Polycythemia vera in a cat with cardiac hypertrophy

Polycythemia vera, a rare and poorly documented disease in cats, was diagnosed in a 4-year-old domestic shorthair cat admitted because of seizures. The diagnosis was made on the basis of high PCV, normal serum erythropoietin concentration (as determined by bioassay, using rabbit bone marrow cells), and elimination of secondary polycythemia as a diagnosis. Cardiac hypertrophy, which might have been secondary to blood hyperviscosity, also was diagnosed. The cat has been treated by periodic phlebotomy and has been without clinical signs of disease for more than 20 months.     

The effect of phlebotomy on canine erythrocyte metabolism.

Enzyme activity declines with erythrocyte age in most mammals. To test this concept in the dog, we decreased the PCV to less than 20 by phlebotomy. The erythrocytes were restored rapidly (1.57 per cent per day). The resulting decline in the mean erythrocyte age was accompanied by increased activity by most of the erythrocyte enzymes studied. Enzymes with lower initial enzymatic activity (hexokinase, pyruvate kinase, 6-phosphogluconate dehydrogenase and glutathione reductase) increased proportionally more than those with higher initial activity (lactate dehydrogenase, 3-phosphoglycerate kinase, glyceraldehyde-3-dehydrogenase and glucose-6-dehydrogenase). Among species, increases in enzyme activity after phlebotomy appear to be related to each species' life span. Most of the metabolites increased concomitantly with the highest reticulocyte period. Diphosphoglycerate concentrations did not change significantly during the experiment.     

Primary erythrocytosis in the cat: Treatment with hydroxyurea

Primary erythrocytosis was diagnosed in six adult neutered domestic cats. All the cats showed varying signs of neurological dysfunction, including seizures, blindness, abnormal behaviour, episodes of ataxia, dilated pupils and foaming at the mouth. Other signs included polyuria, polydipsia, lethargy, wobbly gait, head bobbing and twitching. Affected animals had initially high packed cell volumes (PCV) (0.63 to 0.82 litres/litre) without any identifiable cause of relative or secondary erythrocytosis. Serum erythropoietin concentrations were low or normal in four cats, equivocal in one and undetermined in one. Primary erythrocytosis was diagnosed, rather than polycythaemia vera, as abnormalities often associated with the latter were uncommon (granulocytosis, splenomegaly) or unrecorded (thrombocytosis, hepatomegaly). The six cats were treated with hydroxyurea and five had phlebotomies. All remain well at least 10 months after treatment began, and two have survived more than six years, despite potential complications with hydroxyurea, including neutropenia, anaemia and methaemoglobinaemia.     

Polycythaemia vera in a dog

Polycythaemia vera or primary polycythaemia is a myeloproliferative disorder which is rare in dogs and cats. A case of polycythaemia vera in a dog is described and the available forms of therapy and the problems connected with therapy which may be encountered by veterinary surgeons in general practice are discussed.     

Survey of canine and feline follicular tumours and tumour-like lesions in central Italy

Between January 1985 and June 1997, a total of 4005 skin biopsies were received from dogs and 898 from cats. Follicular tumours and tumour-like lesions together represented 10.4 per cent and 8.1 per cent of all skin tumours in the dog and cat, respectively. The prevalence of tumour-like lesions, such as follicular and dermoid cysts, dilated pore and focal adnexal dysplasia, was highest, representing 41.2 per cent and 68 per cent of all follicular lesions in dogs and cats, respectively. In the dog, follicular tumours were distributed as follows: trichoblastoma (25.6 per cent of all tumours and tumour-like lesions), infundibular keratinising acanthoma, (14 per cent), pilomatricoma (13 per cent), trichoepithelioma (3.9 per cent) and tricholemmoma (2.3 per cent). In the cat, the distribution was 26 per cent for trichoblastoma, 4 per cent for trichoepithelioma and 2 per cent for pilomatricoma. Tumour-like lesions and infundibular keratinising acanthoma in the dog were mostly located on the trunk, trichoblastoma and tricholemmoma on the head, and pilomatricoma on the neck. In the cat, both tumour-like lesions and trichoblastoma were frequently present on the neck and head.     

