Serial changes in the concentrations of cortisol and thyroid hormones in Beagle dogs infected with Babesia rossi.

An experimental infection using Babesia (B.) rossi was performed in healthy male Beagle dogs to assess the changes in endocrine variables during disease. Two dogs were infected with a low dose (LD) of parasite inoculum (104 parasites) and three dogs were infected with a high dose (HD) (108 parasites). Basal serum cortisol, thyroxine (T4), and thyrotropin (TSH) concentrations were measured every second day. Samples were analyzed using a solid- phase, competitive chemiluminescent enzyme immunoassay (Immulyte® 2000, Siemens). Variables were compared between groups and timepoints using linear mixed models. In both groups, the median cortisol concentration increased, whilst the median T4 concentration decreased after infection, with a return towards baseline concentration post treatment. The highest cortisol and the lowest T4 concentrations were reached at 96 h and 108 h post infection, respectively, in the HD group and slightly later at 108 and 144 h post-infection, respectively, in the LD group. A higher cortisol concentration with a more rapid increase, and a lower T4 concentration with a more rapid decline, were associated with disease severity and a higher dose of parasite inoculum. The TSH concentration remained within the reference interval throughout the study period. This study illustrated the temporal changes in endocrine parameters during experimental B. rossi infection and demonstrated that cortisol and T4 tracked the severity of disease, albeit in opposite directions.

Evaluation of acute kidney injury in dogs with complicated or uncomplicated Babesia rossi infection.

Dogs with babesiosis can present with multiple complications, including acute kidney injury (AKI). The objective of this study was to characterize AKI in dogs with babesiosis caused by Babesia rossi at presentation and after treatment. Thirty-five client-owned dogs with B. rossi infection and 10 control dogs were included in this prospective observational study. Blood and urine were collected in Babesia-infected dogs at presentation (T0, n = 35), after 24 h (T24h, n = 11), and after 1 month (T1m, n = 9). The following urinary kidney injury biomarkers were assessed: urinary protein to creatinine ratio (UPC), urinary glomerular injury biomarkers (immunoglobulin G (uIgG) and C-reactive protein (uCRP)), and urinary tubular injury biomarkers (retinol-binding protein (uRBP) and neutrophil gelatinase-associated lipocalin (uNGAL)). Serum functional renal biomarkers were creatinine (sCr) and symmetric dimethylarginine (sSDMA). Post-mortem kidney biopsies were analyzed by light and transmission electron microscopy. At T0, all kidney injury biomarkers were significantly higher in Babesia-infected dogs compared to healthy controls (P < 0.001), while functional renal biomarkers were not significantly different (P > 0.05). At T24h, all urinary tubular injury biomarkers and UPC decreased significantly (P < 0.01), while glomerular injury biomarkers did not (P = 0.084). At T1m, all urinary kidney injury biomarkers decreased to values not significantly different from healthy controls (P > 0.5). Significant changes in functional renal biomarkers were not seen after treatment (P > 0.05). Dogs with complicated babesiosis had significantly higher glomerular injury biomarkers, UPC, and sSDMA compared to uncomplicated cases (P < 0.05), while all tubular injury biomarkers and sCr were not significantly different (P > 0.1). Dogs with babesiosis caused by B. rossi showed transient kidney injury, which was detected by all kidney injury biomarkers, but remained undetected by functional biomarkers. All infected dogs, irrespective of disease severity, suffered comparable kidney injury based on tubular injury biomarker concentrations, while loss of function was seen more often in dogs with complicated babesiosis based on sSDMA results.

Long-term follow-up of owned, free-roaming dogs in South Africa naturally exposed to Babesia rossi.

