Antti Sukura

Toxocara cati is a common intestinal parasite of cats globally. On the mucous membranes, the host’s immune system defends itself against invading pathogens, such as parasites, with immunoglobulin A (IgA) among other mechanisms. The precise role of IgA in T. cati infections is not yet understood. We determined the total IgA levels from serum ( n = 8) and feces ( n = 10) of T. cati -infected cats before and after anthelmintic treatment with a commercial ELISA. These results were compared with IgA levels of nonparasitic cats (serum n = 8, feces n = 6). We also visualized the binding of feline IgA to adult T. cati worms with immunohistochemistry and analyzed the IgA-reactive antigens with Western blot. Five antigenic bands were further analyzed with mass spectrometry. We found no consistency between total IgA levels in serum or feces and T. cati infection. In immunohistochemistry, the intestines, reproductive tracts, excretory canals, and muscle cell bodies of T. cati were the most immunoreactive parts when processed with either Toxocara -positive cat sera or pathogen-free cat serum. When comparing T. cati -infected and pathogen-free cat serum as IgA source in Western blot, most bands showed nonspecific IgA immunoreactivity independent of the host’s Toxocara status. In mass spectrometry, the most prevalent proteins in the selected antigenic bands were two uncharacterized proteins, intermediate filament proteins, endoplasmin, paramyosin, actins, and glutamate dehydrogenase. The combined findings of this study suggest that IgA has mainly nonspecific actions against T. cati .

Objectives: This study aimed to determine the occurrence of gastric Helicobacter species colonization in cats with confirmed gastrointestinal disease and to investigate possible associations between Helicobacter species colonization and gastric histopathological changes. It also aimed to identify the Helicobacter species present in cats in countryX. Methods: Privately owned cats were prospectively enrolled between May 2018 and December 2022. Regardless of the reason for presentation, the owners of all cats presented to the cat clinic during that time period were systematically interviewed regarding chronic gastrointestinal signs. Cats with suspected chronic gastrointestinal disease underwent non-invasive diagnostic evaluation, and those with persistent suspicion proceeded to gastrointestinal biopsies. Full-thickness gastric and small intestinal biopsies were collected from each cat to evaluate histopathological lesions and to determine the presence and localization of Helicobacter species in the stomach. A total of 154 cats that underwent biopsies were included in the study. A subset of Helicobacter-positive samples was further analyzed to the species level using the nanopore sequencing technique. Results: All cats had chronic small intestinal disease. Of these, 79% had inflammatory enteropathy and 21% had lymphoma. Helicobacter species were detected in 75% of cats. Colonization with multiple Helicobacter species was common, with Helicobacter heilmannii being the most prevalent species. Gastritis was present in 58% of cats and occurred with similar frequency in both small intestinal diseases. The presence of Helicobacter species was significantly associated with lymphoplasmacytic gastritis. However, the density of bacterial colonization was not associated with gastritis severity. Conclusions and relevance: Our findings indicate that colonization by Helicobacter species is common in cats with gastrointestinal clinical signs and is associated with chronic lymphoplasmacytic gastritis. Nevertheless, the causal relationship between Helicobacter species and gastritis cannot be established with this study design due to the lack of a control group. Most cats were colonized with mixed Helicobacter species.

The dog, Canis lupus familiaris, is an important model for studying human diseases. Unlike many model organisms, the dog genome has a comparatively poor functional annotation, which hampers gene discovery for development, morphology, disease, and behavior. To fill this gap, we established a comprehensive tissue biobank for both the dog and wolf samples. The biobank consists of 5485 samples representing 132 tissues from 13 dogs, 12 dog embryos, and 24 wolves. In a subset of 100 tissues from nine dogs and 12 embryos, we characterized gene expression activity for each promoter, including alternative and novel, i.e., previously not annotated, promoter regions, using the 5’ targeting RNA sequencing technology STRT2-seq. We identified over 100,000 promoter region candidates in the recent canine genome assembly, CanFam4, including over 45,000 highly reproducible sites with gene expression and respective tissue enrichment levels. We provide a promoter and gene expression atlas with interactive, open data resources, including a data coordination center and genome browser track hubs. We demonstrated the applicability of Dog Genome Annotation (DoGA) data and resources using multiple examples spanning canine embryonic development, morphology and behavior, and diseases across species.

According to our recent necropsy-based study, mastitis is the most common underlying diagnosis of on-farm deaths in Finnish dairy cows. However, it remained unanswered to what extent mastitis has contributed to death of all necropsied cows. In the present study, based on histopathology we detected one third of the necropsied dairy cows having active inflammatory udder lesions (n = 110). The role of mastitis varied and was interpreted by causes of death (underlying, intermediate, immediate, other significant). Mastitis was most commonly either the underlying (28%) or both immediate and underlying cause of death (48%), and only seldom the immediate (4%) or intermediate (4%) cause of death. Mastitis occurred either as the only cause leading to death (mastitis only, MO, 39%), or with many other contributing diseases (multiple diseases, MD, 61%) which were interacting with mastitis and together leading to death. Between these groups (MO vs. MD), time of mastitis occurrence during lactation, producer-reported duration of illness, clinical signs, and medication differed, as well the histopathological severity of mastitis. The cases, where mastitis was the only initial insult, occurred evenly throughout the entire lactation, but the cases with many interacting diseases clustered in early lactation. In multiple diseases -cases mastitis occurred concurrently with metritis (31%), aspiration pneumonia (24%), acute trauma/dystocia (15%), or with other diseases, such as ketosis, hepatic lipidosis, rumenitis, and abomasal diseases. For a pathologist, the gross mastitis diagnosis was most challenging at the beginning of the lactation, especially if inflammation was mild to moderate, suggesting the value of histopathological examination being highest at that time. Also, producers reported mastitis signs less frequently if cow had many simultaneously occurring diseases. Therefore, even if clinical signs of other diseases are present, the udder should be considered a potential cause of illness, and it should be examined, especially in dry and transition period cows.

