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Sacoor C, Marugg JD, Lima NR, Empadinhas N, Montezinho L. Gut-Brain Axis Impact on Canine Anxiety Disorders: New Challenges for Behavioral Veterinary Medicine. Vet Med Int 2024; 2024:2856759. [PMID: 38292207 PMCID: PMC10827376 DOI: 10.1155/2024/2856759] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/29/2022] [Revised: 08/28/2023] [Accepted: 10/25/2023] [Indexed: 02/01/2024] Open
Abstract
Anxiety disorders in dogs are ever-growing and represent an important concern in the veterinary behavior field. These disorders are often disregarded in veterinary clinical practice, negatively impacting the animal's and owner's quality of life. Moreover, these anxiety disorders can potentially result in the abandonment or euthanasia of dogs. Growing evidence shows that the gut microbiota is a central player in the gut-brain axis. A variety of microorganisms inhabit the intestines of dogs, which are essential in maintaining intestinal homeostasis. These microbes can impact mental health through several mechanisms, including metabolic, neural, endocrine, and immune-mediated pathways. The disruption of a balanced composition of resident commensal communities, or dysbiosis, is implicated in several pathological conditions, including mental disorders such as anxiety. Studies carried out in rodent models and humans demonstrate that the intestinal microbiota can influence mental health through these mechanisms, including anxiety disorders. Furthermore, novel therapeutic strategies using prebiotics and probiotics have been shown to ameliorate anxiety-related symptoms. However, regarding the canine veterinary behavior field, there is still a lack of insightful research on this topic. In this review, we explore the few but relevant studies performed on canine anxiety disorders. We agree that innovative bacterial therapeutical approaches for canine anxiety disorders will become a promising field of investigation and certainly pave the way for new approaches to these behavioral conditions.
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Affiliation(s)
- Carina Sacoor
- Vasco da Gama Research Center (CIVG), Vasco da Gama University School (EUVG), 3020–210 Coimbra, Portugal
- Department of Veterinary Sciences, School of Agrarian and Veterinary Sciences (ECAV), University of Trás-os-Montes e Alto Douro (UTAD), 5000–801 Vila Real, Portugal
| | - John D. Marugg
- Center for Neuroscience and Cell Biology (CNC), University of Coimbra, 3004–504 Coimbra, Portugal
- Center for Innovative Biomedicine and Biotechnology (CIBB), University of Coimbra, 3004–504 Coimbra, Portugal
| | - Nuno R. Lima
- Department of Veterinary Sciences, School of Agrarian and Veterinary Sciences (ECAV), University of Trás-os-Montes e Alto Douro (UTAD), 5000–801 Vila Real, Portugal
- Animal and Veterinary Research Centre (CECAV), UTAD, and Associate Laboratory for Animal and Veterinary Science (AL4AnimalS), 5000–801 Vila Real, Portugal
- Innovation in Health and Well-Being Research Unit (iHealth4Well-Being), Polytechnic Health Institute of North (IPSN-CESPU), 4585-116 Gandra, Portugal
| | - Nuno Empadinhas
- Center for Neuroscience and Cell Biology (CNC), University of Coimbra, 3004–504 Coimbra, Portugal
- Center for Innovative Biomedicine and Biotechnology (CIBB), University of Coimbra, 3004–504 Coimbra, Portugal
| | - Liliana Montezinho
- Vasco da Gama Research Center (CIVG), Vasco da Gama University School (EUVG), 3020–210 Coimbra, Portugal
- Center for Neuroscience and Cell Biology (CNC), University of Coimbra, 3004–504 Coimbra, Portugal
- Center for Innovative Biomedicine and Biotechnology (CIBB), University of Coimbra, 3004–504 Coimbra, Portugal
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Schmidt T, Meller S, Talbot SR, Packer RMA, Volk HA. Urinary neurotransmitter analysis and canine behavior assessment. Front Vet Sci 2023; 10:1124231. [PMID: 36814465 PMCID: PMC9939829 DOI: 10.3389/fvets.2023.1124231] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/14/2022] [Accepted: 01/17/2023] [Indexed: 02/09/2023] Open
Abstract
