The experimental transmission of various mycoplasmas of feline origin to domestic cats (Felis catus)

Mycoplasma felis and M. gatae recovered from domestic cats, M. arginini from a cheetah, an unidentified glucose-fermenting mycoplasma from a lion, and M. pulmonis from a rat were inoculated into specific pathogen free (SPF) kittens by the oral, ocular and nasal routes. During the 21-day experimental period a persistent infection was established in a proportion of the kittens challenged with M. felis, M. gatae and M. arginini. The mycoplasma isolated from the lion created a transitory infection in one kitten, but M. pulmonis could not be recovered even 24 hr after inoculation. None of the organisms investigated showed any pathological effect. The implications of this work in relation to the host-specificity and pathogenicity of the feline mycoplasmas are discussed. Résumé. On a inoculé à des chatons axéniques par les voies orales, oculaires et nasales, un Myco-plasmafelis et un M. gatae recueillis de chats domestiques, un M. arginini recueilli d'un guépard, un mycoplasme non identifié à glucose fermentant recueilli d'un lion et un M. pulmonis recueilli d'un rat. Durant la période expérimentale de 21 jours, on a établi une infection persistante dans une proportion des chatons soumis aux tests de Mycoplasma felis, de M. gatae et de M. agrinini. Le mycoplasma isolé recueilli du lion a créé une infection transitoire chez un chaton, mais le M. pulmonis n'a pu être recueilli, même 24 heures après l'inoculation. Aucun des organismes sous investigation n'a montré d'effets pathologiques. On a discuté des implications de ce travail en relation avec la spécifité d'hôtes et la pathogénicité de mycoplasmes félins. Zusammenfassung. Mycoplasma felis und M. gatae von Hauskatzen erlangt, M. arginini von einem Tschita, ein unidentifiziertes Glukose-fermentierendes Mycoplasma von einem Löwen, und M. pulmonis von einer Ratte wurden in keimfreie (SPF) junge Katzen geimpft, auf oralem, Augen- und Nasenweg. Während der 21 tägigen Versuchsperiode wurde eine anhaltende Infektion in den Katzen festgestellt, die dem M. felis, M. gatae und dem M. agrinini ausgesetzt waren. Das Mycoplasma von dem Löwen abgesondert, verursachte eine vorübergehende Infektion eines Kätzchens, aber M. pulmonis konnte selbst 24 Stunden nach der Impfung nicht gefunden werden. Keines der untersuchten Organismen zeigte irgendwelche pathologischen Effekte. Die Folgerungen dieser Arbeit im Verhältnis zu der Gast-Spezifität und Pathogenizität des Katzen-mycoplasmas sind diskutiert.     

Reovirus isolation from healthy dogs in Japan

Twenty-two strains of viruses isolated from apparently healthy dogs were identified as reoviruses on the basis of their biological, physico-chemical and morphological properties. The cross hemagglutination-inhibition test revealed that all of them were of type 1, except one which was of type 3. The significance of reovirus isolation from healthy animals is discussed.     

Lack of evidence for perinatal transmission of Cytauxzoon felis in domestic cats

Cytauxzoon felis is a hemoprotozoan parasite of cats capable of causing severe, often fatal disease during acute infection, but cats that survive the acute stage of disease become chronic carriers. These otherwise healthy carriers are capable of transmitting the infection to other cats via the bite of a vector tick. A variety of other hematoprotozoan parasites are capable of vertical transmission from mother to offspring. If this were possible for C. felis, it could be an important part of the explanation for the apparent emergence of this disease with an increased incidence in an expanding geographic area. We investigated the possibility of perinatal transmission of C. felis from chronically infected cats to their offspring. Two queens produced a total of 14 healthy kittens in three litters. All kittens tested negative for C. felis by microscopic slide review and PCR until they were adopted to private homes at approximately 12 weeks of age. While this does not rule out the possibility of perinatal transmission, it is unlikely to be a common phenomenon.     

SARS-CoV-2 infection in domestic and feral cats: current evidence and implications

Current evidence indicates that cats play a limited role in COVID-19 epidemiology, and pets are probably dead-end hosts of SARS-CoV-2 and pose negligible risks of transmission to humans. Still, one health concept is to be adopted widely as a component of mitigation strategies to tackle the ongoing pandemic. Therefore, in terms of the magnitude of infection and potential to transmit SARS-CoV-2 to humans, our surveillance efforts should mainly focus on mustelids (especially minks, ferrets, and others) for early detection and control of infection. This will ensure that SARS-CoV-2 will not get established in the wild animal population of these susceptible species. We agree with Dr. Passarella Teixeira on the possibility of domestic and feral cats acting as an urban reservoir, subsequently transmitting the virus to human beings. However, it is less likely that such a phenomenon will be reported even if it has occurred due to the efficient and extensive human-to-human transmission of SARS-CoV-2.     

