Relationships between psychological characteristics, academic fit and engagement with academic performance in veterinary medical students.

BACKGROUND: Recognition of the factors that influence academic performance in university students constitutes one of the key objectives of education researchers. Few studies have been conducted in this sphere in relation to veterinary students; however, considering the high levels of depression, anxiety symptoms, and decreased life satisfaction revealed in recent literature for this demographic, understanding these factors is of great importance. Moreover, the literature on veterinary education has mostly focused on cognitive factors as antecedents to academic performance, while very little attention has been directed toward personal characteristics. METHODS: The present cross-sectional study aims to investigate the relationships between psychological characteristics (internal locus of control and self-efficacy), academic fit, well-being (engagement and exhaustion), and academic performance (average grade) among veterinary students. The study was conducted in the Department of Veterinary Sciences at the University of Turin between September 2021 and January 2022 involving 231 students. RESULTS: The results of the Structural Equation Model confirmed a positive relationship between both internal locus of control and self-efficacy and academic fit, which in turn showed a positive relationship with engagement and a negative relationship with exhaustion. Finally, a significant positive relationship between engagement and academic performance was highlighted. Indirect effects were also significant, confirming the mediating role of academic fit and engagement. CONCLUSIONS: The study contributes to the literature by demonstrating the direct and indirect relationships among the variables selected in a sample group of veterinary students. These findings provide information for practical interventions that could support the academic experience and prospects of veterinary students by improving their psychological parameters and well-being.

Concomitant Campylobacteriosis in a Puppy and in Its Caregiver: A One Health Perspective Paradigm in Human-Pet Relationship.

We report a case of laboratory-confirmed Campylobacter (C). jejuni and C. upsaliensis symptomatic infection in a puppy, a French Bouledogue, female, 6 months of age, fed a raw, unbalanced, poultry-based diet (RPD), (48.1 CP, 33% EE, 0.3% Ca, 0.5% Phos, 0.5 Ca/P, on a dry-matter basis), and in its owner. Soon after adoption, the pet and the caregiver showed severe gastrointestinal signs and needed hospitalization. Fecal PCR assays, selective cultures, and antibiotic susceptibility testing were performed, and multi-drug resistant C. jejuni and C. upsaliensis were isolated from the feces of both. The same bacteria were also identified by FISH in the dog colonic biopsies collected during endoscopy. The puppy was prescribed a complete commercial diet for growing dogs, (30.00% CP, 21.00% EE, 1.2% Ca; 1% Phos; as fed) and treated with ciprofloxacin. The dog and the man healed uneventfully and tested negative for further fecal PCR analyses. This report focuses on dog nutritional management and explores the potential routes of exposure, with emphasis on emerging outbreaks related to current pet food fads. Our data support the One Health approach, where veterinarians, physicians, and owners are challenged to build effective stewardship to prevent the spread of zoonoses.

Dog Owners' Attitude toward Veterinary Antibiotic Use and Antibiotic Resistance with a Focus on Canine Diarrhea Management.

An ad hoc questionnaire was designed in order to investigate AMR knowledge amongst Italian dog owners, owner expectations concerning pharmacological treatment of canine AD, and client attitudes towards and compliance with alternative strategies to antimicrobial administration. A total of 250 questionnaires were returned. Most of respondents were female, aged 36-70 and workers. More than a half of participants owned one dog with mixed breed, with Labrador retriever, golden retriever, dachshund, and border collie being the most represented breeds. On average, each dog was treated with an oral antibiotic 1.044 times per year. Intestinal diseases were among the main reasons (19%) for antibiotic prescription. Oral antibiotic courses without veterinary consultation (21%) and anticipated termination of the therapy (17.1%) were less common than reported elsewhere. The majority of respondents knew the meaning of AMR with a significant inverse association between the level of education and the tendency to administer antimicrobials without consulting a clinician (p = 0.004). Most of the owners expected a rapid recovery of clinical signs after a first episode of AD and accepted natural dietary supplementation for treating the condition. Ninety-five percent of the respondents believed that public funding should be spent to study AMR. Even though an acceptable degree of AMR awareness emerged, we feel that further efforts should be made to increase public AMR knowledge and to stimulate proactive measures to fight the phenomenon. On the other hand, the development of guidelines for the treatment of uncomplicated canine AD would help clinicians to rationalize antimicrobial use.

