Hypocalcemia of critical illness in dogs and cats

Plasma Parathyroid Hormone Concentration as a Predictor of Post-Operative Hypocalcemia in Dogs Diagnosed With Primary Hyperparathyroidism and Treated With Parathyroidectomy

BACKGROUND

Hypocalcemia is a relatively common complication after parathyroidectomy for treatment of primary hyperparathyroidism.

OBJECTIVES

To retrospectively evaluate clinical variables in dogs with primary hyperparathyroidism to determine whether or not an association exists between pre-surgical variables and the development of post-surgical hypocalcemia.

ANIMALS

One hundred three dogs diagnosed with primary hyperparathyroidism and treated by parathyroidectomy in seven referral hospitals between 2010 and 2021.

MATERIAL AND METHODS

Data collected from medical records included signalment, physical examination findings, concurrent illnesses, ongoing medications, and clinicopathologic test results (including serum ALP activity, iCa, plasma phosphate and PTH concentrations). Dogs were assigned into groups based on lowest iCa post-surgery: Group1 ≥ 1.1 mmol/L, Group2 < 1.1 mmol/L. The Mann-Whitney U test assessed associations between several variables of interest and the occurrence of post-surgery hypocalcemia. ROC analyses were performed to identify variables that had the potential to predict the development of hypocalcemia after surgery.

RESULTS

The median plasma PTH concentration pre-surgery in dogs which developed hypocalcemia after surgery was significantly higher (232 pg/mL {[IQR] 108-421}) than in dogs which did not develop hypocalcemia after surgery (81.5 pg/mL {IQR 58.5-145.0}; p < 0.001). Plasma PTH concentration had a fair to good ability to predict the development of post-surgery hypocalcemia, with AUC being 0.78 [95% confidence interval 0.67-0.89]. Using a cut-off of ≥ 75 pg/mL, pre-surgery plasma PTH concentration had a sensitivity of 96.6% and specificity of 42.3% for the development of post-surgery hypocalcemia. Dogs that developed hypocalcemia after surgery were older and had lower body weights.

CONCLUSION

Pre-surgery plasma PTH concentrations might be helpful in predicting those dogs at risk of developing hypocalcemia after parathyroidectomy.

Exploring the effects of quercetin-added pancreatic diet on metabolic homeostasis in dogs via metabolomics

OBJECTIVE

To investigate the role of quercetin-added pancreatic prescription food in regulating metabolic homeostasis in dogs.

METHODS

The experimental dogs were divided into a control diet group and a prescription diet group. The control group was fed regular food, while the prescription group was fed pancreatic prescription food (3.9 g of quercetin was added in per 1 kg of food) for 8 weeks. Canine physical examination, complete blood count, and serum biochemical tests were conducted at 0 w, 4 w, and 8 w. Non-targeted metabolomics tests were performed using plasma samples at 0 w and 8 w.

RESULTS

Dogs that received a quercetin-added pancreatic diet supplemented with quercetin showed no changes in the body weight, fasting blood glucose, body condition score, the indexes of whole blood program of red blood cells, white blood cells and platelets, and most blood biochemical indexes, but increased lipase levels in plasma at 8 w. Quercetin significant improved in metabolic homeostasis, especially in fatty acid, amino acid, and bile acid metabolism. Untargeted metabolomics analysis revealed that quercetin activates ABC transport and arginine/proline pathways, suggesting potential benefits for pancreatitis in large animals, while maintaining comparable safety parameters.

CONCLUSIONS

Quercetin-added prescription food enhances fatty acid and amino acid metabolism, demonstrating its potential to promote pancreatic function and sustain metabolic homeostasis.

