anxiety, fear-
fulness, and general obedience [4, 5]. Understanding and addressing any problematic 
behaviors makes it possible to create a positive and harmonious relationship with your 
dog and ensure their well-being [5]. It is also important to consult with a qualified pro-
fessional, such as a veterinarian or a certified dog trainer if you have any concerns about 
your dog's behavior [6,7]. Aggression in dogs is a complex behavior that can manifest in 
various forms, such as barking, growling, snapping, and biting. It is often a response to 
fear, anxiety, or perceived threats, and can be directed toward people, other animals, or 
objects [8, 9, 10]. Aggressive behavior in dogs can be a serious problem, as it can lead to 
injury or damage to property, and can also cause strain on the relationship between the 
dog and its owner [2]. Identifying the underlying cause of aggressive behavior and ad-
dressing it promptly is important, as it can escalate if left unchecked. This may involve 
seeking the help of a qualified professional, such as a veterinarian or a certified dog 
trainer, and implementing a behavior modification plan to modify the dog's aggressive 
behaviors [11]. It is also important to use positive reinforcement training techniques and 
avoid punishment or physical force, as these approaches can often make the problem 
worse. 

Received: 25.12.2022 

Accepted: 30.12.2022 

Published: 30.12.2022 

DOI:10.52331/cvj.v27i3.42 

 

 

 

Copyright: © 2022 by the authors. 

Submitted for possible open access 

publication under the terms and 

conditions of the Creative Commons 

Attribution (CC BY) license 

(http://creativecommons.org/licenses

/by/4.0/). 

mailto:sorinmarza@yahoo.com
mailto:orsolya_kasa@yahoo.com
mailto:mariana.tataru@usamvcluj.ro
mailto:radu.lacatus@usamvcluj.ro
mailto:lucacifelix@yahoo.com
mailto:ionel.papuc@usamvcluj.ro
mailto:sorinmarza@yahoo.com


Cluj Vet J 2021, 27, 3 2 of 5 
 

 
2. Materials and Methods 

The biological material was represented by a number of 187 dogs from a public shelter in the munici-
pality of Satu Mare aged between 1 and 14 years, of which 114 were females and 73 were males. Out of the 
total number of 114 females, 4 were unspayed and out of the 73 males, 7 individuals were not neutered. Of 
the 187 animals, 68 were large, 91 medium, and 28 small. Of the 68 large dogs, 36 were female and 32 were 
male; of the 91 medium-sized individuals, 58 were female and 33 were male; of the 28 small dogs, 20 were 
female and 8 male. Of the total 187 dogs, 6 were purebred and the remaining 181 were mixed. Depending 
on size, the dogs were housed in pens of 2, 3, 4, and 5 individuals and individual pens for females with 
puppies. The pens were made of metal wire and the soil was either cloddy earth or grass, sometimes with 
the presence of gravel. The shelters with the resting place were built of wood, one for each pen. The dogs 
were fed twice a day, in the morning and evening, with commercial dry food and cooked food served in 
communal trays in each pen. Other materials used: dry grain-type food, a rubber bone-type toy with a rope 
of approx. 10 cm at each end.  

The behavior assessment test used consists of two parts, the first part of the test is for observation 
purposes, the examiner is separated from the tested dog by the fences of the pen in which it is sheltered. 
This part includes approaching the animal, first contact by placing the examiner's palm on the pen wall 
while speaking in a friendly tone to the animal, followed by casual then insistent eye contact. Maintaining 
eye contact, the examiner will observe the dog's reaction to a threatening situation, after which he will de-
cide whether to continue with the second part of the test. The last subpoint of the first part is separated from 
the animal after playtime, which can be used to deduce whether the animal might suffer from separation 
anxiety after adoption. 

Between the two parts of the test, the examiner will leave the dog for a few minutes so that he can be 
perceived as a neutral person again. If the dog has shown repeated aggression on two or more tests, the 
testing should be discontinued, or proceed with caution.   

The second part of the test involves direct contact between the examiner and the animal. For this part 
we have added two additional test items from the article "An Evaluation of a Behavior Assessment to De-
termine the Suitability of Shelter Dogs for Rehoming" [1] these being the first sub-point which consists of 
performing 3 head-to-tail and 5 head strokes, assessing the dog's response during the stimuli, during the 
pause between stimuli and after the end of stimuli and the last subpoint of the test, which involves as-
sessing the response to noise and movement. These two subpoints replaced the predator testing and in-
traspecific aggression testing in the original test, which could not be performed in the shelter. The second 
part of the test also includes a simulated routine physical examination by the veterinarian, two obedience 
tests, the dog's reaction to handling the collar, and two assessments of resource guarding, namely food and 
a toy. 

