Biomarkers in canine parvovirus enteritis

Clinical and inflammatory response to antiviral treatments in dogs with parvoviral enteritis

BACKGROUND

Canine parvoviral enteritis (CPE) is a fatal disease worldwide. The treatment of CPE is based mainly on supportive and symptomatic treatment. Antiviral addition to the treatment may result in a higher survival.

OBJECTIVES

This study evaluated the effects of antiviral treatments with a standardized treatment (ST) on the clinical and inflammatory response of dogs with naturally occurring CPE.

METHODS

Twenty-eight dogs with CPE caused by canine parvovirus type 2 were divided randomly into treatment groups. The ST group received fluid, antibiotic, antiemetic, and deworming treatments. The antiviral treatment groups received the same ST with an additional antiviral drug, recombinant feline interferon omega (rFeIFN-ω), oseltamivir (OSEL) or famciclovir (FAM).

RESULTS

Compared to the healthy control, the tumor necrosis factor-α, interleukin-1β, interferon (IFN)-α, IFN-γ, haptoglobin, and C-reactive protein values were high (p < 0.05) on day zero. At presentation, mild lymphopenia, neutropenia, and a high neutrophil to lymphocyte (LYM) ratio (NLR) were also observed. Adding rFeIFN-ω to the ST produced the best improvement in the clinical score with a decreased NLR, while leucocytes remained low and inflammatory markers stayed high on day three. The survival rates of the groups were 85.7% in ST+IFN, 71.4% in ST+OSEL, 71.4% in ST+FAM, and 57.1% in ST groups on day seven.

CONCLUSIONS

Antiviral drugs may be valuable in treating CPE to improve the clinical signs and survival. In addition, the decrease in NLR in favor of LYM may be an indicator of the early prognosis before the improvement of leukocytes, cytokines, and acute phase proteins in CPE.

Retrospective evaluation of hematological ratios in canine parvovirosis: 401 cases

BACKGROUND

The utility of neutrophil-to-lymphocyte ratio (NLR), platelet to-lymphocyte ratio (PLR) and monocyte-to-lymphocyte ratio (MLR) as prognostic indicators has not been investigated in canine parvovirosis (CPV).

HYPOTHESIS

To evaluate whether these hematological ratios obtained at hospital admission in CPV are associated with outcome or duration of hospitalization.

ANIMALS

Four hundred one client-owned dogs presented with CPV. Methods-Retrospective multicenter cohort study. Medical records were reviewed to identify dogs with CPV. Data regarding signalment, complete blood count at admission, duration of hospitalization and outcome were collected.

RESULTS

Of the 401 dogs included in the study, 336 (83.8%) survived to discharge. The median (25th and 75th percentiles) PLR in nonsurvivors (336.56 [159.84-635.77]) was significantly higher than in survivors (217.65 [117.67-389.65]) (P = .003). The area under the receiver-operating characteristic curve for nonsurvival was 0.615 (95% CI [0.593-0.691], P = .003). A cut off of 700 showed a 21.5% sensitivity and 90% specificity for nonsurvival. No association was observed between hospitalization duration and either hematological ratios or total WBC counts. The median (25th and 75th percentiles) lymphocyte count was below reference interval in all dogs and was significantly lower in the dogs which died (0.82 × 109 /L [0.5-1.87]) than in survivors (1.27 × 109 /L [0.73-2.22]) (P = .005). The median (25th and 75th percentiles) monocyte count however was lower in survivors (0.38 × 109 /L [0.29-1.59]), than in nonsurvivors (0.73 × 109 /L [0.1-2]) (P = .002).

CONCLUSIONS

Evaluation of PLR at hospital admission might be a useful marker of disease severity and could have prognostic value in dogs with CPV.

Serum/Faecal S100A12, CRP and lactoferrin can be used to distinguish ınfectious and non-ınfectious canine diarrhoea

OBJECTIVES

This study aimed to evaluate the diagnostic efficacies of selected inflammatory and intestinal biomarkers in cases of infectious and non-infectious diarrhoea in dogs.

METHODS

A total of 60 dogs, 12 healthy (Control Group) and 48 with diarrhoea were used. Viral, Bacterial, Parasitic (infectious) and Nutritional diarrhoea (non-infectious) subgroups (n: 12) were formed according to the aetiology, on the basis of clinical and laboratory examinations. Selected inflammatory and intestinal biomarkers (Calgranulin, S100A12; Lactoferrin, LCTF; C-reactive protein, CRP) were measured both in serum and faecal samples.

RESULTS

Compared to the Control and Nutritional Diarrhoea groups, the infectious diarrhoea groups had higher serum S100A12, LCTF, CRP, blood urea nitrogen, creatinine (CR), alanine transaminase and alkaline phosphatase, and lower glucose (GLU), sodium (Na) and potassium (K) concentrations (p < 0.05); Viral and Parasitic Diarrhoea groups had lower serum albumin (ALB) and total protein (TP) concentrations (p < 0.05). Faecal S100A12, LCTF and CRP concentrations were higher in infectious diarrhoea groups compared to the Control and Nutritional Diarrhoea groups (p < 0.05). Faecal LCTF and CRP concentrations were higher in the Bacterial Diarrhoea group than in the Viral and Parasitic Diarrhoea groups (p < 0.05).

CLINICAL SIGNIFICANCE

It was determined that serum (area under curve, AUC: 0.842 and 0.956) and faecal (AUC: 0.975 and 0.786) S100A12 and CRP concentrations in viral diarrhoea; serum (AUC: 0.956) and faecal (AUC: 0.992) LCTF concentrations in bacterial diarrhoea have diagnostic values in the diagnosis of the presence of intestinal inflammation and damage and can be used in the differential diagnosis of infectious and non-infectious diarrhoea.