Emergency Approach to Acute Seizures in Dogs and Cats

Seizures are a common presentation seen in small animal practices. Seizures require prompt management including initial interventions for triage, stabilization, and treatment with first-line anticonvulsant (AC) drugs like benzodiazepines. Concurrently, ruling out metabolic or extracranial causes with point-of-care diagnostics can help guide further diagnostics and treatments. Analysis of the history and a physical exam are also necessary to rule out common "look-alikes" that require specific diagnostic workup and treatments. Typically, causes of seizures can be grouped into intracranial and extracranial causes, with the latter being easier to diagnose with commonly available tests. This review presents a systematic approach to the diagnosis and treatment of single seizures, cluster seizures, and status epilepticus in dogs and cats.

Clinical effects and adverse effects of intravenous lipid emulsion treatment in dogs and cats with suspected poisoning

This retrospective study aimed to evaluate the effects on the clinical signs of poisoning and adverse effects of intravenous lipid emulsion treatment in 82 animals (dogs and cats) with suspected poisonings over 18 months. Physical examination parameters and state of consciousness were documented every hour after the intravenous administration of a bolus of 2 ml/kg and 0.25 ml/kg/min over 60 minutes of a 20% intravenous lipid emulsion. The modified Glasgow coma scale and laboratory findings (blood gas analysis, triglyceride, lactate) were evaluated initially and three hours after discontinuing intravenous lipid emulsion administration. A statistical evaluation of the occurrence of adverse effects and the development of laboratory values was performed. A decrease in respiratory rate in the second control (8-12 hours) after ILE was observed. Three hours after completing of the intravenous lipid emulsion, triglyceride concentration increased about 10 times (p <0.001). Venous carbon dioxide partial pressure, bicarbonate, base excess, as well as the electrolytes sodium, potassium and ionized calcium decreased significantly (p <0.001). Patients who experienced a worsening of the modified Glasgow coma scale had a higher increase in triglyceride concentrations (p = 0.041) and plasma lactate (p = 0.034) and a larger decrease in bicarbonate concentrations (p = 0.053) compared to others. About 54% (n = 44) of the patients showed adverse effects which could be attributed to the administration of intravenous lipid emulsion and may be associated with a higher triglyceride increase. All of them were completely reversible within 33 hours. Adverse effects associated with intravenous lipid emulsion therapy were observed in half of the patients and were associated with a higher increase in triglycerides.

The Prognostic Utility of Venous Blood Gas Analyses at Presentation in Cats with Cardiogenic Pulmonary Edema

Cats urgently visit emergency hospitals due to respiratory distress, and the chief cause is cardiogenic pulmonary edema (CPE). Although cats with CPE were frequently encountered in clinics, the prognostic factors were poorly reported. The objective of this retrospective study was to investigate the association of physical examination and venous blood gas parameters with the survival of cats with CPE in an emergency hospital. Thirty-six cats with CPE were ultimately included in the present study, and eight of them died within 12 h after their presentation to our hospital. Statistical analyses of clinical parameters between cats that died within 12 h and those that survived for 12 h were conducted using Mann-Whitney U test with Bonferroni correction. Cats that died within 12 h had significantly lower rectal temperatures and higher PvCO₂ than those that did not die within 12 h. Moreover, hypotension and vasoconstrictor use were related to death within 12 h of presentation and higher PvCO₂. These findings indicated the prognostic utility of body temperature and PvCO₂, and the association between hypercapnia and the severity of CPE or hypotension. A large number of prospective studies should be performed to validate these results.

Prognostic Role of Red Cell Distribution Width and Other Routine Clinico-Pathological Parameters in Dogs with Acute Pancreatitis