Changes in the Oxidative Stress Status of Dogs Affected by Acute Enteropathies.

Canine acute enteropathies (AE) are common morbidities primarily managed with supportive therapy. However, in some cases, unnecessary courses of antibiotics are empirically prescribed. Recent studies in humans have hypothesized the use of antioxidants as a possible alternative and/or support to antimicrobial drugs in uncomplicated cases. Considering the global need to reduce the antibiotic use, the aim of the study was to compare the oxidative burden of the diarrhetic population to that of healthy dogs. Forty-five patients suffering from uncomplicated acute diarrhea (AD) and 30 controls were screened for clinical and biochemical parameters, and serum redox indices (reactive oxygen metabolites, dROMs; serum antioxidant capacity, SAC; oxidative stress index, OSi). The average levels of dROMs in AD dogs were significantly higher (p < 0.001) than in healthy dogs, while SAC did not significantly differ between the two groups. However, the OSi values (ratio between dROMs and SAC) significantly increased (p < 0.001) in AD dogs compared to controls. The study demonstrates that canine AD could induce redox imbalance. Although its role in the etiopathogenesis and evolution of the disease should be further investigated, our results suggest that the improvement of the patient oxidative status, possibly through the dietary administration of antioxidants, could support the management of canine AE, reducing the use of antibiotics.

Ivermectin Plasma Concentration in Iberian Ibex (Capra pyrenaica) Following Oral Administration: A Pilot Study.

Sarcoptic mange is considered the main driver of demographic declines occurred in the last decades in Iberian ibex (Capra pyrenaica) populations. Mass treatment campaigns by administration of in-feed acaricides are used as a measure to mitigate the impact of mange in the affected populations. However, there are no data on ivermectin (IVM) pharmacokinetics in this wild caprine, and the treatment through medicated feed is not endorsed by evidence on its effectiveness. The aim of this study is to determine the pharmacokinetic profile of IVM in plasma samples of ibexes after the experimental oral administration of IVM, using high performance liquid chromatography (HPLC) with automated solid phase extraction and fluorescence detection. A dose of 500 µg of IVM per body weight was orally administered in a feed bolus to nine healthy adult ibexes (seven males and two females). Blood samples were collected by jugular venipuncture into heparin-coated tubes at day 1, 2, 3, 4, 7, 10, 15, and 45 post-administration (dpa). The highest plasma concentration of IVM (Cmax = 3.4 ng/ml) was detected 24 h after the oral administration (T1), followed by a rapid decrease during the first week post-administration. Our results reveal that plasma IVM concentration drops drastically within 5 days of ingestion, questioning the effectiveness of a single in-feed dose of this drug to control sarcoptic mange. To the best of our knowledge, this is the first study on plasma availability of oral IVM in ibexes and in any wild ungulate species.

Effects of Compost-Bedded Pack Barn on Circulating Cortisol and Beta-Endorphins in Dairy Cows: A Case Study.

The up-to-date literature suggests that the compost-bedded pack barn housing system is capable of remarkably improving productive and reproductive performance, as well as health status and welfare, in dairy cattle. However, there is currently limited knowledge available on the endocrine and biochemical changes in animals housed in such alternative systems. Therefore, this study aimed to measure blood cortisol (COR) and beta-endorphins (BE) in 22 two-year-old primiparae Fleckvieh cows, who were randomly allotted to the following two different housing systems: CB (n = 11) and FB (n = 11). Blood samples were collected at the beginning of the experiment (T0) and every two months thereafter (T1, T2, and T3). The COR and BE were measured through an immunoenzymatic kit. With the only exception being T0, no differences were observed over time between the two groups, neither for COR nor for BE. However, the blood cortisol levels of the CB cows decreased over time, while a T1 peak was identified in the FB group. On the contrary, both the housing systems displayed numerically higher BE at T3 than at the other experimental times. Therefore, the overall data suggest that the compost-bedded pack barn did not significantly affect the studied parameters. Accordingly, cow welfare should be assessed using a wider panel of animal-based indicators.