Babesia rossi is an important, tick-borne intraerythrocytic protozoan parasite; however, its natural history and epidemiology is poorly understood. Babesia rossi is the most virulent Babesia sp. in domestic dogs and is generally considered to cause severe babesiosis, which is fatal if left untreated. However, subclinical infections and mild disease from B. rossi have been reported, although the clinical progression of these cases was not reported. Therefore, to better understand B. rossi under field conditions, we evaluated its clinical progression and seroprevalence in an owned, free-roaming dog population in Zenzele, South Africa, where the parasite is endemic and prevention is not routine. The entire dog population in Zenzele was monitored intensively at the individual level from March 2008 until April 2014, primarily for a longitudinal study on rabies control. Subsequent evaluation of B. rossi comprised analyses of clinical and laboratory data collected from the Zenzele dog population during the 6 year study period. A substantial proportion (31% (n = 34)) of 109 dogs (randomly selected from every available dog in February/March 2010 older than ~6-8 weeks (n = 246)) tested by Indirect Fluorescent Antibody Test had seroconverted strongly to B. rossi. All 34 dogs were generally consistently healthy adults, determined from regular clinical examinations between March 2008 and April 2014. Blood smear examinations at multiple time points between July 2009 and February 2011 were also undertaken for almost all of these (34) seropositive dogs and all those tested were consistently negative for Babesia spp. Subclinical infections and mild disease were also the main findings for a separate group of 18 dogs positive for Babesia spp. on blood smear examination and confirmed to be infected with B. rossi by Polymerase Chain Reaction - Reverse Line Blot. Almost all of these dogs were positive at only one time point from repeat blood smear examinations between July 2009 and February 2011. We suggest that these observations are consistent with immunity acquired from repeated, low-level exposure to the parasite, generating transient subclinical infections or mild disease. Should this be the case, the use of tick control, particularly in adult dogs in free-roaming populations in B. rossi endemic regions, should be carefully considered.

Renal azotemia and associated clinical and laboratory findings in dogs with Babesia rossi infection.

The occurrence of acute kidney injury in canine babesiosis is not well documented. Furthermore, interpretation of urine specific gravity (USG) to assess renal concentrating ability is hampered by the frequent presence of hemoglobinuria in this disease. This cross-sectional study aimed to test the hypothesis that renal azotemia (RA) is underdiagnosed according to current canine babesiosis literature by determining its occurrence at presentation, using urine osmolality instead of USG to measure urinary concentration. The second objective was to examine potential associations between the presence of RA and selected clinical and laboratory variables at presentation. Medical records available from 3 previously performed prospective data collections were reviewed retrospectively. Client-owned dogs that were diagnosed with babesiosis caused by Babesia rossi, were included if a complete blood count, biochemistry profile, and urinalysis was performed at admission. Urine osmolality was measured to identify dogs with RA. Differences between dogs with RA and dogs without RA were assessed by nonparametric statistics. One hundred and fifty-two dogs were included, of which 26 (17%) were azotemic at admission. The occurrence of RA was 14% (21/152), hence 81% (21/26) of all azotemic dogs were diagnosed with RA. In contrast, when diagnosis of RA was based on an admission USG < 1.030, only 23% (6/26) of the azotemic dogs would have been considered to have RA. Several signalment and clinicopathological findings were found to be associated with the presence of RA, including older age, and the presence of collapse, hypoglycemia, hyperphosphatemia, cerebral babesiosis, and acute respiratory distress syndrome. Lastly, survival at discharge was significantly lower in dogs diagnosed with RA at presentation. Our results clarified that RA is more common than previously reported in B. rossi. This study also demonstrated that USG determination is not a reliable method to evaluate renal concentrating ability in azotemic dogs with babesiosis. Thus, if available, urine osmolality should be part of the diagnostic work-up of dogs infected with B. rossi to avoid misclassification of dogs with RA as having prerenal azotemia. If urine osmolality cannot be measured, clinicians should realize that most azotemic dogs with B. rossi infection have RA.

Biomarkers in canine parvovirus enteritis.

Canine parvovirus (CPV) enteritis has, since its emergence in 1978, remained a common and important cause of morbidity and mortality in young dogs. The continued incidence of parvoviral enteritis is partly due to the virus' capability to evolve into more virulent and resistant variants with significant local gastrointestinal and systemic inflammatory sequelae. This paper reviews current knowledge on historical-, signalment-, and clinical factors as well as several haematological-, biochemical- and endocrine parameters that can be used as diagnostic and prognostic biomarkers in CPV enteritis. These factors include season of presentation, purebred nature, bodyweight, vomiting, leukopaenia, lymphopaenia, thrombocytopaenia, hypercoagulability, hypercortisolaemia, hypothyroxinaemia, hypoalbuminaemia, elevated C-reactive protein and tumour necrosis factor, hypocholesterolaemia and hypocitrullinaemia. Factors contributing to the manifestations of CPV infection are multiple with elements of host, pathogen, secondary infections, underlying stressors and environment affecting severity and outcome. The availability of several prognosticators has made identification of patients at high risk of death and their subsequent targeted management more rewarding.