This study aimed to assess the prognostic value of red cell distribution width (RDW) RDW-to-calcium ratio (RDW/Ca), neutrophils-to-lymphocytes ratio (N/L), platelets-to-lymphocytes ratio (P/L) and other easy to obtain and inexpensive hematological and biochemical parameters in dogs with acute pancreatitis. This is a multicenter, retrospective cohort study including 70 client-owned dogs. The accuracy of clinical and laboratory variables to predict short-term death (i.e., dead by 14 days) was tested by calculating the area under the receiver-operating characteristic curve (AUC). Independent predictors of death were identified using the multivariable Cox proportional hazards regression model. The survival rate was 72.9% (51 dogs) and 19 dogs died within 14 days of admission from AP. RDW and blood urea nitrogen (BUN) had good accuracy to predict short-term dead with AUC of 0.74 and 0.70 at the cut-off of >12.7% and >42 mg/dL, respectively. According to the multivariable model, RDW (hazard ratio and 95% confidence interval [HR, 95% CI] = 5.08, 95% CI = 1.14−22.67; p = 0.03), BUN (HR = 1.00, 95% CI = 1.00−1.01; p < 0.01) and bilirubin (HR = 2.46, 95% CI = 1.38−4.39; p < 0.01) were independent predictors of death. The results indicate that RDW, BUN and bilirubin are useful predictors of short-term death in dogs with acute pancreatitis.

Outcomes of nonsteroidal anti-inflammatory drug toxicosis treated with therapeutic plasma exchange in 62 dogs

BACKGROUND

Therapeutic plasma exchange (TPE) is gaining popularity for the management of nonsteroidal anti-inflammatory drug (NSAID) overdose in dogs.

HYPOTHESIS/OBJECTIVES

Describe a population of dogs treated with TPE for NSAID overdose.

ANIMALS

Sixty-two dogs with NSAID overdose treated with TPE.

METHODS

Multicenter retrospective study of dogs treated with TPE for ibuprofen, carprofen, or naproxen overdose.

RESULTS

The median dose of ibuprofen, carprofen or naproxen ingested was 533 mg/kg (range, 36-4857 mg/kg), 217 mg/kg (range, 88-625 mg/kg) and 138 mg/kg (range, 26-3000 mg/kg), respectively. Based on previously established toxic ranges for each NSAID, 2 (3.2%), 14 (22.6%), and 46 (74.2%) dogs ingested a gastrointestinal, renal, and neurological toxic dose, respectively. The median time between ingestion and presentation was 4 hours (range, 1-20 hours). The median number of plasma volumes processed was 1.6 (range, 0.4-2.2). The median TPE session duration was 2 hours (range, 1-4.5 hours). Circuit clotting developed during 8 (12.9%) sessions. Patient adverse events reported during 21 (33.8%) sessions consisted of urticaria (12.9%), asymptomatic hypocalcemia (9.6%), and hypotension (9.6%). The median duration of hospitalization was 2.25 days (range, 1-11 days). Sixty-one (98.4%) dogs survived to discharge, and none were rehospitalized. Thirty-one (91.1%) of the 34 dogs with at least 1 follow-up visit were not azotemic at the time of reevaluation.

CONCLUSIONS AND CLINICAL IMPORTANCE

This population of dogs managed with TPE had excellent outcomes, even in cases of high NSAID dose ingestion. When TPE is available and the time frame is appropriate, this extracorporeal modality should be considered for the management of NSAID overdose.

Diagnostic performance of predicted ionized calcium in dogs with total hypercalcemia and total hypocalcemia

BACKGROUND

Abnormal total calcium (tCa) values do not necessarily imply dysregulated ionized calcium.

OBJECTIVES

We aimed to evaluate the diagnostic performance of predicted ionized calcium (piCa) regarding true calcium status in dogs with abnormal tCa.

METHODS

This was a cross-sectional multicenter study. piCa and its prediction interval (PI) were calculated in 114 dogs, from three different hospitals, with either increased (62) or decreased tCa (52), All dogs also had ionized calcium and a biochemical profile available. The sensitivity, specificity, predictive values, and diagnostic discordance of piCa to confirm ionized hypercalcemia (iHyperCa) and ionized hypocalcemia (iHypoCa) were calculated using logistic regression analysis.