Antioxidant supplementation during treatment of outpatient dogs with parvovirus enteritis ameliorates oxidative stress and attenuates intestinal injury: A randomized controlled trial

A prospective randomized controlled clinical study was conducted to determine whether antioxidant supplementation as an adjunct therapy alters hemogram, oxidative stress, serum intestinal fatty acid binding protein-2 (IFABP-2) level, fecal viral load, clinical score (CS) and survivability in outpatient canine parvovirus enteritis (CPVE) dogs. The dogs with CPVE were randomized to one of the five treatment groups: supportive treatment (ST) alone, ST with N-acetylcysteine (ST+NAC), resveratrol (ST+RES), coenzyme Q10 (ST+CoQ10) or ascorbic acid (ST+AA). The primary outcome measures were reduction of CS and fecal HA titre, and enhancement of survivability. Secondary outcome measures were reduction of oxidative stress indices and IFABP-2 level from day 0 to day 7. The mean CS and HA titre were significantly (P < 0.05) decreased from day 0 to 7 in ST and all antioxidant groups. The supplementations of NAC, RES and AA along with ST markedly (P < 0.05) reduced the concentrations of malondialdehyde, nitric oxide and IFABP-2 on day 7 as compared to ST alone. Additionally, NAC and RES supplementations markedly (P < 0.05) improved the total leukocyte count and neutrophil count in CPVE-affected dogs. NAC and RES could serve as better antioxidants for the amelioration of oxidative stress in CPVE but, the antioxidants did not confer any additional benefits in reduction of CS, fecal HA tire, or survivability when compared with ST alone.

First genetic detection and characterization of canine parvovirus type 2 (Carnivore protoparvovirus 1) in southwestern Ethiopia

The species Carnivore protoparvovirus 1 includes viruses, e.g. canine parvovirus (CPV-2) and feline panleukopenia virus (FPV), which are among the most relevant for pets, causing extremely severe clinical signs and high fatality rate in dogs and cats. Moreover, a broad range of wild hosts, including endangered ones, were proven to be susceptible. Currently, no data on CPV-2 molecular epidemiology and strain characterization are available in Ethiopia, also considering the frequent contacts between domestic and wild populations. In the present study, a molecular epidemiology survey was performed on 92 fecal samples collected from domestic (n = 84) and stray (n = 8) dogs in southwestern Ethiopia in 2021. Approximately, 10% of the samples tested positive and the complete VP2 sequences of 5 strains were obtained, classified within the CPV-2a (n = 1) and CPV-2c (n = 4) antigenic variants. In most instances, the closest genetic relatives were strains of Chinese origin, which is fully compatible with the intense relationships that have been developing between the two countries, involving human being travels and their pets as well. Considering the clinical relevance of this infection and the risk it poses to local domestic and wild carnivore populations, especially endangered ones, much stronger monitoring and surveillance activity on foreign incoming animals should be performed. More strict constraints on animal introduction, e.g. compulsory vaccination, should also be considered.

Genomic characterization and Phylogenetic evolution of the canine parvoviruses in Iranian dogs, a nationwide study: CPV evolutionary analysis in Iran

Canine Parvo Virus 2(CPV-2) culminated in lots of fatalities in domestic dogs since its emergence in 1978. Mainly, it is responsible for severe hemorrhagic diarrhea, vomiting, and dehydration. CPV-2 has three main variants known 2a, 2b, and 2c. Due to the necessity of monitoring the evolutionary parameters of the virus, and also the lack of comprehensive study of CPV2 in Iran, this study is done for the first time in this country not only to characterize Iranian CPV genomes but also to study the evolutionary parameters and phylodynamics of CPV. The phylogenetic trees were constructed using the Maximum Likelihood (ML) method. By the use of the Bayesian Monte Carlo Markov Chain (BMCMC) method, evolutionary analysis and phylodynamics of the virus were investigated. Phylogenetic results showed that all Iranian isolates were classified in the CPV-2a variant. The central part of Iran was suggested to be the origin of the virus, especially the Alborz province. Before its prevalence throughout the country, the virus circulated in the central part, in Thran, Karaj, and Qom. Mutational analysis showed a positive selection pressure of CPV-2a. Investigating the evolutionary parameters of the virus proposed 1970 to be the date of birth of the virus, with a 95% credible interval between 1953 and 1987. The effective number of infections increased dramatically from 2012 to 2015, then faced a slightly decreasing trend from 2015 to 2019. A considerable up warding pattern was witnessed from the middle of 2019, which can be taken as a concern about the risk of vaccination failure.

A comparison of the Sepsis-2 and Sepsis-3 definitions for assessment of mortality risk in dogs with parvovirus

OBJECTIVE

To evaluate the use of a modified Sepsis-3 (mSepsis-3) definition compared to the currently used modified Sepsis-2 (mSepsis-2) definition to determine whether the mSepsis-2 or mSepsis-3 stratifications were able to identify populations of dogs ultimately more likely to die from canine parvovirus (CPV) infection.

DESIGN

Retrospective, January 2009 to March 2020.

SETTING

A private, small animal, urban, referral emergency and specialty hospital.

ANIMALS

Fifty-nine client-owned dogs hospitalized for treatment of CPV.

INTERVENTIONS

None.

MEASUREMENTS AND MAIN RESULTS

Dogs were divided into mSepsis-2 and mSepsis-3 categories based on the highest level of illness severity reached during hospitalization. Greater illness severity based on mSepsis-2 criteria (ie, sepsis, severe sepsis, septic shock) was associated with an increase in average length of stay (P < 0.001), increase in average cost of stay (P < 0.01), and presence of leukopenia (P < 0.05). An increase in illness severity within the mSepsis-2 criteria was not associated with hyperlactatemia (P = 0.29), presence of neutropenia (P = 0.12), or mortality (P = 0.35). Greater illness severity based on mSepsis-3 criteria (ie, infection only, sepsis, septic shock) was associated with an increase in mortality (P < 0.05), increase in average length of stay (P < 0.001), increase in average cost of stay (P < 0.01), presence of leukopenia (P < 0.01), and presence of neutropenia (P < 0.05). The mSepsis-3 criteria were not associated with the presence of hyperlactatemia (P = 0.68). There was no significant difference between survivors and nonsurvivors in the presence of leukopenia (P = 0.19), neutropenia (P = 0.67), or hyperlactatemia (P = 0.58).

CONCLUSIONS

The mSepsis-3 diagnostic criteria appear to better identify dogs with CPV at higher risk for mortality compared to the mSepsis-2 criteria.