Management of Feline Hyperthyroidism and the Need to Prevent Oxidative Stress: What Can We Learn from Human Research?

Feline hyperthyroidism is a clinical syndrome related to an excessive production of thyroid hormones, and it is considered as a spontaneous animal model for human thyrotoxicosis. Many shared features between the feline and the human disease have been identified so far, including pathogenesis, clinical signs, and treatment options. Although methimazole is considered the first-choice drug in both species, several side effects have been described. Furthermore, methimazole could interfere with the oxidative status, already perturbated by the disease. It has been reported in humans that dietary management, mainly through antioxidant supplementation, could mitigate this oxidative burden. The purpose of the review is to describe current therapeutic options in the course of feline hyperthyroidism and to summarize the state of the art relationship between dietary antioxidants administration and the reduction of methimazole side-effects in humans to support the use of this approach also in cats.

In Vivo Evaluation of a Pectin-Honey Hydrogel Coating on Polypropylene Mesh in a Rat Model of Acute Hernia.

Investigations about ventral hernia repair are focused on improving the quality, resistance, and biocompatibility of mesh. This study compared plain polypropylene mesh with a pectin-honey hydrogel-coated polypropylene mesh in an acute hernia model in rats. Forty Wistar rats, randomly assigned to two groups, were submitted to laparotomy, and a 1 cm × 2 cm fascial defect was created, centered on the midline. Uncoated (group C) or coated mesh (group T) was inserted in an inlay fashion to repair the defect. After 30 days, the rats were euthanized, and the presence of adhesions to the mesh was macroscopically evaluated. Histology and measurement of COX-2 as tissue inflammation markers were used to assess fascia tissue healing. Grades of adhesion were not different between groups. Histological score and COX-2 expression were not significantly different between groups, except for the higher inflammatory response demonstrated in group T. The pectin-hydrogel coated mesh could not reduce adhesion formation compared to uncoated polypropylene mesh but improved peritoneal regeneration and tissue healing.

Equine-Assisted Interventions (EAIs) for Children with Autism Spectrum Disorders (ASD): Behavioural and Physiological Indices of Stress in Domestic Horses (Equus caballus) during Riding Sessions.

Equine-assisted interventions (EAIs) are well-known complementary practices combining physical activity with emotional/cognitive stimulation. They are especially suited for children with autism spectrum disorders (ASD) who need a high degree of physical and psychological enrichment. Even though EAIs have become a common practice, stress responses in horses interacting with individuals that can manifest inappropriate behaviours, such as ASD children, have not been thoroughly investigated. Our multicentre study aimed to investigate behavioural and physiological indices of stress in horses involved in EAI standardised sessions with children with ASD compared to typically developing (TD) children. A controlled within-subject design with repeated measurements involving 19 horses and 38 children was adopted. Stress-related behaviours, heart rate, heart rate variability, and eye temperature were recorded during the riding sessions. Moreover, blood samples were collected from horses before and after each session to monitor changes in blood adrenocorticotropic hormone (ACTH), cortisol, and catecholamines. Results indicate that, in general, stress responses in horses involved in EAIs did not differ as a function of the horse being ridden by children with ASD or TD. A lower sympathetic tone in horses involved in ASD sessions was found, while in the mounting and dismounting phases, horses displayed behavioural signs of stress, independently from children's behaviour. We conclude that professionals working in EAI should increase their awareness of animal welfare and refine riding practices, taking into account horse's needs.

Acute Diarrhea in Dogs: Current Management and Potential Role of Dietary Polyphenols Supplementation.

