Erythrocytic pyruvate kinase deficiency and AB blood types in Australian Abyssinian and Somali cats

Objective   To determine the frequency of the mutant pyruvate kinase (PK) allele, haematological parameters and AB blood types of Abyssinian and Somali cats in Australia.
Design   Complete blood cell and reticulocyte counts, DNA PK mutation testing and blood typing were performed in all cats.
Results   A total of 60 cats (36 Abyssinians, 24 Somalis) were included (37 females, 23 males). For the mutant PK allele, three female Somalis were homozygous (affected, 5%), 17 cats were heterozygous (carrier, 28%) and 40 cats tested negative (normal, 67%). Pedigree analysis revealed common ancestry of affected and many carrier cats. Of affected cats, two had regenerative anaemias and all had reticulocytosis (range 64–390 × 10⁹/L; P < 0.001 compared with normal or carrier cats). The only consistent historical sign was lethargy. One affected cat was euthanased 18 months after testing, because of anaemia, neutropenia, anorexia and weight loss. The mutant allele frequency was 0.19 overall (0.29 in Somalis, 0.13 in Abyssinians). All cats had blood type A. The commercial blood typing card method incorrectly identified 12 cats as having type AB blood.
Conclusions    The frequency of the mutant PK allele is high in Australia. Screening for PK deficiency is indicated before mating and in individual cats of these breeds, even in the absence of anaemia and especially when there is reticulocytosis. Although all cats in the present study had blood type A, blood type B is common in these breeds worldwide. Retyping of any AB typed cats by a laboratory technique is recommended.     

Real-time PCR genotyping assay for canine trapped neutrophil syndrome and high frequency of the mutant allele in Border collies

Trapped neutrophil syndrome is an autosomal recessive inherited neutropenia in Border collies. The causative mutation is a 4 base pair deletion in exon 19 of the canine VPS13B gene. In this study, a real-time PCR assay was developed and a genotyping survey was carried out in Border collies in Japan. The carrier frequency was 11.1%, suggesting that the mutant allele frequency is high enough to warrant measures to control and prevent the disease.     

Progressive retinal atrophy in Abyssinian and Somali cats in the Netherlands (1981-2001)

From 1981 to 2001, 248 Abyssinian and 127 Somali cats in the Netherlands were examined for hereditary eye disease. Distinct ophthalmoscopic signs consistent with hereditary progressive retinal atrophy (PRA) were observed in 11 Abyssinian cats, and subtle signs in 3 Abyssinian cats. A familial relationship was detected in 13 out of 14 of these cats, which supports a hereditary basis to the condition. Distinct funduscopic signs of retinal degeneration were observed at a median age of 4 years. One cat with advanced retinal degeneration was only 7 months old, whereas the remaining 10 cats were between 2 and 12 years old at the time of diagnosis. These differences in the age of onset are suggestive of at least two types of PRA occurring in Abyssinian cats in the Netherlands: a dysplastic, early-onset and a late-onset retinal degeneration. A large-scale and systematic examination programme for hereditary eye disease will be necessary to assess the incidence of PRA in the Dutch population of Abyssinian and Somali cats as a whole, and to provide a basis for a preventive breeding programme.     

Clinical course of pyruvate kinase deficiency in Abyssinian and Somali cats

The objective of this study was to examine clinical signs, laboratory parameters, and course of disease in Abyssinian and Somali cats with pyruvate kinase (PK) deficiency. The clinical course of 25 PK-deficient cats was followed over a time period of 0.8-11.3 years (median 4.3). Eleven cats (age 0.8-7.8 years, median 4.4) did not show signs according to the owners. In 14 cats (age 0.1-5 years, median 1.7) the owners noted lethargy (10), diarrhoea (seven), pale mucous membranes (six), inappetence (six), poor coat quality (six), weight loss (four), icterus (four), and pica (two). Sixteen cats had been used for breeding at least once before diagnosis. Laboratory abnormalities included anaemia (70%), increased aggregated reticulocyte counts (94%), hyperglobulinaemia (80%), hyperbilirubinaemia (53%), and increased liver enzymes (47%). Six of 25 affected cats died (four) or were euthanased (two) at ages ranging from 1.3 to 11.3 years (median 4.1) presumably because of PK-deficiency. These findings emphasise that PK deficiency shows variation in age of onset and severity of signs. As PK-deficient cats can be asymptomatic testing for PK deficiency before breeding is strongly recommended.     

