Review of cobalamin status and disorders of cobalamin metabolism in dogs

Multivariate modular metabolic engineering and medium optimization for vitamin B12 production by Escherichia coli

Vitamin B12 is a complex compound synthesized by microorganisms. The industrial production of vitamin B12 relies on specific microbial fermentation processes. E. coli has been utilized as a host for the de novo biosynthesis of vitamin B12, incorporating approximately 30 heterologous genes. However, a metabolic imbalance in the intricate pathway significantly limits vitamin B12 production. In this study, we employed multivariate modular metabolic engineering to enhance vitamin B12 production in E. coli by manipulating two modules comprising a total of 10 genes within the vitamin B12 biosynthetic pathway. These two modules were integrated into the chromosome of a chassis cell, regulated by T7, J23119, and J23106 promoters to achieve combinatorial pathway optimization. The highest vitamin B12 titer was attained by engineering the two modules controlled by J23119 and T7 promoters. The inclusion of yeast powder to the fermentation medium increased the vitamin B12 titer to 1.52 mg/L. This enhancement was attributed to the effect of yeast powder on elevating the oxygen transfer rate and augmenting the strain's isopropyl-β-d-1-thiogalactopyranoside (IPTG) tolerance. Ultimately, vitamin B12 titer of 2.89 mg/L was achieved through scaled-up fermentation in a 5-liter fermenter. The strategies reported herein will expedite the development of industry-scale vitamin B12 production utilizing E. coli.

Prognostic potential of copper, zinc, copper/zinc ratio, cobalamin, and serum amyloid A in cats with panleukopenia

BACKGROUND

Copper (Cu), zinc (Zn), and the copper/zinc ratio (Cu/Zn), which have been studied in gastrointestinal disorders of humans, may facilitate disease prognosis.

OBJECTIVE

Evaluate the predictive potential of Cu, Zn, cobalamin, and serum amyloid A (SAA) as prognostic indicators in cats with feline panleukopenia (FPV) on admission.

ANIMALS

Client-owned cats diagnosed with FPV and controls.

METHODS

Serum Cu and Zn concentrations were assessed using the spectrophotometric method and serum concentrations of SAA and cobalamin were measured by chemiluminescent immunoassay.

RESULTS

On admission, survivor cats with FPV had significantly higher serum Cu and SAA concentrations and Cu/Zn ratios and significantly lower serum Zn and cobalamin concentrations than controls. Furthermore, non-survivor cats with FPV had significantly higher serum Cu and SAA concentrations and Cu/Zn ratios and significantly lower cobalamin concentrations than survivors and controls. Prognostic thresholds were calculated, with positive predictive value (PPV) for survival of 90% for Cu (≥120.3 μg/dL), 90% for Cu/Zn (≥1.34), 90% for cobalamin (≤430.4 pg/mL), and 90% for SAA (≥0.85 mg/L).

CONCLUSIONS AND CLINICAL IMPORTANCE

Cu (0.93 area under curve [AUC]), Cu/Zn (0.95 AUC), cobalamin (0.98 AUC), and SAA (0.98 AUC) were excellent biomarkers for predicting prognosis in cats with FPV. Their effectiveness, as assessed by sensitivity (100%), specificity (80%), AUC (0.98), and PPV (90%) from receiver operating characteristic analysis, emphasizes the performance of cobalamin and SAA.

Efficacy and tolerance of oral versus parenteral cyanocobalamin supplement in hypocobalaminaemic dogs with chronic enteropathy: a controlled randomised open-label trial

OBJECTIVES

Determine comparative tolerance of daily oral and weekly parenteral cobalamin supplementation, in hypocobalaminaemic dogs with chronic enteropathy. Determine whether oral is as effective as parenteral supplementation at achieving eucobalaminaemia, in hypocobalaminaemic dogs with protein-losing enteropathy, severe hypocobalaminaemia or high canine inflammatory bowel disease activity index at inclusion.

MATERIALS AND METHODS

Thirty-seven client-owned dogs with hypocobalaminaemia and clinical signs of chronic enteropathy were prospectively enrolled in three UK referral centres. Dogs were randomly allocated to daily oral for 12 weeks or weekly parenteral cobalamin supplementation for 6 weeks and one additional dose 4 weeks later. Serum cobalamin, body condition score, canine inflammatory bowel disease activity index and bodyweight were assessed at inclusion, weeks 7 and 13. Serum methylmalonic acid concentration was evaluated at inclusion and at week 13. Owners completed treatment adherence, palatability, tolerance and satisfaction questionnaires at week 13.

RESULTS

Nineteen dogs completed the study. All dogs orally supplemented achieved normal or increased cobalaminaemia at weeks 7 and 13. There was no statistical difference in cobalamin concentration at week 13 in dogs treated with oral or parenteral supplementation, regardless of presence of protein-losing enteropathy, severity of hypocobalaminaemia or canine inflammatory bowel disease activity index at inclusion. Serum methylmalonic acid concentration was not significantly different between oral and parenteral groups, neither were treatment adherence, satisfaction, and tolerance scores at week 13.

CLINICAL SIGNIFICANCE

Oral is as effective and as well-tolerated as parenteral cobalamin supplementation in hypocobalaminaemic dogs with chronic enteropathy and severe clinical or biochemical phenotypes, and should be considered as a suitable treatment option regardless of disease severity.

Evaluation of the Blood Neutrophil-to-Lymphocyte Ratio (NLR) as a Diagnostic and Prognostic Biomarker in Dogs with Portosystemic Shunt

The neutrophil-to-lymphocyte ratio (NLR) can help in assessing inflammatory diseases, sepsis, and chronic hepatic conditions in humans. Dogs with congenital portosystemic shunts (PSSs) have signs of generalized inflammation, and the clinical signs can overlap with other conditions, including hypoadrenocorticism (HOC). Thus, the potential diagnostic and prognostic value of leukocyte ratios as surrogate markers was assessed in a retrospective case-control study including 106 dogs diagnosed with PSSs. The disease control groups were dogs with parenchymal hepatopathy (PH; n = 22) or HOC (n = 31). In the PSS dogs, the blood NLRs were associated with the severity of systemic inflammation but not with the shunt type, hepatoencephalopathy, systemic infection, or hypoglycemia. The baseline NLRs did not differ between the three disease groups, between medically and surgically treated PSS dogs, or between those with successful PSS ligation and dogs experiencing peri-/post-surgical complications. However, dogs requiring two consecutive surgical interventions had significantly higher NLRs, and an NLR of <2.53 distinguished dogs with successful shunt ligation in one surgery from those requiring two consecutive surgeries for PSS closure. The blood NLR might be a useful clinicopathologic variable in PSS, but its value in helping differentiate PSS from HOC cases appears low. Integrating the NLR into a diagnostic algorithm may allow for a prediction of the number of surgical interventions required.

Hypocobalaminaemia in dogs with acute gastrointestinal diseases

OBJECTIVES

The objectives of this study were to investigate the prevalence of hypocobalaminaemia in dogs with acute gastrointestinal diseases and to evaluate its relationship with disease severity and outcome.

MATERIALS AND METHODS

Medical records of dogs presented for acute gastrointestinal signs that a serum cobalamin concentration measured between September 2019 and 2021 were included in this study. Hypocobalaminaemia was defined as serum cobalamin concentration <200 pmol/L, and low-normal cobalamin was defined as serum cobalamin concentration of 200 to 295 pmol/L. Duration of clinical signs prior to presentation, Acute Patient Physiologic and Laboratory Evaluation (APPLE) fast score, length of hospitalisation and outcome were recorded.