The utility of uric acid assay in dogs as an indicator of functional hepatic mass.

Uric acid was used as a test for liver disease before the advent of enzymology. Three old studies criticised uric acid as a test of liver function. Uric acid, as an end-product of purine metabolism in the liver, deserved re-evaluation as a liver function test. Serum totalbile acids are widely accepted as the most reliable liver function test. This study compared the ability of serum uric acid concentration to assess liver function with that of serum pre-prandial bile acids in dogs. In addition, due to the renal excretion of uric acid the 2 assays were also compared in a renal disease group. Using a control group of healthy dogs, a group of dogs with congenital vascular liver disease, a group of dogs with non-vascular parenchymal liver diseases and a renal disease group, the ability of uric acid and pre-prandial bile acids was compared to detect reduced functional hepatic mass overall and in the vascular or parenchymal liver disease groups separately. Sensitivities, specificities and predictive value parameters were calculated for each test. The medians of uric acid concentration did not differ significantly between any of the groups, whereas pre-prandial bile acids medians were significantly higher in the liver disease groups compared with the normal and renal disease group of dogs. The sensitivity of uric acid in detecting liver disease overall was 65% while the specificity of uric acid in detecting liver disease overall was 59%. The sensitivity and specificity of uric acid in detecting congenital vascular liver disease was 68% and 59%, respectively. The sensitivity and specificity of uric acid in detecting parenchymal liver disease was 63% and 60%, respectively. The overall positive and negative predictive values for uric acid in detecting liver disease were poor and the data in this study indicated uric acid to be an unreliable test of liver function. In dogs suffering from renal compromise serum uric acid concentrations may increase into the abnormal range due to its renal route of excretion.

Serial haematology results in transfused and non-transfused dogs naturally infected with Babesia rossi.

This prospective longitudinal study investigated the progression of haematological changes in 32 transfused and 54 non-transfused dogs naturally infected with Babesia rossi over the 1st 6 days following diagnosis and treatment. The effect of patient age on the results of complete blood counts was determined. Haematology data were analysed at presentation and at 24 hours, 3 days and 6 days after presentation. Dogs were treated with diminazene aceturate at diagnosis and a blood transfusion was given if deemed clinically required. Mildly to moderately regenerative normocytic normochromic anaemia was observed in all dogs throughout the study period. Transfused dogs more often had an inflammatory leukogram at presentation and at 24 hours, than dogs that were not transfused. In dogs with a left shift, a concurrent normal or decreased segmented neutrophil count was found more commonly than neutrophilia. Severe thrombocytopenia that resolved within a week was common. Blood transfusion alleviated the anaemia, but had no significant effect on white blood cell or platelet responses. Blood cell responses were not significantly influenced by age. In conclusion, the red blood cell and white blood cell responses were less than expected in dogs with babesiosis, given the degree of anaemia and inflammation present. The magnitude of thrombocytopenia and rapid return of the platelet count to normal suggested a possible immune-mediated mechanism for the thrombocytopenia.

Preliminary evaluation of the BrEMA1 gene as a tool for associating babesia rossi genotypes and clinical manifestation of canine Babesiosis.

