Acta Veterinaria Scandinavica最新文献

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.

Background: Pulmonary hypertension (PH) detection in cats may be challenging. Pulmonary venous stenosis (PVS) is rare in cats and can lead to PH. The only reported PVS case received a post-mortem diagnosis. Imaging during the cat's lifetime established the diagnosis in this case.

Case presentation: A 2 year-old Norwegian Forest cat was diagnosed with pulmonary oedema and PH secondary to cor triatriatum sinister (CTS) and showed improved breathing following two subcutaneous furosemide treatments, 1 and 2 mg/kg, during an overnight stay at the referral veterinary hospital. Sildenafil alone (0.69 mg/kg, PO, BID) was prescribed post-discharge to address PH without diuretics. Post-discharge from the referral veterinary hospital, collapse and pre-syncope were suspected to be due to PH. Consequently, sildenafil was titrated weekly, starting at 1.09 mg/kg BID and increasing to 1.63 mg/kg BID. Pre-syncope and collapse resolved, and pulmonary opacities reduced considerably, although concerns remained that increased pulmonary blood flow to suspected CTS from sildenafil might worsen cardiogenic pulmonary oedema. The patient was also treated with rivaroxaban (2.5 mg/head, SID), considering the increased risk of thrombus formation due to blood flow stasis and endothelial damage. Thirty-eight days later, the cat presented for the first time to our hosipital (Azabu University Veterinary Teaching Hospital) for examination. On echocardiography, a continuous mosaic blood flow (maximum and minimum velocity, 3.14 m/s; estimated pressure gradient, 39.4 mmHg) was observed in two enlarged pulmonary veins. Pulmonary artery enlargement (main pulmonary artery to thoracic aorta ratio: 1.90), pulmonary vein stenosis (PVS), and diffuse bilateral ground-glass lung opacities were observed using computed tomography. PH with unilateral PVS involving two out of the three right pulmonary veins, specifically the right cranial and right middle pulmonary veins, along with pulmonary parenchymal disease, was diagnosed. The cat was further treated with furosemide (1 mg/kg, BID, PO) with no clinical signs but succumbed to acute dyspnoea 51 days after the first visit.

Conclusions: Unilateral PVS should be considered in young cats with a localised alveolar pattern and no left atrial enlargement, because the prognosis may be poor. Severe PH with PVS may coexist with lung disease. If sildenafil is used, it should be started at a low dose and monitored closely.

Dystocia affects on average 3-8% of all pregnancies in purebred cats. Nonpedigree cats are also affected, but the incidence is unknown. The causes of dystocia and the optimal treatment are largely unexplored in cats. The aims of the present retrospective study were to describe feline dystocia cases and to evaluate kitten mortality in relation to factors associated with dystocia in cats. Medical records of 111 cases (107 queens) treated for dystocia from 2017 to 2024 were retrieved from client files at the University Animal Hospital in Uppsala, Sweden. At the initiation of treatment, 276 kittens remained in utero or in the birth canal. The total kitten mortality rate, including that of kittens born before treatment but excluding four kittens that were euthanized at the owner's request, was 40.9%. The mortality of kittens born after treatment was 44.1%, excluding four kittens euthanized at the owner's request. Two queens died, one of which was euthanized at the owner's request. Among all the cases, 91 (82.0%) were surgically treated, with caesarean section, or en bloc resection in two patients. Ovariohysterectomy was performed in 47.2% of the queens that were surgically treated. Medical treatment was initiated in 30 patients, and was successful in 11 of them, and 19 were further surgically treated after only partial or no success. The success rate of medical treatment was thus 36.7%. Eight queens were hypocalcaemic. Maternal hyperglycaemia was present in 65.5% of the cases and significantly increased the risk of kitten mortality. The estimated duration of second-stage labour before admission did not affect kitten mortality. Disturbed labour (total or partial uterine inertia) was the most common cause of dystocia. Feline dystocia was associated with high kitten mortality but low mortality in queens. Most queens with dystocia were treated surgically, but medical treatment with calcium and/or oxytocin was efficient in cases with non-obstructive dystocia, and ≤ 3 foetuses remaining. Hypocalcaemia may contribute to dystocia in a minority of cases. Maternal hyperglycaemia increased the risk of mortality before discharge. Diagnosing dystocia may be challenging in cats, as there is no clear association between the length of the parturition process and mortality.

The purpose of ante- and post-mortem inspections at slaughterhouses is to ensure that meat and other relevant food products of animal origin are safe for human consumption. However, these inspections can also be useful for detecting animal health and welfare issues. In cattle, traumatic injuries from on-farm incidents, transport or handling at the slaughterhouse are indications of both reduced animal welfare and increased risk of food waste, ultimately resulting in economic losses for both farmers and slaughterhouses. This observational study aimed to investigate the prevalence and seasonal variation of traumatic injuries in cows and heifers reared on organic and conventional farms in Sweden. The study includes slaughter remarks and condemnations from meat inspection data from 336,071 animals slaughtered between 2020 and 2022. Two types of injuries were analysed: "chronic traumatic injuries" (CTI) sustained on-farm and "acute traumatic injuries" (ATI) sustained during transport or at the slaughterhouse. Logistic regression models were developed to assess the influence of production system and season. Results show a higher prevalence of CTI in animals from conventional farms (9.8%) compared to organic farms (6.9%; P < 0.001), which may indicate that animals from organic farms are managed and handled in a way that makes them better prepared for challenges that they are later exposed to on-farm prior to slaughter. ATI were more frequent in animals from organic farms during the grazing period (interaction between production system and season: P = 0.002), which may indicate that animals from organic farms find the transition to the slaughterhouse environment more abrupt and stressful during the grazing period. Condemnations due to injuries were significantly higher for animals with CTI or ATI compared to animals without these specific remarks. These findings highlight the importance of pre-slaughter management, both on-farm and at the slaughterhouse, and slaughterhouse design in improving animal welfare and reducing food as well as economic losses associated with carcase condemnations.