Acta Veterinaria Scandinavica最新文献

Background: Canine leishmaniosis, caused by Leishmania infantum, is a vector-borne disease. The immune response in infected dogs determines the clinical outcome, with a strong cell-mediated immune response linked to parasite control and mild clinical signs, while a humoral-dominant response is associated with severe disease. Low antibody levels in clinically asymptomatic dogs with negative molecular and/or parasitological test results may reflect prior exposure or the early stages of Leishmania infection. In contrast, elevated antibody levels are typically correlated with a high parasitic burden and active disease. The detection of dogs with clinical leishmaniosis and null-specific immune response against L. infantum is uncommon. However, this presentation has also been described in human leishmaniasis with the absence of humoral response detected by conventional serological methods.

Case presentation: Case 1, a 9-year-old Border Collie, showed splenomegaly and Leishmania amastigotes within splenic macrophages. Case 2, a 10-month-old French Bulldog, had chronic anorexia and malabsorption syndrome with granulomatous splenitis and amastigotes confirmed by immunohistochemistry. Finally, case 3, a 7-year-old cross-breed, presented with cutaneous nodules and nasal ulcerative dermatitis, with Leishmania amastigotes detected histologically and confirmed by immunohistochemistry. All dogs were seronegative by two quantitative serological tests including indirect immunofluorescent test and enzyme-linked immunosorbent assay. The identification of the parasite in the affected organ established a clear cause-and-effect relationship. Consequently, anti-Leishmania treatment was initiated, consisting of allopurinol (10 mg/kg orally twice daily) and meglumine antimoniate (50 mg/kg subcutaneously twice daily for four weeks) in cases 1 and 3. In case 1, a favourable clinical response was noted, with a normal abdominal ultrasound and a negative result by quantitative molecular test from material obtained via ultrasound-guided splenic puncture. In case 3, the administration of meglumine antimoniate resulted in the resolution of dermatological signs. Clinical follow-up and anti-Leishmania treatment could not be performed for case 2.

Conclusions: These findings highlight the diagnostic challenges in detecting clinical leishmaniosis in seronegative dogs. The absence of a specific humoral response should be considered, emphasizing the importance of using multiple diagnostic methods, including cytology, and histopathology with immunohistochemistry. This case series underscores the need for a comprehensive approach in diagnosing and managing canine leishmaniosis.

Bovine Respiratory Disease (BRD) is the main health concern in calf-rearing units. It is a major cause of increased antibiotic use and the leading cause of morbidity and mortality in calves. Vaccination protocols against BRD for calf-rearing units are difficult to implement in practice. The aim of this study was to evaluate the effect of the vaccination protocol including intranasal and subcutaneous vaccinations on mortality, antibiotic treatment rate, and average daily gain (ADG). The vaccination protocol consisted of intranasal BRD vaccination when the calves arrived at the rearing unit at the age of two to four weeks and two subcutaneous BRD vaccinations at two and three months of age. Mortality, antibiotic treatments, and ADG were recorded and evaluated from arrival until six months of age. The batches that arrived at the rearing unit prior to the beginning of the trial were used as the historic control group. Altogether, 740 vaccinated and 914 unvaccinated calves were enrolled to the study. A total of 88 calves (5.3%) died or were euthanized during the study period, of which 29 (32.9%) were vaccinated and 59 (67.1%) unvaccinated. In the logistic mixed model, the vaccination protocol decreased mortality (odds ratio 0.57, P = 0.036). The deaths occurred mostly during the pre-weaning period and only six calves died after weaning. During the study period, 1592 (96.3%) of the calves were treated with antibiotics at least once. In 90% of the courses, respiratory infections were the cause of antibiotic therapy. The mean antibiotic treatment rate for vaccinated calves (2.3 courses/calf, standard deviation [SD] 1.2) was lower than unvaccinated calves (2.4 courses/calf, SD 1.3) (P = 0.003). The average daily weight gain during the entire study period did not differ between the groups (vaccinated calves 1.08 kg/d, SD 0.12; unvaccinated calves 1.09 kg/d, SD 0.13). The vaccination protocol used in this study decreased the odds ratio for mortality but did not affect ADG. The difference in number of antibiotic treatments used for BRD was clinically negligible. A limitation of the study design is the interpretation of the effect of the historical control group which may affect the results through seasonal variation.