Babesia rossi, an intraerythrocytic protozoan, causes a severe, often life-threatening disease of domestic dogs. Dogs treated early for B. rossi infection usually recover from the disease, but dogs left untreated or treated at a later stage of infection seldom survive. Dogs infected with B. rossi have varied clinical manifestations that can be categorized as uncomplicated (with a good prognosis) or complicated (with a poor prognosis). One hundred twenty-one blood samples were collected from dogs presented to the Onderstepoort Veterinary Academic Hospital and diagnosed with babesiosis by the use of a thin blood smear. An additional 20 samples were obtained from Babesia-infected dogs from private clinics around the Onderstepoort, Johannesburg, Durban, White River, and Cape Town areas. The samples were screened by PCR targeting the Babesia rossi erythrocyte membrane antigen gene (BrEMA1) and by sequencing of the polymorphic region (i.e., region with a variable number of hexapeptide repeats). Analysis of PCR products revealed 11 different gene profiles, visualized by gel electrophoresis. Twelve distinct BrEMA1 genotypes were identified by sequencing, but the numbers of hexapeptide repeats varied from 6 to 31 (classified as genotype6 to genotype31). The genotypes were retrospectively compared to the clinical case data. The most frequently encountered B. rossi parasites were those attributed to genotype19 (36.2%), genotype28 and genotype29 (20.6% each), and genotype11 (12.7%). These genotypes were also the ones associated with the poorest prognosis. This preliminary finding suggests clinically important differences between the various B. rossi genotypes identified.

The scintigraphic evaluation of the pulmonary perfusion pattern of dogs hospitalised with babesiosis.

The possibility of coagulopathy in Babesia canis rossi infections in the canine patient has been suggested in the literature, but minimal work has been done to evaluate the clinicopathological nature of it in further detail. Pulmonary thromboembolism (PTE) has not yet been implicated in canine babesiosis (CB), but may also be one of the causes of the sudden dyspnoea and tachypnoea that are frequently seen in complicated CB patients. The objective of this study was to prospectively evaluate the scintigraphic pulmonary perfusion pattern in hospitalised dogs with babesiosis in an attempt to ascertain whether a scintigraphic pattern consistent with clinically relevant PTE does indeed occur in these patients. The study consisted of a normal control group of 9 mature healthy Beagle dogs (group 1) and a Babesia group with 14 dogs of a variety of breeds that were naturally infected with Babesia (group 2). Pulmonary perfusion scintigraphy was performed after making thoracic radiographs and performing a blood gas analysis in both groups. The scintigraphic images were visually inspected for changes suggestive of PTE, but not a single dog in group 2 had pleural-based, wedge-shaped perfusion defects which would have resulted in a high probability for clinically relevant PTE. The scintigraphic pulmonary perfusion pattern demonstrated was not significantly different between the 2 groups (P = 1.00).

Detection of a Theileria species in dogs in South Africa.

A Theileria species was detected by PCR in blood samples collected from dogs in the Pietermaritzburg area and was also found in dogs presented at the Outpatients Clinic of the Onderstepoort Veterinary Academic Hospital (OVAH), in the Pretoria area, South Africa. In the Pietermaritzburg area, 79 of the 192 samples were positive, while 3 out of 1137 of the Onderstepoort samples were positive. Three positive samples from Pietermaritzburg were co-infected with Ehrlichia canis. PCR positive samples were further analysed by the Reverse Line Blot (RLB) and sequence analysis. Phylogenetic analysis of the 18S rRNA full-length gene sequences of one sample (VT12) from Pietermaritzburg and two samples from OVAH (BC281 and BC295) revealed a close relationship with sequences of Theileria species (sable). Clinical signs of the dogs that were examined at Pietermaritzburg and OVAH included an immune-mediated condition with severe thrombocytopenia. These findings identify a Theileria sp. in dogs for the first time in South Africa and add yet another microorganism to the growing list of haemoprotozoan parasites infecting dogs worldwide. The clinical significance of this infection in dogs is poorly resolved.

Prognostic usefulness of blood leukocyte changes in canine parvoviral enteritis.

BACKGROUND: Despite treatment, many dogs still die of complications related to canine parvoviral (CPV) enteritis. Effective prognostication would be beneficial in managing this disease. HYPOTHESIS: We hypothesize that the occurrence of leukocytopenias at admission and at 24 and 48 hours after admission, and changes in absolute leukocyte counts over time, could be used to predict outcome. ANIMALS: Sixty-two puppies with confirmed CPV. METHODS: A prospective study was performed. CBC was performed daily until discharge or death (in which case a postmortem examination was performed). RESULTS: Of the nonsurvivors (10/62; 16%), 9 died because of complications of the disease and 1 was euthanized because of a poor prognosis. There was a statistical significant difference in the occurrence of leukocytopenias between groups at 24 and 48 hours postadmission. The survivors showed a significant increase over time in certain leukocyte types (specifically lymphocytes) compared with values at admission. The positive predictive value for survivors was high. Nonsurvivors had marked thymic and lymphoid atrophy and marked bone marrow hypocellularity. CONCLUSION: An accurate prognosis could be obtained at 24 hours after admission by evaluating the change in total leukocyte, band neutrophil, lymphocyte, monocyte, and eosinophil counts.