Acute diarrhea is one of the most common reasons why pet owners seek veterinary care for their canine companions. In many cases, signs resolve spontaneously or with symptomatic therapy without a specific cause being discovered. However, life-threatening cases can occur. The etiology is complex, including infectious diseases (endoparasites, virus, bacteria, protozoa, fungal agents) by both zoonotic and non-zoonotic pathogens, dietary indiscretion, endocrine diseases, and stress (e.g., travel or environmental changes). In the last years, the role played by oxidative stress in the pathogenesis of acute and chronic enteropathies, independently from the initial noxa, has been highlighted by many researches in both humans and animals. As a result, a series of dietary antioxidant compounds have been studied for their potential use in the treatment of intestinal inflammation. This review summarizes the traditional therapeutic and nutritional options to manage canine acute diarrhea, highlighting the need to explore the role of oxidative stress and potential antioxidant supplementation, especially polyphenols, during acute diarrheic episodes.

Behavioral Therapy and Fluoxetine Treatment in Aggressive Dogs: A Case Study.

Canine aggression is a major concern, affecting millions of people worldwide, and treatment can be challenging even for skilled veterinarians. Empiric use of fluoxetine is sometimes attempted, although few data regarding long-term effects in aggressive dogs are available. The aim of the study was to investigate clinical effectiveness of fluoxetine (1.5 mg/kg/die PO) combined with a behavior modification program for treatment of canine dominance-related aggression. Circulating levels of fluoxetine, norfluoxetine, and serotonin (5-HT) were also measured. Eight dogs with a diagnosis of dominance aggression (owner-directed) were enrolled. Before treatment (T0), and after one (T1), two (T2), four (T3), and six (T4) months of fluoxetine administration, clinical outcomes were graded using a five-point frequency scale (0-4), and blood samples were collected to measure fluoxetine/norfluoxetine (high-performance liquid chromatography) and 5-HT (ELISA) levels. Following treatment, a decrease in behavioral test scores was observed at T1-T4. Increasing concentrations of circulating fluoxetine and norfluoxetine were measured throughout the follow-up. Correlation between norfluoxetine levels and clinical scores was observed at T4. Starting from T1, a significant decrease in 5-HT levels was observed. Our data suggest that fluoxetine (1.5 mg/kg/day) when associated with behavior treatment is effective in controlling canine aggression over a six-month period, and that, in dogs norfluoxetine levels seem reliable in predicting clinical efficacy.

Open-label clinical trial of rectally administered levetiracetam as supplemental treatment in dogs with cluster seizures.

BACKGROUND: Treatment options for at-home management of cluster seizures (CS) and status epilepticus (SE) are limited. The pharmacokinetics of levetiracetam (LEV) after rectal administration in both healthy and epileptic dogs has been investigated recently. HYPOTHESIS/OBJECTIVES: To investigate the clinical efficacy of rectally administered LEV in preventing additional seizures in dogs presented for CS and SE. We hypothesized that rectal administration of LEV in addition to a standard treatment protocol would provide better control of seizure activity as compared with the standard treatment protocol alone. ANIMALS: Fifty-seven client-owned dogs with CS or SE. METHODS: Prospective open-label clinical trial. Patients included in the study were assigned to receive either a standard treatment protocol comprising IV/rectal diazepam and IV phenobarbital q8h (control group) or a standard treatment protocol in association with a single dose of 40 mg/kg LEV rectally (rectal LEV group). Dogs that experienced no additional seizures were defined as responders, whereas those that showed additional seizure activity were classified as nonresponders. RESULTS: Twenty-one dogs were assigned to the rectal LEV group, and 36 to control group. Given the small number of cases of SE, statistical analysis was performed only on patients with CS. The response rate was 94% in the rectal LEV group and 48% in the control group (P < .001). CONCLUSIONS AND CLINICAL IMPORTANCE: Rectally administered LEV combined with a standard treatment protocol provided good control of seizure activity in patients with CS. The validity of these results should be confirmed in a double-blinded, placebo-controlled clinical trial.

Pharmacokinetics of rectal levetiracetam as add-on treatment in dogs affected by cluster seizures or status epilepticus.

