Feline Injection-Site Sarcoma and Other Adverse Reactions to Vaccination in Cats.

Vaccine-associated adverse events (VAAEs), including feline injection-site sarcomas (FISSs), occur only rarely but can be severe. Understanding potential VAAEs is an important part of informed owner consent for vaccination. In this review, the European Advisory Board on Cat Diseases (ABCD), a scientifically independent board of feline medicine experts, presents the current knowledge on VAAEs in cats, summarizing the literature and filling the gaps where scientific studies are missing with expert opinion to assist veterinarians in adopting the best vaccination practice. VAAEs are caused by an aberrant innate or adaptive immune reaction, excessive local reactions at the inoculation site, an error in administration, or failure in the manufacturing process. FISS, the most severe VAAE, can develop after vaccinations or injection of other substances. Although the most widely accepted hypothesis is that chronic inflammation triggers malignant transformation, the pathogenesis of FISS is not yet fully understood. No injectable vaccine is risk-free, and therefore, vaccination should be performed as often as necessary, but as infrequently as possible. Vaccines should be brought to room temperature prior to administration and injected at sites in which FISS surgery would likely be curative; the interscapular region should be avoided. Post-vaccinal monitoring is essential.

Vaccination of Immunocompromised Cats.

Immunocompromise is a common condition in cats, especially due to widespread infections with immunosuppressive viruses, such as feline immunodeficiency virus (FIV) and feline leukaemia virus (FeLV), but also due to chronic non-infectious diseases, such as tumours, diabetes mellitus, and chronic kidney disease, as well as treatment with immunosuppressive drugs, such as glucocorticoids, cyclosporins, or tumour chemotherapy. In this review, the European Advisory Board on Cat Diseases (ABCD), a scientifically independent board of experts in feline medicine from eleven European countries, discusses the current knowledge and rationale for vaccination of immunocompromised cats. So far, there are few data available on vaccination of immunocompromised cats, and sometimes studies produce controversial results. Thus, this guideline summarizes the available scientific studies and fills in the gaps with expert opinion, where scientific studies are missing. Ultimately, this review aims to help veterinarians with their decision-making in how best to vaccinate immunocompromised cats.

Encephalitozoon cuniculi infection in cats: European guidelines from the ABCD on prevention and management.

OVERVIEW: Encephalitozoon cuniculi is a common obligate intracellular microsporidian parasite of rabbits that is increasingly recognised as a pathogen of cats and other mammalian species. These guidelines aim to review the literature on feline E cuniculi infection and provide recommendations on prevention and management. INFECTION IN CATS: E cuniculi infection should be considered as a differential diagnosis in cases of feline uveitis and cataract formation. It is not significantly associated with either chronic kidney disease or meningoencephalitis. E cuniculi infection is more common in stray or feral cats than in pet cats. DIAGNOSIS AND TREATMENT: Serological tests for antibody detection in the blood are easy to perform and can be useful for diagnosis, but their specificity is low as antibodies have been found in apparently healthy cats. PCR appears to be more sensitive than histopathology for diagnosis, and is more sensitive when performed on cataractous lenses compared with aqueous humour, although ease of sampling is an obvious limitation. Treatment is with fenbendazole for 3 weeks and phacoemulsification to remove microsporidia from cataractous lenses. ZOONOTIC RISK: E cuniculi is a potential zoonotic agent, and there is a particular risk to immunocompromised humans posed by infected rabbits. Albeit infrequent, spore shedding has been identified in cats, so care should be taken around infected cats.

Dirofilarioses in cats: European guidelines from the ABCD on prevention and management.

OVERVIEW: Dirofilaria immitis and Dirofilaria repens are the most important filarial worms, causing heartworm disease and subcutaneous dirofilariosis, respectively. D repens is currently considered an emerging zoonotic agent in Europe. LIFE CYCLE AND INFECTION: Filarial worms infect mainly dogs, but also cats, ferrets, wild carnivores and humans. The life cycle involves an intermediate mosquito host. Compared with dogs, cats are imperfect hosts for dirofilarial worms. After inoculation, only a low number of L3 larvae develop to the adult stage in a small percentage of cats. Heartworm disease in cats may be associated with severe pulmonary thromboembolism and an eosinophilic inflammatory response in the lungs, potentially leading to sudden death. Otherwise self-cure occurs in most cases after 18-48 months. Subcutaneous dirofilariosis may present as subcutaneous nodules or dermatitis. DIAGNOSIS AND TREATMENT: Diagnosis in cats is more difficult compared with dogs and needs a multistep approach (antigen and antibody tests, as well as diagnostic imaging). Cats with acute heartworm disease require stabilisation within an intensive care unit. Cats with respiratory signs or suggestive radiographic changes should receive prednisolone and follow-up with a similar multistep approach. Adulticidal therapy is not safe in cats. PREVENTION: In endemic areas cats should receive year-round chemoprophylaxis from 2 months of age.