Retrospective diagnosis of feline GM2 gangliosidosis variant 0 (Sandhoff-like disease) in Japan: possible spread of the mutant allele in the Japanese domestic cat population

GM2 gangliosidosis variant 0 (human Sandhoff disease) is a lysosomal storage disease caused by simultaneous deficiencies of acid beta-hexosaminidase (Hex) A and Hex B due to an abnormality of beta-subunit, a common component in these enzyme molecules, which is coded by the HEXB gene. In the present study, a retrospective diagnosis was performed in 2 previous suspected cases of feline Sandhoff-like disease using a DNA test to detect the causative mutation identified previously in 4 cats in 2 other families of Japanese domestic cats. Enzymic analysis was also performed using stored leukocytes and plasma collected from the subject families in order to investigate the usefulness of enzymic diagnosis and genotyping of carriers. The DNA test suggested that the 2 cases were homozygous recessive for the mutation. Consequently, 6 cats homozygous for the same mutation have been found in 4 separate locations of Japan, suggesting that this mutant allele may be spread widely in the Japanese domestic cat populations. In enzymic analysis, Hex A and Hex B activities in leukocytes and plasma measured using 4-methylumbelliferyl N-acetyl-beta-D-glucosaminide as a substrate were negligible in affected cats, compared with those in normal and carrier cats. However, there was a wide overlap in enzyme activity between normal and carrier cats. Therefore, it was concluded that enzymic analysis is useful for diagnosis of affected cats, but is not acceptable for genotyping of carriers.     

Distribution of Feline Blood Types Detected in the Copenhagen Area of Denmark

Jensen, A. L., A. B. Olesen and J. Arnbjerg: Distribution of feline blood types detected in the Copenhagen area of Denmark. Acta vet. scand., 1994, 35, 121-124.–The purpose of the present study was to make the first survey of the distribution of feline AB blood types in the Copenhagen area of Denmark. A total of 244 cats (139 purebred cats and 105 Domestic Shorthair cats) were tested. 93% of all tested cats had blood type A. Neither an AB nor an O type cat was detected and thus, the frequency of blood type B among all tested cats was 7%. Most type B cats were purebred cats (Birman, British Shorthair and Persian cats). No association between sex and blood type could be demonstrated among British Shorthair and Persian cats. Thus, the present study indicates that cats in Denmark predominantly have blood type A, and that blood type B cats are rare, except for certain breeds such as Birman and British Shorthair cats.     

Anemia, splenomegaly, and increased osmotic fragility of erythrocytes in Abyssinian and Somali cats

OBJECTIVE: To determine clinical and clinicopathologic features of a chronic intermittent severe hemolytic anemia characterized by erythrocyte osmotic fragility in Abyssinian and Somali cats. DESIGN: Case series. ANIMALS: 13 Abyssinian and 5 Somali cats. PROCEDURES: History, pedigree information, and results of routine laboratory tests, special erythrocyte studies, and histologic evaluation of splenic and hepatic specimens were analyzed. RESULTS: Age at which clinical signs of anemia were first apparent ranged from 6 months to 5 years. Ten cats had splenomegaly. Most often, the PCV was between 15 and 25%, but it was as low as 5% at some times. The anemia was characterized by macrocytosis and mild to moderate reticulocytosis, but no poikilocytosis. Hyperglobulinemia, lymphocytosis, mild hyperbilirubinemia, and high hepatic enzyme activities were common findings. Results of Coombs tests and tests for infectious diseases were negative. The erythrocytic osmotic fragility was high in affected cats (mean osmotic fragility, 0.66 to 0.78%), compared with healthy cats (0.48 to 0.58). No specific membrane protein abnormality, erythrocyte enzyme deficiency, or hemoglobinopathy was identified. Histologic evaluation of splenic and hepatic specimens revealed extramedullary hematopoiesis and hemosiderosis. Four of the 5 Somali cats were closely related. CONCLUSIONS AND CLINICAL RELEVANCE: On the basis of results of pedigree analyses, the apparent breed predilection, and the exclusion of other known causes of anemia in cats, we believe that the hemolytic anemia in these cats was likely a result of a novel hereditary erythrocyte defect. A genetic predisposition to immune-mediated destruction of erythrocytes could not be ruled out.     

