Taste reactivity patterns in domestic cats (Felis silvestris catus)

The present study is aimed at finding taste reactivity patterns in domestic cats (Felis silvestris catus) which reflect 'liking' or perceived palatability. Three groups of nonstressed cats living in households were formed which a priori were expected to differ in motivational state for eating food items (more or less hungry), and which were offered two different food items differing in general taste properties (more or less flavourful food, MFF and LFF, respectively) around the time that they were fed their normal food. Analysis of the amount of food eaten showed that MFF was consumed regardless of hunger level and that LFF was consumed depending on the hunger level of cats: the more hungry cats ate more of LFF than the less hungry cats. Analysis of post-meal behavioural sequences showed that the 'MFF consumption sequence' differed from the 'LFF refusal sequence' and that the 'LFF consumption sequence' strongly resembled the 'MFF consumption sequence' but also contained elements of the 'LFF refusal sequence'. Subsequent analysis of the frequencies and total durations of behavioural patterns showed that two kinds of patterns existed, possibly reflecting two 'palatability dimensions': hedonic taste reactivity patterns (lick/sniff feeding bowl, lip lick and groom face) and aversive taste reactivity patterns (lick/sniff food and lick nose). These dimensions may be combined to obtain a single palatability score.     

The function of allogrooming in domestic cats (Felis silvestris catus); a study in a group of cats living in confinement

Grooming interactions (n=83) occurring in a group of non free-ranging adult neutered male (n=14) and female (n=11) domestic cats (Felis silvestris catus) were analysed. Grooming was not induced by the proximity (distance <=0.5 m) of another animal. Grooming was in general directed at the head-neck area. Higher ranking animals groomed lower ranking animals more often than the other way round. Groomers tended to adopt ‘higher’ (standing, sitting upright) postures than groomees (sitting, lying). Agonistic behaviour occurred in 35% of interactions. Groomers showed offensive behaviour more often than groomees, most often after grooming a partner. Furthermore groomers often groomed themselves after grooming a partner. The degree of relatedness of animals did not affect the frequencies or durations of grooming. These results are consistent with the hypothesis that allogrooming in domestic cats may be a way of redirecting (potential) aggression in situations in which overt aggression is too costly. The data were previously presented at the 29th International Congress of the International Society for Applied Ethology (van den Bos, R. (1995) Allogrooming in domestic cats in confinement, Proceedings of the 29th International Congress of the International Society for Applied Ethology, S.M. Rutter et al. (Eds.), pp. 109–110)     

The social function of tail up in the domestic cat (Felis silvestris catus)

We investigated the social function of tail up in order to verify its possible relationship with the hierarchical organization of a social group. Domestic cats live at higher densities than their ancestor which is a solitary species. Since the signals needed by solitary animals have different properties than those needed by group-living individuals, signalling pattern utilised by the domestic cat has inevitably changed. Kittens displayed the tail up when greeting their mother; this behaviour can also be observed in wild species. But, in domestic cat the tail up can be also observed when an adult individual meets another one and it signals the intention to interact amicably. Rank order affected the display of tail up posture: it was more frequently displayed by low-ranking cats, and high-ranking individuals received it more often than other members of the social group. Then, tail up seems to be a signal by means of which a cat shows the recognition of the higher social status of the individual to whom is directed. We confirmed the association between tail up and other affiliative behavioural patterns and the individual variability in displaying them. Considerations on the evolution of the tail up as a visual signal will be discussed.     