Behavioral problems are highly prevalent in domestic dogs, negatively affecting the quality of life of dogs and their owners. In humans and dogs, neuropsychological or neurobehavioral disorders can be associated with deviations in various neurotransmitter systems. Previous evidence has revealed correlations between urinary neurotransmitters and various behavioral disorders; however, a causal relationship has not yet been conclusively demonstrated. Non-invasive urinary neurotransmitter analysis may identify specific biomarkers, which enable a more differentiated assessment of canine behavioral disorders in the future and contribute to more effective neuromodulatory treatment decisions and monitoring. This approach could offer new insights into underlying pathomechanisms of canine neurobehavioral disorders. This study assessed urinary neurotransmitter levels and the descriptive behavior profile of 100 dogs using established rating scales (Canine Behavioral Assessment and Research Questionnaire, Attention Deficit Hyperactivity Disorder Rating Scale, Dog Personality Questionnaire, Canine Cognitive Dysfunction Rating Scale), and explored relationships between these variables. No correlation was found between urinary neurotransmitters and the assessed behavior profiles; however, age-, sex- and neuter-related influences were identified. The lack of correlation could be explained by the many confounding factors influencing both behavior and urinary neurotransmitter excretion, including age, sex and neuter status effects, and methodological issues e.g., low discriminatory power between anxiety and aggression in the descriptive behavior evaluation. Urinary neurotransmitter testing could not be validated as a tool for canine behavior evaluation in this study. However, reliable assessment methods with low susceptibility to human biases could be valuable in the future to support behavioral-phenotype diagnoses.
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Affiliation(s)
- Teresa Schmidt
- Department of Small Animal Medicine and Surgery, University of Veterinary Medicine, Hannover, Germany
- Centre for Systems Neuroscience, University of Veterinary Medicine Hannover, Hannover, Germany
| | - Sebastian Meller
- Department of Small Animal Medicine and Surgery, University of Veterinary Medicine, Hannover, Germany
| | - Steven Roger Talbot
- Hannover Medical School, Institute for Laboratory Animal Science, Hannover, Germany
| | - Rowena Mary Anne Packer
- Department of Clinical Science and Services, Royal Veterinary College, Hatfield, United Kingdom
| | - Holger Andreas Volk
- Department of Small Animal Medicine and Surgery, University of Veterinary Medicine, Hannover, Germany
- Centre for Systems Neuroscience, University of Veterinary Medicine Hannover, Hannover, Germany
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A Preliminary Study on the Interplay between the Serum Levels of Neurotransmitters and Thyroid Hormones for the Evaluation of the Behavioral Phenotype of Dogs. Animals (Basel) 2023; 13:ani13030411. [PMID: 36766302 PMCID: PMC9913781 DOI: 10.3390/ani13030411] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/03/2023] [Revised: 01/23/2023] [Accepted: 01/25/2023] [Indexed: 01/28/2023] Open
Abstract
A total of 112 dogs (49 males and 63 females) belonging to different breeds (i.e., Boxer, Cirneco dell'Etna, Fonni's Dog, Labrador, Crossbreed, German Shepherd, Pit Bull, Shar-Pei, Yorkshire) were analyzed to compare the serum concentration of serotonin, dopamine, norepinephrine, prolactin, beta-endorphins, thyroxine (T4), triiodothyronine (T3), thyroid-stimulating hormone (TSH), and assess whether these parameters can be correlated with the behavioral phenotype of the investigated breeds. T4 was above or below the threshold in 61% and 14% of dogs, respectively; T3, in contrast, 41% of dogs showed values below the limit, while 26% above it. TSH was within the reference range in 58% of dogs; 94% of the dogs had prolactin in the reference range and only five animals showed values above the limit. For beta-endorphins, 49% of dogs had values above the limit, while 46% had values within the reference range. Serotonin and dopamine values below physiological limits were found in 62% and 70% of dogs, respectively. Finally, 61% of the dogs showed norepinephrine values within the reference range. The study confirmed that the assessment of the serum values of hormones and neurotransmitters in dogs could be useful to better understand the behavioral phenotype of the animal and could be useful for breeders and trainers for the selection of the most suitable subjects for specific tasks.