Altered neutrophil-to-lymphocyte ratio in sepsis secondary to canine parvoviral enteritis treated with and without an immunomodulator in puppies

Neutrophil-to-lymphocyte ratio (NLR) is a cheap and easy-to-obtain biomarker that mirrors the balance between innate and adaptive immunity. Cortisol and catecholamines have been identified as major drivers of NLR. High cortisol levels increase neutrophils while simultaneously decreasing lymphocyte counts. Likewise, endogenous catecholamines may cause leukocytosis and lymphopenia. Thus, NLR allows us to monitor patient severity in conditions such as sepsis. Twenty-six puppies with sepsis secondary to canine parvoviral enteritis were treated with and without an immunomodulator. Our group determined the NLR and the plasmatic cortisol levels by chemiluminescence, and norepinephrine (NE) and epinephrine (E) by HPLC during the first 72 h of clinical follow-up. Our results showed that at admission puppies presented an NLR value of 1.8, cortisol of 314.9 nmol/L, NE 3.7, and E 3.3 pmol/mL. Both treatments decreased admission NLR values after 24 h of treatment. However, only the puppies treated with the immunomodulator (I) remained without significant changes in NLR (0.7-1.4) compared to the CT group, and that showed a significant difference (P < 0.01) in their NLR value (0.4-4.6). In addition, we found significant differences in the slope values between the admission and final values of NLR (P < 0.005), cortisol (P < 0.02), and E (P < 0.05) between treatments. Then, our data suggest that the immunomodulator positively affects the number of lymphocytes and neutrophils involved in NLR as well as major drivers like cortisol and epinephrine, which is reflected in clinical parameters and survival.

Concomitant Infections With Canine Parvovirus Type 2 and Intracellular Tick-Borne Pathogens in Two Puppy Dogs

In this report the concomitant infection with canine parvovirus type 2 (CPV-2), Hepatozoon canis and Ehrlichia canis in two puppy dogs from Southern Italy is described. Dogs were referred to a veterinary university hospital for the acute onset of lethargy and gastrointestinal signs. A complete clinical and clinicopathological evaluation was carried out and the multiple infection was confirmed by microscopic detection of inclusion bodies in peripheral blood smear, rapid immunoenzymatic tests, indirect fluorescent antibody tests, and molecular assays. Sequence analysis revealed that the CPV-2 identified belonged to the 2c variant and had amino acid residues in the predicted VP2 protein typical of “Asian-like” strains widespread in Asia and occasionally reported in Romania, Nigeria and Italy, particularly in the region of Sicily. Numerous monocytes were infected by both H. canis gamonts and E. canis morulae, suggesting that this co-infection is not accidental and that E. canis preferably infects those cells parasitized by H. canis. The clinical presentation of these animals was severe but supportive cares associated with early etiological therapy allowed a good prognosis. Movement of puppies from geographic areas where vector-borne pathogens are endemic must be carefully evaluated and core vaccinations and ectoparasite prevention treatments must be rigorously adopted.

Experimental study of tropism of cultivated canine parvovirus in the immunogenesis organs of puppies

The immune system unites the organs and the tissues that protect the organism against genetically alien cells or substances entering the organism from the environment. Canine parvovirus is an etiologic agent of hemorrhagic gastroenteritis and causes a significant problem for veterinary medicine due to high level of morbidity and mortality, mostly among dogs, because of fast progression without immune-complement response. In this study, based on the results of our clinical, virological, histological, histochemical and morphological assays, we determined the pathogenetic role of parvovirus in sick dogs experimentally infected per os, specifically with isolated canine parvovirus (Antaeus) with titer of infectious activity equaling 3.80 ± 0.008 lg TCID50/cm, cultivated on heterological cell cultures. This allowed us to clarify, add to and generalize the data on the pathogenesis of the disease and determine pathohistological and histochemical changes in the immunogenesis, since the studied virus expresses immune-suppressive properties, leading to ruination of the locomotor ability of the organism and fast lethal outcome. The study of pathomorphological changes was carried out using pathoanatomical and histologic methods. Pathoanatomical material from the autopsy of puppies aged 45 days was fixed in 10% aqueous solution of neutral formaline and embedded in paraffin. Having parvoviral infection, dogs experience pathomorphologic changes in immune-complement organs, indicating inhibition of the immunogenesis function during an infectious disease of viral etiology. In the immunogenesis organs of puppies with the experimental reconstruction of parvoviral enteritis, we microscopically determined the following: edema of the cortex and medulla, disorganization of thymic corpuscules, and impairment of processes of differentiation of lymphocytes in the cortex and medulla of the thymic lobules; edema and large areas of accumulation of hemosiderin in the spleen as a result of breakdown of large amount of erythrocytes; acute inflammatory hyperemia of the parenchyma, swelling of sinuses, serous and serous-hemorrhagic lymphadenitis in lymph nodes. The complex of histologic changes in the immune protection organs, which we found in the conditions of experimental reconstruction of parvoviral infection, can be considered a distinct criterion for pathomorphologic differentiation diagnostics of parvoviral enteritis in dogs.

Serum cobalamin concentrations in dogs infected with canine parvoviral enteritis

OBJECTIVE

To compare the serum cobalamin concentrations in canine parvovirus (CPV)-infected dogs with those of healthy control dogs.

Animals

45 dogs with CPV enteritis and 17 healthy age-matched control dogs.

Procedures

Infection was confirmed by visualization of CPV-2 through fecal electron microscopy. All dogs received supportive care. Serum samples taken at admission were used to determine cobalamin, C-reactive protein, and albumin concentrations.

Results

Serum cobalamin concentrations were significantly lower in the CPV-infected group (median [interquartile range], 173 pmol/L [< 111 to 722 pmol/L]) than in healthy control dogs (379 pmol/L [193 to > 738 pmol/L). There was no association between cobalamin concentration and C-reactive protein or albumin concentration.

Clinical Relevance

While hypocobalaminemia was common in CPV-infected dogs, the clinical relevance of this finding remains to be determined. Studies assessing markers of cellular cobalamin deficiency in dogs with CPV infection appear warranted.

Antimicrobial Resistance (AMR) of Bacteria Isolated from Dogs with Canine Parvovirus (CPV) Infection: The Need for a Rational Use of Antibiotics in Companion Animal Health

Canine parvovirus type 2 (CPV-2) represents a major viral threat to dogs. Considering the potential effects of pets on antimicrobial resistance, information on the CPV and associated bacterial co-infections is limited. The aim of this study was to analyze the antimicrobial susceptibility and multidrug-resistance profiles of bacterial species from tissue samples of dogs with canine parvovirus infection. A set of PCR assays and sequence analyses was used for the detection and the molecular characterization of the CPV strains and other enteric viruses. Bacterial isolation, the determination of antimicrobial susceptibility via the disk diffusion method, and the determination of the minimum inhibitory concentration were performed. The detection of β-lactamase genes and toxin genes for specific bacteria was also carried out. CPV infection was confirmed in 23 dogs. Forty-three bacterial strains were isolated and all showed phenotypic resistance. Seventeen multidrug-resistant bacteria and bacteria with high resistance to third- and fourth-generation cephalosporins and metronidazole were detected. Almost 50% of the isolated Enterobacteriaceae were positive for at least one β-lactamase gene, with the majority carrying more genes as well. The evidence for multi-resistant bacteria with the potential for intra- or cross-species transmission should be further considered in a One Health approach.