Artificial insemination in domestic cats (Felis catus)

Artificial insemination (AI) in cats represents an important technique for increasing the contribution of genetically valuable individuals in specific populations, whether they be highly pedigreed purebred cats, medically important laboratory cats or endangered non-domestic cats. Semen is collected using electrical stimulation, with an artificial vagina or from intact or excised cauda epididymis. Sperm samples can be used for AI immediately after collection, after temporary storage above 0 degrees C or after cryopreservation. There have been three and five reports on intravaginal and intrauterine insemination, respectively, and one report on tubal insemination with fresh semen. In studies using fresh semen, it was reported that conception rates of 50% or higher were obtained by intravaginal insemination with 10-50x10(6) spermatozoa, while, in another report, the conception rate was 78% after AI with 80x10(6) spermatozoa. After intrauterine insemination, conception rates following deposition of 6.2x10(6) and 8x10(6) spermatozoa were reported to be 50 and 80%, respectively. With tubal insemination, the conception rate was 43% when 4x10(6) spermatozoa were used, showing that the number of spermatozoa required to obtain a satisfactory conception rate was similar to that of cats inseminated directly into the uterus. When frozen semen was used for intravaginal insemination the conception rate was rather low, but intrauterine insemination with 50x10(6) frozen/thawed spermatozoa resulted in a conception rate of 57%. Furthermore, in one report, conception was obtained by intrauterine insemination of frozen epididymal spermatozoa. Overall, there have been few reports on artificial insemination in cats. The results obtained to date show considerable variation, both within and among laboratories depending upon the type and number of spermatozoa used and the site of sperm deposition. Undoubtedly, future studies will identify the major factors required to consistently obtain reliable conception rates, so that AI can become a practical technique for enhancing the production of desirable genotypes, both for laboratory and conservation purposes.     

Naturally occurring Sarcocystis infection in domestic cats (Felis catus)

Equine protozoal myeloencephalitis is an important neurological disease of horses in the United States. Consequently, there is an active research effort to identify hosts associated with the primary causative agent, Sarcocystis neurona. The purpose of this study was to determine whether the domestic cat (Felis catus) is a natural host for S. neurona. Muscle sections from 50 primarily free-roaming domestic cats were examined for the presence of sarcocysts. Serum from cats in this group and another group of 50 free-roaming cats were evaluated for the presence of S. neurona antibody. Sarcocysts were found in five of 50 (10%) cats, and S. neurona antibody in five of 100 (5%) cats. Morphological, molecular (including ribosomal RNA genes), and biological characterisation of these sarcocysts showed that they were not S. neurona or S. neurona-like. Sarcocysts found in the cats were identified morphologically as Sarcocystis felis, a common parasite of wild felids. The life cycle of S. felis is not known, and prior to this study, no molecular marker for S. felis existed. Although cats were found to be infected with S. felis sarcocysts, serological data provided evidence of possible infection with S. neurona as well. Further work is needed to determine the role of the domestic cat in the life cycle of S. neurona.     

Morphological discriminants of Scottish wildcats (Felis silvestris), domestic cats (F. catus) and their hybrids

Skull characters of wildcats ( Felis silvestris ), classed as 'old', 'recent' or 'modern', depending on collection date, were compared with those of domestic cats ( F. catus ) and hybrids, using Fisher Linear Discriminant Functions, Principal Component Analyses and Canonical Variates. A key is derived for classification of individual (unknown) skulls. All analyses indicate that 'recent' and 'modern' wildcats were different from those collected earlier, and implied marked changes in the rate of hydridization during this century. We suggest that the older wildcat populations were a relatively 'pure' form but more recent populations contain a significant hybrid component. Although there may be a trend towards re-establishment of the earlier type, an alternative conclusion is that the 'pure' form of wildcat is effectively extinct in Scotland.     

When domestic cat (Felis silvestris catus) population structures interact with their viruses

Many theoretical studies have proposed different causal mechanisms by which the structure of a host population could have important implications for life history traits of pathogens. However, little information is available from real systems to test these hypotheses. The domestic cat, Felis silvestris catus, whose populations exhibit a great variability in social and spatial structure, represent an ideal case study to assess this question. In the present article, we show how cat population structure may have influenced the evolution of feline viruses and, in return, how these viruses may have modified the genetic structure of cat populations. To cite this article: D. Pontier et al., C. R. Biologies 332 (2009).     

