Effect of age on reference intervals of serum biochemical values in kittens

Physiological and morphological characterization of endangered European wildcats from the Iberian lineage: Reference values for conservation

The European wildcat (Felis silvestris), particularly its Iberian lineage, is experiencing an important population decline due to various threats. For this reason, we started in 2017 an intensive monitoring of a population of this species in southeastern Spain. To determine their physiological status, we conducted health checks on wildcats during 2017-2023. We captured and anesthetized 10 males (six adults and four non-adults) and 14 females (eight adults and six non-adults) for the collection of biometric measurements and biological samples through a standardized handling protocol. All sampled wildcats were monitored after their release through radio-tracking and/or camera-trapping for at least three months. The collected samples were used to perform morphological, hematological, biochemical, and endocrine analyses. We found that all the physiological parameters fell within previously established ranges (when available) and may serve as a reference for future studies on the wildcat. The studied Iberian wildcats were larger than the wildcats from temperate Europe, which do not conform to Bergmann's rule. This could be the result of an adaptation of Iberian wildcats to capture larger prey (i.e., European rabbit Oryctolagus cuniculus) in the Mediterranean region, and calls for a reassessment of the taxonomic status of the Iberian lineage of this felid. Finally, as revealed by the monitored individuals, the handling protocol proved to be optimal, resulting in a practical guidance for further field surveys.

Serum electrolyte abnormalities in cats with chronic inflammatory enteropathy

BACKGROUND

Limited information is available on electrolyte abnormalities in cats with chronic inflammatory enteropathy (CIE).

HYPOTHESIS/OBJECTIVES

Report the prevalence of electrolyte abnormalities in cats with CIE compared to other gastrointestinal disorders, and determine their association with disease and outcome variables in cats with CIE.

ANIMALS

Three hundred twenty-eight client-owned cats from 2 referral hospitals: CIE (132), alimentary small cell lymphoma (29), acute gastroenteritis (48), and healthy controls (119).

METHODS

Retrospective study comparing serum electrolyte concentrations at time of diagnosis among the 4 groups of cats, and associations with clinical signs, intestinal mucosal fibrosis scores, treatment subclassification and outcome in CIE.

RESULTS

Cats with CIE had lower sodium and higher potassium concentrations and lower sodium: potassium ratios compared with healthy cats (P < .001, P = .01, and P < .001, respectively). Cats with CIE and a duodenal mucosal fibrosis score of 2 had lower sodium and lower total calcium concentrations compared with cats that had a score of 0 (P = .02 and P = .01). Cats with CIE and a colonic mucosal fibrosis score of 1 had higher potassium concentrations and lower sodium: potassium ratios compared with cats that had a score of 0 (P = .03 and P = .01). Cats with CIE that died as a result of their disease had higher potassium concentrations and lower sodium: potassium ratios compared to cats that were alive (P = .02 and P = .01).

CONCLUSIONS AND CLINICAL IMPORTANCE

Electrolyte abnormalities occur with CIE and, in particular, in cats with higher fibrosis scores and worse outcomes. Further research should aim to determine the pathogenesis of these findings and identify novel therapeutic targets for cats with CIE.

Serum symmetric dimethylarginine in older dogs: Reference interval and comparison of a gold standard method with the ELISA

BACKGROUND

Serum symmetric dimethylarginine (SDMA) is used to screen for renal dysfunction in dogs. The gold standard technique for measuring SDMA, liquid chromatography-tandem mass spectrometry (LC-MS/MS) is not widely available. Age-specific reference intervals for SDMA in older dogs are lacking.

OBJECTIVES

Prospective study in older dogs to validate a commercially available LC-MS/MS method for SDMA, compare SDMA concentrations with concentrations measured using ELISA and obtain a reference interval (RI) for older dogs using both methods.

ANIMALS

Client-owned older dogs undergoing health screening.

METHODS

The LC-MS/MS method was analytically validated (limit of detection, precision, and linearity). Serum was sent cooled overnight for ELISA or was frozen at -80°C until batch analysis using LC-MS/MS. Results of LC-MS/MS and ELISA were compared and RIs for older dogs were calculated according to international guidelines.