Pan-European Study on the Prevalence of the Feline Leukaemia Virus Infection - Reported by the European Advisory Board on Cat Diseases (ABCD Europe).

Feline leukaemia virus (FeLV) is a retrovirus associated with fatal disease in progressively infected cats. While testing/removal and vaccination led to a decreased prevalence of FeLV, recently, this decrease has reportedly stagnated in some countries. This study aimed to prospectively determine the prevalence of FeLV viraemia in cats taken to veterinary facilities in 32 European countries. FeLV viral RNA was semiquantitatively detected in saliva, using RT-qPCR as a measure of viraemia. Risk and protective factors were assessed using an online questionnaire to report geographic, demographic, husbandry, FeLV vaccination, and clinical data. The overall prevalence of FeLV viraemia in cats visiting a veterinary facility, of which 10.4% were shelter and rescue cats, was 2.3% (141/6005; 95% CI: 2.0%-2.8%) with the highest prevalences in Portugal, Hungary, and Italy/Malta (5.7%-8.8%). Using multivariate analysis, seven risk factors (Southern Europe, male intact, 1-6 years of age, indoor and outdoor or outdoor-only living, living in a group of ≥5 cats, illness), and three protective factors (Northern Europe, Western Europe, pedigree cats) were identified. Using classification and regression tree (CART) analysis, the origin of cats in Europe, pedigree, and access to outdoors were important predictors of FeLV status. FeLV-infected sick cats shed more viral RNA than FeLV-infected healthy cats, and they suffered more frequently from anaemia, anorexia, and gingivitis/stomatitis than uninfected sick cats. Most cats had never been FeLV-vaccinated; vaccination rates were indirectly associated with the gross domestic product (GDP) per capita. In conclusion, we identified countries where FeLV was undetectable, demonstrating that the infection can be eradicated and highlighting those regions where awareness and prevention should be increased.

Haemoplasmosis in cats: European guidelines from the ABCD on prevention and management.

OVERVIEW: Haemoplasmas are haemotropic bacteria that can induce anaemia in a wide range of mammalian species. Infection in cats: Mycoplasma haemofelis is the most pathogenic of the three main feline haemoplasma species known to infect cats. ' Candidatus Mycoplasma haemominutum' and ' Candidatus Mycoplasma turicensis' are less pathogenic but can result in disease in immunocompromised cats. Male, non-pedigree cats with outdoor access are more likely to be haemoplasma infected, and ' Candidatus M haemominutum' is more common in older cats. All three haemoplasma species can be carried asymptomatically. Transmission: The natural mode of transmission of haemoplasma infection is not known, but aggressive interactions and vectors are possibilities. Transmission by blood transfusion can occur and all blood donors should be screened for haemoplasma infection. DIAGNOSIS AND TREATMENT: PCR assays are the preferred diagnostic method for haemoplasma infections. Treatment with doxycycline for 2-4 weeks is usually effective for M haemofelis-associated clinical disease (but this may not clear infection). Little information is currently available on the antibiotic responsiveness of ' Candidatus M haemominutum' and ' Candidatus M turicensis'.

Phylogenomic analysis of the complete sequence of a gastroenteritis-associated cetacean adenovirus (bottlenose dolphin adenovirus 1) reveals a high degree of genetic divergence.