Increased survival in puppies affected by Canine Parvovirus type II using an immunomodulator as a therapeutic aid

Canine parvovirus type II (CPV-2) infection induces canine parvoviral enteritis (CPE), which in turn promotes sepsis and systemic inflammatory response syndrome (SIRS). Mortality in this disease is usually registered within 48-72 h post-hospitalization, the critical period of the illness. It has been recently described that the use of an immunomodulator, whose major component is monomeric ubiquitin (mUb) without the last two glycine residues (Ub∆GG), in pediatric human patients with sepsis augments survival. It is known that CXCR4 is the cell receptor of extracellular ubiquitin in humans. This work aimed to explore the effect of one immunomodulator (human Dialyzable Leukocyte Extract-hDLE) as a therapeutic auxiliary in puppies with sepsis and SIRS induced by CPE. We studied two groups of puppies with CPV-2 infection confirmed by polymerase chain reaction. The first group received conventional treatment (CT) and vehicle (V), while the second group received CT plus the immunomodulator (I). We assessed both groups' survival, clinical condition, number of erythrocytes, neutrophils, and lymphocytes during the hospitalization period. In addition, hematocrit, hemoglobin, plasma proteins and cortisol values, as well as norepinephrine/epinephrine and serotonin concentration were determined. Puppies treated with CT + I showed 81% survival, mild clinical signs, and a significant decrease in circulating neutrophils and lymphocytes in the critical period of the treatment. In contrast, the CT + V group presented a survival of 42%, severe clinical status, and no improvement of the parameters evaluated in the critical period of the disease. We determined in silico that human Ub∆GG can bind to dog CXCR4. In conclusion, the administration of a human immunomodulator (0.5 mg/day × 5 days) to puppies with CPE under six months of age reduces the severity of clinical signs, increases survival, and modulates inflammatory cell parameters. Further studies are necessary to take full advantage of these clinical findings, which might be mediated by the human Ub∆GG to canine CXCR4 interaction.

Molecular characterization of canine parvovirus from domestic dogs in Nigeria: Introduction and spread of a CPV-2c mutant and replacement of older CPV-2a by the "new CPV-2a" strain

Canine parvovirus (CPV) is a contagious and highly pathogenic virus of dogs. After its first report in 1978, the CPV original type (CPV-2) was rapidly and totally replaced by three antigenic variants named CPV-2a, CPV-2b and CPV-2c that circulate in various countries at different frequencies and recently reported in Nigeria. This study describes the molecular characterization of 28 CPV strains in dogs presenting with gastroenteritis in veterinary clinics at Lagos and Ibadan, Nigeria. The results show the predominance (92.8%) of CPV-2a, while CPV-2c was found only in two samples. Phylogenetic analyses revealed that the CPV Nigerian strains were closely related to Asian strains and 26 CPV-2a out of 28 CPV sequences fell into 2 different subclades consistent with predicted amino acid mutations at position 267, 321, 324 and 440. Lys321Asn was evident in all the Nigerian strains whilst Phe267Tyr and Tyr324Ile were observed in 96.4% of the sequences, respectively. Thr440Ala occurred in 89.3% of sequences from this study. The new CPV-2a was predominant and appears to have replaced other CPV-2a strains in South-western Nigeria whilst the CPV-2c strain which is identical to the isolate recently reported in Northern Nigeria, may have been introduced in this country at the time of this study. Monitoring virus epidemiology is important to better understand the dynamics of CPV evolution and the eventual need to change or improve existing vaccination strategies.

Prognostic indicators at presentation for canine parvoviral enteritis: 322 cases (2001-2018)

OBJECTIVE

To evaluate clinicopathological prognostic indicators associated with survival based on hematology and serum biochemistry profile findings at presentation of dogs with canine parvoviral enteritis (CPE). Secondary objectives were to describe the signalment, history, physical examination findings, and progression of disease while in hospital and correlate them to survival.

DESIGN

Retrospective study from medical records of dogs diagnosed with CPE between 2001 and 2018.

SETTING

University teaching hospital.

ANIMALS

Three hundred twenty-two dogs diagnosed with CPE that received in-hospital treatment.

INTERVENTIONS

None.

MEASUREMENTS AND MAIN RESULTS

Of 322 hospitalized dogs, 294 dogs (91%) survived infection with a median hospitalization time of 79 hours. Multivariable analysis showed that glucose (P = 0.04), total magnesium (P = 0.011), and the dichotomized variable of a low HCT (P = 0.033) on presentation were significantly associated with survival. For every 1 mmol/L (18 mg/dL) decrease in glucose concentration, cases had 1.85 lower odds of survival. For every 0.1 mmol/L (0.2 mEq/L) increase in total magnesium concentration, cases had 2.50 lower odds of survival. Cases with a low HCT had 10.69 lower odds of survival. On univariable analyses, non-survivors had a lower median body weight (P = 0.006) and presented more commonly for diarrhea (P = 0.015). At least 1 episode of diarrhea (P = 0.003) and hematochezia or melena (P < 0.001) in hospital were negatively associated with outcome, in addition to the persistence of diarrhea (P = 0.026) and hyporexia (P = 0.018) in hospital for 5 to 6 days.

CONCLUSIONS

Survival rates of 91% were achieved with in-hospital treatment in this cohort of dogs. Negative biochemical prognostic indicators affecting survival include a low HCT, decreased blood glucose concentrations, and increased total serum magnesium concentrations at presentation.

Detection of environmental contamination with feline and canine parvoviruses: new perspectives and challenges

AIMS

To develop a protocol for environmental sampling to detect parvoviruses of dogs and cats in the environment.