BACKGROUND: Levetiracetam can be used for seizure control alone or in combination with other antiepileptic medications. A previous study achieved the minimum targeted serum drug concentration after rectal administration of levetiracetam in healthy dogs. The purpose of the present study was to determine the pharmacokinetics of rectal LEV in dogs presented for cluster seizures or status epilepticus and potentially in treatment with other anti-epileptic drugs. Furthermore, preliminary information on response to this treatment as add-on to the standard treatment protocol is reported. RESULTS: Eight client-owned dogs were enrolled. Plasma levetiracetam concentrations (measured at 0, 30, 60, 90, 120, 180, 240, 360, 720, and 1440 min after drug administration) reached the minimum target concentration (5 µg/ml) at 30 min in all but one patient. At T1 (30 min) the mean concentration was 28.2 ± 15.5 µg/ml. Plasma concentrations remained above the targeted minimum concentration in all patients until 240 min and in 7/8 until 360 min. Six out of eight patients experienced no seizures in the 24-h period after hospitalization and were classified as "responders". CONCLUSIONS: Minimum plasma levetiracetam concentration can be reached after rectal administration of 40 mg/kg in dogs affected by cluster seizures and status epilepticus and concurrently receiving other antiepileptic drugs. These preliminary results may encourage the evaluation of rectal levetiracetam as an additional treatment option for cluster seizures and status epilepticus in a larger number of dogs.

Pectin-honey hydrogel: Characterization, antimicrobial activity and biocompatibility.

BACKGROUND: Novel pectin-honey hydrogels have been developed and characterized as medical device. Ideally, a wound dressing should maintain optimal fluid affinity, permit moisture evaporation, protect the wound from microbes, and have shape-conformability, biocompatibility, and antibacterial activity. OBJECTIVE: A novel, simple and fast method to produce pectin-honey wound dressings is described. METHODS: The properties of these pectin-honey hydrogels were investigated, including swelling ability, water vapour transmission rate, hydrogen peroxide production, methylglyoxal content and antibacterial activity. Biocompatibility was assessed by proliferation assays using cultured fibroblast cells and by in vivo study with subcutaneous and intraperitoneal implantation in rats. RESULTS: Hydrogel showed a good water vapour transmission rate, fluid uptake and were not cytotoxic for fibroblasts. The hydrogel demonstrated good antibacterial activity toward clinically relevant pathogens, including S. aureus and E. coli. Biocompatibility was confirmed by the measurement of plasma levels of interleukin (IL)1 beta, IL-6, tumour necrosis factor (TNF) alpha, and prostaglandin (PG)E2. No histological changes were observed. CONCLUSIONS: The presence of a natural active component, conformability, and complete resorbability are the main characteristics of this new biocompatible biomaterial that is well tolerated by the body, possibly improves healing, may be used for surgical complications prevention, with a simple and inexpensive production process.

Equine Assisted Interventions (EAIs): Methodological Considerations for Stress Assessment in Horses.

Equine assisted interventions (EAIs) are recently facing an increasing popularity, and are characterized by a wide diversity of practices. However, information on the welfare of animals involved in this kind of activity is often lacking. Horses are highly susceptible to work stressors related to physical constraints and/or to the need to control emotions while interacting with humans. Considerations of the emotional state of horses involved in EAIs have multiple valences: for the safety of humans and animals involved, for the quality and efficacy of interventions, as well as for ethical reasons. The aim of this unsystematic narrative review is to summarize the different approaches used for the evaluation of horses' stress responses, investigate their application in the context of EAIs, and discuss some methodological considerations for researchers and practitioners involved in EAI. The sources of information are mostly based on electronic databases (i.e., Medline, Scopus and Google scholar), as well as on hand searches of the references of retrieved literature, and discussions with experts in the field. At present, a few studies have investigated horses' stress responses during EAIs, and further studies are recommended, with the final aim to derive a reliable multidimensional method for assessing a horse's reaction during therapeutic programs, ultimately helping professionals to better develop interventions by taking into consideration the animal's perspective.