Identification and genotyping of feline infectious peritonitis-associated single nucleotide polymorphisms in the feline interferon-γ gene

Feline infectious peritonitis (FIP) is an immune-mediated, highly lethal disease caused by feline coronavirus (FCoV) infection. Currently, no protective vaccine or effective treatment for the disease is available. Studies have found that some cats survive the challenge of virulent FCoV isolates. Since cellular immunity is thought to be critical in preventing FIP and because diseased cats often show a significant decrease in interferon-γ (IFN-γ) production, we investigated whether single nucleotide polymorphisms (SNP) in the feline IFN-γ gene (fIFNG) are associated with the outcome of infection. A total of 82 asymptomatic and 63 FIP cats were analyzed, and 16 SNP were identified in intron 1 of fIFNG. Among these SNP, the fFING + 428 T allele was shown to be a FIP-resistant allele (p = 0.03), and the heterozygous genotypes 01C/T and +408C/T were found to be FIP-susceptible factors (p = 0.004). Furthermore, an fIFNG + 428 resistant allele also showed a clear correlation with the plasma level of IFN-γ in FIP cats. For the identification of these three FIP-related SNP, genotyping methods were established using amplification refractory mutation system PCR (ARMS-PCR) and restriction fragment length polymorphisms (RFLP), and the different genotypes could easily be identified without sequencing. The identification of additional FIP-related SNP will allow the selection of resistant cats and decrease the morbidity of the cat population to FIP.     

The prevalence of feline A/B blood types in the Sydney region

OBJECTIVE: To determine the distribution of A/B blood types in pedigree and crossbred cats in the Sydney region, and to estimate the associated risk of administering incompatible blood in an unmatched random transfusion. DESIGN: A prospective/retrospective study of blood specimens collected from both sick and healthy cats. MATERIALS AND METHODS: Blood was collected from 355 cats from the Sydney region over a 12-year period from 1992 to 2003. Specimens were obtained from 187 domestic crossbred cats (short and long-haired) and 168 pedigree cats. The blood type of each cat was determined by one of three different laboratories using standard methods that varied over the duration of the survey. RESULTS: The distributions of blood types obtained by the three laboratories were not significantly different. The prevalence of type-A, type-B and type-AB blood types in crossbred cats was 62%, 36% and 1.6%, respectively. This is the highest percentage of type-B cats so far reported for an outbred population of domestic cats, and is significantly higher than the 26% reported previously for cats in the Brisbane region. The calculated frequency for the type-B allele assuming Hardy-Weinberg equilibrium for this feline population is 0.60; the corresponding frequency of the type-A allele is thus approximately 0.40. The calculated proportion of random transfusions from this population giving rise to an incompatible blood transfusion is 46%, with half of these being life-threatening events. The calculated proportion of random matings from this population at risk for developing neonatal isoerythrolysis is 23%. The distribution of A and B blood types for pedigree cats was in general agreement with data reported previously for cats in North America and Europe, suggesting that the distribution of blood types in these purebred populations is relatively consistent throughout the world. CONCLUSIONS: The prevalence of type B cats in the owned domestic and pedigree cat population is so high that blood typing or cross matching prior to transfusion should be mandatory, except in Siamese/Oriental cats.     

Diagnostic, treatment, and prevention protocols for feline heartworm infection in animal sheltering agencies

Cats are at risk for heartworm infection (Dirofilaria immitis) wherever the disease is endemic in dogs. Diagnosis is more difficult in cats, and little information is available regarding effective palliative and curative treatments for infected cats. In contrast to the challenges of diagnosis and treatment, chemoprophylaxis is highly effective, and current guidelines call for preventive medications to be administered to all cats in endemic areas. The purpose of this study was to survey feline heartworm management protocols used by 400 animal shelters and foster programs in the endemic states of Alabama, Florida, Georgia, and Mississippi. Only 23% of shelters performed feline heartworm testing. The most common reasons for not testing were expense (36%), lack of treatment options for infected cats (18%), and because the agency considers heartworm infections in cats to be less important than in dogs (12%). Most agencies (69%) did not provide preventive medication to cats. Reasons included because testing was not performed (36%), expense (35%), and the perception that local heartworm risk was low (10%). When preventive was provided, feline-labeled broad-spectrum products were used more commonly (81%) than livestock products (14%). The survey also indicated that many policy decisions were based on inaccurate knowledge of feline heartworm prevalence and pathogenesis. Issues of cost, feasibility, and education prevent most Southeastern sheltering agencies from adequately protecting cats against heartworm disease. Practical guidelines tailored to the needs of these agencies should be developed. Subsidized testing and preventive products may facilitate implementation of feline heartworm management protocols in sheltering agencies.     