METHODS AND RESULTS

Environmental contamination was carried out using different dilutions of parvovirus-contaminated materials; further field samplings were performed in areas in which clinical cases of parvovirus infections were present. Sterile cotton swabs and sponges for microbial surface sampling were used. Viruses were detected in these samples with different methods: conventional PCR, nested PCR and real-time PCR, detecting viral DNA; virus isolation, detecting infectious virus; and a commercial rapid enzyme immunoassay, detecting viral antigen. No substantial differences were observed in the two sampling methods, although the sponge was more convenient for sampling rough surfaces. Molecular assays were the most sensitive methods, identifying even very low amounts of viral DNA (up to 10 copies of viral DNA/10 µl of sample). Virus isolation and the rapid test detected the viruses only at the highest viral concentrations, both in the experimental setting and field conditions.

CONCLUSIONS

Environmental sampling and molecular protocols were effective in detecting environmental contamination with parvoviruses.

SIGNIFICANCE AND IMPACT OF THE STUDY

The protocol will be useful to identify possible sources of infection and to assess the efficacy of disinfection protocols in the environment.

Assessment of certain biomarkers for predicting survival in response to treatment in dogs naturally infected with canine parvovirus

Canine parvovirus (CPV) enteritis is an important cause of morbidity and mortality in puppies despite aggressive treatment. Identification of reliable biomarkers for CPV enteritis is essential to determine the severity, duration of hospitalization, and predict the clinical outcome. Meanwhile, the biomarkers will assist in decision-making with clients about the further course of treatment or euthanasia. The present study was conducted to evaluate the changes of total leukocyte count (TLC), neutrophil count, and serum concentrations of creatine kinase-MB (CK-MB), lactate dehydrogenase (LDH), intestinal fatty acid binding protein-2 (IFABP-2), albumin, ceruloplasmin (Cp), cortisol, free triiodothyronine (FT₃) and free thyroxine (FT₄) in survivors and non-survivors as a predictor of the clinical outcome. Marked leukopenia, neutropenia, hypoalbuminemia, elevated levels of CK-MB, IFABP-2, Cp, and cortisol were noticed in CPV-infected dogs than healthy dogs but, LDH, FT₃ and FT₄ concentrations did not differ significantly. The CPV-infected non-survivors had persistent leukopenia, neutropenia and elevated CK-MB, IFABP-2, Cp and cortisol concentrations at 72 h of commencement of treatment. In CPV-infected survivors, TLC and neutrophil count were significantly increased, and CK-MB, IFABP-2, Cp and cortisol concentrations were significantly decreased at 72 h of commencement of treatment. The positive predictive values (PPVs) for survival using cut-off value of TLC (>3.2 × 10³/μL), neutrophil count (>1.65 × 10³/μL), CK-MB (≤234.50 U/L), IFABP-2 (≤7.61 ng/mL), Cp (≤0.605 g/L) and cortisol (≤16.90 ng/mL) were determined as 89.47%, 88.88%, 94.73%, 93.33%, 94.44% and 89.47%, respectively with better area under receiver operating characteristic (ROC) curve as well as sensitivity. The magnitude of decrease in TLC, neutrophil count, and increase in CK-MB, IFABP-2, Cp and cortisol concentrations at 72 h of initiation of treatment in dogs with parvoviral enteritis could be useful indicators for the prognosis of the disease. Based on sensitivity (%) and specificity (%) from ROC curve analysis and PPV (%), it is concluded that serum CK-MB concentration will serve as the most useful biomarker followed by Cp and absolute neutrophil count.

Lifestyle as Risk Factor for Infectious Causes of Death in Young Dogs: A Retrospective Study in Southern Italy (2015-2017)

Infectious diseases are a common cause of death in young dogs. Several factors are thought to predispose young dogs to microbiological infections. Identifying the cause of death is often a challenge, and broad diagnostic analysis is often needed. Here, we aimed to determine the infectious causes of death in young dogs aged up to 1 year, examining how it relates to age (under and over 6 months), lifestyle (owned versus ownerless), breed (purebred and crossbreed), and gender. A retrospective study was conducted in a 3-year period (2015-2017) on 138 dead dogs that had undergone necropsy and microbiological diagnostics. Enteritis and pneumonia were the most commonly observed lesions. Polymicrobism was more prevalent (62.3%) than single-agent infections and associated with a higher rate of generalised lesions. Ownerless dogs showed over a three-fold higher predisposition to viral coinfections than owned dogs. Above all, canine parvovirus was the most prevalent agent (77.5%), followed by canine coronavirus (31.1%) and canine adenovirus (23.9%); ownerless pups had a higher predisposition to these viruses. Escherichia coli (23.9%), Clostridium perfringens type A (18.1%), and Enterococcus spp. (8.7%) were the most commonly identified bacteria, which mostly involved in coinfections. A lower prevalence of CDV and Clostridium perfringens type A was observed in puppies under 6 months of age. In conclusion, this study is the first comprehensive survey on a wide panel of microbiological agents related to necropsy lesions. It lays the groundwork for future studies attempting to understand the circulation of infectious agents in a determined area.

Risk, prognosis and causality of parvo viral enteritis in dogs in Sri Lanka

We studied the causal variation, prognosis and risk factors of parvo viral enteritis using both molecular and statistical analysis. A multivariate factor analysis was performed to see the effect of the breed, age, vaccination status and the leukocyte counts on disease severity and survival. Twenty PCR amplicons (partial VP2 gene) from vaccinated dogs were sequenced to identify the variants. A total of 109 samples were positive for parvo viral DNA, 71 of which were from dogs who have received at least one dose of CPV-2 vaccine. Over 90% were leukopenic on 2^nd and 3^rd day of diarrhoea. Age < 6 months was negatively correlated with leukocyte count and the leukocyte count was negatively correlated with survival. Dobermans and Labradors showed significant negative correlation with survival. All variants of parvovirus affected dogs with the 2c being the predominant (2c = 12, 2a = 7, 2b = 1). All 20 strains harboured three additional amino acid substitutions (i.e. Phe267Tyr, Ser297Ala and Tyr324Ile) and warrant further studies on potential changes of the antigenicity of the virus.

Comparison and validation of different models and variable selection methods for predicting survival after canine parvovirus infection

BACKGROUND

Canine parvovirus (CPV) represents one of the major infections in dogs. While supportive therapy significantly reduces mortality, other approaches have been reported to provide significant benefits. Unfortunately, the high cost of these treatments is typically a limiting factor. Consequently, a reliable prognostic tool allowing for an informed therapeutic approach would be of great interest. However, current methods are essentially based on 'a priori' selection of predictive variables, which could limit their predictive potential.