Secondary polycythaemia associated with high plasma erythropoietin concentrations in a dog with a necrotising pyelonephritis

An 11-year-old mixed breed dog was presented with anorexia, apathy and intermittent macrohaematuria, absolute polycythaemia (packed cell volume, 80 per cent; red blood cell, 12.2 x 10(6)/microl) and elevated erythropoietin concentrations. A renal mass was detected by ultrasonography and, following total nephrectomy, diagnosed as necrotising pyelonephritis. After surgery, the haematological parameters and erythropoietin values returned to normal, suggesting that the pyelonephritis was the cause of the polycythaemia. While secondary polycythaemia because of a non-neoplastic condition of the kidneys occasionally occurs in human beings, it has only extremely rarely been reported in dogs. This is the first case report of a unilateral pyelonephritis causing secondary polycythaemia in a dog.     

Effects of dietary protein and stage of lactation on the haematology and erythrocyte enzymes activities of high-producing dairy cattle.

Blood samples were collected monthly over a nine-month period from 19 high-producing Holstein-Friesian dairy cows. Dry cows on the lowest (13 per cent) protein ration had the highest mean values for packed cell volume (PCV), haemoglobin (Hb) and red blood cells (RBC). Among the lactating cows, the group on the 13 per cent protein diet had the highest mean PCV, Hb and RBC values. Other constituents were not affected significantly by dietary protein levels. Packed cell volume, RBC, Hb, serum iron (SI), iron binding capacity (IBC) and serum albumin concentrations decreased early in lactation and rose to pre-lactation levels by mid-lactation. PCV and Hb concentrations remained low for periods up to four months. RBC count was lowest in the second month while albumin concentration was lowest in the first month and remained low up to the second month. IBC was lowest in the first month of lactation while SI concentrations were lowest in the third month. There were no significant variations in the activities of erythrocyte glucose-6-phosphate dehydrogenase (G6PD), 6-phosphogluconate dehydrogenase (6PGD) and reduced glutathione (GSH). The 13 per cent protein ration had no anaemia-inducing effect on the cows.     

Complications of exploratory coeliotomy in 70 cats

Records of all cats that had undergone exploratory coeliotomy at the University of Edinburgh during the period November 1995 to July 2002 were reviewed. Seventy records were retrieved. There were 30 cats in which infection or inflammatory disorders predominated, 17 cats with neoplasia, three cats with trauma and 20 cats with other disorders. Exploratory coeliotomy was performed for diagnostic purposes in 28 cats (40 per cent), treatment in 34 cats (49 per cent) and for diagnosis and treatment in eight cats (11 per cent). Methods of intraoperative diagnosis included incisional biopsy of abdominal organs (52 cats), cytology (two cats), microbiology (17 cats) and gross appearance (17 cats). Fifty-eight cats (83 per cent) survived the hospitalisation period. Complications occurred in 18 cats (26 per cent) and were related to anaesthesia (four cats), the underlying disease process (15 cats), surgery (five cats) and were undetermined in one cat.     

Intussusception in 12 cats

The medical records of 12 cats presented with intussusception and diagnosed at the University of Sydney Veterinary Teaching Hospital and the Sylvania Veterinary Hospital were reviewed. Eleven cats were less than one year old at the time of diagnosis. No breed or sex predilections were determined. The most consistent clinical signs were anorexia (83 per cent), weight loss (83 per cent) and a palpable abdominal mass (92 per cent). Vomiting (58 per cent) and diarrhoea (50 per cent) were seen less frequently in these cats compared with the reported incidence of these signs in dogs. In 10 cats the intussusception was corrected surgically. Manual reduction was successful in three of the cats but six required end-to-end anastomosis following intestinal resection and in one cat a typhlectomy was performed. Postoperative ileus complicated recovery in three cases. Recurrence of the intussusception at a different site occurred in two of these cases. One cat with recurrence of intussusception died and the cat with ileus but not recurrence was euthanased one month after the original surgery.     

Survival of 54 cats with oral squamous cell carcinoma in United Kingdom general practice