RESULTS

Thirty-three dogs were included. Seventeen dogs were diagnosed with acute gastrointestinal disease of unknown aetiology, seven dogs with parvoviral enteritis, three dogs with acute haemorrhagic diarrhoea syndrome and six dogs with miscellaneous diseases. The prevalence of hypocobalaminaemia in this population was 30.3% and low-normal cobalamin concentration was detected in 18.2% of dogs. There was no statistically significant relationship between the detection of hypocobalaminaemia or low-normal cobalamin and the duration of clinical signs before presentation, length of hospitalisation or Acute Patient Physiologic and Laboratory Evaluation fast score on admission. Mortality rate was 3%.

CLINICAL SIGNIFICANCE

Hypocobalaminaemia and low-normal cobalamin are common findings in dogs with acute gastrointestinal diseases. The therapeutic significance and potential implications for prognosis of hypocobalaminaemia in these patients requires further investigation.

Expression of the cobalamin transporters cubam and MRP1 in the canine ileum-Upregulation in chronic inflammatory enteropathy

Chronic inflammatory enteropathy (CIE) in dogs, a spontaneous model of human inflammatory bowel disease (IBD), is associated with a high rate of cobalamin deficiency. The etiology of hypocobalaminemia in human IBD and canine CIE remains unknown, and compromised intestinal uptake of cobalamin resulting from ileal cobalamin receptor deficiency has been proposed as a possible cause. Here, we evaluated the intestinal expression of the cobalamin receptor subunits, amnionless (AMN) and cubilin (CUBN), and the basolateral efflux transporter multi-drug resistance protein 1 (MRP1) in 22 dogs with CIE in comparison to healthy dogs. Epithelial CUBN and AMN levels were quantified by confocal laser scanning microscopy using immunohistochemistry in endoscopic ileal biopsies from dogs with (i) CIE and normocobalaminemia, (ii) CIE and suboptimal serum cobalamin status, (iii) CIE and severe hypocobalaminemia, and (iv) healthy controls. CUBN and MRP1 expression was quantified by RT-qPCR. Receptor expression was evaluated for correlation with clinical patient data. Ileal mucosal protein levels of AMN and CUBN as well as mRNA levels of CUBN and MRP1 were significantly increased in dogs with CIE compared to healthy controls. Ileal cobalamin receptor expression was positively correlated with age, clinical disease activity index (CCECAI) score, and lacteal dilation in the ileum, inversely correlated with serum folate concentrations, but was not associated with serum cobalamin concentrations. Cobalamin receptor downregulation does not appear to be the primary cause of hypocobalaminemia in canine CIE. In dogs of older age with severe clinical signs and/or microscopic intestinal lesions, intestinal cobalamin receptor upregulation is proposed as a mechanism to compensate for CIE-associated hypocobalaminemia. These results support oral supplementation strategies in hypocobalaminemic CIE patients.

The Use of Diets in the Diagnosis and Treatment of Common Gastrointestinal Diseases in Dogs and Cats

The nutritional health of dogs and cats is important to pet owners around the world. Nutrition is inextricably linked to the health of the gastrointestinal system and vice versa. Gastrointestinal signs, such as vomiting, diarrhea, anorexia, or weight loss, are one of the most common reasons that dog and cat owners make non-routine appointments with veterinarians. Those patients are evaluated systematically to identify and/or rule out the causes of the symptoms. Some causes of chronic diarrhea are within the gastrointestinal tract while others are secondary to pathogenic factors outside the digestive system. Some useful biomarkers of chronic intestinal disease (enteropathy) exist in serum and feces. After determination that the clinical signs are due to primary gastrointestinal disease and that there is no parasitism, specific diets are used for at least two weeks. There are several types of diets for pets with chronic enteropathies. There are limited ingredient diets and hydrolyzed protein diets with reduced levels of allergens. There are also highly digestible and fiber-enhanced diets. Some diets contain probiotics and/or prebiotics. If symptoms do not improve and the patient is stable, a diet from a different class may be tried. For chronic enteropathies, the prognosis is generally good for symptom resolution or at least improvement. However, if interventions with novel diets do not ameliorate the symptoms of chronic enteropathy, then antibiotic, anti-inflammatory, or immunosuppressant therapy or further, more invasive diagnostics such as taking an intestinal biopsy, may be indicated. Pancreatitis is a common gastrointestinal disease in dogs and cats and patients may present with mild to severe disease. Many patients with mild to moderate disease can be successfully treated with early supportive care, including feeding a low-fat diet. A novel pharmaceutical, fuzapladib (Panoquell-CA1) looks very promising for treating more severe forms of acute pancreatitis in dogs. Maintenance on a low-fat diet may prevent pancreatitis in at-risk dogs. Future advances in medicine will allow pet owners and veterinarians to use dietary management to maximize the health of their dogs and cats.

Prevalence of neoplasia and concurrent diseases in dogs and cats with hypercobalaminemia: A retrospective case-control study

BACKGROUND

Hypercobalaminemia is infrequently reported in companion animals and is considered of low clinical significance. Recent studies have described its association with inflammatory, immune-mediated, endocrine, and neoplastic conditions in dogs and cats.

OBJECTIVES

We aimed to investigate the association between hypercobalaminemia and neoplasia in companion animals and to identify other concurrent diseases or clinicopathologic changes.

METHODS

This is a retrospective, case-control study. Medical records of patients with measured serum cobalamin concentration (2015-2020) and no history of prior supplementation were reviewed. Hypocobalaminemic animals were excluded. Variables were compared between groups (hypercobalaminemic vs. normocobalaminemic) using non-parametric statistics. Data are presented as median (range).

RESULTS

Thirty-five dogs and eight cats were hypercobalaminemic. At baseline, neoplasia was confirmed in 4/35 hypercobalaminemic dogs versus 11/70 control dogs (P = 0.77) and 0/8 hypercobalaminemic cats versus 3/16 control cats (P = 0.53). Cases without neoplasia at baseline were followed for 409 (13-1854) days (dogs, n = 78) and 395 (28-1670) days (cats, n = 21). During follow-up, neoplasia was diagnosed in 4/27 hypercobalaminemic dogs versus 3/51 control dogs (P = 0.23) and 1/8 hypercobalaminemic cats versus 0/13 control cats (P = 0.38). Pancreatitis was more frequent in hypercobalaminemic dogs (P = 0.006). Hypercobalaminemic dogs had higher serum total protein (P = 0.014), globulin (P = 0.001), and CRP (P = 0.032) concentrations and lower serum sodium (P = 0.012) and chloride (P = 0.033) concentrations than controls. Hypercobalaminemic cats had higher serum total protein concentrations than controls (P = 0.008).

CONCLUSION

Our results suggest that hypercobalaminemia is not associated with the presence or development of neoplasia in dogs and cats but may be associated with systemic inflammatory conditions, including pancreatitis, in dogs.

Efficacy of an elemental diet in achieving clinical remission in dogs with chronic enteropathy

BACKGROUND

Diet may induce clinical remission in dogs with chronic enteropathy (CE). Elemental diets (EDs), providing protein as amino acids, modulate intestinal immunity and microbiome in rodents and humans.

HYPOTHESIS

Evaluate the impact of an amino acid-based kibble (EL) on CE clinical activity and gastrointestinal (GI)-relevant variables.

ANIMALS

Client-owned dogs (n = 23) with inadequately controlled CE.

METHODS

Prospective, uncontrolled clinical trial. Diagnostic evaluation including upper and lower GI endoscopy was performed before study entry. Canine chronic enteropathy clinical activity index (CCECAI), serum biomarkers, and fecal microbiome were evaluated before and after 2 weeks of EL. Dogs with stable or improved CE remained in the study for another 6 weeks. Pre- and post-EL clinical and microbiological variables were compared statistically using a mixed model.