A pectin-honey hydrogel prevents postoperative intraperitoneal adhesions in a rat model.

BACKGROUND: Adhesions are a common postoperative surgical complication. Liquid honey has been used intraperitoneally to reduce the incidence of these adhesions. However, solid barriers are considered more effective than liquids in decreasing postoperative intra-abdominal adhesion formation; therefore, a new pectin-honey hydrogel (PHH) was produced and its effectiveness was evaluated in a rat cecal abrasion model. Standardized cecal/peritoneal abrasion was performed through laparotomy in 48 adult Sprague-Dawley rats to induce peritoneal adhesion formation. Rats were randomly assigned to a control (C) and treatment (T) group. In group T, PHHs were placed between the injured peritoneum and cecum. Animals were euthanized on day 15 after surgery. Adhesions were evaluated macroscopically and adhesion scores were recorded and compared between the two groups. Inflammation, fibrosis, and neovascularization were histologically graded and compared between the groups. RESULTS: In group C, 17 of 24 (70.8%) animals developed adhesions between the cecum and peritoneum, while in group T only 5 of 24 (20.8%) did (p = 0.0012). In group C, one rat had an adhesion score of 3, sixteen had scores of 2, and seven rats had scores of 0. In group T, four rats had adhesion scores of 2, one rat had an adhesion score of 1 and nineteen have score 0 (p = 0.0003). Significantly lower grades of inflammation, fibrosis, and neovascularization were seen in group T (p = 0.006, p = 0.001, p = 0.002, respectively). CONCLUSION: PHH is a novel absorbable barrier that is effective in preventing intra-abdominal adhesions in a cecal abrasion model in rats.

Genetic and phenotypic characterisation of Escherichia coli producing cefotaximase-type extended-spectrum ß-lactamases: first evidence of the ST131 clone in cats with urinary infections in Italy.

The incidence of cefotaximase (CTX-M)-type extended-spectrum ß-lactamase (ESBL)-producing Escherichia coli has increased dramatically in humans and animals since the middle of the last century. E coli that produce CTX-M ß-lactamase represent a major cause of urinary tract infections, and pose a significant therapeutic challenge to both human and veterinary medicine. As data on uropathogenic CTX-M-producing strains in cats are limited, the aim of this study was to describe the genetic character and antibiotic resistance phenotypes of CTX-M-producing E coli isolated from cats with cystitis. Seven of 15 E coli bacteria isolated from 138 urine samples had the CTX-M gene and were therefore included in this study. These isolates were screened by polymerase chain reaction for the presence of 14 extra-intestinal virulence factors, class 1 and class 2 integrons, and to identify their phylogenetic groups. Multi-locus sequence typing (MLST) of the strains and susceptibility testing (disc diffusion method) were also performed. Virulence factor iutA was the most frequent determinant identified (86.7%), and the majority of CTX-M-producing strains (n = 5) carried class 1 integrons. MLST allowed us to discriminate four known sequence types (ST131, ST555, ST602, ST155) and three novel sequence types (ST3847, ST3848, ST4181). To the best of our knowledge, this is the first study to report uropathogenic CTX-M-producing E coli ST131 in cats in Italy. Accurate diagnostics and prudent use of antimicrobials are recommended to avoid the spread of multidrug-resistant pathogens in veterinary medicine and to prevent their transmission to humans.

Effects of housing and short-term transportation on hormone and lymphocyte receptor concentrations in beef cattle.