RESULTS

The LC-MS/MS method showed good linearity (r2  = .99) and precision (coefficient of variation <10%), with a laboratory RI between 8.0 and 14.0 μg/dL. Paired measurements were available from 118 different dogs. Median SDMA concentration were 9.4 (range, 5.0-21.2) using LC-MS/MS and 12.0 (range, 5.0-22.0) μg/dL using ELISA. Both methods significantly differed with a mean difference of 2.2 μg/dL. The RI for older dogs for LC-MS/MS was 4.4-15.0 μg/dL, and for ELISA was 6.4-17.4 μg/dL.

CONCLUSIONS AND CLINICAL IMPORTANCE

The ELISA provided significantly higher SDMA concentrations compared to the validated LC-MS/MS method, indicating the need for device- or assay-specific RI. The obtained age-specific RI for SDMA is considerably higher in older dogs compared to the general laboratory RI.

Topics on maternal, fetal and neonatal immunology of dogs and cats

Birth and the first few weeks of age are critical periods of developing the immune system of puppies and kittens and adapting to an environment containing a variety of infectious agents. The survival rate during these periods depends mainly on the newborn's immune capacity to prevent and combat infections. Although most components of innate and adaptive immunity are present at birth, responses are slow and immature compared to adults. Due to immunological immaturity and the endotheliochorial placental structure, circulating concentrations of immunoglobulins in dogs and cats at birth are quite low. Thus, newborns need a prompt and immediate immune response, which is essentially provided by defense cells and maternal antibodies via colostrum. Failure to ingest colostrum is correlated with high mortality rates in the neonatal period. Concurrently, factors related to pregnant, such as pregnancy physiological immunosuppression and nutritional and health states, can directly influence newborn immunity and health. Therefore, understanding the maternal and neonatal immunological aspects, importance of colostrum, risk factors for failure to transfer passive immunity and colostrum substitute strategies are essential to ensure the survival of the litter.

Clinical enzymology of the dog and cat

Clinical enzymology studies the enzyme activity in serum or other body fluids for the diagnosis, prognosis or monitoring of a variety of diseases. Clinical enzymology has greatly benefited from advances in technology and is now an integral part of laboratory analysis. However, to maximise the clinical benefits of serum enzyme measurement, clinicians and clinical pathologists must have a good understanding of the pathophysiology behind serum enzyme alterations. They must also be aware of the preanalytical and analytical factors that can affect the accuracy of serum enzyme activity measurement. This review article first covers the basic concepts of clinical enzymology and the general mechanisms related to serum enzyme alterations. Then, the review discusses the potential effects of various preanalytical and analytical factors on enzyme activity measurement. Lastly, it explores the pathophysiology and clinical use of various serum enzymes in canine and feline medicine. The present review article aims to be a comprehensive one-stop source for clinical pathologists and small animal practitioners.

Hereditary myotonia in cats associated with a new homozygous missense variant p.Ala331Pro in the muscle chloride channel ClC-1

Three-related cats were evaluated for a history of short-strided gait and temporary recumbency after startle. Neurological examination, electromyography (EMG), muscle biopsies, and a chloride voltage-gated channel 1 (CLCN1) molecular study were performed. Clinically, all 3 cats presented myotonia with warm-up phenomenon and myotonic discharges during EMG examination. Muscle biopsies showed normal muscle architecture and variation in the diameter of myofiber size with the presence of numerous hypertrophic fibers. The molecular study revealed a missense variant (c.991G>C, p.Ala331Pro) in exon 9 of the CLCN1 gene, responsible for the first chloride channel extracellular loop. This mutation was screened in 104 control phenotypically normal unrelated cats, and all were wildtype. The alanine at this position is conserved in ClC-1 (chloride channel protein 1) in different species, and 2 mutations at this amino acid position are associated with human myotonia. This is the third CLCN1 mutation described in the literature associated with hereditary myotonia in cats and the first in domestic animals located in an extracellular muscle ClC-1 loop.

Haematological and biochemical reference intervals in healthy Ragdoll cats

OBJECTIVES

Breed-specific reference intervals (RIs) may be necessary to avoid misinterpretation of laboratory results. The main aim of this study was to establish haematobiochemical RIs for Ragdoll cats.

METHODS

Forty-two clinically healthy adult (0.8-10 years old) Ragdoll cats (Ragdoll population [RP]) and 60 non-Ragdoll cats as the control population (CP) were prospectively enrolled. Results of haematology, biochemistry and total thyroxine (TT4) were used to determine both Ragdoll-specific and general feline population RIs for each variable using Reference Value Advisor software according to the Clinical and Laboratory Standards Institute guidelines and the American Society of Veterinary Clinical Pathology guidelines.