RESULTS

After 2 weeks of EL, 15 of 22 dogs (68%; 95% confidence interval [CI], 47%-84%) consuming the diet were classified as responders with a median (range) decrease in CCECAI from 6 (3-12) to 2 (0-9; P < .001). Fourteen of 15 responders and 2/7 nonresponders at 2 weeks completed the trial; all 16 were experiencing adequate control at week 8 with a median CCECAI of 2 (0-3). In total, 16/23 dogs (70%; 95% CI, 49%-84%) were responders. Feeding EL caused shifts in fecal bacterial communities, which differed between responders and nonresponders. Serum biomarker concentrations were unchanged throughout the study apart from serum alkaline phosphatase activity.

CONCLUSIONS

Exclusive feeding of EL improved clinical signs in 16 of 23 dogs with uncontrolled CE. Fecal microbiome shifts were associated with response to diet and may represent a mechanism for clinical improvement.

Serum cobalamin and methylmalonic acid concentrations in juvenile dogs with parvoviral enteritis or other acute enteropathies

BACKGROUND

Low serum cobalamin concentrations have been associated with ileal malabsorption in dogs with chronic enteropathy. Increased serum methylmalonic acid (MMA) concentrations indicate cobalamin deficiency on a cellular level. Few studies have evaluated serum cobalamin concentrations or methylmalonic acid concentrations in juvenile dogs with parvoviral enteritis or nonparvoviral acute enteropathies.

OBJECTIVES

Evaluate serum cobalamin and methylmalonic acid concentrations in juvenile dogs (6 weeks to 10 months old) with parvoviral enteritis or nonparvoviral acute enteropathy.

ANIMALS

Thirty-one juvenile dogs with parvoviral enteritis, 29 dogs with nonparvoviral acute diarrhea (NPVAD), and 40 healthy juvenile control dogs.

METHODS

Single-center, prospective, observational, cross-sectional study. Serum cobalamin and, when sufficient serum was available, MMA concentrations were measured.

RESULTS

Most serum cobalamin concentrations were within the adult reference interval. Serum cobalamin concentrations in healthy dogs (median, 848 ng/L; range, 293-1912 ng/L) were significantly higher than in dogs with parvoviral enteritis (P = .0002; median, 463 ng/L; range, <150-10 000 ng/L) or dogs with NPVAD (P = .02; median, 528 ng/L; range, 160-8998 ng/L). Serum MMA concentrations were not significantly different between groups (healthy dogs: median, 796 nmol/L; range, 427-1933 nmol/L; parvoviral enteritis: median, 858 nmol/L; range, 554-3424 nmol/L; NPVAD: median, 764 nmol/L; range, 392-1222 nmol/L; P = .1).

CONCLUSIONS AND CLINICAL IMPORTANCE

Juvenile dogs with parvoviral enteritis or NPVAD had lower serum cobalamin concentrations than healthy juvenile dogs. However, based on serum MMA concentrations cellular cobalamin deficiency was not apparent.

The inorganic chemistry of the cobalt corrinoids - an update

The inorganic chemistry of the cobalt corrinoids, derivatives of vitamin B₁₂, is reviewed, with particular emphasis on equilibrium constants for, and kinetics of, their axial ligand substitution reactions. The role the corrin ligand plays in controlling and modifying the properties of the metal ion is emphasised. Other aspects of the chemistry of these compounds, including their structure, corrinoid complexes with metals other than cobalt, the redox chemistry of the cobalt corrinoids and their chemical redox reactions, and their photochemistry are discussed. Their role as catalysts in non-biological reactions and aspects of their organometallic chemistry are briefly mentioned. Particular mention is made of the role that computational methods - and especially DFT calculations - have played in developing our understanding of the inorganic chemistry of these compounds. A brief overview of the biological chemistry of the B₁₂-dependent enzymes is also given for the reader's convenience.

ACVIM consensus statement guidelines on diagnosing and distinguishing low-grade neoplastic from inflammatory lymphocytic chronic enteropathies in cats

BACKGROUND

Lymphoplasmacytic enteritis (LPE) and low-grade intestinal T cell lymphoma (LGITL) are common diseases in older cats, but their diagnosis and differentiation remain challenging.

OBJECTIVES

To summarize the current literature on etiopathogenesis and diagnosis of LPE and LGITL in cats and provide guidance on the differentiation between LPE and LGITL in cats. To provide statements established using evidence-based approaches or where such evidence is lacking, statements based on consensus of experts in the field.

ANIMALS

None.

METHODS

A panel of 6 experts in the field (2 internists, 1 radiologist, 1 anatomic pathologist, 1 clonality expert, 1 oncologist) with the support of a human medical immunologist, was formed to assess and summarize evidence in the peer-reviewed literature and complement it with consensus recommendations.

RESULTS

Despite increasing interest on the topic for clinicians and pathologists, few prospective studies were available, and interpretation of the pertinent literature often was challenging because of the heterogeneity of the cases. Most recommendations by the panel were supported by a moderate or low level of evidence. Several understudied areas were identified, including cellular markers using immunohistochemistry, genomics, and transcriptomic studies.

CONCLUSIONS AND CLINICAL IMPORTANCE

To date, no single diagnostic criterion or known biomarker reliably differentiates inflammatory lesions from neoplastic lymphoproliferations in the intestinal tract of cats and a diagnosis currently is established by integrating all available clinical and diagnostic data. Histopathology remains the mainstay to better differentiate LPE from LGITL in cats with chronic enteropathy.

Vitamin B12 in Cats: Nutrition, Metabolism, and Disease

Cobalamin is a water-soluble molecule that has an important role in cellular metabolism, especially in DNA synthesis, methylation, and mitochondrial metabolism. Cobalamin is bound by intrinsic factor (IF) and absorbed in the ileal tract. The IF in cats is synthesized exclusively by pancreatic tissue. About 75% of the total plasma cobalamin in cats is associated with transcobalamin II, while in this species, transcobalamin I is not present. In cats, the half-life of cobalamin is 11-14 days. Diagnostic biomarkers for B12 status in cats include decreased levels of circulating total cobalamin and increased levels of methylmalonic acid. The reference interval for serum cobalamin concentrations in cats is 290-1500 ng/L, and for the serum methylmalonic acid concentration, it is 139-897 nmol/L. Therapy for hypocobalaminemia mainly depends on the underlying disease. In some cases, subcutaneous or intramuscular injection of 250 μg/cat is empirically administered. In recent years, it has been demonstrated that oral cobalamin supplementation can also be used successfully in dogs and cats as a less invasive alternative to parental administration. This review describes the current knowledge regarding B12 requirements and highlights improvements in diagnostic methods as well as the role of hypocobalaminemia in its associated diseases.

Fecal Microbiota, Bile Acids, Sterols, and Fatty Acids in Dogs with Chronic Enteropathy Fed a Home-Cooked Diet Supplemented with Coconut Oil

Medium-chain fatty acids (MCFAs) are considered to be interesting energy sources for dogs affected by chronic enteropathies (CE). This study analyzed the clinical scores, fecal microbiota, and metabolomes of 18 CE dogs fed a home-cooked diet (HCD) supplemented with virgin coconut oil (VCO), a source of MCFA, at 10% of metabolizable energy (HCD + VCO). The dogs were clinically evaluated with the Canine Chronic Enteropathy Activity Index (CCECAI) before and at the end of study. Fecal samples were collected at baseline, after 7 days of HCD, and after 30 days of HCD + VCO, for fecal score (FS) assessment, microbial analysis, and determination of bile acids (BA), sterols, and fatty acids (FA). The dogs responded positively to diet change, as shown by the CCECAI improvement (p = 0.001); HCD reduced fecal fat excretion and HCD + VCO improved FS (p < 0.001), even though an increase in fecal moisture occurred due to HCD (p = 0.001). HCD modified fecal FA (C6:0: +79%, C14:0: +74%, C20:0: +43%, C22:0: +58%, C24:0: +47%, C18:3n-3: +106%, C20:4n-6: +56%, and monounsaturated FA (MUFA): -23%, p < 0.05) and sterol profile (coprostanol: -27%, sitostanol: -86%, p < 0.01). VCO increased (p < 0.05) fecal total saturated FA (SFA: +28%, C14:0: +142%, C16:0 +21%, C22:0 +33%) and selected MCFAs (+162%; C10:0 +183%, C12:0 +600%), while reducing (p < 0.05) total MUFA (-29%), polyunsaturated FA (-26%), campesterol (-56%) and phyto-/zoosterols ratio (0.93:1 vs. 0.36:1). The median dysbiosis index was <0 and, together with fecal BA, was not significantly affected by HCD nor by VCO. The HCD diet increased total fecal bacteria (p = 0.005) and the abundance of Fusobacterium spp. (p = 0.028). This study confirmed that clinical signs, and to a lesser extent fecal microbiota and metabolome, are positively influenced by HCD in CE dogs. Moreover, it has been shown that fecal proportions of MCFA increased when MCFAs were supplemented in those dogs. The present results emphasize the need for future studies to better understand the intestinal absorptive mechanism of MCFA in dogs.