. 

3. Results and Discussion 
Out of a total of 187 dogs examined, 20 individuals were discontinued for safety reasons. In the sec-

ond part of the test, sub-point 7, which tests resource guarding (the dog will be offered a toy which will then 
be removed), no dog showed interest in the toy offered. 

In the first part of the test, in the first subpoint consisting of approaching the animal, 7 dogs, of which 
4 females and 3 males, 4 large and 3 small, showed an aggressive reaction, manifested by growling, show-
ing fangs, and offensive posture.  Of these, 3 females and 2 males, 4 large and 1 medium-sized, were 
known to exhibit aggressive behavior at the shelter. Of the five dogs, one female and one male were not 
neutered. These 5 dogs fall into the category of intra- and interspecific aggression, dominance aggression, or 
perhaps territorial aggression. Of the 7 dogs we did not continue examining, we observed one female dog 
with 10-day-old puppies. The medium-sized female Metis, about 2 years old, showed aggression towards 
the examiner, with growling and intent to bite. This behavior is normal and is related to the post-parturition 
hormonal status and the presence of pups. The last dog with an aggressive reaction to this sub-point was a 
medium-sized Metis male, about 5 years old, which showed aggression towards humans. For the following 
sub-point of the first part of the test, i.e. First Contact, Touch I, Touch II, Occasional Eye Contact, and In-
sistent Eye Contact, in addition to the 7 where we did not continue the second part of the behavioral test, in 
the sub-point Touch II a small female showed aggressive reaction by growling and leaving the examination 



Cluj Vet J 2021, 27, 3 3 of 5 
 

environment. On casual eye contact, 20 dogs, 13 females and 7 males, 7 large, 7 medium, and 6 small dogs 
showed a fear reaction; fear is a major factor that can trigger aggressive behavior. When confronted with 
insistent eye contact, 33 dogs reacted defensively (moved away from the examiner). In the next sub-point, 
threat, where the examiner strikes the pen wall while adopting an offensive posture and maintaining in-
sistent eye contact with the animal, 13 dogs reacted aggressively, including the 7 that did not continue with 
the second part of the test. Of the 13 dogs, 9 were female and 4 male, 6 large and 7 medium-sized. On the 
same sub-point of the test, 66 dogs, 45 females, and 21 males, 21 large, 28 medium, and 17 small showed a 
defensive attitude (moving away from the examiner).  

These two reactions represent responses to a potentially dangerous stimulus that may show resource 
defense behavior (in this case bodily integrity), which up to a certain limit is a normal reaction on the part of 
the animal (normally a dog that feels threatened only attacks when it has no alternative escape from the 
dangerous situation and only enough to allow it to escape). 

 In the last sub-point of the first part of the test, 92 individuals fell into the "bark/yapping/jump on 
the fence" reaction, of which 47 were females and 45 males, 35 were large, 48 were medium and 9 were 
small. These dogs may have separation anxiety after adoption. 

In the second part of the test, in the first sub-point consisting of three head-to-tail and five head 
strokes, 10 individuals exhibited an aggressive reaction by attempting to avoid contact with the examiner, 
growling, and displaying the intention to bite. Of the 10 dogs, 9 were female and 1 male, 3 large, 5 medium, 
and 2 small. On this sub-item, in 9 of the dogs we did not continue the examination for safety reasons (6 
females and 3 males, 5 large and 4 medium). 13 dogs, of which 8 females and 5 males, 3 large, 4 medium 
and 6 small showed fear reaction, immobility or leaving the environment. We proceeded with caution when 
examining them because fear is a major factor that can trigger aggressive behavior. In the physical exami-
nation, 12 individuals we did not continue the examination: 9 females and 3 males, 6 large, 5 medium, and 1 
small, including the 9 individuals we did not continue the testing in the previous subpoint. 19 dogs had a 
bad reaction to the physical examination, characterized by avoiding contact with the examiner or leaving 
the examination environment. None of the 19 dogs externalized an intention to bite. 