RESULTS

For each analyte, RIs of the RP were calculated and compared with those obtained from the CP. Haematocrit, haemoglobin, mean cell volume, mean cell haemoglobin concentration, reticulocyte absolute count, platelet count and lymphocyte absolute number were statistically different from the CP. Biochemistry RIs revealed a statistical difference in creatinine kinase (CK), total protein, urea, creatinine, glucose, total calcium and iron.

CONCLUSIONS AND RELEVANCE

Haematobiochemical RIs of the general feline population must be used with caution in Ragdoll cats when it comes to iron and glucose concentrations, CK activity and absolute lymphocyte number. For these parameters, the use of breed-specific RIs is suggested. The docile and more relaxed nature of this breed may explain these differences and further investigations are necessary to better understand the results. Furthermore, investigations are needed to evaluate the possible benefits of breed-specific urea RIs.

Case Report: A Case Series Linked to Vitamin D Excess in Pet Food: Cholecalciferol (Vitamin D3) Toxicity Observed in Five Cats

Cholecalciferol (vitamin D3) toxicity caused by defective pet food formulations is a rare occurrence described in cats. Nevertheless, it poses a health risk, even though the affected pet food is not fed as the sole diet. Excessive vitamin D3 intake might cause hypercalcemia and soft tissue mineralization, which are findings that prompt clinicians to further investigate the feasible etiology. This case series describes the effects of an extremely high vitamin D3 intake in five young cats caused by the consumption of a fish-based complementary kitten pet food (KPF) that was fed to all of the cats as part of their diet (cases 1, 2, and 3) or eaten exclusively (cases 4 and 5). Due to the different amounts of vitamin D3 consumed, diagnostic examinations showed different degrees of severity of hypercalcemia and azotemia as well as different radiographic findings in cases where diagnostic imaging was performed (cases 2, 4, and 5). All of the cats were treated by withdrawing the affected food and providing medical management of the hypercalcemia. All of the cats recovered, except for two persistent azotemic cats, which developed chronic kidney disease. The goal of this case series is, therefore, to describe the occurrence and resolution of an acute vitamin D3 toxicity due to the highest amount of dietary vitamin D3 intake that has ever been described in domestic cats.

The new age of renal biomarkers: does SDMA solve all of our problems?

Within clinical small animal practice, diagnosis of both chronic kidney disease and acute kidney injury is common. To assess renal function, measurement of glomerular filtration rate is considered the gold standard. Currently, routine tests of kidney function include surrogate markers of glomerular filtration rate such as serum creatinine, and urea, each with their own limitations, whilst urine protein to creatinine ratio gives an indication of glomerular and tubular handling of protein, and urine specific gravity information about urine concentrating ability by the kidney. These parameters are used together with historical and physical examination data to give a diagnosis of kidney disease following which creatinine, proteinuria and blood pressure are used to stage chronic kidney disease and, together with urine output, grade acute kidney injury according to the International Renal Interest Society. However, there has been much concern that creatinine is insensitive when used to indicate early decline in renal function and this has highlighted the need for additional methods of diagnosing and monitoring these patients, with the potential to allow earlier therapeutic intervention. Symmetric dimethylarginine is a novel biomarker, which has been shown to perform as a surrogate marker of glomerular filtration rate in small animals. This article will review current research on symmetric dimethylarginine and the ways in which it may be utilised in small animal practice; current research supports the use of symmetric dimethylarginine as a screening test for detection of early chronic kidney disease according to International Renal Interest Society guidelines, but further research is required in to the usefulness of symmetric dimethylarginine as a tool for monitoring disease and the effect of non-renal influences.

First report of Cytauxzoon sp. infection in domestic cats in Switzerland: natural and transfusion-transmitted infections

BACKGROUND

Cytauxzoonosis is an emerging tick-borne disease of domestic and wild felids. Cytauxzoon felis induces severe and often fatal disease in domestic cats. In Europe, clinical and subclinical infections caused by Cytauxzoon sp. are described. We report the first cases of Cytauxzoon sp. infection in domestic cats in Switzerland.

METHODS

Clinical and laboratory data and results of PCR analyses were collected from Cytauxzoon sp. PCR-positive cats and the cats followed for up to 851 days.