RESULTS

iHyperCa was found in 28% and 66% of hyperphosphatemic and non-hyperphosphatemic dogs with tCa above the reference interval upper limit, respectively. The piCa correctly classified dogs with iHyperCa in 72.2% of those with hyperphosphatemia and 93.2% of those without hyperphosphatemia. Comparatively, elevating the tCa threshold to 12 mg/dL properly classified dogs 50% and 75% of the time in hyperphosphatemic and non-hyperphosphatemic dogs, respectively. iHypoCa was found in only 31/52 (60%) dogs with decreased tCa. The piCa correctly classified 55.2 to 100% of dogs with iHypoCa depending on the hospital. The PI demonstrated high sensitivity for iHyperCa (100%) and high specificity for both iHyperCa (100%) and iHypoCa (100%).

CONCLUSIONS

Evaluating tCa alone does not reliably determine ionized calcium status. Even with hyperphosphatemia, piCa and its PI represent a reliable alternative to interpret abnormal tCa values when ionized calcium measurements are not available. However, if the tCa reference interval is notably different from 7.6 to 11.4 mg/dL, piCa values might be under/overestimated.

Clinical features of muscle cramp in 14 dogs

BACKGROUND

Muscle cramps (MCs) are prolonged, involuntary, painful muscle contractions characterized by an acute onset and short duration, caused by peripheral nerve hyperactivity.

OBJECTIVES

To provide a detailed description of the clinical features and diagnostic findings in dogs affected by MCs.

ANIMALS

Fourteen dogs.

METHODS

Multicenter retrospective case series. Cases were recruited by a call to veterinary neurologists working in referral practices. Medical records and videotapes were searched for dogs showing MCs. The follow-up was obtained by telephone communication with the owner and the referring veterinarian.

RESULTS

Three patterns of presentation were identified depending on the number of affected limbs and presence/absence of migration of MCs to other limbs. In 9/14 (64%) of dogs, MCs were triggered by prompting the dogs to move. 8/14 (58%) dogs were overtly painful with 6/14 (42%) showing mild discomfort. The cause of MCs was hypocalcemia in 11/14 (79%) dogs: 9 dogs were affected by primary hypoparathyrodism, 1 dog by intestinal lymphoma and 1 dog by protein losing enteropathy. In 3/14 cases (21%) the cause was not identified, and all 3 dogs were German Shepherds.

CONCLUSIONS AND CLINICAL IMPORTANCE

Muscle cramps can manifest in 1 of 3 clinical patterns. Muscle cramps are elicited when dogs are encouraged to move and do not always appear as painful events, showing in some cases only discomfort. The main cause of MCs in this study was hypocalcemia consequent to primary hypoparathyroidism. In dogs having MCs of unknown etiology, idiopathic disease or paroxysmal dyskinesia could not be ruled out.

Clinical characteristics and short-term outcomes for rabbits with signs of gastrointestinal tract dysfunction: 117 cases (2014-2016)

OBJECTIVE

To describe the clinical findings and short-term outcomes for rabbits with signs of gastrointestinal tract dysfunction or rabbit gastrointestinal syndrome (RGIS).

ANIMALS

117 client-owned rabbits.

PROCEDURES

The electronic medical records database of a veterinary teaching hospital was searched to identify rabbits that were examined because of altered or absent food intake and decreased or absent fecal output between June 1, 2014, and June 30, 2016. For each rabbit, information extracted from the record included history of prior episodes of gastrointestinal tract dysfunction, signalment, physical examination and diagnostic test results, and outcome.

RESULTS

117 of the 484 (24%) rabbits examined at the hospital during the study period met the inclusion criteria and were enrolled in the study. Fifty-nine and 58 rabbits were managed on an inpatient and outpatient basis, respectively. Gastrointestinal stasis without overt obstruction was diagnosed for 43 rabbits on the basis of abdominal radiographic, ultrasonographic, or necropsy results. Many rabbits had concurrent disease and biochemical abnormalities. Fifteen, 18, and 84 rabbits died, were euthanized, and survived to hospital discharge, respectively. Rabbits that were hypothermic (rectal temperature, ≤ 36.6°C [97.9°F]) during the initial examination were 5 times as likely to die or be euthanized as were euthermic rabbits, after controlling for potential confounders.