 In sub-point submission I, in 18 dogs we did not continue the test 14 females, and 4 males; 9 large, 8 
medium, and 1 small. Only one dog, a medium-sized male, showed an aggressive reaction, manifested by 
growling and the intention to bite. A total of 22 individuals, of which 16 were females and 6 males, 8 large, 5 
medium, and 9 small, reacted defensively by leaving the examination environment and avoiding contact 
with the examiner. 

 In the next sub-point, Submission II, in 19 dogs we did not continue the examinations for safety 
reasons 14 females, 5 males; 9 large, 9 medium, and 1 small. Only one large male dog showed an aggressive 
reaction, growling and baring its teeth. A total of 25 individuals did not allow themselves to be positioned 
but did not show aggression. A total of 14 dogs, 9 females and 5 males, 5 large, 3 medium, and 6 small, 
showed fear/avoidance reactions. Fear is a major factor that can trigger aggressive behavior. 

In the sub-item "Handling of slag", 19 dogs were not examined further. 12 individuals externalized 
aggressive behavior, 8 females and 4 males; 6 large, 3 medium, and 3 small, by avoiding contact with the 
examiner, growling and having the intent to bite. In the sub-item "Handling of slag", 19 dogs were not 
examined further. 12 individuals externalized aggressive behavior, 8 females and 4 males; 6 large, 3 me-
dium, and 3 small, by avoiding contact with the examiner, growling and having the intent to bite. Of the 
dogs examined, 29 animals, 18 females, 11 males, 2 large, 11 medium, and 6 small, refused to be led but did 
not exhibit aggressive behavior. These dogs are dominant, upon a forceful intention of handling from the 
examiner they might show aggression. 

When guarding resources, a total of 24 individuals, including 14 females and 10 males, 6 large, 14 
medium, and 4 small, reacted aggressively by threatening, growling, and displaying the intention to bite. 
These dogs exhibit possessive/defensive resource aggression. On a total of 20 individuals, we did not per-
form this test for safety reasons. 

No individual showed aggressive behavior on the last subitem of the test, reaction to noise and 
movement. Instead, 18 dogs, 11 females and 7 males, 6 large and 3 small, showed fear, immobility, or 
leaving the examination environment. 

 
 
 



Cluj Vet J 2021, 27, 3 4 of 5 
 

4. Conclusions and Recommendations: 
Of the 187 dogs examined, in a total of 27 individuals we discontinued further behavioral testing for 

safety reasons. These dogs showed either dominant aggression, interspecific aggression, or territorial ag-
gression. 

Age was not a major factor influencing aggressive reactions from dogs, with the majority of dogs 
falling into the 5-8 and 9-14 age categories. 

Of the dogs that showed aggression, the majority were large and medium-sized, with smaller indi-
viduals most often showing fear. 

The sex of the animal did not play a significant role in the manifestation of aggressive behavior; of 
those that expressed aggression, the number of females was approximately as high as the number of males. 

The types of aggression encountered in the two shelters were: dominance aggression, posses-
sive/resource defense aggression, territorial aggression, interspecific aggression, and maternal aggression. 

Of the categories of aggression observed in the tests, the most common were possessive/defensive 
aggression for resources (represented by food) and dominance aggression. 

By housing dogs according to size, temperament, and age, we have not encountered cases of intra-
specific aggression; 

We did not observe fear-induced aggression because dogs that exhibited fear or defensive behavior 
were able to move away from the examiner and did not have to attack; 

For the behavioral health of the dogs but also to increase the chances of adoption of the shelter dog, it 
is recommended to engage in socialization with the animals through play programs and other activities 
with the dogs at least once a week. 

The test used is a quality tool for assessing aggression in dogs. 
 

Author Contributions: Conceptualization, I.P. and O.K.; methodology, S.M.M.; validation, R.L., F.D.L.; investigation, 
M.T.; data curation, S.M.M.; writing—original draft preparation, I.P.; writing—review and editing, L.R.; supervision, 
I.P.; project administration, O.K.; All authors have read and agreed to the published version of the manuscript”. 

Funding: This research received no external funding.  

Institutional Review Board Statement: Not applicable. 

Data Availability Statement: The data supporting the results can be requested from the corresponding author. 

Acknowledgments: We thank the Free Life Satu Mare Association for the collaboration at the shelter level. 

Conflicts of Interest: The authors declare no conflict of interest. 

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	1. Introduction
	2. Materials and Methods
	3. Results and Discussion
	4. Conclusions and Recommendations:
	References