RESULTS

The cases were three two-month old kittens from the same litter (Cases 1-3) and two adult domestic shorthair cats (Cases 4 and 5). The cats originated from the north-west and west of Switzerland. Cases 1-3 presented with moderate to severe regenerative anaemia and intraerythrocytic inclusions. Cytauxzoon sp. was confirmed by PCR and sequencing. The kittens made a clinical and haematological recovery after blood transfusion and/or treatment with azithromycin and atovaquone, but erythroparasitaemia persisted. Case 4 presented with severe non-regenerative anaemia. Case 5 was healthy and used as a blood donor for Case 4. Following blood transfusion, Case 4 showed intraerythrocytic inclusions, and Cytauxzoon sp. was confirmed in both Cases 4 and 5 using PCR and sequencing. Case 4 achieved clinical and haematological remission after treatment with azithromycin, atovaquone and immunosuppressive drugs. Eight months later, Case 4 was presented again with anaemia but tested Cytauxzoon sp. PCR-negative. Sequencing of 1637 bp of the 18S rRNA gene of Cytauxzoon sp. revealed 100% nucleotide sequence identity among isolates of Cases 1-3 and between isolates of Cases 4 and 5, and 99% sequence identity between isolates of all cases. Phylogenetic analysis revealed the closest relationship of the Swiss isolates to Cytauxzoon sp. isolates from domestic cats and wild felids from France, Spain and Romania and to Cytauxzoon manul from a Pallas's cat.

CONCLUSIONS

This is the first report of Cytauxzoon sp. infection in domestic cats in Switzerland. It is also the first report of infection in very young kittens and transmission of Cytauxzoon sp. to an adult cat by transfusion of blood from an asymptomatic cat. The cats recovered but some developed chronic asymptomatic erythroparasitaemia for up to 28 months. Domestic cats may act as reservoirs for Cytauxzoon sp. in Europe and blood donor cats should be screened for this agent by PCR.

Effect of transmucosal corn syrup application on postoperative blood glucose concentrations in kittens

Objectives The aim of the study was to determine the effect of a common clinical practice, the transmucosal (TM) application of corn syrup, on postoperative blood glucose concentrations in kittens. Methods This study was designed as a randomized controlled trial. Seventy-five kittens between the age of 8 and 16 weeks scheduled for surgical sterilization by gonadectomy at an animal shelter were enrolled. Kittens were randomly assigned to either a routine treatment group that received the shelter's typical postoperative application of corn syrup immediately following gonadectomy or to a control group that did not receive typical treatment. Three blood glucose measurements were obtained per kitten: baseline reading prior to preoperative examination, immediately postoperatively and 20 mins postoperatively. The median values of the 20 min postoperative blood glucose reading for the control and treatment groups were compared using the Wilcoxon rank-sum test. Results Postoperative application of corn syrup to the oral mucosa of kittens did not result in significant elevations in blood glucose compared with controls. No kitten was hypoglycemic (⩽60 mg/dl) at any point during the study. Conclusions and relevance TM application of corn syrup did not affect postoperative blood glucose concentrations in kittens. Protocols that use routine TM administration of corn syrup in kittens should be re-evaluated.

Evaluation of two raw diets vs a commercial cooked diet on feline growth

Objectives The objective of this study was to determine if two raw feline diets were nutritionally adequate for kittens. Methods Twenty-four 9-week-old kittens underwent an Association of American Feed Control Officials' (AAFCO) 10 week growth feeding trial with two raw diet groups and one cooked diet group (eight kittens in each). Morphometric measurements (weight, height and length), complete blood counts, serum chemistry, whole blood taurine and fecal cultures were evaluated. Results Overall, the growth parameters were similar for all diet groups, indicating the two raw diets used in this study supported feline growth, within the limitations of an AAFCO growth feeding trial. Kittens fed the raw diets had lower albumin ( P = 0.010) and higher globulin ( P = 0.04) levels than the kittens fed the cooked diet. These lower albumin levels were not clinically significant, as all groups were still within normal age reference intervals. A red cell microcytosis ( P = 0.001) was noted in the combination raw diet group. Increases in fecal Clostridium perfringens were noted in all groups, along with positive fecal Salmonella serovar Heidelberg and Clostridium difficile toxin in the combination raw diet group. Conclusions and relevance The majority of the parameters for feline growth were similar among all groups, indicating the two raw diets studied passed an AAFCO growth trial. In theory, it is possible to pass an AAFCO growth trial but still have nutrient deficiencies in the long term due to liver and fat storage depots. Some of the raw feeders had elevated globulin and microcytosis, likely associated with known enteropathogenic exposure. Disease risks to both pets and owners are obvious. Additional research in this area is needed to investigate the impact of raw diets on the health of domestic cats.