CONCLUSIONS AND CLINICAL RELEVANCE

Results indicated that the prognosis was generally good for rabbits with signs of RGIS unless they were hypothermic during initial examination. Prospective studies are warranted to further elucidate and characterize RGIS and assess the efficacy of various treatments and outcomes for affected rabbits.

The Role of Serum Calcium Level in Intracerebral Hemorrhage Hematoma Expansion: Is There Any?

Spontaneous intracerebral hemorrhage (ICH) is a devastating form of stroke, with a high rate of mortality and morbidity. Even with the best current medical or surgical interventions, outcomes remain poor. The location and initial hematoma volume are strong predictors of mortality. Hematoma expansion (HE) is a further marker of poor prognosis that may be at least partly preventable. Several risk factors for HE have been identified, including baseline ICH volume, anticoagulation, and computed tomography angiography spot signs. Recent studies have shown the correlation of serum calcium (Ca⁺⁺) levels on admission with HE. Low serum Ca⁺⁺ level has been associated with larger hematoma volume at the time of presentation, HE, and worse outcome. Although the causal and mechanistic links between low serum Ca⁺⁺ level and HE are not well understood, several mechanisms have been proposed including coagulopathy, platelet dysfunction, and higher blood pressure (BP) in the context of low serum Ca⁺⁺ level. However, low serum Ca⁺⁺ level might be only a biomarker of the adaptive response due to acute inflammatory response following acute ICH. The purpose of the current review is to discuss the evidence regarding the possible role of low serum Ca⁺⁺ level on HE in acute ICH.

Development and validation of a multivariate predictive model to estimate serum ionized calcium concentration from serum biochemical profile results in cats

BACKGROUND

Measurement of serum ionized calcium is not always available in practice. Total calcium (tCa) might not be reliable for determination of calcium status in cats.

OBJECTIVES

To predict serum ionized calcium concentration from signalment, biochemistry profile and T4, and compare predicted ionized calcium (piCa) to tCa.

ANIMALS

A total of 1701 cats from two hospitals.

METHODS

Cross-sectional study. Cats with serum ionized calcium, biochemistry profile and T4 available were screened over 6 years and included in the training set (569 cats) to create a multivariate adaptive regression splines model to calculate piCa. Diagnostic performances of tCa and piCa and its prediction interval (PI) were compared in 652 cats from the same institution (test set) and 480 cats from a different hospital (external set).

RESULTS

The final model included tCa, chloride, albumin, cholesterol, creatinine, BUN, body condition score, GGT, age, and potassium. For hypercalcemia, piCa was highly specific (test set: 99.8%; confidence interval [CI]: 99.5-100; external set: 97%; CI: 95.3-98.7) but poorly sensitive (test set: 30.4%; CI: 18.3-42.4; external set: 42.5%; CI: 31.7-53.3). For hypocalcemia, piCa was also highly specific (test set: 81.6%; CI: 78-85; external set: 99.6%; CI: 99-100) but poorly sensitive (test set: 57.6%; CI: 50.6-64.6; external set: 0%). These diagnostic performances were comparable to those of tCa. The upper and lower limits of piCa PI had high sensitivity for detecting ionized hypercalcemia and hypocalcemia, respectively.

CONCLUSIONS AND CLINICAL IMPORTANCE

Predicted ionized calcium is useful to confirm suspected hypercalcemia in cats and screen for hypercalcemia and hypocalcemia.

Severity of Ionized Hypercalcemia and Hypocalcemia Is Associated With Etiology in Dogs and Cats

Background: Calcium disorders are common in small animals, but few studies have investigated the etiology of ionized hypercalcemia and hypocalcemia in large populations. This study aimed to determine the incidence of ionized calcium disorders in dogs and cats treated at a tertiary referral clinic and to describe the associated diseases.