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Bochiș TA, Imre K, Marc S, Vaduva C, Florea T, Dégi J, Voia OS, Pop C, Ţibru I. The Variation of Serotonin Values in Dogs in Different Environmental Conditions. Vet Sci 2022; 9:vetsci9100523. [PMID: 36288136 PMCID: PMC9607218 DOI: 10.3390/vetsci9100523] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/02/2022] [Revised: 09/15/2022] [Accepted: 09/22/2022] [Indexed: 11/14/2022] Open
Abstract
Simple Summary The multiple implications of serotonin in behavior manifestations have shaped the goal of the present study, which was to evaluate the variation of serum serotonin levels in different experimental groups of dogs to establish whether serum serotonin levels could serve as indicators of aggressive behavior, especially when adoption is considered. The experimental groups were divided into three variants: Variant 1—two groups of medium (n = 6) and small (n = 4) breed shelter dogs; Variant 2—dogs with owners (n = 15) and dogs without owners but in foster care (n = 10), after administration of pre-spaying/neutering anesthesia; and Variant 3—dogs in different behavioral states (n = 8), classified as follows: M1—happy, M2—aggressive, M3—calmed status, post-exposure to a stressful situation, compared to the reference time referred to as M0. Significant results were found between M1 and M2 (p ≤ 0.05, decrease of serotonin by 89.61 ng/mL), as well as between M2 and M3 (p ≤ 0.008, increase by 112.78 ng/mL). Following anesthesia, the average mean serotonin values were significantly lower (p ≤ 0.003), by 63.85 ng/mL, in stray dogs compared to dogs with owners, leading to a presumptive conclusion that serotonin levels could serve as indicators for potentially aggressive behaviors. Abstract Serotonin is considered to be the neurotransmitter that controls several types of behavior: aggressiveness, impulsivity, food selection, stimulation, sexual behavior, reaction to pain, and emotional manifestations. The aim of this study was to determine the serotonin values in 43 dogs, divided into three different experimental variants: (1) between two groups of medium (n = 6) and small (n = 4) breed shelter dogs; (2) in dogs with (n = 15) and without (n = 10) owners after administration of pre-spaying/neutering anesthesia; (3) in different behavioral states (n = 8) classified as follows: M1—happy, M2—aggressive, M3—calmed status, post-exposure to a stressful situation, compared to the reference time referred to as M0. There were no significant differences (p ≥ 0.05) regarding the serotonin values between the two groups of medium and small breed shelter dogs. Following anesthesia, the average mean serotonin values were significantly lower (p ≤ 0.003), by 63.85 ng/mL, in stray dogs compared to dogs with owners. No significant differences (p ≥ 0.05) were found when comparing the reference time M0 to M1, M2, and M3. The differences decreased significantly (p ≤ 0.05), by 89.61 ng/mL, between M1 and M2 and increased significantly (p ≤ 0.008), by 112.78 ng/mL, between M2 and M3.