Quantitative assay of electromyograms during mastication in domestic cats (Felis catus)

Mastication has been studied by cinematography with synchronized electromyography (computer quantified and analyzed), while unanesthetized, freely feeding cats (Felis catus) were reducing equivalent-sized chunks of raw and cooked beef and cooked chicken. Cats reduce food on one side at a time, and their chewing cycles show both horizontal and anteroposterior deflections. Food objects are shifted from side to side by lateral jerks of the head and movements of the tongue. During the opening phase, the lower jaw is rotated relatively straight downward, and the digastric muscles are active in bilateral symmetry. Near the end of opening, the head jerks upward, both zygomaticomandibulares start to fire, and opening acceleration of the mandible decreases. Closing starts with horizontal displacement of the mandibular canines toward the working side, accompanied by asymmetrical activities from the working side deep temporalis and the balancing side medial pterygoid, as well as a downward jerk of the head. As closing proceeds, the mandibular canines remain near the working side and the working side zygomaticomandibularis and deep masseter are very active. Near the end of closing, the mandibular canine on the working side moves toward the midline, and adductors, digastrics, and lateral pterygoids of both sides are active. The adductors of the working side are generally more active than those of the balancing side. During a reduction sequence, the number and shape of the masticatory cycles, as well as movements of the head, during a reduction sequence are affected significantly by food type. As reduction proceeds, the duration of bite and the muscular activity (as characterized by number and amplitude of spikes) change significantly among muscles of the working and balancing sides. The adductors of the working side are generally most active when cats chew raw beef, less for cooked beef, and least for cooked chicken. In general, the adductor activity reflects food consistency, whereas that of the digastrics and lateral pterygoids reflects more the vertical and lateral displacements of the mandible. Statistical analysis documents that the methods of electrode insertion and test give repeatable results for particular sites in different animals. Thus, it should be possible to compare these results with those produced while other mammalas are masticating.     

Revealing cryptic genetic structuring in an urban population of stray cats (Felis silvestris catus)

Urban stray cat populations have previously been shown to be organized in moderately to strongly genetically differentiated colonies. However, the spatial pattern of this genetic differentiation and the possibility that some cryptic genetic structure occurs have not been investigated. Firstly, we combine a pairwise Fst method, a fully Bayesian clustering method and a multivariate analysis to show that the spatial structure of 17 urban stray cat colonies (Nancy, France) does not match the underlying genetic structure. These colonies are structured in two clusters at the uppermost hierarchical level. Additionally, geographic proximity between colonies does not explain their genetic homogeneity. The spatial pattern in genetic differentiation seems more to be a mixture between low global structure and some highly localized structure, comprising isolated colonies. Variations in the local ecological and social constraints on immigration between colonies may explain this pattern. Secondly, we show that the overall current immigration rate is low (8%). Our results suggest that dispersal does not play a major role in the process of homogenization of allelic frequencies. Our study provides a case-study on the use of Bayesian clustering and assignment methods on a real, small data set with numerous fragmented populations; a population structure that is of high relevance in conservation biology.     

Transmission of Toxoplasma gondii in an urban population of domestic cats (Felis catus)

Toxoplasma gondii is a protozoan parasite that infects humans and animal species worldwide. The relative importance of each potential transmission route in the complex life cycle of this coccidia is largely unknown, due to the lack of studies taking into account all routes simultaneously. In this study, we analyzed the transmission of T. gondii in an urban population of stray cats captured between 1993 and 2004. Analyzing prevalence, our aim was to determine which factors influence transmission in this population. Specific anti-T. gondii IgG antibodies were detected using the modified agglutination test. Firstly, we analyzed the kinetics of antibody titers in cats captured several times, using mixed linear models and correspondence analysis. We showed that antibody titers did not vary significantly with time and that titer 40 was the best threshold to separate individuals into two serological groups. Overall, prevalence was only 18.6%, thus transmission of T. gondii is infrequent in this population. As expected, a highly significant association was detected between age and presence of IgG antibodies. Prevalence was lowest in kittens aged 3-4 months, suggesting that newborn kittens may carry maternal antibodies and that vertical transmission is rare. After taking into account the effect of age, logistic regression showed that antibody carriage was related to factors that possibly related to the survival of oocysts: localization in the study site, origin of the cats, maximal temperatures and rain. Our results suggest that in this population, vertical transmission is rare, low predation limits prevalence, and oocyst survival is a determining factor in the risk of infection. We discuss the more general importance of conditions determining oocyst survival in the life cycle of T. gondii.     