Methods: An electronic database of electrolyte analyses conducted at the Cornell University Hospital for Animals from 2007 to 2017 was searched. Dogs and cats with ionized hypercalcemia or hypocalcemia were identified based on institution reference intervals. Duplicate case entries were removed. Medical records were reviewed to identify the cause of the calcium abnormality. Chi-squared analysis with Bonferroni adjustment was performed to compare frequencies of disease processes between mild and moderate-severe disturbances.

Results: The database included 15,277 dogs and 3,715 cats. Hypercalcemia was identified in 1,641 dogs and 119 cats. The incidence of canine and feline hypercalcemia was 10.7 and 3.2%, respectively. Hypocalcemia was identified in 1,467 dogs and 450 cats. The incidence of canine and feline hypocalcemia was 9.6% and 12.1%, respectively. The most common pathologic causes of hypercalcemia in dogs were malignancy-associated (12.9%), parathyroid-dependent (4.6%) and hypoadrenocorticism (1.7%). In cats, malignancy-associated hypercalcemia (22.7%), kidney injury (13.4%) and idiopathic hypercalcemia (12.6%) were most common. Dogs presenting with moderate-severe hypercalcemia vs. mild hypercalcemia were significantly more likely to have hyperparathyroidism, malignancy-associated hypercalcemia or hypervitaminosis D, whereas cats were significantly more likely to have malignancy-associated hypercalcemia or idiopathic hypercalcemia. The most common pathologic causes of hypocalcemia in dogs were critical illness (17.4%), kidney injury (10.4%) and toxicity (7.5%). In cats, kidney injury (21.6%), urethral obstruction (15.1%), and critical illness (14.7%) were most frequent. Dogs presenting with moderate-severe hypocalcemia were significantly more likely to have hypoparathyroidism, kidney injury, eclampsia or critical illness, whereas cats were significantly more likely to have kidney injury, soft tissue trauma or urethral obstruction.

Conclusions: Mild calcium disturbances are most commonly associated with non-pathologic or transient conditions. Malignancy-associated hypercalcemia is the most common cause of ionized hypercalcemia in dogs and cats. Critical illness and kidney injury are frequent causes of ionized hypocalcemia in both species.

Development of a Multivariate Predictive Model to Estimate Ionized Calcium Concentration from Serum Biochemical Profile Results in Dogs

BACKGROUND

Ionized calcium concentration is the gold standard to assess calcium status in dogs, but measurement is not always available.

OBJECTIVES

(1) To predict ionized calcium concentration from biochemical results and compare the diagnostic performance of predicted ionized calcium concentration (piCa) to those of total calcium concentration (tCa) and 2 corrected tCa formulas; and (2) to study the relationship between biochemical results and variation of measured ionized calcium concentration (miCa).

ANIMALS

A total of 1,719 dogs with both miCa and biochemical profile results available.

METHODS

Cross-sectional study. Using 1,200 dogs, piCa was determined using a multivariate adaptive regression splines model. Its accuracy and performance were tested on the remaining 519 dogs.

RESULTS

The final model included creatinine, albumin, tCa, phosphorus, sodium, potassium, chloride, alkaline phosphatase, triglycerides, and age, with tCa, albumin, and chloride having the highest impact on miCa variation. Measured ionized calcium concentration was better correlated with piCa than with tCa and corrected tCa and had higher overall diagnostic accuracy to diagnose hypocalcemia and hypercalcemia, but not significantly for hypercalcemia. For hypercalcemia, piCa was as sensitive (64%) but more specific (99.6%) than tCa and corrected tCa. For hypocalcemia, piCa was more sensitive (21.8%) and as specific (98.4%) as tCa. Positive and negative predictive values of piCa were high for both hypercalcemia (90% and 98%, respectively) and hypocalcemia (70.8% and 87.7%, respectively).

CONCLUSIONS AND CLINICAL IMPORTANCE

Predicted ionized calcium concentration can be obtained from readily available biochemical and patient results and seems more useful than tCa and corrected tCa to assess calcium disorders in dogs when miCa is unavailable. Validation on external data, however, is warranted.