Canine chronic enteropathy—Current state-of-the-art and emerging concepts

Over the last decade, chronic inflammatory enteropathies (CIE) in dogs have received great attention in the basic and clinical research arena. The 2010 ACVIM Consensus Statement, including guidelines for the diagnostic criteria for canine and feline CIE, was an important milestone to a more standardized approach to patients suspected of a CIE diagnosis. Great strides have been made since understanding the pathogenesis and classification of CIE in dogs, and novel diagnostic and treatment options have evolved. New concepts in the microbiome-host-interaction, metabolic pathways, crosstalk within the mucosal immune system, and extension to the gut-brain axis have emerged. Novel diagnostics have been developed, the clinical utility of which remains to be critically evaluated in the next coming years. New directions are also expected to lead to a larger spectrum of treatment options tailored to the individual patient. This review offers insights into emerging concepts and future directions proposed for further CIE research in dogs for the next decade to come.

Homocysteine Concentration in the Serum of Dogs Naturally Infected with Leishmania Spp. – Association with the Stage of the Disease, Therapy, and Clinical Pathology Data

Progressive tissue injury in canine leishmaniosis (CL) is related to the deposition of immune complexes, which induces vasculitis and leads to endothelial dysfunction. Homocysteine (Hcy) increase may worsen endothelial dysfunction, but data concerning its concentration in different CL stages and links to the acute phase response and oxidative stress are missing. We compared Hcy levels between dogs with mild (N=24) and moderate CL without treatment (N=17) and treated with anti-Leishmania drugs and vitamin B supplements (N=9). Dogs with moderate CL, regardless of therapy administration, had more distinct clinical signs, lower erythron values, and a higher level of acute-phase proteins (APPs), IgG against Leishmania spp., urea and creatinine, than dogs with mild CL. Hcy values did not differ between stages, but treated dogs had the lowest levels of Hcy. An inverse relationship existed between Hcy and the CL stage, therapy, levels of IgG, and clinical pathology data. The only positive relationship existed between Hcy and the erythron state. The disease stage and therapeutic intervention were not related to the oxidative stress level, except in the case of paraoxonase-1/Hcy ratio, indicating favorable conditions for antioxidative defense in treated dogs. In conclusion, changes in Hcy levels indicated its possible involvement with endothelial dysfunction and inverse relationship to tissue injury evaluated by APPs. Finally, Hcy might be an early marker of favorable conditions for endothelium recovery in CL.

Relationship between serum cobalamin concentration and endoscopic ileal appearance and histology in dogs with chronic inflammatory enteropathy

Background

It has not been determined whether ileal appearance differs among dogs with chronic inflammatory enteropathy (CIE) and different serum concentrations of cobalamin.

Objective

To compare endoscopic and histologic ileal findings in dogs with CIE and different serum cobalamin concentrations and then evaluate the correlation of ileal changes to cobalamin serum concentration using updated scoring systems to assess the ileum.

Animals

Sixty‐eight dogs with CIE.

Methods

Retrospective study. Frequency of ileal features and ileal histologic and endoscopic scores (IHS and IES) were obtained and compared among CIE dogs with severe hypocobalaminemia (SHC; <200 ng/L), hypocobalaminemia (HC; 200‐350 ng/L), or normocobalaminemia (NC; >350 ng/L). The correlation of IHS and IES with cobalamin was evaluated.

Results

Friability, villus atrophy, crypt dilatation, epithelial injury, and intraepithelial lymphocytes were more frequent in SHC than in NC dogs (all P ≤ .01). Median SHC‐IES (2; range, 0‐4) was higher than NC‐IES (1; range, 0‐5; P = .004). Median SHC‐IHS (6; range, 3‐9) was higher than HC‐IHS (4; range, 1‐7; P < .001) and NC‐IHS (3; range, 1‐8; P < .001). Cobalamin concentration correlated negatively with IES (ρ = −.34, P = .005) and IHS (ρ = −.58, P < .001).

Conclusions and Clinical Importance

Ileal features and involvement degree markedly differed when cobalamin was <200 or >350 ng/L in CIE dogs. With updated scales to assess the mucosa, greater ileal damage was associated with lower serum cobalamin concentration.

Perspectives and Advances in Probiotics and the Gut Microbiome in Companion Animals

As the number of households that raise dogs and cats is increasing, there is growing interest in animal health. The gut plays an important role in animal health. In particular, the microbiome in the gut is known to affect both the absorption and metabolism of nutrients and the protective functions of the host. Using probiotics on pets has beneficial effects, such as modulating the immune system, helping to reduce stress, protecting against pathogenic bacteria and developing growth performance. The goals of this review are to summarize the relationship between probiotics/the gut microbiome and animal health, to feature technology used for identifying the diversity of microbiota composition of canine and feline microbiota, and to discuss recent reports on probiotics in canines and felines and the safety issues associated with probiotics and the gut microbiome in companion animals.

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.

Persistent hypercobalaminemia three months after successful gradual attenuation of extrahepatic shunts in dogs: a prospective cohort study

Background

Deficiencies in vitamin A and D and disorders in the vitamin B complex are often present in people with chronic liver diseases. So far, the serum concentrations of these vitamins have not yet been studied in dogs with congenital extrahepatic portosystemic shunts (EHPSS), who also have some degree of liver dysfunction. The objective was to assess serum vitamin concentrations in dogs with EHPSS from diagnosis to complete closure. A prospective cohort study was performed using ten client-owned dogs with EHPSS, closed after gradual surgical attenuation. Serum concentrations of vitamin A, 25-hydroxyvitamin D, folic acid, cobalamin and methylmalonic acid (MMA) were measured at diagnosis prior to institution of medical therapy, prior to surgery, and three months after gradual attenuation and complete closure of the EHPSS.

Results

At diagnosis, median serum concentrations of vitamin A, 25-hydroxyvitamin D and folic acid were 18.2 μg/dL (8.8 - 79.5 μg/dL), 51.8 ng/mL (19.4 - 109.0 ng/mL), and 8.1 μg/L (5.2 - 14.5 μg/L), respectively, which increased significantly postoperatively (88.3 μg/dL (51.6 - 182.2 μg/dL, P=0.005), 89.6 ng/mL (49.3 - >150.0 ng/mL, P =0.005), and 14.8 μg/L (11.5 - 17.7 μg/L, P <0.001), respectively). Median serum cobalamin concentrations were 735.5 ng/L (470 - 1388 ng/L) at diagnosis and did not significantly decrease postoperatively (P =0.122). Both at diagnosis and three months postoperatively 7/10 dogs had hypercobalaminemia.