OBJECTIVES: To determine the survival of 54 cats with histologically confirmed feline oral squamous cell carcinoma (FOSCC) treated in UK general practice and to determine factors predictive for survival. METHODS: Cases were identified from consecutive samples submitted for histological diagnosis. Observational and survival data were collated retrospectively from submitting practices. Immunohistochemical analysis of cyclooxygenase (COX) expression variables was available using previously published data. Kaplan-Meier product limit estimation for overall survival and Cox proportional hazards regression for potential explanatory variables were performed. RESULTS: The overall median survival time was 44 days [95 per cent confidence interval (CI): 31-79] and 1 year survival was 9.5 per cent. Variables associated with survival were whether the cat was pedigree [hazard ratio (HR)=8.17, 95 per cent CI: 1.96-34.12], whether the cat received non-steroidal anti-inflammatory drug (NSAID) therapy after diagnosis (HR=0.46, 95 per cent CI: 0.21-0.98) and whether the COX-1 staining distribution was patchy rather than diffuse (HR=0.25, 95 per cent CI: 0.08-0.014). CLINICAL SIGNIFICANCE: This study suggests that although the prognosis for inoperable FOSCC remains poor, palliative treatments may offer a survival advantage that compares favourably with more aggressive treatment methods. Further work is needed to evaluate NSAID therapy in this disease, in particular to determine whether the potential survival advantage is because of an analgesic or anticancer effect or both. COX-1 distribution patterns may have a role as a prognostic indicator in this disease.     

Differentiation of porcine circovirus 1 and 2 in formalin-fixed, paraffin-wax-embedded tissues from pigs with postweaning multisystemic wasting syndrome by in-situ hybridisation

Non-radioactive digoxigenin (DIG)-labelled probes that can differentiate porcine circovirus (PCV) 1 from PCV2 in formalin-fixed, paraffin-wax-embedded tissues by in-situ hybridisation were developed. A 349 base pair (bp) DNA fragment from open reading frame (ORF) 1 of PCV1 and a 481 bp DNA fragment from ORF2 of PCV2 generated by polymerase chain reaction (PCR) were used as PCV1 and PCV2 probes, respectively. A specific DIG-labelled PCV1 DNA probe did not hybridise with PCV2-infected PK-15 cells and vice versa. From the 40 field cases with postweaning multisystemic wasting syndrome tested by in-situ hybridisation, 30 (75 per cent) cases were PCV2-positive only and 10 (25 per cent) cases were positive for both PCV1 and PCV2. PCV1 and PCV2 DNAS were detected mainly in the macrophages of lymph nodes and spleens. Positive cells typically exhibited a dark brown to black reaction product mainly in the cytoplasm but also occasionally in the nucleus. In-situ hybridisation together with the differential probes developed in the present study represent an additional tool capable of differentiating of both types of PCV in formalin-fixed, paraffin-wax-embedded tissues.     

Prevalence of chlamydia, toxoplasma, toxocara and ringworm in farm cats in south-west England

The prevalence of infection with Chlamydia psittaci, Toxoplasma gondii, Toxocara cati and Microsporum canis was examined in 51 cats on 22 sheep farms in the Bristol area. Serum antibody to C psittaci and T gondii was present in 45 per cent and 47 per cent of cats, respectively. At the time of sampling C psittaci was isolated from 6 per cent of the cats, T cati was identified in 63 per cent of faecal samples but neither T gondii nor M canis was isolated. When examined according to the farm of origin, 22.7 per cent of farms had cat populations with no evidence of infection with C psittaci or T gondii. Of the remainder, 45.5 per cent supported cat populations with evidence of both infections and 31.8 per cent had evidence of T gondii infection alone. None of the farms had cat populations with evidence of C psittaci infection alone. Two of the cats infected with C psittaci were excreting viable organisms in the faeces. The possible significance of this to the epidemiology of ovine enzootic abortion is discussed.     

Thyroid function in the cat: assessment by the TRH response test and the thyrotrophin stimulation test

Changes in total thyroxine (T4), free T4 and total tri-iodothyronine (T3) were measured in 13 cats after the intravenous injection of varying doses of thyrotrophin stimulating hormone (TSH) (0–5 U/cat n = 6; 1 U/cat n = 8; 1 U/kg bodyweight, n = 7) or thyrotrophin releasing hormone (TRH) (100 ug/cat, n = 10). All three doses of TSH resulted in a significant (P < 0–05) rise in T4, free T4 and T3 levels, with the mean peak in hormone concentrations occurring six to eight hours after injection. The three doses of TSH all appeared to produce maximal stimulation of thyroid hormone secretion. The mean percentage increase in hormone concentrations at seven hours following the three doses of TSH ranged from 167 to 198 per cent for T4, 240 to 365 per cent for free T4, and 73 to 116 per cent for T3. Following administration of TRH there was also a significant (P < 0–05) rise in T4, and free T4. The mean peak in T4 and free T4 levels occurred at four hours, and mean increases in hormone levels at this time were 92 per cent for T4, and 198 per cent for free T4. The administration of TRH produced little change in T3 levels. TSH administration resulted in a significantly higher (P < 0–05) percentage peak increase in T4, free T4 and T3 levels at all three dosages than did TRH.     