Adenoviruses are common pathogens in vertebrates, infecting a wide range of hosts, but only having rarely been detected and correlated with disease in cetaceans. This article describes the first complete genomic sequence of a cetacean adenovirus, bottlenose dolphin adenovirus 1 (BdAdV-1), detected in captive bottlenose dolphin population (Tursiops truncatus) suffering from self-limiting gastroenteritis. The complete genome sequence of BdAdV-1 was recovered from data generated by high-throughput sequencing and validated by Sanger sequencing. The genome is 34,080bp long and has 220 nucleotides long inverted terminal repeats. A total of 29 coding sequences were identified, 26 of which were functionally annotated. Among the unusual features of this genome is a remarkably long 4380bp E3 ORF1, that displays no sequence homology with the corresponding E3 regions of other adenoviruses. In addition, the fiber protein only has 26% identity with fiber proteins described in other adenoviruses. Three hypothetical proteins were predicted. The phylogenetic analysis indicates that the closest known relative to BdAdV-1 is an adenovirus detected in bottlenose dolphin (KR024710), with an amino acid sequence identity between 36 and 79% depending on the protein. Based on the phylogenic analysis, the BdAdV-1 appears to have co-evolved with its host. The results indicate that BdAdV-1 belongs to the Mastadenovirus genus of the Adenoviridae family, however, it is clearly different from other adenoviruses, especially in the 3'-end of the viral genome. The high degree of sequence divergence suggests that BdAdV-1 should be considered as a novel species in the Mastadenovirus genus. The study also demonstrates the usefulness of high-throughput sequencing to obtain full-length genomes of genetically divergent viruses.

Anaplasma, Ehrlichia and Rickettsia species infections in cats: European guidelines from the ABCD on prevention and management

OVERVIEW: Anaplasma species, Ehrlichia species and Rickettsia species are vector-borne pathogens infecting a wide variety of mammals, but causing disease in very few of them. Infection in cats: Anaplasma phagocytophilum is the most important feline pathogen among these rickettsial organisms, and coinfections are possible. Little information is available on the pathogenesis of these agents in cats. Clinical signs are usually reported soon after tick infestation. They are mostly non-specific, consisting of fever, anorexia and lethargy. Joint pain may occur. Infection in humans: Some rickettsial species ( A phagocytophilum, Ehrlichia chaffeensis, Ehrlichia ewingii, Rickettsia conorii, Rickettsia rickettsii, Rickettsia felis, Rickettsia typhi and Candidatus Neoehrlichia mikurensis) are of zoonotic concern. Direct contact with cat saliva should be avoided because of potential contamination by R felis. Infected cats are 'sentinels' of the presence of rickettsial pathogens in ticks and fleas in a given geographical area, and they signal a risk for people exposed to vectors.

The effect of preprocessing by sequence-independent, single-primer amplification (SISPA) on metagenomic detection of viruses.

Compared to routine diagnostics, screening for pathogens in outbreak situations, with or without intentional release, poses demands on the detection technology to not only indicate the presence of already known causative agents but also novel and unexpected pathogens. The metagenomic approach to detecting viral pathogens, using unbiased high-throughput sequencing (HTS), is a well-established methodology with a broad detection range and wide applicability on different sample matrices. To prepare a sample for HTS, the common presequencing steps include homogenization, enrichment, separation (eg, magnetic separation), and amplification. In this initial study, we explored the benefits and drawbacks of preprocessing by sequence-independent, single-primer amplification (SISPA) of nucleic acids by applying the methodology to artificial samples. More specifically, a synthetic metagenome was divided into 2 samples, 1 unamplified and 1 diluted, and amplified by SISPA. Subsequently, both samples were sequenced using the Ion Torrent Personal Genome Machine (PGM), and the resulting datasets were analyzed by using bioinformatics, short read mapping, de novo assembly, BLAST-based taxonomic classification, and visualization. The results indicate that even though SISPA introduces a strong amplification bias, which makes it unsuitable for whole-genome sequencing, it is still useful for detecting and identifying viruses.

ABCD: Update of the 2009 guidelines on prevention and management of feline infectious diseases.

OVERVIEW: In this article, the ABCD guidelines published in the JFMS Special Issue of July 2009 (Volume 11, Issue 7, pages 527-620) are updated by including previously unavailable and novel information. For a better picture, the reader is advised to consult that issue before focusing on the novel features.

Prevention of infectious diseases in cat shelters: ABCD guidelines.