Folliculogenesis in the domestic cat (Felis catus)

The dynamic regulation of mammalian folliculogenesis is a key component of the reproductive process. Traditionally, the rodent had been used as a model to study ovarian function and reproductive physiology due to the availability of animals, their relatively short cycle length, high rate of fecundity and short generation interval. We maintain that much basic information can be determined using domestic cat ovaries retrieved from local veterinary clinics following routine spaying, without having the expense of maintaining a colony of laboratory cats. Studies of normal feline reproductive physiology and advances in reproductive technology may be extrapolated for use in endangered non-domestic felids. Increased understanding of feline reproduction will be beneficial to veterinary medicine, and to groups working to control feral cat populations. It is important to examine reproductive mechanisms in alternative animal models as there are a vast number of threatened and endangered species in which we lack the critical reproductive information needed to assist in preserving their long-term survival.     

An autosomal genetic linkage map of the domestic cat,Felis silvestris catus

We report on the completion of an autosomal genetic linkage (GL) map of the domestic cat (Felis silvestris catus). Unlike two previous linkage maps of the cat constructed with a hybrid pedigree between the domestic cat and the Asian leopard cat, this map was generated entirely with domestic cats, using a large multi-generational pedigree (n = 256) maintained by the Nestlé Purina PetCare Company. Four hundred eighty-three simple tandem repeat (STR) loci have been assigned to linkage groups on the cat's 18 autosomes. A single linkage group spans each autosome. The length of the cat map, estimated at 4370 cM, is long relative to most reported mammalian maps. A high degree of concordance in marker order was observed between the third-generation map and the 1.5 Mb-resolution radiation hybrid (RH) map of the cat. Using the cat 1.9 × whole-genome sequence, we identified map coordinates for 85% of the loci in the cat assembly, with high concordance observed in marker order between the linkage map and the cat sequence assembly. The present version represents a marked improvement over previous cat linkage maps as it (i) nearly doubles the number of markers that were present in the second-generation linkage map in the cat, (ii) provides a linkage map generated in a domestic cat pedigree which will more accurately reflect recombination distances than previous maps generated in a hybrid pedigree, and (iii) provides single linkage groups spanning each autosome. Marker order was largely consistent between this and the previous maps, though the use of a hybrid pedigree in the earlier versions appears to have contributed to some suppression of recombination. The improved linkage map will provide an added resource for the mapping of phenotypic variation in the domestic cat and the use of this species as a model system for biological research.     

Retroviruses and sexual size dimorphism in domestic cats (Felis catus L.).