Conclusions

Serum concentrations of vitamin A, 25-hydroxyvitamin D and folic acid significantly increase after surgical attenuation. Nevertheless, persistent hypercobalaminemia is suggestive of ongoing liver dysfunction, despite successful surgery.

Dietary management of chronic enteropathy in dogs

Chronic idiopathic enteropathy is a clinical condition defined by the exclusion of infectious, metabolic or neoplastic causes of gastrointestinal signs and is categorised by a response to treatment including management with diet change, immunosuppressant medication or interventions that directly target the microbiome (e.g. antibiotics, faecal transplantation or probiotics). Animals that fail these therapies are categorised as non-responsive or refractory chronic idiopathic enteropathy. This specific categorisation implies that nutritional intervention is only needed for a subset of patients with enteropathy. However, often dogs with chronic idiopathic enteropathy are malnourished, have nutrient malabsorption or have gastrointestinal inflammation that occurs as a result of a breakdown in tolerance to luminal antigens including microorganism or dietary components. Thus, all dogs with chronic idiopathic enteropathy benefit from a nutritional assessment and targeted nutritional intervention. Among dogs presenting for chronic idiopathic enteropathy, the response rate to diet alone is roughly 50% in the referral population giving the impression that the overall response could be even higher especially when more than one nutritional intervention is attempted and strict adherence is maintained. The objectives of this review article are to outline the nutritional approach to a dog with chronic idiopathic enteropathy, including the nutritional assessment, and to highlight areas for nutritional intervention.

[Chronic enteropathies in cats - diagnostic and therapeutic approach]

Chronic enteropathies are characterized by persistent or recurrent gastrointestinal signs including vomiting, diarrhoea, weight loss, anorexia and lethargy for a minimum duration of 3 weeks. Diagnosis is by excluding other disease processes and includes faecal examinations, blood screenings (e. g., thyroidal, pancreatic, liver dysfunctions, investigation for infectious diseases, vitamin B₁₂ status), diagnostic imaging, histopathological evaluation using biopsies from several different gastrointestinal segments and the response to therapeutic trials. Chronic inflammatory enteropathies are classified as food-responsive enteropathy (FRE), antibiotic-responsive enteropathy (ARE), immunosuppressant-responsive or, similarly -refractory enteropathy (IRE). Small-cell (low-grade) alimentary lymphoma (LGAL), a crucial differential diagnosis, is predominantly seen in older cats. The feline chronic enteropathy activity index (FCEAI), a clinical scoring system, was established to objectively assess the severity of clinical illness and to evaluate the response to treatment. In general, the prognosis depends on the underlying aetiology. Cats diagnosed with FRE typically have a good long-term prognosis with adequate dietary management. The response to treatment varies in cats with IRE, with same cats experiencing frequent relapses of clinical signs and still others being non-responsive to treatment. Prognosis for LGAL, with adequate treatment, is usually fair to good (median survival time 510-704 days).

Low serum folate concentrations in dogs with non-associative immune-mediated haemolytic anaemia

BACKGROUND

Folate deficiency in people can occur in conditions causing increased demand, including haemolytic anaemia. This has not been investigated in dogs with non-associative immune-mediated haemolytic anaemia (IMHA).

METHODS

Cohort study of 15 dogs with non-associative IMHA. Haematocrit (HCT) and serum folate concentrations were measured at presentation and each subsequent venipuncture performed for monitoring. The relationship between serum folate concentrations and HCT was investigated using linear and logistic mixed-effects regression models and in paired samples using a one-tailed paired t-test.

RESULTS

Low serum folate concentrations occurred in five of 15 dogs. In 126 samples, a significant positive relationship was found between HCT and corresponding serum folate concentrations. A significant relationship was found between dichotomised folate concentrations (below the reference interval or within/above the reference interval) and HCT and between serum folate concentrations and dichotomised HCT (less than or equal/above 0.30 L/L). For paired samples (available in eight dogs), the mean serum folate concentration of samples with the lowest HCT was significantly lower than that of samples in which the HCT first exceeded 0.30 L/L.

CONCLUSIONS

Low serum folate concentrations were observed in some dogs with non-associative IMHA. Further studies are needed to determine the cause and investigate whether folate supplementation would be beneficial.

Effects of Allogeneic Mesenchymal Stem Cell Transplantation in Dogs with Inflammatory Bowel Disease Treated with and without Corticosteroids

Simple Summary

The conventional treatment of canine inflammatory bowel disease (IBD) includes corticosteroids, but they cannot contain the disease effectively in a percentage of patients. Still, their suppression can lead to a worsening. Moreover, the application of mesenchymal stem cells (MSCs) as an alternative has yielded promising results. However, they have been always infused after a washout period of any other immunosuppressants. Therefore, the feasibility and effects of the combination of stem cells and prednisone in IBD-dogs will be evaluated for the first time in this study. A single infusion of MSCs were administered to a group of IBD-dogs without any treatment and to another having prednisone treatment with poor response. The changes in two clinical indices, albumin and cobalamin concentration were assessed after one, three, six and 12 months. In both groups, an alleviation of the disease severity and an increase in albumin and cobalamin concentrations were observed at each visit. In parallel, the steroid dosage was gradually reduced until it was suppressed in all patients a year after the stem cell infusion. Therefore, the benefits of stem cell transplantation in dogs with inflammatory bowel disease receiving or not prednisone are significant and lasting.

Abstract

Mesenchymal stem cells have proven to be a promising alternative to conventional steroids to treat canine inflammatory bowel disease (IBD). However, their administration requires a washout period of immunosuppressive drugs that can lead to an exacerbation of the symptoms. Therefore, the feasibility and effects of the combined application of stem cells and prednisone in IBD-dogs without adequate response to corticosteroids was evaluated for the first time in this study over a long- term follow up. Two groups of dogs with IBD, one without treatment and another with prednisone treatment, received a single infusion of stem cells. The clinical indices, albumin and cobalamin were determined prior to the infusion and after one, three, six and 12 months. In both groups, all parameters significantly improved at each time point. In parallel, the steroid dosage was gradually reduced until it was suppressed in all patients a year after the cell therapy. Therefore, cell therapy can significantly and safely improve the disease condition in dogs with IBD receiving or not receiving prednisone. Furthermore, the steroid dosage can be significantly reduced or cancelled after the stem cell infusion. Their beneficial effects are stable over time and are long lasting.

[Granulomatous colitis in a French Bulldog puppy]

A 6-month-old French bulldog was presented due to chronic large intestinal diarrhea of 4 months duration. The diagnostic procedures initiated by the referring veterinarian had resulted in a tentative diagnosis of chronic enteropathy, however treatment consisting of elimination diet as well as antibiotic, anthelmintic, anti-inflammatory and immunosuppressive medication had been unsuccessful. By means of endoscopy and histological examination, pronounced erosions and ulcerations of the colonic mucosa were detected. Fluorescence in situ hybridization enabled the identification of invasive Escherichia coli within the colonic mucosa and colonic macrophages, allowing for the diagnosis of granulomatous colitis. The dog showed complete remission of clinical signs following 8 weeks of treatment with enrofloxacin. This case report describes the first successful treatment of granulomatous colitis with enrofloxacin in a French bulldog puppy in Germany and is intended to sensitize the reader to this disease in (young) dogs.