OVERVIEW: Recommendations are given in relation to infectious diseases in rescue shelters. The ABCD recognises that there is a wide variation in the design and management of shelters, and that these largely reflect local pressures. These guidelines are written with this diverse audience in mind; they point to the ideal, and also provide for some level of compromise where this ideal cannot immediately be attained. In addition consideration should be given to general requirements in order to optimise overall health and wellbeing of cats within the shelter. HOUSING: Compartmentalisation of the shelter into at least three individual sections (quarantine area for incoming cats, isolation facilities for sick or potentially infectious cats, and accommodation for clinically healthy, retrovirus-negative cats) can facilitate containment of a disease outbreak, should it occur. STANDARD OF CARE: Incoming cats should receive a full health check by a veterinary surgeon, should be dewormed and tested for retrovirus infections (feline leukaemia virus [FeLV] and/or feline immunodeficiency virus [FIV]) in regions with high prevalence and in shelters that allow contact between cats. Cats which are not rehomed should receive a regular veterinary check-up at intervals recommended by their veterinarian. VACCINATION: Each cat should be vaccinated as soon as possible against feline panleukopenia virus (FPV), feline herpesvirus (FHV-1) and feline calicivirus (FCV) infections. HYGIENE: Adequate hygiene conditions should ensure that contact between shedders of infectious agents and susceptible animals is reduced as efficiently as possible by movement control, hygiene procedures of care workers, barrier nursing, cleaning and disinfection. STRESS REDUCTION: Stress reduction is important for overall health and for minimising the risk of recrudescence and exacerbation of infectious diseases. In general, a special effort should be made to rehome cats as soon as possible.

Matrix vaccination guidelines: ABCD recommendations for indoor/ outdoor cats, rescue shelter cats and breeding catteries.

OVERVIEW: This article presents, in a user-friendly, tabluated form, the ABCD's current vaccination recommendations for four broad categories of cats: outdoor cats (ie, those with access outdoors that come into contact with other cats outdoors); indoor cats (ie, those with no contact with other cats from outdoors); rescue shelter cats; and cats in breeding catteries. Note that it is not always possible to make a clear distinction between these various categories and the definition in any individual case is left up to the veterinary surgeon conducting the vaccination interview.

Aujeszky's disease/pseudorabies in cats: ABCD guidelines on prevention and management.

OVERVIEW: Although pseudorabies in swine - Aujeszky's disease - has been eradicated from many pork-producing countries, the virus may still lurk in other vertebrate species and cause feline cases. Infection occurs through the ingestion of uncooked meat and organ material and presents as an acute encephalitis with a short incubation period and a rapidly fatal outcome. The ABCD considers this reason enough to include a review of this, now very rare, condition in this Special Issue.

Cowpox virus infection in cats: ABCD guidelines on prevention and management.

OVERVIEW: The misnomer 'cowpox' has historical roots: cats rather acquire the virus from small rodents. It has a wide host spectrum (including man) and causes skin lesions, predominantly on the head and paws. Progressive proliferative ulcerations in kittens and immunosuppressed cats may take a fatal course. Cat owners should be informed about the zoonotic risk.

Feline viral papillomatosis: ABCD guidelines on prevention and management.

OVERVIEW: Papillomaviruses are epitheliotropic and cause cutaneous lesions in man and several animal species, including cats. INFECTION: Cats most likely become infected through lesions or abrasions of the skin. Species-specific viruses have been detected but human and bovine related sequences have also been found, suggesting cross-species transmission. CLINICAL SIGNS: In cats, papillomaviruses are associated with four different skin lesions: hyperkeratotic plaques, which can progress into Bowenoid in situ carcinomas (BISCs) and further to invasive squamous cell carcinomas (ISCCs); cutaneous fibropapillomas or feline sarcoids; and cutaneous papillomas. However, papillomaviruses have also been found in normal skin. DIAGNOSIS: Papillomavirus-induced skin lesions can be diagnosed by demonstration of papillomavirus antigen in biopsies of skin lesions, or detection of papillomavirus-like particles by electron microscopy and papillomavirus DNA by polymerase chain reaction (PCR). TREATMENT: Spontaneous regression might be expected. In cases of ISCC, complete excision should be considered if possible.

Bartonella species infection in cats: ABCD guidelines on prevention and management.