Blood type A and B frequencies in Turkish Van and Angora cats in Turkey

Blood typing of domestic cats has been performed in domestic and purebred cats in various parts of the world and is important in clinical practice in order to prevent neonatal isoerythrolysis (NI) and acute haemolytic transfusion reactions. Prevalence of blood types vary greatly between breeds of cats. Turkish Van and Angora cats are different breeds that originated in geographically distinct regions of Turkey. The present survey determined the frequency of blood types in these Turkish pedigreed cats in Turkey. Ethylenediaminetetraacetic-acid anti-coagulated blood of a total of 113 Turkish Van and Angora cats were examined for blood typing using a slide and tube agglutination assay. Of the 85 Van cats surveyed, 40% had type A, and 60% had type B blood. Of the 28 Turkish Angora cats, 53.6% had type A, and 46.4% had type B blood. No type AB cats were found between both breeds. There was no significant association between blood types and gender of both Angora and Van cats or eye colours of Van cats (P > 0.05). Although these are limited surveys, the overall prevalence of type B cats in these two breeds was very high compared with the results of previous studies worldwide. It appears likely that blood type incompatibilities responsible for feline NI and transfusion reactions are occurring in these breeds. The risk of transfusion incompatibility in Turkish Angora and Van cats was 46.4 and 60%, respectively. It is therefore strongly recommended to breeders and clinicians that blood typing be performed prior to breeding and transfusing cats.     

Intestinal Tritrichomonas suis (=T. foetus) infection in Japanese cats

Tritrichomonas suis (=T. foetus) has recently been reported to be a causative agent of chronic large-bowel diarrhea in cats. While the disease was previously attributed to Pentatrichomonas hominis, the etiologic agent for feline trichomonal diarrhea was identified as T. suis. Although feline trichomonosis due to T. suis has been reported at prevalences ranging from 14 to 31% in Europe and the U.S., no reports of the pathogen have been published to date in Japan. In 2008, however, we encountered a case of feline trichomonosis at the Veterinary Teaching Hospital of Hokkaido University. The parasite was identified as T. suis by nested PCR amplification of partial internal transcribed spacer region 1 and 5.8S ribosomal RNA gene sequences with T. suis-specific primers and DNA sequencing of the amplified products. We then conducted surveys for feline trichomonosis in three different animal hospitals using either cultivation and/or PCR-based assays. The results revealed that 13 of 147 samples (8.8%) were positive for T. suis, and that 5 of the 13 infected cats, which ranged between 1 month and 7.5 years-old, showed chronic diarrhea. Seven of the infected cats were purebred and 6 were mixed breed. These findings suggested that feline trichomonosis is prevalent in Japan, and that T. suis may play a role as a causative agent of feline chronic diarrhea.     

Feline immunodeficiency virus infection in cats of Japan

A seroepidemiologic survey for feline immunodeficiency virus (FIV) infection was conducted in Japan. Between June and December 1987, individual sera (n = 3,323) were submitted by veterinary practitioners from many parts of the country. Specimens were from 1,739 cats with clinical signs suggestive of FIV infection and from 1,584 healthy-appearing cats seen by the same practitioners. The overall FIV infection rate among cats in Japan was 960/3,323 cats (28.9%). The infection rate was more than 3 times higher in the clinically ill cats, compared with that in the healthy cats of the same cohort (43.9 vs 12.4%). Male cats were 1.5 times as likely to be infected as were females. Almost all FIV-infected cats were domestic cats (as opposed to purebred cats). Complete clinical history was available for 700 of 960 FIV-infected cats. Of these 700 FIV-infected cats, 626 (89.4%) were clinically ill, and the remainder did not have clinical signs of disease. The mean age at the time of FIV diagnosis for the 700 cats was 5.2 years, with younger mean age for males (4.9 years) than for females (5.8 years). Most of the infected cats (94.7%) were either allowed to run outdoors or had lived outdoors before being brought into homes. The mortality for FIV-infected cats during the 6 months after diagnosis was 14.7%, and the mean age at the time of death was 5.7 years. Concurrent FeLV infection was seen in 12.4% of the FIV-infected cats, but this was not much different from the historical incidence of FeLV infection in similar groups of cats not infected with FIV.(ABSTRACT TRUNCATED AT 250 WORDS)     

Acute Hemolytic Transfusion Reaction in an Abyssinian Cat With Blood Type B

After receiving a transfusion with unmatched blood, an anemic Abyssinian cat developed an acute hemolytic transfusion reaction. Similar to many other purebred cats, the recipient had type B blood with strong serum anti-A alloantibodies, whereas the donor had blood type A. Subsequent transfusions with type B blood proved effective and without adverse reactions. This case of a clinical A-B incompatibility reaction emphasizes the need for blood typing and/or crossmatching prior to transfusing cats.     

Frequencies of feline blood types in Hungary

Feline blood group determination is done as a routine diagnostic method in numerous countries. Blood transfusion reactions and feline neonatal isoerythrolysis (FNI) can be avoided with the identification of different feline blood groups. The present study is the first investigation in Hungary during which 100 cats have been examined from all over the country. These cats were out of six breeds: European domestic shorthair, Persian mix, Persian, Abyssinian, Siamese and British shorthair. In the Hungarian feline population European domestic shorthair are most common but other breeds also occur. European domestic shorthair, Persian mix, Abyssianian, Siamese and British shorthair individuals all belonged to blood type A (100%). Blood type B was found very rarely and only in Persian cats. One-third of the Persian cats were categorised into blood type B, whilst type AB was not found during the study.     