BCG-malaria co-Infection has paradoxical effects on C57BL/6 and A/J mouse strains.

Bacillus Calmette-Guérin (BCG) infection of the spleen is a potent modifier of splenic function. Prior to malaria infection, we infected two mouse strains of differing susceptibility to Plasmodium chabaudi AS (C57BL/6 and A/J) with this mycobacterium. We then evaluated aspects of spleen cell composition, architecture and cytokine expression, and correlated these with the outcome. BCG preinfection resulted in protection of the A/J mice but paradoxically resulted in mortality of the C57BL/6 mice. The latter developed higher parasitaemias that peaked earlier than the A/J mice rendered resistant by BCG. BCG infection induced remarkable changes to splenic histology examined by H&E staining, but there were no consistent differences between mouse strains. C57BL/6 mice had higher absolute numbers of all immune cell phenotypes than did A/J mice, and higher macrophage and dendritic cell proportions. BCG-induced resistance in A/J mice was associated with an increased CD4+ expression of IFN-gamma whilst induced death in C57BL/6 mice was associated with excessive IFN-gamma expression. A moderate TH1 response in the A/J model may have been responsible for the improved survival, and an excessive TH1 response in the C57BL/6 model may have contributed to their death.

Molecular characterisation of Babesia gibsoni infection from a pit-bull terrier pup recently imported into South Africa.

Canine babesiosis caused by Babesia gibsoni was diagnosed in a 3-month-old Pit-bull pup during a routine clinical examination. Diagnosis was confirmed by way of smear examination, PCR, Reverse Line Blot (RLB) and sequence analysis which showed 100% homology with B. gibsoni (Japan AB118032) and Babesia sp. (Oklahoma) (AF205636). Haematology showed moderate anaemia and severe thrombocytopenia. Treatment was initiated with diminazene aceturate (Berenil RTU) followed by 2 doses of imidocarb diproprionate (Forray-65) 3 days and 14 days later, respectively. Babesia gibsoni DNA was still detectable 2 weeks post-treatment on the PCR/RLB test. A 10-day course of combination drug therapy using atovaquone and azithromycin was initiated. Blood samples taken on Day 1 and Day 40 after completion of treatment were negative for B. gibsoni DNA on PCR/RLB test. The implications of a possible introduction of B. gibsoni into South Africa are discussed.

The elevated serum urea:creatinine ratio in canine babesiosis in South Africa is not of renal origin.

Pigmented serum, usually due to free haemoglobin and/or bilirubin, is a common finding in dogs with babesiosis, resulting in interference with all biochemical tests that rely on photochemistry. This is particularly true of urea and creatinine determinations, complicating the diagnosis of acute renal failure, which is a serious complication of babesiosis. A disproportionately raised serum urea concentration of unknown origin occurs in severely anaemic canine babesiosis patients and gives rise to an increased serum urea:creatinine ratio. The assay for cystatin-C, an excellent measure of glomerular filtration rate, is unaffected by free serum haemoglobin, and due to its different intrinsic origins, is free of influence by the metabolic derangements and organ pathology, other than renal disease, encountered in canine babesiosis. Serum cystatin-C was used to compare the concentrations of serum urea and serum creatinine in dogs with the severely anaemic form of canine babesiosis as well as a canine babesiosis-free reference group. Mean serum urea and mean serum urea:creatinine ratio were significantly elevated in the babesia-infected group relative to the reference population in this study. Mean serum creatinine and mean serum cystatin-C were within the reference ranges. Therefore an elevated urea:creatinine ratio in canine babesiosis in the presence of a normal serum creatinine concentration is considered to be caused by an elevated serum urea concentration and is most likely of non-renal origin. Serum creatinine was therefore as specific a measure of renal function as serum cystatin-C in canine babesiosis in this study. The sensitivity of serum creatinine as a measure of renal function was not established by this study. Serum urea, however, proved to be of little use compared to serum cystatin-C and serum creatinine. Serum urea should therefore not be used to diagnose renal failure in canine babesiosis.