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Affiliation(s)
- Timea Andrea Bochiș
- Faculty of Veterinary Medicine, Banat’s University of Agricultural Sciences and Veterinary Medicine “King Michael I of Romania”, 300645 Timișoara, Romania
- Correspondence: (T.A.B.); (O.S.V.)
| | - Kálmán Imre
- Faculty of Veterinary Medicine, Banat’s University of Agricultural Sciences and Veterinary Medicine “King Michael I of Romania”, 300645 Timișoara, Romania
| | - Simona Marc
- Faculty of Veterinary Medicine, Banat’s University of Agricultural Sciences and Veterinary Medicine “King Michael I of Romania”, 300645 Timișoara, Romania
| | - Cristina Vaduva
- Faculty of Veterinary Medicine, Banat’s University of Agricultural Sciences and Veterinary Medicine “King Michael I of Romania”, 300645 Timișoara, Romania
| | - Tiana Florea
- Faculty of Veterinary Medicine, Banat’s University of Agricultural Sciences and Veterinary Medicine “King Michael I of Romania”, 300645 Timișoara, Romania
| | - János Dégi
- Faculty of Veterinary Medicine, Banat’s University of Agricultural Sciences and Veterinary Medicine “King Michael I of Romania”, 300645 Timișoara, Romania
| | - Octavian Sorin Voia
- Faculty of Animal Resources Bioengineering, Banat’s University of Agricultural Sciences and Veterinary Medicine “King Michael I of Romania”, 300645 Timișoara, Romania
- Correspondence: (T.A.B.); (O.S.V.)
| | - Călin Pop
- Faculty of Veterinary Medicine, Banat’s University of Agricultural Sciences and Veterinary Medicine “King Michael I of Romania”, 300645 Timișoara, Romania
| | - Ioan Ţibru
- Faculty of Veterinary Medicine, Banat’s University of Agricultural Sciences and Veterinary Medicine “King Michael I of Romania”, 300645 Timișoara, Romania
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Coria-Avila GA, Pfaus JG, Orihuela A, Domínguez-Oliva A, José-Pérez N, Hernández LA, Mota-Rojas D. The Neurobiology of Behavior and Its Applicability for Animal Welfare: A Review. Animals (Basel) 2022; 12:ani12070928. [PMID: 35405916 PMCID: PMC8997080 DOI: 10.3390/ani12070928] [Citation(s) in RCA: 12] [Impact Index Per Article: 6.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/04/2022] [Revised: 03/17/2022] [Accepted: 03/31/2022] [Indexed: 12/12/2022] Open
Abstract
Simple Summary Animal welfare is the result of physical and psychological well-being and is expected to occur if animals are free: (1) from hunger, thirst and malnutrition, (2) from discomfort, (3) from pain, (4) to express normal behavior, and (5) from fear and distress. Nevertheless, well-being is not a constant state but rather the result of certain brain dynamics underlying innate motivated behaviors and learned responses. Thus, by understanding the foundations of the neurobiology of behavior we fathom how emotions and well-being occur in the brain. Herein, we discuss the potential applicability of this approach for animal welfare. First, we provide a general view of the basic responses coordinated by the central nervous system from the processing of internal and external stimuli. Then, we discuss how those stimuli mediate activity in seven neurobiological systems that evoke innate emotional and behavioral responses that directly influence well-being and biological fitness. Finally, we discuss the basic mechanisms of learning and how it affects motivated responses and welfare. Abstract Understanding the foundations of the neurobiology of behavior and well-being can help us better achieve animal welfare. Behavior is the expression of several physiological, endocrine, motor and emotional responses that are coordinated by the central nervous system from the processing of internal and external stimuli. In mammals, seven basic emotional systems have been described that when activated by the right stimuli evoke positive or negative innate responses that evolved to facilitate biological fitness. This review describes the process of how those neurobiological systems can directly influence animal welfare. We also describe examples of the interaction between primary (innate) and secondary (learned) processes that influence behavior.