METHODS

In the present study, the predictive performances in terms of CPV enteritis survival likelihood of an operator-validated logistic regression were compared with those of more flexible methods featured by automatic variable selection. Several anamnestic, clinical, haematological and biochemical parameters were collected from 134 dogs at admission in a veterinary practice. Animal status was monitored until dismissal or death (mortality=21.6%).

RESULTS

The best automatic variable selection method (random forest) showed excellent discriminatory capabilities (AUC=0.997, sensitivity=0.941 and specificity=1) compared with the logistic regression model (AUC=0.831, sensitivity=0.882 and specificity=0.652), when evaluated on a fully independent test data set. The implemented approaches allowed to identify antithrombin, serum aspartate aminotransferase, serum lipase, monocyte and lymphocyte count as the clinical parameter combination with the highest predictive capability, thus limiting the panel of required tests.

CONCLUSION

The model validated in the present study allows prompt prediction of disease severity at admission and provides objective and reliable criteria to support the clinician in selection of the therapeutic approach.

Serum D-lactate concentrations in dogs with parvoviral enteritis

BACKGROUND

Dogs infected with canine parvovirus (CPV) have compromised intestinal epithelial barrier integrity. Production of D-lactate by enteric bacteria may directly reflect disease severity or contribute to metabolic acid-base status in these dogs.

HYPOTHESIS

Serum D-lactate concentration will be increased in CPV dogs compared to healthy controls and correlate with markers of disease severity and acid-base status.

ANIMALS

Dogs with CPV undergoing treatment (n = 40) and healthy control dogs (n = 9).

METHODS

Prospective observational study. Dogs with CPV had a baseline and daily CBC, venous blood gas with serum electrolyte concentrations, composite clinical severity score, and serum D-lactate concentration performed. A single serum D-lactate measurement was obtained from healthy control dogs.

RESULTS

The CPV dogs had a higher D-lactate concentration (mean ± SD) of 469 ± 173 μM compared to controls, 306 ± 45 μM (P < .001). There was no difference in baseline D-lactate concentrations for CPV survivors (474 ± 28 μM), versus nonsurvivors (424 ± 116 μM; P = .70). D-lactate concentration decreased over the first 4 days of treatment (-9.6 μM/d; P = .46). Dogs hospitalized for <4 days had lower baseline D-lactate concentrations compared to those hospitalized ≥4 days (400 ± 178 μM versus 520 ± 152 μM; P = .03). No sustained correlation over time between serum D-lactate concentration and clinical severity score or recorded acid-base results.

CONCLUSIONS AND CLINICAL IMPORTANCE

Serum D-lactate concentrations are higher in dogs with CPV compared to healthy controls but do not appear to be clinically relevant. No relationship identified between serum D-lactate concentrations and markers of CPV disease severity, acid-base status, or outcome.

Socioeconomic, geographic and climatic risk factors for canine parvovirus infection and euthanasia in Australia

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11 % of Australian veterinary hospitals reported >40 canine parvovirus cases in 2016.

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Socioeconomic disadvantage was the strongest risk factor for canine parvovirus.

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Euthanasia is the leading cause of fatality for canine parvovirus related disease.

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Hottest month of the year is associated with canine parvovirus case occurrence.

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Low rainfall is associated with higher canine parvovirus cases.

Infection of canids with canine parvovirus (CPV) can result in severe, often fatal disease. This study aimed to examine climatic, socioeconomic and geographic risk factors for CPV infection and CPV-associated euthanasia in Australia. Australian veterinary hospital responses (534; 23.5 %) to a national veterinary survey of CPV case occurrences and euthanasias in 2016 were used. Severe caseloads (>40 cases per annum) were reported by 26 (11 %) hospitals (median 60 cases; IQR 50–110). Case reporting, case numbers, and without-treatment euthanasia were significantly associated with disadvantage across all Socio-Economic Index for Areas quintiles (p < 0.0001) – the greater the disadvantage, the more reports. Strong negative correlations were found between case numbers and the Index of Relative Socioeconomic Disadvantage (r_SP = –0.3357, p < 0.0001) and also between euthanasia and the Index of Education and Occupation (r_SP = –0.3762, p < 0.0001). Hospitals in more remote areas were also more likely to report cases and to euthanize without treatment (p < 0.0001). Of the climate variables, temperature of the hottest month was most strongly positively correlated with case numbers (r_SP = 0.421, p < 0.0001), and lower annual rainfall was associated with more case-reporting hospitals (p < 0.0001). These results confirm that socioeconomic disadvantage is a significant risk-factor for CPV infection and outcome, and high temperature may also contribute to risk.

Canine parvovirus (CPV) phylogeny is associated with disease severity

After its first identification in 1978, canine parvovirus (CPV) has been recognized all around the world as a major threat for canine population health. This ssDNA virus is characterized by a high substitution rate and several genetic and phenotypic variants emerged over time. Overall, the definition of 3 main antigenic variants was established based on specific amino acid markers located in a precise capsid position. However, the detection of several minor variants and incongruence observed between the antigenic classification and phylogeny have posed doubts on the reliability of this scheme. At the same time, CPV heterogeneity has favored the hypothesis of a differential virulence among variants, although no robust and consistent demonstration has been provided yet. The present study rejects the antigenic variant concept and attempts to evaluate the association between CPV strain phylogeny, reconstructed using the whole information contained in the VP2 coding gene, and several clinical and hemato-biochemical parameters, assessed from 34 CPV infected dogs at admission. By using different statistical approaches, the results of the present study show an association between viral phylogeny and host parameters ascribable to immune system, coagulation profile, acute phase response and, more generally, to the overall picture of the animal response. Particularly, a strong and significant phylogenetic signal was proven for neutrophil count and WBC. Therefore, despite the limited sample size, a relation between viral phylogeny and disease severity has been observed for the first time, suggesting that CPV virulence is an inherited trait. The likely existence of clades with different virulence highlights once more the relevance of intensive epidemiological monitoring and research on CPV evolution to better understand the virulence determinants, their epidemiology and develop adequate countermeasures.