Comparison of effects of uncomplicated canine babesiosis and canine normovolaemic anaemia on abdominal splanchnic Doppler characteristics--a preliminary investigation.

A preliminary study was conducted to compare uncomplicated canine babesiosis (CB) and experimentally induced normovolaemic anaemia (EA) using Doppler ultrasonography of abdominal splanchnic vessels. Fourteen dogs with uncomplicated CB were investigated together with 11 healthy Beagles during severe EA, moderate EA and the physiological state as a control group. Canine babesiosis was compared with severe EA, moderate EA and the physiological state using Doppler variables of the abdominal aorta, cranial mesenteric artery (CMA), coeliac, left renal and interlobar, and hilar splenic arteries, and the main portal vein. Patterns of haemodynamic changes during CB and EA were broadly similar and were characterised by elevations in velocities and reductions in resistance indices in all vessels except the renal arteries when compared with the physiological state. Aortic and CMA peak systolic velocities and CMA end diastolic and time-averaged mean velocities in CB were significantly lower (P < 0.023) than those in severe EA. Patterns of renal haemodynamic changes during CB and EA were similar. However, the renal patterns differed from those of aortic and gastrointestinal arteries, having elevations in vascular resistance indices, a reduction in end diastolic velocity and unchanged time-averaged mean velocity. The left renal artery resistive index in CB was significantly higher (P < 0.025) than those in EA and the physiological state. Renal interlobar artery resistive and pulsatility indices in CB were significantly higher (P < 0.016) than those of moderate EA and the physiological state. The similar haemodynamic patterns in CB and EA are attributable to anaemia, while significant differences may additionally be attributed to pathophysiological factors peculiar to CB.

The diagnosis and management of snakebite in dogs--a southern African perspective.

Cases of snakebite envenomation are frequently presented to veterinary practitioners in southern Africa. Despite this, no published guidelines exist on how this medical emergency should be managed. Southern African snake venoms can be classified into 3 main types based on the main mechanism of venom action and clinical presentation. A polyvalent antivenom is manufactured in South Africa and contains antibodies against the most important southern African snake venoms. The cytotoxic venoms are represented mainly by the puff-adder (Bitis arietans), Mozambique spitting cobra (Naja mossabica), black-necked spitting cobra (Naja nigricollis) (in the Western Cape and Namibia) and the stiletto snake (Atractaspis bibronii). These venoms may cause dramatic local swelling, high morbidity and low mortality and infrequently require the use of antivenom for survival (the only cytotoxic venoms used to prepare the antivenom are the puff-adder and Mozambique spitting cobra). The neurotoxic venoms (represented chiefly by the non-spitting cobras and mambas) cause high mortality due to rapid onset of paresis and require antivenom and mechanical ventilatory support which is life-saving. The boomslang (Dispholidus typus) and the vine snake (coagulopathic venom) rarely bite humans but dogs may be bitten more frequently. These venoms cause a consumption coagulopathy and successful treatment of boomslang bites requires the use of snake species-specific monovalent antivenom. There is no antivenom available for treating vine snake (Thelotornis capensis), berg adder (Bitis atropos), night adder (Causus spp.), stiletto snake and other lesser adder bites. There are some important differences between the way snakebites are managed in humans and dogs.

The use of liposomal amphotericin B in the management of Xylohypha bantiana mycosis in a dog.

Xylohypha bantiana is a rare neurotropic fungal infection reported in humans, dogs and cats. In dogs it has only been identified on post mortem examination and thus no successful treatments have previously been reported. Amphotericin B is a potent antifungal drug with a low therapeutic index because of its nephrotoxicity. Liposomal encapsulation of the drug has resulted in much safer use in humans. This article reports a case of Xylohypha bantiana infection in a dog that was diagnosed antemortally and managed with liposomal amphotericin B, which resulted in the prolongation of quality of life for an infection that invariably results in rapid death.

The mixed acid-base disturbances of severe canine babesiosis.