Neonatal Neospora caninum infection in dogs: isolation of the causative agent and experimental transmission

Neospora caninum infection was diagnosed in 5 young dogs from 2 litters with a common parentage. The pups were born healthy, but developed hind limb paresis 5 to 8 weeks after birth. The predominant lesions were polyradiculoneuritis and granulomatous polymyositis. Neospora caninum was seen microscopically in sections of naturally infected pups, and was isolated in cell cultures, mice, and dogs inoculated with infected canine tissues. Antibodies to N caninum were detected in sera of infected dogs by indirect fluorescent antibody test.     

Frequencies of blood type A, B and AB in non-pedigree domestic cats in Turkey

OBJECTIVES: To determine the distribution of blood types and to estimate the proportion of matings at risk for neonatal isoerythrolysis in non-pedigree domestic cats. METHODS: The present survey determined the frequency of blood types in 301 cats from four distinct regions of Turkey. Ethylenediaminetetraacetic acid-anticoagulated blood samples were typed by simple tube and slide agglutination assays. Serum obtained from type B cats and an anti-B solution, prepared with Triticum vulgaris, were used to determine type A and type B blood, respectively. RESULTS: Of the 301 cats typed, 220 had type A blood, 74 had type B and seven had type AB. There was a significant difference (P<0.01) between the locations of the cats, with fewer type B cats in the eastern than in the western parts of Turkey. Risk for the development of neonatal isoerythrolysis due to A-B mismatch was estimated to be 18.6 per cent. CLINICAL SIGNIFICANCE: The overall type B frequency in Turkish domestic cats is high. Thus, untyped transfusions in these cats carry a high risk of life-threatening acute haemolytic transfusion reactions and neonatal isoerythrolysis. It is therefore strongly recommended that blood typing be performed before breeding or transfusing in order to minimise blood type incompatibility risks.     

A network model of H5N1 avian influenza transmission dynamics in domestic cats

Naturally occurring cases of influenza in cats owing to the H5N1 strain have been reported in several countries. A cat reservoir of H5N1 in the United States could provide an environment for zoonotic disease spread to humans. This scenario was the impetus to develop a model to study potential transmission of H5N1 virus in domestic cats utilizing information on cat ownership and cat-cat interaction patterns, in addition to biological properties of the virus. The roaming behaviour of cats significantly influenced epidemic dynamics, as demonstrated by the simulation results from this model. A better understanding of the behaviour of domestic cats and the H5N1 influenza virus can be used to predict epidemic dynamics following the introduction of H5N1 virus into the United States and to develop effective strategies to prevent virus transmission to both cats and humans.     

Characterization of the mutations causing hemophilia B in 2 domestic cats

The purpose of the present study was to determine the normal sequence for the gene encoding factor IX in cats and to characterize the genetic basis for hemophilia B in 2 unrelated male, domestic, mixed-breed cats. Genomic DNA sequence for the entire coding region of the factor IX gene was determined in the affected cats and compared to the sequence obtained from a healthy cat. The factor IX gene in cats encodes a mature protein consisting of 420 amino acids, unlike genes in humans and dogs that encode 415 and 413 amino acid proteins, respectively. Affected cat 1 had a single nucleotide change in exon 8 at the 1st nucleotide position of the codon encoding an arginine (CGA to TGA) at amino acid position 338. This mutation would be predicted to result in the appearance of a premature stop codon in the portion of the gene encoding much of the catalytic domain of the protein. Affected cat 2 had a single nucleotide change in exon 4 at the 2nd nucleotide position of the codon encoding amino acid 82 (TGT to TAT), which would be predicted to result in the substitution of a tyrosine for a cysteine. This substitution would likely result in disruption of a disulfide bond crucial to normal protein structure and function. This study represents the 1st time hemophilia B has been characterized at the molecular level in cats.     

The Arthus reaction in domestic cats

A classic Arthus reaction was elicited in normal domestic cats using chicken red blood cells as antigen. The response was quantitated grossly by measuring the area of the resulting skin bleb at several set time intervals and by microscopic examination of biopsies taken at the conclusion of each of the trials. This method produced an intense Arthus reaction in each of the cats tested.