Prevalence of Salmonella in juvenile dogs affected with parvoviral enteritis

Salmonellosis is a disease of major zoonotic importance and canine parvovirus is a potentially fatal cause of canine enteritis with a world-wide distribution. Persistent isolation of Salmonella during routine environmental sampling surveys of a hospital ward, reserved for the treatment of dogs with canine parvovirus infection, prompted investigation into a possible source. We hypothesised that dogs affected by canine parvovirus would have a higher prevalence of faecal salmonellae compared to an apparently healthy cohort. Seventy-four client-owned dogs naturally infected with canine parvovirus and 42 apparently healthy client-owned dogs were included in the study. This prospective, longitudinal, observational study was conducted over an 18-month period. Fresh faecal samples were collected from dogs aged 6 weeks to 9 months diagnosed with canine parvovirus infection and admitted for treatment, and from apparently healthy dogs presented for vaccination or routine hospital procedures. Faeces were submitted for the isolation, antimicrobial susceptibility testing and serotyping of salmonellae. The prevalence of faecal Salmonella shedding was 22% and 31% for the affected and apparently healthy dogs, respectively, which was not statistically different. No significant associations between Salmonella status and possible risk factors or continuous variables such as age, body weight and duration of hospitalisation were identified. All the Salmonella isolates (n = 32) were resistant to penicillin G, lincomycin and tylosin. Salmonellae from nine different serotypes were identified. The prevalence of Salmonella shedding in both groups was higher than that commonly reported, yet similar to those in previous reports on young dogs, shelter dogs or dogs fed a raw meat diet.

Assessment of acute kidney injury in canine parvovirus infection: Comparison of kidney injury biomarkers with routine renal functional parameters

Dogs with naturally occurring canine parvovirus (CPV) infection are at risk of developing acute kidney injury (AKI) due to several factors, including severe dehydration, hypotension and sepsis. Serum creatinine (sCr) and serum urea are insensitive markers for the assessment of early kidney injury. Therefore, the aim of this study was to investigate potential kidney injury in dogs with CPV infection using both routine renal functional parameters and several kidney injury biomarkers. Twenty-two dogs with CPV infection were prospectively enrolled and compared with eight clinically healthy control dogs. Urinary immunoglobulin G (uIgG) and C-reactive protein (uCRP) were measured to document glomerular injury, whereas urinary retinol-binding protein (uRBP) and neutrophil gelatinase-associated lipocalin (uNGAL) served as markers for tubular injury. These biomarkers were compared to routine renal functional parameters, including sCr, serum urea, urinary protein:creatinine ratio (UPC) and urine specific gravity (USG). Dogs with CPV infection had significantly higher concentrations of uIgG, uCRP, uRBP and uNGAL compared to healthy dogs. In contrast, sCr was significantly lower in dogs with CPV infection compared to controls, while serum urea was not significantly different. UPC and USG were both significantly higher in CPV-infected dogs. This study demonstrated that dogs with CPV infection had evidence of AKI, which remained undetected by the routine functional markers sCr and serum urea, but was revealed by UPC, uIgG, uCRP, uRBP and uNGAL. These results emphasize the added value of novel urinary kidney injury biomarkers to detect canine patients at risk of developing AKI.

Bioclimatic and altitudinal variables influence the potential distribution of canine parvovirus type 2 worldwide

Canine parvovirus type 2 (CPV‐2) is extremely contagious and causes high rate of morbidity to many wild carnivores. It has three variants (CPV‐2a, CPV‐2b, and CPV‐2c) that are distributed worldwide with different frequencies and levels of genetic and antigenic variability. The disease poses a threat to the healthy survival and reproduction of wildlife. The research on the relationship between CPV‐2 epidemic and environmental variables is lacking. To fill this research gap, we used maximum entropy (MaxEnt) approach with principal component analysis (PCA) to evaluate the relation between CPV‐2 and environmental variables and to create a world risk map for this disease. According to the PCA results, 18 environmental variables were selected from 68 variables for subsequent analyses. MaxEnt showed that annual mean temperature, isothermality, altitude, November precipitation, maximum temperature of warmest month, and precipitation of warmest quarter were the six most important variables associated with CPV‐2 distribution, with a total of 77.7% percent contribution. The risk of this disease between 18°N and 47°N was high, especially in the east of China and the United States. These results support further prediction of risk factors for this virus to help secure the health and sustainable survival of wild carnivores.

Evaluation of an outpatient protocol in the treatment of canine parvoviral enteritis

OBJECTIVE

To compare 2 treatment protocols (standard in-hospital versus modified outpatient) in affecting the duration of treatment or survival of dogs with parvoviral enteritis.

DESIGN

Prospective, randomized study.

SETTING

University teaching hospital.

ANIMALS

Client-owned dogs with naturally acquired parvovirus were randomized to receive either an inpatient (n = 20) or outpatient (n = 20) treatment protocol.

INTERVENTIONS

Both groups received intravenous (IV) fluid resuscitation and correction of hypoglycemia at hospital admission. Following stabilization, basic inpatient interventions included administration of IV fluids, administration of cefoxitin (22 mg/kg IV q 8 h), and maropitant (1 mg/kg IV q 24 h). Basic outpatient interventions (provided in-hospital) included administration of subcutaneous (SC) fluid (30 mL/kg q 6 h), administration of maropitant (1 mg/kg SC q 24 h) and cefovecin (8 mg/kg SC once). Using daily electrolyte and glucose evaluations, dextrose and potassium supplementation was provided intravenously (inpatients) or orally (outpatients) as indicated. Rescue criteria were used in both groups for analgesia and nausea. All dogs were syringe fed a commercial canine convalescence diet (1 mL/kg PO q 6 h) until voluntary appetite returned.

MEASUREMENTS AND MAIN RESULTS

Protocol success, defined as survival to hospital discharge, was 90% (18/20) for the inpatient group compared to 80% (16/20) for the outpatient group (P = 0.66). There was no difference detected in duration of hospitalization for inpatient dogs (4.6 ± 2 days) versus outpatient dogs (3.8 ± 1.8 days, P = 0.20). Metabolic disturbances were frequent in the outpatient group, with 50% of dogs requiring dextrose supplementation and 60% of dogs requiring potassium supplementation.

CONCLUSIONS

An outpatient protocol may be a reasonable alternative for dogs that cannot receive standard in-hospital treatment for parvoviral enteritis. Diligent supportive care and monitoring are still required to optimize treatment of dogs with parvoviral enteritis in an outpatient setting.