Disseminated Mycobacterium avium infection in young cats: overrepresentation of Abyssinian cats

Disseminated Mycobacterium avium-intracellulare complex (MAC) infection was diagnosed in 10 young cats (1-5 years of age) from Australia or North America between 1995 and 2004. A further two cats with disseminated mycobacteriosis (precise agent not identified) were recognised during this period. Of the 12, 10 were Abyssinian cats, one was a Somali cat and one was a domestic shorthair cat. None of the cats tested positive for either FeLV antigen or FIV antibody. The clinical course of these infections was indolent, with cats typically presenting for weight loss, initially in the face of polyphagia, with a chronicity of up to several months. Additional clinical features included lower respiratory tract signs and peripheral lymphadenomegaly. A marked diffuse interstitial pattern was evident in thoracic radiographs, even in cats without overt respiratory involvement. Hair clipped to perform diagnostic procedures tended to regrow slowly, if at all. Diagnosis was generally made by obtaining representative tissue specimens from mesenteric lymph nodes, liver or kidney at laparotomy, or from a popliteal lymph node. The primary antecedent event was most likely colonisation of either the alimentary or respiratory tract, followed by local invasion and eventual lymphatic and haematogenous dissemination. Nine cases were treated using combination therapy with agents effective for MAC infection in human patients. Two cats are still undergoing initial therapy and have responded. Of the remaining seven, all responded during long courses (5-14 months) of clarithromycin combined with either clofazimine or rifampicin, and a fluoroquinolone or doxycycline. Of these, three cats remain well (with durations between 2 months and 2 years following therapy); two developed recurrent disease (at 3 months and 2 years, respectively, following therapy) and have restarted therapy. The remaining two cats improved 1 year and 5 months, respectively, after diagnosis but ultimately succumbed. The two cats in which therapy was restarted have improved dramatically. Certain lines of Abyssinian and Somali cats likely suffer from a familial immunodeficiency that predisposes them to infection with slow-growing mycobacteria such as MAC.     

Serum amyloid A protein concentration measured by radial immunodiffusion in Abyssinian and non-Abyssinian cats

Serum amyloid A (SAA) protein concentration was determined by use of radial immunodiffusion (RID) in 4 groups of cats: Abyssinian cats with amyloidosis, healthy Abyssinian cats without clinical evidence of amyloidosis, hospitalized non-Abyssinian cats, and clinically normal non-Abyssinian cats. Mean SAA concentration in Abyssinian cats with amyloidosis was significantly (P = 0.05) higher than mean SAA concentration in healthy Abyssinian cats without clinical evidence of amyloidosis and in hospitalized non-Abyssinian cats. Mean SAA concentration in clinically normal non-Abyssinian cats was significantly (P = 0.05) lower than mean SAA concentration in healthy Abyssinian cats without clinical evidence of amyloidosis and in hospitalized non-Abyssinian cats. Affected and healthy Abyssinian cats, however, could not reliably be distinguished on the basis of SAA concentration, because of the wide range of SAA values in these 2 groups of cats.     

Feline immunodeficiency virus, feline leukemia virus and Toxoplasma gondii in stray and household cats in Kerman-Iran: Seroprevalence and correlation with clinical and laboratory findings

This study was carried out to determine the seroprevalence of feline leukemia virus (FeLV), feline immunodeficiency virus (FIV) and Toxoplasma gondii (T. gondii) infection among stray and owned cats in southeastern Iran and to identify the influence of age, sex, lifestyle, health status, and laboratory findings on seropositivity. The overall infection rate for FIV, FeLV, and T. gondii was 19.2%, 14.2%, and 32.1% respectively. Results of the multivariate logistic regression analysis showed that old adults more likely to be seropositive than juveniles for FIV, FeLV, and T. gondii (adjusted odds ratios [ORs], 1.84, 1.56, and 2.57 respectively). Anemic and diseased cats ([ORs], 6.62 and 0.9) were at a greater risk of testing positive for FeLV. Male cats were 4.91 times as likely to have FIV as were female and hyperglobulinemia was significantly more prevalent in FIV-infected cats ([ORs], 3.4). In conclusion, FIV and FeLV seem to be endemic in Iran and retroviral-associated immunosuppression may be a risk factor for active toxoplasmosis in infected cats.