Serum cobalamin concentrations in dogs with leishmaniosis before and during treatment

Hypocobalaminemia in dogs is most commonly associated with gastrointestinal disorders leading to impaired absorption and utilization of cobalamin. The objectives of this study were to compare serum cobalamin concentrations between dogs with leishmaniosis and clinically healthy dogs, and to assess possible alterations of serum cobalamin concentrations in dogs with leishmaniosis at different timepoints during treatment. Fifty-five dogs with leishmaniosis and 129 clinically healthy dogs were prospectively enrolled. Diagnosis of leishmaniosis was based on clinical presentation, positive serology and microscopic detection of Leishmania amastigotes in lymph node aspiration smears. Twenty of the dogs with leishmaniosis were treated with a combination of meglumine antimonate and allopurinol for 28 days and serum cobalamin concentrations were measured in blood samples that were collected before initiation of treatment (timepoint 0) and on days 14 and 28. In order to estimate alterations of serum cobalamin concentrations during treatment, cobalamin concentrations were measured in blood samples from 20 out of 55 dogs with leishmaniosis at all timepoints. Serum cobalamin concentrations were significantly lower in dogs with leishmaniosis before treatment (median: 362 ng/L; IQR: 277-477 ng/L) compared to clinically healthy dogs (median: 470 ng/L; IQR: 367-632 ng/L; P = 0.0035). Serum cobalamin concentrations increased significantly in dogs with leishmaniosis on day 14 of treatment compared to timepoint 0 (P = 0.02). In the present study, serum cobalamin concentrations were significantly lower in dogs with leishmaniosis compared to clinically healthy dogs. In addition, there was an increase in serum cobalamin concentrations during treatment. The clinical significance of hypocobalaminemia in dogs with leishmaniosis remains to be determined.

Diseases associated with hypercobalaminemia in dogs in United Kingdom: A retrospective study of 47 dogs

Cobalamin concentration is often assessed in clinical practice but little is known about the significance of hypercobalaminemia. The objective of this retrospective study was to identify the conditions associated with hypercobalaminemia in dogs and to investigate association with clinicopathological variables. Medical records of dogs having serum cobalamin measured between 2016 and 2018 were reviewed. One hundred sixty dogs were included and 47 (29%) showed hypercobalaminemia. Dogs with hypercobalaminemia had gastrointestinal (57%), hepatic (11%), neurological (11%), endocrine (9%), renal (4%), pancreatic (2%), and miscellaneous (6%) diseases. Overall, 11% had neoplasia. This distribution was not significantly different from that for hypocobalaminemic and normocobalaminemic dogs. There were significantly more dogs with hyperfolatemia in the hypercobalaminemia group. These results suggest that in clinical practice hypercobalaminemia is commonly identified in gastrointestinal and hepatic disease in dogs, but can also be seen with endocrine and neurological conditions. The frequency of hyperfolatemia alongside hypercobalaminemia may reflect common metabolic pathways.

Effect of withholding food on serum concentrations of cobalamin, folate, trypsin-like immunoreactivity, and pancreatic lipase immunoreactivity in healthy dogs

OBJECTIVE

To evaluate the effects of withholding food on the results for measurements of serum concentrations of cobalamin, folate, canine pancreatic lipase immunoreactivity (cPLI), and canine trypsin-like immunoreactivity (cTLI) in healthy dogs.

ANIMALS

11 healthy employee- or student-owned dogs.

PROCEDURES

Food was withheld from the dogs for 12 hours, baseline blood samples were collected, then dogs were fed. Postprandial blood samples collected 1, 2, 4, and 8 hours later were assessed. A mixed-effects ANOVA model with fasting duration (time) as a fixed factor and dog as a random effect was fit for each analyte variable. Additionally, a mixed-effects ANOVA model controlling for the variable of time was fit to assess whether lipemia affected serum concentrations of the analytes.

RESULTS

The median serum cobalamin concentration was lower at 4 hours (428 ng/L) and 8 hours (429 ng/L) postprandially, compared with baseline (479 ng/L), but this difference was not clinically meaningful. Although there were no substantial differences in serum concentrations of folate, cPLI, or cTLI, postprandial changes in serum concentrations of cTLI or folate could potentially affect diagnoses in some dogs.

CONCLUSIONS AND CLINICAL RELEVANCE

Although results indicated that feedings rarely resulted in clinically important differences in the median serum concentrations of cobalamin, folate, cPLI, or cTLI in healthy dogs, given the further processing required for lipemic samples, withholding food for at least 8 hours is an appropriate recommendation when measuring these analytes. Similar research is needed in dogs with gastrointestinal disease to determine whether the withholding of food is necessary when measuring these analytes in affected dogs.

From Bench Top to Clinics: How New Tests Can Be Helpful in Diagnosis and Management of Dogs with Chronic Enteropathies

In this article, we review different tests that have been researched in dogs with chronic enteropathy. The usefulness of these tests either to assess etiology, to differentiate between treatment response, or to monitor treatment response is discussed. The tests are divided in those that are commercially available and those that hold promises for further development.

Coagulation status, fibrinolysis, and platelet dynamics in dogs with chronic inflammatory enteropathy

Background

Coagulation status is poorly understood in dogs with chronic inflammatory enteropathy (CIE). Fibrinolytic activity and platelet dynamics have not been evaluated in CIE dogs.

Objectives

To assess coagulation status and fibrinolysis in normoalbuminemic CIE dogs (CIE‐N) and CIE dogs with protein‐losing enteropathy (CIE‐PLE) compared to healthy controls (HC). To evaluate thromboelastography (TEG) variable differences between groups and for correlations with clinicopathologic data. To report platelet dynamics in CIE dogs.

Animals

Twenty‐five client‐owned dogs with CIE (n = 16 CIE‐N; n = 9 CIE‐PLE); 14 HC beagle dogs.

Methods

All dogs had tissue factor + tissue plasminogen activator TEG. Nine of 25 CIE dogs had whole blood impedance platelet aggregometry. The TEG variables and coagulation data were compared between all CIE vs HC dogs, CIE‐N dogs vs HC, and CIE‐PLE dogs vs HC. Clinicopathologic and coagulation data were available for CIE dogs and assessed for correlation to TEG variables.

Results

Dogs with CIE had higher maximum amplitude (MA; P < .001), longer clot lysis times (CLTs; P < .001), lower % lysis after 30 minutes (LY30; P < .001), and % lysis after 60 minutes (LY60; P < .001) compared to HC, suggesting hypercoagulability and hypofibrinolysis. When separated out, both CIE‐N and CIE‐PLE dogs had higher MA, longer CLT, and lower LY30 and LY60 compared to HC. Serum albumin and 25‐hydroxyvitamin D (25[OH]D) concentrations, and plasma antithrombin and fibrinogen concentrations moderately correlated with MA.

Conclusions and Clinical Importance

Normoalbuminemic and hypoalbuminemic CIE dogs were considered hypercoagulable based on TEG compared to HC. Some CIE dogs displayed hypofibrinolytic phenotypes on TEG.

Nutritional Management for Dogs and Cats with Gastrointestinal Diseases

Gastrointestinal (GI) disease encompasses a wide variety of conditions, often with similar clinical signs. In order to optimize diet selection and nutritional management for dogs and cats with GI disease, it is important to consider a patient's nutritional assessment, problem list, specific nutrients of concern, and other factors. This review summarizes the process of utilizing this information to select a diet for a patient with GI disease as well as target levels for nutrients of concern. Overall, it is important to make an individualized recommendation and reassess the patient to make additional adjustments to the nutritional plan as needed as well as establishing target levels for nutrients of concern.

Clinical characteristics and long-term outcome of E. coli-associated granulomatous ileocolitis in dogs: five cases (2010-2014)

OBJECTIVES

To describe the clinical characteristics and long-term outcome of Escherichia coli-associated granulomatous ileocolitis in dogs.

METHODS

Retrospective review of medical records from dogs with periodic acid-Schiff positive (PAS+) granulomatous ileocolitis and mucosally invasive E. coli in the ileum and colon. Initial bacterial colonisation was evaluated using fluorescence in situ hybridization (FISH) in all dogs and corroborated with colonic and/or ileal culture, when performed.