OVERVIEW: Over 22 Bartonella species have been described in mammals, and Bartonella henselae is most common worldwide. Cats are the main reservoir for this bacterium. B henselae is the causative agent of cat scratch disease in man, a self-limiting regional lymphadenopathy, but also of other potentially fatal disorders in immunocompromised people. INFECTION: B henselae is naturally transmitted among cats by the flea Ctenocephalides felis felis, or by flea faeces. A cat scratch is the common mode of transmission of the organism to other animals, including humans. Blood transfusion also represents a risk. DISEASE SIGNS: Most cats naturally infected by B henselae do not show clinical signs but cardiac (endocarditis, myocarditis) or ocular (uveitis) signs may be found in sporadic cases. B vinsonii subspecies berkhoffii infection has reportedly caused lameness in a cat affected by recurrent osteomyelitis and polyarthritis. DIAGNOSIS: Isolation of the bacterium is the gold standard, but because of the high prevalence of infection in healthy cats in endemic areas, a positive culture (or polymerase chain reaction) is not confirmatory. Other compatible diagnoses must be ruled out and response to therapy gives a definitive diagnosis. Serology (IFAT or ELISA) is more useful for exclusion of the infection because of the low positive predictive value (39-46%) compared with the good negative predictive value (87-97%). Laboratory testing is required for blood donors. DISEASE MANAGEMENT: Treatment is recommended in the rare cases where Bartonella actually causes disease.

Pasteurella multocida infection in cats: ABCD guidelines on prevention and management.

OVERVIEW: Pasteurella species are part of the normal oral flora of cats. They are also a common cause of infection in this species and an important zoonotic agent. INFECTION IN CATS: Pasteurella species are commonly isolated from subcutaneous abscesses and pyothorax in cats. They may also cause secondary lower respiratory tract infection and have been associated with spinal empyema and meningoencephalomyelitis. INFECTION IN HUMANS: Disease in humans mainly occurs after a cat bite or scratch, but may also be transmitted via respiratory secretions from cats in close contact with a person. Signs of local infection after a cat bite appear in a few hours (3-6 h). Severe disease and a fatal outcome mostly occur in immunocompromised people, but have also been reported in immunocompetent healthy individuals. Cat ownership by immunocompromised people may carry a risk.

Coxiellosis/Q fever in cats: ABCD guidelines on prevention and management.

OVERVIEW: Q fever is a zoonotic disease caused by Coxiella burnetii. Farm animals and pets are the main reservoirs of infection. INFECTION: Cats become infected by ingestion or inhalation of organisms from contaminated carcases of farm animals, or tick bites. Infection is common, as shown by several serological studies. CLINICAL SIGNS: Experimentally, fever, anorexia and lethargy have been noted. In the field, infection usually remains subclinical. Abortion might occur. C burnetii has been isolated from the placenta of aborting cats, but also from cats experiencing normal parturition. DIAGNOSIS: Infection with C burnetii can be diagnosed by isolation of the agent or serology. PREVENTION: Most important is the potential zoonotic risk. Cats suspected of having been exposed to C burnetii might shed organisms during parturition. Wearing gloves and a mask when attending parturient or aborting cats can minimise the risk of infection. Tick prevention is recommended.

Leptospira species infection in cats: ABCD guidelines on prevention and management.

OVERVIEW: Leptospirosis is a bacterial disease affecting a variety of domestic and wild animals as well as humans worldwide. Leptospirosis has been reported in over 150 mammalian species. It is considered an emerging infectious disease in humans and in dogs. Subclinically infected wild and domestic animals serve as reservoir hosts and are a potential source of infection for incidental hosts and humans. INFECTION: Reports of leptospirosis in cats are rare, but the importance of cats shedding Leptospira species and serving as a source of infection has recently gained attention. Leptospira species antibodies are commonly present in the feline population, and Leptospira species shedding of cats with outdoor exposure has been demonstrated. Cats mostly become infected through transmission from hunting rodents. SIGNIFICANCE: The role of healthy carrier cats as a source of contamination, as well as the role of leptospires as a pathogen in cats, are likely underestimated.

Yersinia pestis infection in cats: ABCD guidelines on prevention and management.

OVERVIEW: Plague, the medieval 'Black Death', is caused by a Gram-negative coccobacillus, Yersinia pestis, which also infects cats. As in people, it is transmitted from rodents through flea bites; it occurs in Asia, Africa and the Americas in flea-infested regions, all year round, and where rodent reservoirs are abundant. A poor prognosis is associated with high fever, and the pulmonary and septicaemic forms. Antibiotic therapy, flea control and avoidance of rodent contacts have made this infection manageable.