Thirty-four dogs suffering from severe babesiosis caused by Babesia canis rossi were included in this study to evaluate acid-base imbalances with the quantitative clinical approach proposed by Stewart. All but 3 dogs were severely anemic (hematocrit <12%). Arterial pH varied from severe acidemia to alkalemia. Most animals (31 of 34; 91%) had inappropriate hypocapnia with the partial pressure of CO2 < 10 mm Hg in 12 of 34 dogs (35%). All dogs had a negative base excess (BE; mean of - 16.5 mEq/L) and it was below the lower normal limit in 25. Hypoxemia was present in 3 dogs. Most dogs (28 of 34; 82%) were hyperlactatemic. Seventy percent of dogs (23 of 33) were hypoalbuminemic. Anion gap (AG) was widely distributed, being high in 15, low in 12, and normal in 6 of the 33 dogs. The strong ion difference (SID; difference between the sodium and chloride concentrations) was low in 20 of 33 dogs, chiefly because of hyperchloremia. Dilutional acidosis was present in 23 of 34 dogs. Hypoalbuminemic alkalosis was present in all dogs. Increase in unmeasured strong anions resulted in a negative BE in all dogs. Concurrent metabolic acidosis and respiratory alkalosis was identified in 31 of 34 dogs. A high AG metabolic acidosis was present in 15 of 33 dogs. The lack of an AG increase in the remaining dogs was attributed to concurrent hypoalbuminemia, which is common in this disease. Significant contributors to BE were the SID, free water abnormalities, and AG (all with P < .01). Mixed metabolic and respiratory acid-base imbalances are common in severe canine babesiosis, and resemble imbalances described in canine endotoxemia and human malaria.

Chronic idiopathic intestinal pseudo-obstruction in an English bulldog.

A case of chronic idiopathic intestinal pseudo-obstruction in an English bulldog is described. The dog was presented with chronic weight loss and vomiting. An intestinal obstruction was suspected based on clinical and radiological findings. A diagnosis of chronic idiopathic intestinal pseudo-obstruction was made on the basis of full thickness intestinal biopsies. The dog was refractory to any antiemetic therapy. Necropsy revealed marked atrophy and fibrosis of the tunica muscularis, together with a mononuclear cell infiltrate extending from the duodenum to the colon. This case was presented with clinical findings consistent with visceral myopathy in humans--namely, atony and dilatation of the whole gut--but the histological findings resembled sclerosis limited to the gastrointestinal tract.

Canine distemper infections, with special reference to South Africa, with a review of the literature.

Canine distemper virus is a member of the genus Morbillivirus of the family Paramyxoviridae that causes severe disease in dogs and a range of wild mammals. The clinical signs relate essentially to the respiratory, gastrointestinal and central nervous systems. In South Africa, infection with Ehrlichia canis and canine parvovirus may present similarly Many dogs will initially present with a wide range of central nervous system signs without any history of systemic disease. A recent South African study evaluating ante mortem diagnosis highlighted the importance of recognising clinical signs, cerebrospinal fluid IgG titres, serum IgM titres and immunocytochemistry of epithelial tissue. A 2-year retrospective evaluation of cerebrospinal fluid samples collected from dogs presented to the Onderstepoort Veterinary Academic Hospital indicates that distemper infection is common, and this disease should routinely be suspected in cases of diverse neurological disease in dogs. The South African dog population is specifically at high risk for the disease because of the large pool of unvaccinated, reproductively-active dogs that expose the wildlife resources of the country to risk of fatal disease. Outbreaks of disease in dogs continue to occur in developed and developing communities in both vaccinated and unvaccinated dogs worldwide, and have also been described in a wide range of free-ranging wildlife, including seals, dolphins and lions, and in endangered zoo animals. Modified live virus vaccines have contributed markedly to disease control in the dog population but have caused mortality in some wild carnivores. New recombinant vaccines are being developed that will be safe in wild animals. The pathogenesis of CNS demyelination has been compared to various important demyelinating diseases in humans and, amongst other things, relates to down-regulation of the oligodendrocyte gene coding for myelin synthesis and non-immunocyte CNS cell expression of type II major histocompatibility receptors. Early CNS lesions are characterised by demyelination and later lesions by perivascular round cell cuffing. Treatment is supportive.