RESULTS

Four boxer dogs and 1 French Bulldog with PAS+ granulomatous ileocolitis (GIC) were evaluated. All dogs had chronic diarrhoea refractory to empirical therapy. Ileocolonoscopy revealed mucosal haemorrhage and ulceration in the ileum (3/4) and colon (5/5). E. coli were visualised as clusters within the ileal and colonic mucosa. Complete (CR, 4/5) or partial (PR, 1/5) clinical response to fluoroquinolones was noted in all dogs within 30 days. CR was sustained in three of four dogs (median disease-free interval 40 months, range 16 to 60). Two dogs relapsed while receiving fluoroquinolones. Repeat biopsy isolated multidrug-resistant, mucosally invasive E. coli in the ileum (1/2) and colon (2/2). Targeted antimicrobial therapy was associated with long-term PR (78 months) in both dogs.

CLINICAL SIGNIFICANCE

Concurrent E. coli-associated granulomatous inflammation in the ileum and colon did not impart a poor clinical outcome or lack of response to the conventional standard of care for granulomatous colitis in dogs that were aggressively diagnosed and treated. Clinical outcome was influenced by antimicrobial resistance, with response dependent upon antimicrobial therapy informed by susceptibility testing.

Ménétrier-like disease in a Pointer with concurrent granulomatous gastritis, helicobacteriosis and leishmaniosis: a case report

Background

Ménétrier-like disease is a rare hypertrophic canine gastropathy, reported in only seven dogs. Clinical signs are vomiting, anorexia and weight loss. Macroscopically, giant cerebriform gastric mucosal folds are typically seen in the corpus and fundus of the stomach. Histopathologically, fundic mucous cell hyperplasia and loss of parietal and chief cells are typical.

Case presentation

A nine-year-old spayed female Pointer had a history of intermittent vomiting, marked weight loss and hypoalbuminaemia. A gastroduodenoscopy was performed three times within three months with macroscopic changes remaining the same. The gastric mucosa of the corpus, fundus and proximal antrum was markedly irregular, with cerebriform mucosal folds. In the first gastric biopsies, histopathology revealed a moderate granulomatous gastritis, with a severe manifestation of Helicobacter-like organisms. Treatment for Helicobacter spp. decreased the vomiting slightly. The dog was diagnosed with concurrent leishmaniosis; the conventional anti-Leishmania treatment decreased the vomiting moderately, the hypoalbuminaemia resolved and the dog gained weight back to a normal body condition. Granulomatous gastritis was not present in the gastric biopsies after these treatments. The dog increased vomiting when palliative treatment (maropitant citrate, ondansetron and esomeprazole) was discontinued, and thus, full-thickness biopsies of the stomach were taken and Ménétrier-like disease was diagnosed. The affected area was too large to be surgically removed; thus, palliative treatment was reinstated. The dog remained clinically well 39 months after the first clinical presentation.

Conclusions

This is the first report of Ménétrier-like disease in a dog with a simultaneous manifestation of granulomatous gastritis, helicobacteriosis and leishmaniosis. The clinical signs decreased after treatment of helicobacteriosis and leishmaniosis, but vomiting remained probably as a sign of Ménétrier-like disease. Treatment options for dogs are surgical removal of the abnormal area or palliative treatment. In humans, promising results for a cure have been shown with cetuximab treatment, a human monoclonal antibody, but no canine antibody is commercially available yet. The dog here was doing well 39 months after first presentation, which is the longest reported survival time for Ménétrier-like disease with only palliative treatment in dogs. Full-thickness biopsies are preferred in macroscopic hypertrophic lesions of the stomach for better assessment of Ménétrier-like disease.

Blood neutrophil-to-lymphocyte ratio (NLR) as a diagnostic marker in dogs with chronic enteropathy

Few routinely available biomarkers are clinically useful in assessing dogs with chronic enteropathy (CE) and aid in CE subclassification. The diagnostic potential of the blood neutrophil-to-lymphocyte ratio (NLR) has not been evaluated in canine CE. We evaluated the NLR in 93 dogs with CE (no steroid treatment for ≥2 wk prior) and tested for an association with clinical, clinicopathologic, and histologic characteristics and also with CE subclassification. NLR was significantly higher in CE dogs with severe clinical disease than dogs with mild clinical disease (p = 0.047). Hypoalbuminemia (p < 0.001), but not hypocobalaminemia, was associated with higher NLRs. NLR was correlated with fecal alpha₁-proteinase inhibitor concentrations (ρ = 0.47) and the serum-to-fecal alpha₁-proteinase inhibitor ratio (ρ = -0.48; both p < 0.001) but not with serum or fecal inflammatory markers nor with the overall histologic score (all p > 0.05). Dogs with steroid- or other immunosuppressant-responsive (IRE) or nonresponsive enteropathy (NRE) had significantly higher NLRs (median: 7.3) than dogs with food-responsive enteropathy (FRE; median: 3.0; p = 0.003), and a NLR ≥5.5 best distinguished both groups of dogs. No difference in NLR was detected between dogs with IRE and dogs diagnosed with NRE. These findings suggest that leukogram changes (i.e., NLR) could be clinically useful in canine CE, and that neutrophils might play a role in the systemic inflammatory response associated with canine CE. The NLR can be easily assessed on routine hematology and can potentially aid in the subclassification of dogs with CE based on the response to treatment.

Anemia, iron deficiency, and cobalamin deficiency in cats with chronic gastrointestinal disease

BACKGROUND

Iron deficiency and cobalamin deficiency, as sequelae to chronic gastrointestinal (GI) disease, could result in anemia and increased morbidity in cats with chronic enteropathies.

OBJECTIVE

To evaluate iron deficiency in cats with chronic GI disease and its relationship with hypocobalaminemia, anemia, and disease severity.

ANIMALS

Twenty client-owned cats with primary GI disease.

METHODS

Prospective, cross-sectional study. Cats were enrolled at the time of evaluation for chronic GI disease, after exclusion of comorbidities. CBC with reticulocyte indices, iron metabolism (serum iron and ferritin concentrations, total iron binding capacity [TIBC]), serum methylmalonic acid (MMA), cobalamin, and folate concentrations, pancreatic lipase and trypsin-like immunoreactivity, and disease severity were evaluated.

RESULTS

Anemia (hematocrit <30%), iron deficiency, and cobalamin deficiency were diagnosed in 4/20, 7/20, and 8/20 cats, respectively. Hematocrit (r_s = -.45; P < .05) and body condition score (r_s = -.60; P < .01) negatively correlated with MMA. Median TIBC was lower in cats with increased vs normal MMA (218 μg/mL; range, 120-466 μg/mL vs 288 μg/mL; range, 195-369 μg/mL; P = .02). Hematocrit (r_s = .51; P = .02), reticulocyte MCV (r_s = .52; P = .02), reticulocyte hemoglobin content (r_s = .71; P < .001), and percent transferrin saturation (r_s = .79; P < .0001) positively correlated with serum iron concentration.

CONCLUSIONS AND CLINICAL IMPORTANCE

Functional iron deficiency was common in cats with chronic GI disease. Associations between hypocobalaminemia, iron parameters, and hematologic parameters warrant further investigation on the impact of iron deficiency on chronic GI disease morbidity in cats.

Serum homocysteine concentration in dogs with immunosuppressant-responsive enteropathy

Background

Homocysteine (HCY) was evaluated in healthy and chronic enteropathic dogs, however no studies on dogs with immunosuppressant-responsive enteropathy are available.

Objectives

The aim was to evaluate serum HCY concentrations and its prognostic role in dogs with immunosuppressant-responsive enteropathy compared to healthy dogs.

Methods

Serum HCY concentration was statistically compared between 24 healthy dogs and 29 dogs with immunosuppressant-responsive enteropathy. Correlation analyses between serum total protein, albumin (ALB), C-reactive protein (CRP), folate and cobalamin, and serum HCY concentration were performed in immunosuppressant-responsive enteropathic dogs.