The experiment was designed to evaluate the effects of housing system and short-term transportation on the pituitary and adrenal response and on blood progesterone concentrations of beef cattle. Since the use of steroid hormones in farm animals has been banned in the EU (Council Directive 96/22/EC), it seems important to study the possible modifications in serum progesterone concentrations induced by stress in cattle. Thirty-two, 6 months old male Piedmontese beef cattle (16 reared in a littered loose house, Group A, and 16 housed in a littered tying stall barn, Group B) were blood sampled at T1 (6 months old), T2 (12 months old), T3 (18 months old, before transportation to the slaughterhouse) and T4 (after transportation to the slaughterhouse) in order to measure hormonal concentrations and lymphocyte glucocorticoid (GR) and ß-adrenergic (ß-AR) receptor concentrations. Circulating hormone concentrations were measured using commercial radioimmunoassay kits, whereas lymphocyte receptor density was determined through binding assays. In beef cattle housed in tie stall barn a significant increase in serum cortisol concentration was observed at T3, whereas there was no effect of the housing system on blood progesterone concentrations. Short-term transportation caused a significant increase in blood cortisol and catecholamine concentrations in both groups, whereas lymphocyte GR and ß-AR significantly decreased in Group A. Our data confirm the activation of the hypothalamic-pituitary-adrenal axis and the catecholaminergic system in short-term transportation and suggest that the stress-induced increase in circulating progesterone concentrations does not exceed the limit established by pending legislation.

Regulation of tissue beta-adrenergic, glucocorticoid and androgen receptors induced by repeated exposure to growth promoters in male veal calves.

Biochemical modifications induced by a combination of anabolic compounds in target organs of male veal calves have been evaluated. Six male Friesian crossbred calves were treated with of 17beta-estradiol, dexamethasone sodium phosphate and clenbuterol or served as controls. beta-Adrenoceptors (beta-ARs) were measured in myocardium, lung, spleen, cerebral cortex, hippocampus, thalamus, hypothalamus, and hypophysis, glucocorticoid receptors (GRs) in the spleen and androgen receptors (AnRs) in the testis, by binding assay. A significant decrease in beta-ARs was observed in all tissue samples from treated animals. In the spleen the two GR subtypes found, low (LA) and high (HA) affinity GRs, were down-regulated by the treatment. A significant (P<0.05) decrease of testis weight and a significant (P<0.05) up-regulation of AnRs was also observed. Our data demonstrate that long-term treatment with anabolic compounds markedly affects receptor concentrations in target organs of male veal calves. Thus, studies investigating biological assays as screening methods to detect such compounds should be encouraged.

Modifications of serotonergic and adrenergic receptor concentrations in the brain of aggressive Canis familiaris.

The aim of the study was to measure beta-adrenergic (beta-AR) and serotonergic (5-HTR) receptor concentrations in different brain areas (frontal cortex, hippocampus, hypothalamus and thalamus) of normal and aggressive dogs. Eight adult male dogs, 4.2+/-0.6 years old, showing no clinical signs but aggression, were used for the study. Eight healthy male dogs, 4.4+/-0.8 years old, with no history of neurological and/or behavioural disorders and accidental death, were used as controls. The whole frontal cortex, hippocampus, thalamus and hypothalamus were collected after euthanasia and plasma membrane fractions obtained by ultracentrifugation. beta-AR and 5-HTR were measured by binding assays using specific radioligand [(-)[3H]CGP 12177 and 5-hydroxy[3H]-tryptamine trifluoroacetate, respectively]. A significant decrease in beta-AR levels was observed in the frontal cortex (P=0.001), hippocampus (P<0.0001), and thalamus (P<0.0001) of aggressive dogs compared to controls. As far as 5-HTR are concerned, two receptor subtypes were detected. The two subtypes were classified as low-affinity (5-HTR LA) and high-affinity (5-HTR HA) serotonergic receptors for [3H]-hydroxytryptamine, on the basis of their affinity for [3H]-hydroxytryptamine. 5-HTR LA significantly increased in the whole central nervous system (CNS) area of aggressive dogs (frontal cortex P=0.071; hippocampus P=0.0013; thalamus P<0.0001; hypothalamus P=0.0004); 5-HTR HA significantly increased only in the thalamus (P=0.0005) and hypothalamus (P=0.0002). Results suggest the possible role played by the catecholaminergic and serotonergic systems in canine aggressive behaviour. The understanding of the biological basis of canine aggression may enable the development of pharmacological treatments that would target specific neurotransmitter systems.