Reliability of clinical diagnosis and laboratory testing techniques currently used for identification of canine parvovirus enteritis in clinical settings

Canine parvovirus type 2 (CPV-2) is the main etiological agent of viral enteritis in dogs. Actually in literature, CPV-2 has been reported with clinical signs that vary from the classical disease, and immunochromatography test and PCR technique have been introduced to veterinary hospitals to confirm CPV-2 diagnosis and other infections. However, the reliability of these techniques has been poorly analyzed. In this study, we evaluated the sensitivity and specificity of veterinary clinical diagnosis, immunochromatography test and PCR technique. Our data indicate that variations in the clinical signs of CPV-2 complicate the gathering of an appropriate diagnosis; and immunochromatography test and PCR technique do not have adequate sensitivity to diagnose positive cases.

Measurements of C-reactive protein (CRP) and nerve-growth-factor (NGF) concentrations in serum and urine samples of dogs with neurologic disorders

BACKGROUND

The purpose of this study was to prove the hypothesis that C-reactive protein (CRP) and nerve growth factor (NGF) may be potential biomarkers for lower urinary tract disorders and may be able to distinguish between micturition dysfunctions of different origin in dogs with spinal cord diseases. NGF- and CRP- concentrations were measured in serum and urine samples using specific ELISA-Kits. Results in urine were standardized by urine-creatinine levels.

RESULTS

CRP in serum was detectable in 32/76 and in urine samples in 40/76 patients. NGF could be measured in all serum and in 70/76 urine samples. Urinary CRP concentrations were significantly higher in dogs with micturition dysfunction (p = 0.0009) and in dogs with different neurological diseases (p = 0.0020) compared to the control group. However, comparing dogs with spinal cord disorders with and without associated micturition dysfunction no significant difference could be detected for NGF and CRP values in urine or serum samples. Additionally, levels did not decrease significantly, when measured at the time when the dogs regained the ability to urinate properly (urinary NGF p = 0.7962; urinary CRP p = 0.078). Urine samples with bacteria and/or leukocytes had no significant increase in urinary NGF (p = 0.1112) or CRP (p = 0.0534) concentrations, but higher CRP-levels in urine from dogs with cystitis were found compared to dogs without signs of cystitis.

CONCLUSIONS

From these data we conclude that neither CRP nor NGF in urine or serum can be considered as reliable biomarkers for micturition disorders in dogs with spinal cord disorders in a clinical setting, but their production might be part of the pathogenesis of such disorders. Significantly higher levels of CRP could be found in the urine of dogs with micturition dysfunctions compared to control dogs. This phenomenon could potentially be explained by unspecific extrahepatic CRP production by smooth muscle cells in the dilated bladder.

Canine parvovirus in Australia: A comparative study of reported rural and urban cases

Canine parvovirus (CPV) is a highly contagious and often fatal disease reported worldwide. Outbreaks occur throughout Australia, and it has been suggested that disproportionally more CPV cases occur in rural locations. However, evidence to support this suggestion-and possible reasons for such a predisposition-has not existed until now. In this study a total of 4870 CPV cases reported from an Australian disease surveillance system between September 2009 and July 2014 were analysed. Australian postcodes were classified as rural or urban (based on human population density) and reported CPV cases were then categorised as rural or urban based on their reported home postcode. Parvovirus cases were predominately young (<12 months), entire, unvaccinated, mixed-breed dogs. More than twice as many of the reported cases were from a rural area (3321 cases) compared to an urban area (1549 cases). The overall case fatality rate was 47.2%; it was higher for those CPV cases reported from urban areas (50.6%) than rural areas (45.5%). A greater proportion of rural cases were younger, entire dogs compared to urban cases. The final multivariable model of CPV cases being reported from a rural area included age (<12 months) and vaccination status (never vaccinated) as significant predictors. Poor socioeconomic status might be a reason for the decision of rural owners not to vaccinate their dogs as readily as urban owners. The excess reporting of rural CPV cases compared to urban cases and the predictive risk factors identified in this study can be used by veterinarians to reduce the incidence of CPV by educating owners about the disease and promoting better vaccination programs in rural areas. This study also supports that the increased risk of CPV in rural areas may necessitate a need for increased vigilance around preventing CPV disease spread, additional care with puppies which are the most susceptible to this disease and tighter vaccination protocols, compared to urban areas.

Genotyping of Canine parvovirus in western Mexico

Canine parvovirus (CPV) is one of the most common infectious agents related to high morbidity rates in dogs. In addition, the virus is associated with severe gastroenteritis, diarrhea, and vomiting, resulting in high death rates, especially in puppies and nonvaccinated dogs. To date, there are 3 variants of the virus (CPV-2a, CPV-2b, and CPV-2c) circulating worldwide. In Mexico, reports describing the viral variants circulating in dog populations are lacking. In response to this deficiency, a total of 41 fecal samples of suspected dogs were collected from October 2013 through April 2014 in the Veterinary Hospital of the University of Guadalajara in western Mexico. From these, 24 samples resulted positive by polymerase chain reaction, and the viral variant was determined by restriction fragment length polymorphism. Five positive diagnosed samples were selected for partial sequencing of the vp2 gene and codon analysis. The results demonstrated that the current dominant viral variant in Mexico is CPV-2c. The current study describes the genotyping of CPV strains, providing valuable evidence of the dominant frequency of this virus in a dog population from western Mexico.

The central role of chloride in the metabolic acid-base changes in canine parvoviral enteritis

The acid–base disturbances in canine parvoviral (CPV) enteritis are not well described. In addition, the mechanisms causing these perturbations have not been fully elucidated. The purpose of the present study was to assess acid–base changes in puppies suffering from CPV enteritis, using a modified strong ion model (SIM). The hypothesis of the study was that severe acid–base disturbances would be present and that the SIM would provide insights into pathological mechanisms, which have not been fully appreciated by the Henderson–Hasselbalch model.

The study analysed retrospective data, obtained from 42 puppies with confirmed CPV enteritis and 10 healthy control dogs. The CPV-enteritis group had been allocated a clinical score, to allow classification of the data according to clinical severity. The effects of changes in free water, chloride, l-lactate, albumin and phosphate were calculated, using a modification of the base excess algorithm. When the data were summated for each patient, and correlated to each individual component, the most important contributor to the metabolic acid–base changes, according to the SIM, was chloride (P < 0.001). Severely-affected animals tended to demonstrate hypochloraemic alkalosis, whereas mildly-affected puppies had a hyperchloraemic acidosis (P = 0.007). In conclusion, the acid–base disturbances in CPV enteritis are multifactorial and complex, with the SIM providing information in terms of the origin of these changes.