Canine ovariectomy is a commonly performed procedure in veterinary practice and can be done via an open celiotomy or a laparoscopic approach. Laparoscopy requires different psychomotor skills from those involved in open surgery. Many of these basic skills can initially be acquired through simulation-based training. Surgical simulation training benefits both the surgeon and the patient by offering the acquisition of new skills in a less stressful environment while lowering the risk for the patient. Virtual reality (VR) simulation training is well established in human medicine, but no VR modules have previously been available for veterinary procedure training for laparoscopy. This project aimed to develop a VR simulator module for canine laparoscopic ovariectomy on the simulator LapSim^® (Surgical Science, Gothenburg, Sweden). The simulator module could offer veterinary surgeons the opportunity to gain the basic technical skills required for canine laparoscopic ovariectomy. Surgeons with experience in laparoscopic ovariectomy acted as content experts, and the development was a stepwise iterative process. The three-port technique was chosen; it included locating and lifting the uterine horn and sealing and transecting tissue to free the ovaries. The organs and tissues the surgeon interacted with during the simulation were the spleen, intestines, pancreas, ovaries, uterine horns, suspensory ligaments, mesometrium and mesovarium. The module included simulating haemorrhage from the spleen, ovarian and uterine vessels. Suggestions for the continued development of the simulation were identified. Examples were an increased haptic feel in some instances of tissue manipulation and the possibility of introducing a variation in the length of the ovarian pedicle. The last step of the simulated procedure included visual guidance for verification of haemostasis. Even though guidance is not part of a real-life operation, identifying anatomical landmarks was considered valuable from an educational perspective. A validity investigation study has been initiated to evaluate the module as an assessment tool.

Background: The COVID-19 pandemic has caused over 776 million confirmed cases and more than 7 million deaths worldwide. In addition to humans, various animal species have exhibited natural infections, with mink being the only farmed animals consistently linked to severe illness and zoonotic transmission to humans. This study investigates histological pulmonary lesions in Danish farm mink infected with severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2), focusing on groups with different clinical signs and outcomes.

Results: Histopathological evaluations revealed lesions in SARS-CoV-2-positive mink with and without clinical signs of disease. The main findings in lungs from SARS-CoV-2-positive mink in all study groups were extensive respiratory epithelial damage, acute diffuse alveolar damage, and vascular lesions, including the formation of thrombi. Additionally, immunohistochemical staining confirmed the presence of viral particles primarily in the respiratory epithelia. Lymphoid cells exhibited nodular and perivascular aggregates similar to bronchus-associated lymphoid tissue in older SARS-CoV-2 infected and uninfected mink, indicating a potential age-related feature of mink lungs.

Conclusions: The presence of subclinical and long-term pulmonary lesions associated with SARS-CoV-2 infections in farm mink suggests that the impact of outbreaks may be more serious than clinical signs records indicate. The current SARS-CoV-2 surveillance system on Danish mink farms does not properly address such problems and repeated outbreaks on farms could occur without detection if there are no clinical signs or increased mortality due to SARS-CoV-2. The severity of subclinical lesions reveals hidden health and welfare challenges in mink, underscoring the need for improved prevention measures, surveillance and understanding of long-term impact of SARS-CoV-2 infection in mink.

The giant panda (Ailuropoda melanoleuca) is a rare and vulnerable species facing threats from bacterial infections. The extensive use of antibiotics in disease prevention has raised concerns about antibiotic resistance, which reduces treatment efficacy and poses environmental and public health risks. This study aims to analyze the resistance profiles of Escherichia coli (E. coli) in captive pandas, providing insights into the antibiotic resistance genes within their gut microbiota. Twenty-two E. coli isolates were obtained from the feces of 22 captive giant pandas, and whole-genome sequencing was conducted. Sequence types and evolutionary relationships were determined through Multi-Locus Sequence Typing (MLST) and core genome Multi-Locus Sequence Typing (cgMLST), while virulence and resistance genes were identified. Core genome SNP analysis was performed to establish genetic relationships, and AST was conducted to evaluate antibiotic resistance profiles. Whole-genome sequencing revealed 15 distinct sequence types (STs), with ST48 (22.7%, 5 isolates) and ST212 (18.2%, 4 isolates) identified as the dominant lineages. Further resolution using cgMLST revealed that ST48 encompassed multiple cgSTs distributed across different evolutionary branches, while all ST212 isolates belonged to a single cgST. These results demonstrate the utility of cgMLST in resolving genetic diversity and isolate relationships within dominant lineages. Core genome SNP-based phylogenetic analysis grouped isolates with similar serotypes and STs, including a pathogenic cluster closely related to a panda-derived E. coli isolate (AMSHJX04). A total of 88 virulence genes (average 52 per isolate) were widespread, including those involved in iron acquisition systems (yagZ/Y), fimbriae-associated genes (fimA/H), and type II secretion systems (gspM/K). Antimicrobial susceptibility testing (AST) showed 59.1% resistance to ciprofloxacin, 18.2% to norfloxacin, and 13.6% to tetracycline, while all isolates remained sensitive to gentamicin and amikacin. Resistance profiling identified 78 resistance genes, primarily efflux pumps (acrB/D, emrA/B) and tetracycline-related mutations (emrK/Y). The gut microbiota of captive giant pandas harbors multiple antibiotic resistance genes, indicating a risk of resistance gene spread. Diverse sequence types, virulence genes, and phylogenetic relationships reveal the genetic complexity of E. coli in this species. Some isolates showed genetic similarities to pathogenic E. coli, emphasizing the need for continuous bacterial monitoring. This threatens antibiotic efficacy, increases infection risks, and complicates health management, underscoring the urgency of addressing resistance in panda conservation.