Resolution of renal adenocarcinoma-induced secondary inappropriate polycythaemia after nephrectomy in two cats

Two cases of secondary, inappropriate polycythaemia caused by renal adenocarcinoma in domestic shorthair cats, are described. The cats were 9 and 12 years old and both were presented because of generalised seizures presumably due to hyperviscosity. Both cats had a markedly increased haematocrit (0.770 and 0.632 l/l) and thrombocytosis (744 x 10(9)/l and 926 x 10(9)/l). An abdominal ultrasound revealed a mass in the cranial pole of one kidney in both cats. Serum erythropoietin (EPO) concentration was within the reference interval (RI) in both cats but was inappropriately high considering the markedly increased haematocrit. The cats were initially stabilised and managed by multiple phlebotomies and intravenous fluid therapy and underwent nephrectomy of the affected kidney later on. Both the polycythaemia and thrombocytosis resolved following surgery. Postoperative serum EPO concentration, measured in one cat, decreased markedly. Histopathology of the affected kidneys confirmed a diagnosis of renal adenocarcinoma. Both cats were stable for an 8-month follow-up period; however, one cat had developed a stable chronic kidney disease (CKD), while the other was represented 8 months postoperatively due to dyspnoea, and had radiographic evidence of lung metastasis, presumably because of the spread of the original renal tumour and was euthanased. Initial stabilisation of polycythaemic cats should include multiple phlebotomies. Nephrectomy should be considered in cats with secondary, inappropriate, renal adenocarcinoma-related polycythaemia when only one kidney is affected by the tumour, and provided that the other kidney's function is satisfactory. Nephrectomy should be expected to resolve the polycythaemia and lead to normalisation of serum EPO concentration.     

Prevalence of feline leukaemia virus and antibodies to feline immunodeficiency virus in cats in the United Kingdom

A representative sample of the pet cat population of the United Kingdom was surveyed. Blood samples from 1204 sick and 1007 healthy cats of known breed, age and sex were tested for antibodies to feline immunodeficiency virus (FIV) and feline leukaemia virus (FeLV). The prevalence of FIV was 19 per cent in sick cats and 6 per cent in healthy cats, and the prevalence of FeLV was 18 per cent in sick cats and 5 per cent in healthy cats; both infections were more common in domestic cats than in pedigree cats. Feline immunodeficiency virus was more prevalent in older cats but FeLV was more prevalent in younger cats. There was no difference between the prevalence of FeLV in male and female cats but male cats were more likely to be infected with FIV than female cats. No interaction was demonstrated between FIV and FeLV infections. Of the cats which were in contact with FIV in households with more than one cat, 21 per cent had seroconverted. The prevalence of FeLV viraemia in cats in contact with FeLV was 14 per cent. The clinical signs associated with FIV were pyrexia, gingivitis/stomatitis and respiratory signs, and with FeLV, pyrexia and anaemia. It was concluded that both viruses were significant causes of disease, and that the cats most likely to be infected with FIV were older, free-roaming male cats and for FeLV, younger, free-roaming cats.     

Comparative studies on N''Dama and zebu cattle following repeated infections with Trypanosoma congolense

Twenty N'Dama and eight zebu cattle were inoculated intradermally with bloodstream forms of a cloned strain of Trypanosoma congolense originating from East Africa. All inoculated cattle became parasitaemic. Zebus showed consistently higher levels of parasitaemia and lower packed red cell volume (PCV) percentages than did N'Damas. Three of the eight zebus required treatment when high numbers of trypanosomes were present in the blood and PCV values dropped below 15 per cent. None of the N'Dama cattle needed treatment. Statistical analysis was performed on the data to assess the variability of parasitaemia and PCV levels before and during infection of the N'Dama cattle. The variation in PCV values was large between individuals during the early stages of the disease and diminished as infection continued. After trypanocidal drug treatment and a recovery period of 14 months, the same animals were inoculated intradermally with T congolense bloodstream forms isolated and cloned in The Gambia. Differences in susceptibility to the ensuing disease were apparent when comparing N'Dama and zebu cattle. Five zebu cattle needed trypanocidal drug treatment, while none of the N'Damas needed drug intervention. Ranking the 20 infected N'Damas according to average PCV levels revealed that the animals responded similarly to both infections.     