Pet dogs are a valuable natural animal model for studying relationships between primary immunodeficiencies and susceptibility to Pneumocystis and other opportunistic respiratory pathogens. Certain breeds, such as the Cavalier King Charles Spaniel, are over-represented for Pneumocystis pneumonia (PCP), suggesting the presence of a primary immunodeficiency in the breed. Here, we report the discovery of a CARMIL2 nonsense variant in three Cavalier King Charles Spaniel dogs with either PCP (n = 2) or refractory Bordetella pneumonia (n = 1). CARMIL2 encodes a protein that plays critical roles in T-cell activation and other aspects of immune function. Deleterious CARMIL2 variants have recently been reported in human patients with PCP and other recurrent pneumonias. In addition to opportunistic respiratory infection, the affected dogs also exhibited other clinical manifestations of CARMIL2 deficiencies that have been reported in humans, including early-onset gastrointestinal disease, allergic skin disease, mucocutaneous lesions, abscesses, autoimmune disorders, and gastrointestinal parasitism. This discovery highlights the potential utility of a natural canine model in identifying and studying primary immunodeficiencies in patients affected by PCP.

The worldwide problem of increasing dairy cow mortality is widespread in modern production systems, it causes economic losses, and indicates problems with herd health and welfare. Most studies on causes of dairy cow mortality are limited as they are based on secondary register data, or questionnaires for producers or veterinarians, and neither necropsies nor histopathologic analyses are usually performed. For this reason, no definite causes for dairy cow deaths have been determined making it difficult or impossible to implement effective preventive measures. The objectives of this study were to (1) determine the causes of on-farm mortality of Finnish dairy cows, (2) determine the usefulness of routine histopathologic analysis in bovine necropsies, and (3) assess how reliable producers' perception about the cause of death is. Underlying diagnoses of on-farm deaths were determined through necropsy of 319 dairy cows at an incineration plant. The necropsy data were combined with background information obtained from online questionnaires covering cow and herd records. Mastitis was the most common underlying diagnosis of death (26.6%), followed by digestive disorders (15.4%), other known disorders (13.8%), calving-associated disorders (12.2%), and locomotion disorders (11.9%). The underlying diagnoses of death varied during different stages of lactation and with parity. A large proportion of the study cows (46.7%) died during the first 30 d after calving, and of those, 63.6% died during the first 5 d. A routine histopathologic analysis was performed in every necropsy, and it changed the preliminary gross diagnosis in 18.2% of the cases. Producers' perception about the cause of death agreed with the necropsy-based underlying diagnosis of death in 42.8% of the cases. It was most consistent for mastitis, calving disorders, locomotion diseases, and accidents. In cases where producers had no insights about the cause of death, necropsy revealed the final underlying diagnosis in 88.2% of cases, demonstrating the usefulness of necropsy. Based on our findings, necropsies provide useful and reliable information to develop control programs for cow mortality. Including routine histopathologic analysis in necropsies, more accurate information may be obtained. Furthermore, targeting preventive measures on transitional cows may be most effective, as the number of deaths was highest at this time.

Background: Caryospora bigeneticais an intracellular protozoan parasite, which in its primary hosts, typically snakes, is found it the intestine. Extraintestinal multiplication with the development of tissue cysts takes place in secondary hosts, which are normally prey for snakes. Natural infection in domestic animals has been reported only in dogs; this is the first report ofC. bigeneticainfection in a cat.Case presentation: A stray kitten developed nodular dermatitis after being adopted by a shelter. Firm swelling, nodules, and crusts were present mainly on the nasal bridge, eyelids, and pinnae. Histopathology and cytology revealed severe pyogranulomatous inflammation with abundant intracellular organisms suggestive of apicomplexan protozoa. Treatment with clindamycin 13 mg/kg twice daily was initiated, but the cat was euthanized because of the worsening condition. Transmission electron microscopy confirmed parasite’s apicomplexan origin postmortem, and the causative agent was identified asC. bigeneticaby polymerase chain reaction and DNA sequencing.Conclusions: We present the first case of a naturally occurring infection withC. bigeneticain a cat. Although the definitive etiological diagnosis relied on molecular identification, the abundance of unsporulated oocysts and caryocysts and the parasite's effective reproduction within macrophages and in several other cell types might have enabled differentiation from other protozoal infections and allowed a presumptive diagnosis through cytology and histopathology.