Background: This report describes a case of extraskeletal osteosarcoma in the proximal urethra of a male neutered cat, highlighting the associated clinical challenges.

Case presentation: A 9-year-old male neutered domestic shorthair cat presented to the referring veterinarian with symptoms of stranguria, dysuria, and haematuria. Following abdominal radiographs, the cat was referred to a specialty centre for abdominal ultrasound and surgical intervention. During an exploratory laparotomy aimed at removing a suspected urolith, it became clear that the removal was not feasible, leading to the decision to euthanize the cat while still under anaesthesia. Histopathological examination of the urinary bladder and urethra confirmed the presence of an osteosarcoma in the urethra.

Conclusions: While extraskeletal osteosarcoma has been documented in cats, there are no known reports specifically detailing osteosarcomas of the urethra and bladder in this species. When cats present with stranguria and dysuria, and the diagnosis is not evidently an urolith, osteosarcoma should be considered among the differential diagnoses. Further diagnostic imaging, such as a CT scan, may be warranted to ensure accurate diagnosis and appropriate management.

Background: A lumbosacral transitional vertebra (LTV) is a congenital anomaly with reported prevalences ranging from 0 to 67% in different dog breeds, implying possible genetic differences. LTV has been associated with canine hip dysplasia (CHD) and degenerative lumbosacral stenosis (DLSS). Genetic parameters, including heritability estimates, are important for understanding the genetic influence on specific traits and for evaluating the effectiveness of possible genetic selection in reducing the prevalence of disorders. This study aimed to determine the heritability of LTV in nine dog breeds in Norway and estimate the genetic correlation with CHD.

Results: The heritability estimates for LTV across the nine breeds ranged from low to moderate (0.056-0.314), while the heritability estimates for CHD were moderate to high (0.254-0.580). The estimates of genetic correlations between the two traits were mostly non-significant and varied strongly among breeds in size and direction.

Conclusions: This study indicated that genetic factors influence LTV in several breeds and that there is a potential to reduce the prevalence by genetic selection, even if the heritability estimates of LTV ranged from low to moderate. The heritability estimates of CHD were within the range reported earlier, ranging from moderate to high. There was no general indication of a genetic correlation between LTV and CHD across breeds.

Background: The preservation of epididymal spermatozoa is useful for saving important genetic material from valuable individuals who die suddenly or have to be castrated. The birth of puppies after artificial insemination with canine epididymal spermatozoa has been reported in only a few cases. Surgical insemination with frozen-thawed epididymal spermatozoa has resulted in pregnancies, but usually with low conception rates. Freshly collected and chilled epididymal canine semen has also resulted in conception after vaginal insemination. Considering the invasiveness of surgical insemination and the almost unlimited storage time of cryopreserved spermatozoa, transcervical intrauterine insemination with frozen-thawed epididymal spermatozoa would be beneficial. It has the potential to use genetic material that would otherwise be lost, both in domestic dogs and for the preservation of wild threatened canids.

Case presentation: A 7-year-old, 20 kg male hunting dog was injured by a wild boar during hunting, and euthanasia was recommended for welfare reasons. Because the dog was a hunting champion in a numerically very small breed, the owner wanted to have spermatozoa preserved for future breeding. The dog was anaesthetised, both testes were removed, and the dog was thereafter euthanized. Spermatozoa from both caudae epididymides were released in a prewarmed Uppsala extender with the mincing method. The samples were routinely frozen with the Uppsala method. A half-filled straw was used for test thawing, resulting in 20% motile spermatozoa with slow progressive movement. Three years later, a 23-month-old bitch of the same breed was inseminated with endoscopically guided transcervical intrauterine sperm deposition. She was inseminated once, five days after a serum progesterone value of 6.9 nmol/mL was reached, and two days after a value of 24.8 nmol/mL was reached. The total amount of cryopreserved spermatozoa was used (a total dose of 1087 × 10⁶ spermatozoa and 217 × 10⁶ progressively motile spermatozoa remaining after test thawing). Eight puppies were born 59 days after insemination.