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Affiliation(s)
- Genaro A. Coria-Avila
- Instituto de Investigaciones Cerebrales, Universidad Veracruzana, Avenida Luis Castelazo S/N, Col. Industrial Ánimas, Xalapa 91190, Mexico;
- Correspondence: (G.A.C.-A.); (D.M.-R.)
| | - James G. Pfaus
- Instituto de Investigaciones Cerebrales, Universidad Veracruzana, Avenida Luis Castelazo S/N, Col. Industrial Ánimas, Xalapa 91190, Mexico;
- Department of Psychology and Life Sciences, Charles University, 182 00 Prague, Czech Republic
- Czech National Institute of Mental Health, 250 67 Klecany, Czech Republic
| | - Agustín Orihuela
- Facultad de Ciencias Agropecuarias, Universidad Autónoma del Estado de Morelos, Cuernavaca 62209, Mexico;
| | - Adriana Domínguez-Oliva
- Neurophysiology, Behavior and Animal Welfare Assessment, DPAA, Universidad Autónoma Metropolitana (UAM), Unidad Xochimilco, Mexico City 04960, Mexico; (A.D.-O.); (N.J.-P.); (L.A.H.)
| | - Nancy José-Pérez
- Neurophysiology, Behavior and Animal Welfare Assessment, DPAA, Universidad Autónoma Metropolitana (UAM), Unidad Xochimilco, Mexico City 04960, Mexico; (A.D.-O.); (N.J.-P.); (L.A.H.)
| | - Laura Astrid Hernández
- Neurophysiology, Behavior and Animal Welfare Assessment, DPAA, Universidad Autónoma Metropolitana (UAM), Unidad Xochimilco, Mexico City 04960, Mexico; (A.D.-O.); (N.J.-P.); (L.A.H.)
| | - Daniel Mota-Rojas
- Neurophysiology, Behavior and Animal Welfare Assessment, DPAA, Universidad Autónoma Metropolitana (UAM), Unidad Xochimilco, Mexico City 04960, Mexico; (A.D.-O.); (N.J.-P.); (L.A.H.)
- Correspondence: (G.A.C.-A.); (D.M.-R.)
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Serotonin and Tryptophan Serum Concentrations in Shelter Dogs Showing Different Behavioural Responses to a Potentially Stressful Procedure. Vet Sci 2020; 8:vetsci8010001. [PMID: 33374183 PMCID: PMC7824451 DOI: 10.3390/vetsci8010001] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/12/2020] [Revised: 12/16/2020] [Accepted: 12/22/2020] [Indexed: 11/25/2022] Open
Abstract
In mammals, serotonin (5-HT) levels depend on the availability of tryptophan (TRP). Low 5-HT concentrations have been linked to behavioural disorders in dogs. This study aimed at investigating possible differences in dogs’ serum TRP and 5-HT concentrations according to their behavioural response to a potentially stressful procedure. Thirty-nine physically healthy shelter dogs, 15 females and 24 males, mean age = 5.6 years, were categorized by a certified veterinary behaviourist according to their behavioural response to medical examination and blood collection, in: relaxation, stress signals, tension without growling, tension with growling, escape attempts, and aggression attempts. Extraction and quantification of 5-HT and TRP were performed using a HLPC method. Data were statistically analysed, applying Chi-square and Spearman tests. Results showed no significant difference in TRP (χ2 = 2.084, p = 0.555) nor 5-HT (χ2 = 0.972, p = 0.808) serum concentrations among different categories of dogs; however, some categories were underrepresented (relaxation = 20.5%, stress signals = 30.8%, tension without growling = 43.6%, tension with growling = 5.1%, escape attempts = 0%, aggression attempts = 0%). No correlation between serum TRP and 5-HT concentrations was found (ρ = 0.086, p = 0.602). Serum 5-HT levels do not seem to be associated with dogs’ behavioural response to a stressful situation nor with serum TRP concentrations. The relationship between serum TRP and 5-HT concentrations and behaviour needs further research.
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Overall KL. Why we need large population level studies in veterinary behavior and behavioral medicine. J Vet Behav 2020. [DOI: 10.1016/j.jveb.2020.07.010] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/25/2022]
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