Glycated haemoglobin in various pathological conditions: investigations based on a new, fully automated method

A new automated affinity chromatographic method for determining glycated haemoglobin (GHb) in dogs and cats was tested. The method appeared to be practical, quick and accurate. The reference range, calculated on the basis of 50 healthy dogs and 43 healthy cats, lay between 2·4 and 3·4 per cent in dogs and 2·0 and 2·9 per cent in cats. Concentrations were not influenced by age or gender. GHb levels obtained for 21 dogs and 18 cats with newly diagnosed diabetes mellitus were significantly higher than those of the control animals, ranging from 4·5 to 8·6 per cent (median 6·1) in dogs and from 2·7 to 6·0 per cent (median 3.8 per cent) in cats. The GHb levels in 31 normoglycaemic dogs with anaemia ranged from 2·3 to 4·3 per cent (median 3·3 per cent), and those of 22 normogiycaemic cats with anaemia from 2·6 to 3·9 per cent (median 3·2 per cent); both sets of levels were significantly elevated compared to control group values. GHb concentrations in animals with polycythaemia, azotaemia or liver disease showed no significant deviations from the control group; in individual cases they were slightly elevated compared to the reference range. The automated measuring method employed can be used to determine GHb in dogs and cats. Anaemic animals should generally be excluded from the GHb determination.     

Molecular analysis of isolates of feline calicivirus from a population of cats in a rescue shelter.

Two visits, six weeks apart, were made to a cat rescue shelter and single oropharyngeal swabs were taken from all the compliant cats. Feline calicivirus was isolated from 14 of 45 swabs (31 per cent) taken on the first visit and 12 of 46 swabs (26 per cent) taken on the second visit. Nucleotide sequences were obtained for nine isolates from the first visit, six isolates from the second visit, and for the vaccine virus used in the cattery. Distance analysis showed that the majority of the isolates could be assigned to one of two groups. All the isolates obtained from cats sharing the same pen or isolates obtained from the same cat on successive visits, were less than 5 per cent distant, whereas most of the isolates from cats in different pens were more than 20 per cent distant. Phylogenetic analysis showed that at least seven distinct field isolates were present in the cattery. The only good evidence for virus transmission within the cattery was a case in which two viruses isolated from cats in different pens had sequences that were less than 5 per cent distant.     

Distribution of T and B cells in thymus, blood and lymph nodes of the cat.

The proportions of T and B cells in the thymus, blood and lymph nodes were estimated in cats from three months to three years of age. T cells were identified by formation of E rosettes with guinea-pig red blood cells and B cells by the presence of surface immunoglobulin (Ig) as shown by the mixed antiglobulin reaction. Using a double test, it was shown that these methods identify separate, non-overlapping cell populations. The proportions of T cells shown in the thymus ranged from 10-73 per cent, in the blood 5-62 per cent and in the nodes, 5-44 per cent. Cells with surface Ig ranged from 0-10 per cent in the thymus, 26-68 per cent in the blood and 32-18 per cent in the nodes. Two cats with lymphadenopathy had unusually high B cell counts and one cat with depletion of the thymus was deficient in peripheral T cells. Papain treatment reduced or abolished E rosette formation by T cells.     

Percutaneous fine-needle biopsy of deep thoracic and abdominal masses in dogs and cats

Percutaneous fine-needle biopsy was used to investigate thoracic and abdominal masses in the dog and cat. One hundred and thirty-two cases were included in the study; 20 cases were excluded from the comparative study due to poor cellularity or blood contamination (retrieval rate 86.8 per cent). One hundred samples (56 dogs and 44 cats) were classified by cytology as neoplastic. All the cytological diagnoses of neoplasia were confirmed by histological samples obtained either by non-surgical methods, at surgery or during postmortem examination. No false positive diagnoses of neoplasia were made. Thirty-two samples were cytologically classified as 'negative for neoplasia'. Subsequent histological examination revealed 18 true negative and 14 false negative results. The procedure had an overall 89.4 per cent (118 cases out of 132) agreement between the diagnosis of inflammatory disease versus neoplasia, with a sensitivity of 87.8 per cent, a specificity of 100 per cent, a predictive value of a positive test of 100 per cent and a predictive value of a negative test of 56.3 per cent.