Conclusions: Although rarely reported, artificial insemination with cryopreserved epididymal canine spermatozoa is an alternative in preserving valuable genetic animals when a male is injured beyond recovery.

Background: There are multiple infectious agents of cats around the world; those transmitted by direct contact among cats, hunting, or exposure to fleas or ticks are frequently the most common. Some infectious disease agents have been reported in cats in Sweden; for example, Anaplasma phagocytophilum infection was first reported in a cat in this country. However, there has not been a study in Sweden that reported test results for agents with different transmission cycles in cats with and without signs of clinical disease. Thus, the aims of this study were to (i) investigate prevalence of exposure to Anaplasma species, Bartonella species, Ehrlichia species, haemotropic Mycoplasma species, feline foamy virus (FFV), Felis catus gammaherpesvirus (FcaGHV1), feline immunodeficiency virus (FIV), feline leukemia virus (FeLV) and Toxoplasma gondii in cats residing in the Southern part of Sweden (ii) compare prevalence in samples between 3 groups of cats (cats with fever and/or anemia, cats without any signs of infectious disease, and cats that were either stray cats or stable cats).

Results: Overall, antibodies were detected against FcaGHV1 (67%, CI 57-76%), FFV (45%, CI 35-55%), Bartonella species (43%, CI 34-54%), T. gondii (37%. CI 28-47%), and FIV (3.3%, CI 1.1-9.2%). FeLV antigen was detected in one cat (1.1%, CI 0.19-5.9%). Haemotropic Mycoplasma DNA was amplified in seven cats (7.6%, CI 3.7-15%). All five samples with successful sequencing were 'Candidatus M. haemominutum'. The one cat (1.1%, CI 0.19-5.9%) that was positive for B. henselae DNA also had a Bartonella spp. titer of 1:1024. Anaplasma and Ehrlichia spp. DNA were not amplified from any cat.

Conclusions: The antibody test results suggest that many of these cats were exposed to other cats (FFV, FcaGHV1, FIV, FeLV), had inadequate flea control (Bartonella spp.), and were fed undercooked meat or allowed to hunt (T. gondii). While infection was common, the only haemotropic Mycoplasma amplified from these cats was the relatively non-pathogenic 'Candidatus M. haemominutum'. As previously documented for each of these agents, the presence of a positive test result or infection by one or more organisms is not always associated with illness.

Background: Actinobacillus pleuropneumoniae (APP) is a Gram-negative bacterium that causes respiratory disease in pigs, resulting in significant economic losses and reduced animal welfare. In Sweden, the drug of choice for treatment of APP infections is benzylpenicillin. However, limited pharmacokinetic and pharmacodynamic data for benzylpenicillin in pigs have led to variations in recommended dosing regimens. In this study, the impact of different dosing regimens and benzylpenicillin preparations on the progression of APP infection in pigs was investigated. Two experimental trials involving a total of 66 pigs were conducted. Pigs were intranasally inoculated with a pathogenic strain of APP serotype 2, and treatment was initiated upon the appearance of clinical signs. Two intramuscularly administered benzylpenicillin formulations, an aqueous and an oil-based suspension, were used with varying dosing regimens. The clinical outcome was assessed based on respiratory signs and rectal temperature measurements. Blood samples were collected for measuring white blood cell counts, serum antibody levels, and acute-phase protein concentrations. Necropsies were performed to evaluate lung lesions and to reisolate APP.

Results: The results indicated that benzylpenicillin dosing regimens of 20-30 mg/kg administered every 12 h achieved larger benzylpenicillin plasma-exposure compared to the labelled dose of 10-30 mg/kg every 24 h. The oil-based suspension demonstrated superior efficacy compared to the aqueous suspension. Dosing regimens that maintain effective plasma concentrations of benzylpenicillin were shown to have better clinical outcomes as measured by reduced lung lesions at necropsy. Increased benzylpenicillin exposure was associated with a better ranking of overall treatment response.

Conclusions: Several dosing regimens that increased the plasma benzylpenicillin exposure were associated with better clinical success than the labelled doses. The findings support the treatment of APP-infected pigs with optimised benzylpenicillin dosing regimens. Optimising the use of existing antibiotics is crucial given the limited development of new antimicrobial agents and the need to combat antimicrobial resistance with regards to both human and animal health.