Results

The associations between serum HCY concentration and clinical, histological, endoscopic scores and follow-up were evaluated. Mean serum HCY concentration was higher in immunosuppressant-responsive enteropathic dogs compared to control dogs (30.22 ± 8.67 µmol/L vs. 5.26 ± 2.78 µmol/L; p < 0.0001). No association between serum HCY concentration and total protein, ALB, CRP, folate concentration as well as, clinical score, histological and endoscopic scores was found. A negative correlation between serum HCY concentration and cobalamin was noted (p = 0.0025, r = −0.54). No significant difference in HCY was found between responsive and non-responsive dogs or between survivors and non-survivors.

Conclusions

Although, serum HCY concentration was higher in immunosuppressant-responsive enteropathy, its prognostic value remains unclear. However, further prospective, large-scale studies are warranted to better investigate the possible prognostic role of HCY in immunosuppressant-responsive enteropathic dogs.

A large deletion on CFA28 omitting ACSL5 gene is associated with intestinal lipid malabsorption in the Australian Kelpie dog breed

Inborn errors of metabolism are genetic conditions that can disrupt intermediary metabolic pathways and cause defective absorption and metabolism of dietary nutrients. In an Australian Kelpie breeding population, 17 puppies presented with intestinal lipid malabsorption. Juvenile dogs exhibited stunted postnatal growth, steatorrhea, abdominal distension and a wiry coat. Using genome-wide association analysis, an associated locus on CFA28 (P_raw = 2.87E^-06) was discovered and validated in a closely related population (P_raw = 1.75E^-45). A 103.3 kb deletion NC_006610.3CFA28:g.23380074_23483377del, containing genes Acyl-CoA Synthetase Long Chain Family Member 5 (ACSL5) and Zinc Finger DHHC-Type Containing 6 (ZDHHC6), was characterised using whole transcriptomic data. Whole transcriptomic sequencing revealed no expression of ACSL5 and disrupted splicing of ZDHHC6 in jejunal tissue of affected Kelpies. The ACSL5 gene plays a key role in long chain fatty acid absorption, a phenotype similar to that of our affected Kelpies has been observed in a knockout mouse model. A PCR-based diagnostic test was developed and confirmed fully penetrant autosomal recessive mode of inheritance. We conclude the structural variant causing a deletion of the ACSL5 gene is the most likely cause for intestinal lipid malabsorption in the Australian Kelpie.

Relationship between Vitamin B12 and Cobalt Metabolism in Domestic Ruminant: An Update

Cobalt, as a trace element, is essential for rumen microorganisms for the formation of vitamin B12. In the metabolism of mammals, vitamin B12 is an essential part of two enzymatic systems involved in multiple metabolic reactions, such as in the metabolism of carbohydrates, lipids, some amino acids and DNA. Adenosylcobalamin and methylcobalamin are coenzymes of methylmalonyl coenzyme A (CoA) mutase and methionine synthetase and are essential for obtaining energy through ruminal metabolism. Signs of cobalt deficiency range from hyporexia, reduced growth and weight loss to liver steatosis, anemia, impaired immune function, impaired reproductive function and even death. Cobalt status in ruminant animals can be assessed by direct measurement of blood or tissue concentrations of cobalt or vitamin B12, as well as the level of methylmalonic acid, homocysteine or transcobalamin in blood; methylmalonic acid in urine; some variables hematological; food consumption or growth of animals. In general, it is assumed that the requirement for cobalt (Co) is expressed around 0.11 ppm (mg/kg) in the dry matter (DM) diet; current recommendations seem to advise increasing Co supplementation and placing it around 0.20 mg Co/kg DM. Although there is no unanimous criterion about milk production, fattening or reproductive rates in response to increased supplementation with Co, in some investigations, when the total Co of the diet was approximately 1 to 1.3 ppm (mg/kg), maximum responses were observed in the milk production.

Imerslund-Grasbeck syndrome in a cross-breed dog

Imerslund-Gräsbeck syndrome is an autosomal recessive disease reported only in certain pure-breed dogs. An 18-month-old, male neutered beagle cross-breed was presented for evaluation of severe lethargy, progressive weakness and anorexia. Main clinicopathological findings included low body condition score (2.5/9), severe muscle atrophy, several neurological abnormalities, mild normochromic, normocytic, non-regenerative anaemia, severe hypocobalaminemia and mild proteinuria. Extensive diagnostic tests ruled out most of differential diagnoses for the aforementioned clinicopathological abnormalities and genetic evaluation showed that the dog was heterozygous for two previously described mutations affecting the CUBN gene, the beagle and the border collie variants. The dog showed an excellent clinical response to oral cobalamin supplementation with no relapse after 4 months. In conclusion, this case creates awareness that Imerslund-Gräsbeck syndrome should be considered even in mixed-breed dogs with compatible clinical signs and that two different pathogenic CUBN mutations in compound heterozygosity can lead to a typical Imerslund-Gräsbeck syndrome phenotype.

Efficacy of intramuscular hydroxocobalamin supplementation in cats with cobalamin deficiency and gastrointestinal disease

Background

In humans, absorption and tissue retention rates of intramuscularly administered hydroxocobalamin (OH‐Cbl) are superior compared to cyanocobalamin (CN‐Cbl). Supplementation with OH‐Cbl has not been described in cats.

Objectives

To evaluate effects of parenteral OH‐Cbl supplementation on clinical signs, serum Cbl and methylmalonic acid (MMA) concentrations in hypocobalaminemic cats with gastrointestinal disease.

Animals

Twenty‐three client‐owned cats.

Methods

Prospective study. Serum Cbl and MMA concentrations were determined at enrollment (t0), immediately before the 4th OH‐Cbl IM injection (300 μg, given q2 weeks) (t1), and 4 weeks after the 4th injection (t2). Severity of clinical signs (activity, appetite, vomiting, diarrhea, body weight) was graded at each time point and expressed as clinical disease activity score.

Results

Median clinical disease activity score decreased significantly from t0 (6; range, 2‐10) to t1 (1; range, 0‐6) and t2 (1; range, 0‐9). Median serum Cbl concentration increased significantly from 111 pmol/L (range, 111‐218; reference range, 225‐1451 pmol/L) at t0 to 1612 pmol/L (range, 526‐14 756) (P < .001) at t1, and decreased again significantly to 712 pmol/L (range, 205‐4265) (P < .01) at t2. Median baseline serum MMA concentration at t0 (802 nmol/L; range, 238‐151 000; reference range, 120‐420 nmol/L) decreased significantly (P < .001) to 199 nmol/L (range, 29‐478) at t1, and was 205 nmol/L (range, 88‐734) at t2. Serum MMA concentrations normalized in 22/23 cats at t1, and were not significantly higher at t2 compared to t1.

Conclusions and Clinical Importance

The herein described OH‐Cbl injection scheme appears efficacious for normalization of cellular Cbl deficiency in cats with gastrointestinal disease.

Review of cobalamin status and disorders of cobalamin metabolism in dogs

Disorders of cobalamin (vitamin B₁₂) metabolism are increasingly recognized in small animal medicine and have a variety of causes ranging from chronic gastrointestinal disease to hereditary defects in cobalamin metabolism. Measurement of serum cobalamin concentration, often in combination with serum folate concentration, is routinely performed as a diagnostic test in clinical practice. While the detection of hypocobalaminemia has therapeutic implications, interpretation of cobalamin status in dogs can be challenging. The aim of this review is to define hypocobalaminemia and cobalamin deficiency, normocobalaminemia, and hypercobalaminemia in dogs, describe known cobalamin deficiency states, breed predispositions in dogs, discuss the different biomarkers of importance for evaluating cobalamin status in dogs, and discuss the management of dogs with hypocobalaminemia.