Hochberg and co-workers have predicted that an increase in host adult mortality due to parasites is balanced by an earlier age at first reproduction. In polygynous species we hypothesize that such a pattern would lead to diverging selection pressure on body size between sexes and increased sexual size dimorphism. In polygynous mammals, male body size is considered to be an important factor for reproductive success. Thus, under the pressure of a virulent infection, males should be selected for rapid growth and/or higher body size to be able to compete successfully as soon as possible with opponents. In contrast, under the same selection pressure, females should be selected for lighter adult body size or rapid growth to reach sexual maturity earlier. We investigated this hypothesis in the domestic cat Felis catus. Orange cats have greater body size dimorphism than non-orange cats. Orange females are lighter than non-orange females, and orange males are heavier than non-orange males. Here, we report the extent to which orange and non-orange individuals differ in infection prevelance for two retroviruses, feline immunodeficiency virus (FIV) and feline leukaemia virus (FeLV). FIV is thought to be transmitted almost exclusively through aggressive contacts between individuals, whereas FeLV transmission occurs mainly through social contacts. The pattern of infection of both diseases is consistent with the higher aggressiveness of orange cats. In both sexes, orange cats are significantly more infected by FIV, and tend to be less infected by FeLV than other cats. The pattern of infection is also consistent with an earlier age at first reproduction in orange than in non-orange cats, at least for females. These results suggest that microparasitism may have played an important role in the evolution of sexual size dimorphism of domestic cats.     

A suite of genetic markers useful in assessing wildcat (Felis silvestris ssp.)-domestic cat (Felis silvestris catus) admixture

The wildcat (Felis silvestris ssp.) is a conservation concern largely due to introgressive hybridization with its congener F. s. catus, the common domestic cat. Because of a recent divergence and entirely overlapping ranges, hybridization is common and pervasive between these taxa threatening the genetic integrity of remaining wildcat populations. Identifying pure wildcats for inclusion in conservation programs using current morphological discriminants is difficult because of gross similarity between them and the domestic, critically hampering conservation efforts. Here, we present a vetted panel of microsatellite loci and mitochondrial polymorphisms informative for each of the 5 naturally evolved wildcat subspecies and the derived domestic cat. We also present reference genotypes for each assignment class. Together, these marker sets and corresponding reference genotypes allow for the development of a genetic rational for defining "units of conservation" within a phylogenetically based taxonomy of the entire F. silvestris species complex. We anticipate this marker panel will allow conservators to assess genetic integrity and quantify admixture in managed wildcat populations and to be a starting point for more in-depth analysis of hybridization.     

Isozyme activities in the domestic cat (Felis catus)

Horizontal starch-gel electrophoresis was performed on domestic cat blood and stained for 6-phosphogluconic dehydrogenase (6-PGD), lactate dehydrogenase (LDH) and tetrazolium oxidase. A polymorphism was found for 6-PGD; LDH and tetrazolium oxidase were monomorphic. These systems were tested on cats of English, Mexican and American origin.     

Duodenal microanatomy of the domestic cat (Felis catus)

Duodenal samples were taken from similar locations in six cats, processed, stained, and examined via light microscope. There were no prominent circular folds (plicae circulares) or stratum compactum (lamina subglandularis). The 1072 microns x 201 microns villi were covered by 46 microns high columnar epitheliocytes proximally which decreased in height (41 microns) distally and displayed a 1.1-1.7 microns striated border. Globular leukocytes, mononuclear cells, and twenty-eight goblet cells (exocrinocytus calciformis) per villus were seen. The intestinal gland (crypt of Lieberkuhn) epithelium was 20 microns tall and had a less distinct striated border. The 515 microns simple straight tubular intestinal gland layer displayed distal branching. Many mitotic figures, 12 goblet cells per gland, and occasional columnar to triangular cells with red cytoplasmic granules were seen. The thickness of the lamina propria mucosa (glandular portion) decreased from proximal to distal (563-465 microns). The lamina muscularis mucosa had two layers and decreased in thickness distally (71-28 microns). The proximal muscularis mucosa was penetrated by the ducts of submucosal (Brunner's, duodenal) glands. The tela submucosa decreased in thickness distally (593-192 microns) and contained submucosal glands with 11.5-75 microns lumina for the first 1.5-2.5 cm. However, submucosal glands could be found to a distance of 8 cm. The glandular epithelium ranged from 7.5-22.5 microns in height. Only one type of secretory cell was observed, with both mucous and serous properties. The tunica muscularis ranged from 190-1425 microns (median thickness of 557 microns) and had two layers.