Serum Biochemical Phenotypes in the Domestic Dog

The serum or plasma biochemical profile is essential in the diagnosis and monitoring of systemic disease in veterinary medicine, but current reference intervals typically take no account of breed-specific differences. Breed-specific hematological phenotypes have been documented in the domestic dog, but little has been published on serum biochemical phenotypes in this species. Serum biochemical profiles of dogs in which all measurements fell within the existing reference intervals were retrieved from a large veterinary database. Serum biochemical profiles from 3045 dogs were retrieved, of which 1495 had an accompanying normal glucose concentration. Sixty pure breeds plus a mixed breed control group were represented by at least 10 individuals. All analytes, except for sodium, chloride and glucose, showed variation with age. Total protein, globulin, potassium, chloride, creatinine, cholesterol, total bilirubin, ALT, CK, amylase, and lipase varied between sexes. Neutering status significantly impacted all analytes except albumin, sodium, calcium, urea, and glucose. Principal component analysis of serum biochemical data revealed 36 pure breeds with distinctive phenotypes. Furthermore, comparative analysis identified 23 breeds with significant differences from the mixed breed group in all biochemical analytes except urea and glucose. Eighteen breeds were identified by both principal component and comparative analysis. Tentative reference intervals were generated for breeds with a distinctive phenotype identified by comparative analysis and represented by at least 120 individuals. This is the first large-scale analysis of breed-specific serum biochemical phenotypes in the domestic dog and highlights potential genetic components of biochemical traits in this species.

Osteoporotic risk and physeal closure in prepubertal ovariohysterectomized cats

We aimed to examine the early effects of prepubertal ovariohysterectomy (P-OHE) on bone loss and proximal physeal closure in cats. Fourteen kittens randomly underwent P-OHE or sham operations (S-OP) at three months (mo) of age and were allocated to group I and group II. Each mo between four and nine mo of age, dual-energy X-ray absorptiometry (DEXA) scans were performed to determine the total body bone mineral density (BMD) and bone mineral content (BMC). Proximal radial physeal closure and radial length were determined by radiography. Bone-specific alkaline phosphatase (BAP), carboxy-terminal collagen teleopeptide (CTX), 17-β estradiol, progesterone, calcium (Ca) and phosphorus (P) were measured in the serum samples. No significant differences were observed between the groups in terms of BMD, BMC, BAP, BAP/CTX, P, progesterone and body weight (BW) (between 4 and 9mo) and for Ca (between 5 and 9mo) and for CTX levels (between 4 and 8mo). The 17-β estradiol was significantly higher at 6, 8 and 9mo of age in the S-OP group due to puberty (P=0.02, P=0.03 and P=0.02 respectively). Although there was a significant difference (P=0.0002) between the P-OHE and S-OP groups in terms of the proximal radial physeal closure times (7.43±0.20mo and 6.14±0.14mo, respectively), no significant difference was observed for the mean radius length (10.59±0.10cm and 10.06±0.27cm, respectively) at the last evaluation time. In conclusion, prepubertal ovariohysterectomized cats do not have any osteoporotic risks until nine mo of age and exhibit a delayed physeal closure time without a change in radius length.

Mineral metabolism in growing cats: changes in the values of blood parameters with age

The purpose of this study was to describe changes in calcium, phosphorus, magnesium, parathyroid hormone, calcitriol and calcidiol in cats from 3 to 15 months of age. Fourteen European shorthair healthy cats of both sexes (seven males, seven females) belonging to a research colony were studied from 3 to 15 months of age. Plasma concentrations of total calcium, ionised calcium, albumin, phosphorus, magnesium, intact parathyroid hormone (I-PTH), whole parathyroid hormone (W-PTH), calcidiol and calcitriol were measured at 3, 6, 9, 12 and 15 months of age. From 3 months of age to adulthood cats showed a decrease in calcium (both total and ionised), phosphorus and magnesium. No major changes in PTH were evident, although the ratio of W-PTH:I-PTH decreased significantly with age. A reciprocal change in vitamin D metabolites (decrease in calcitriol and increase in calcidiol) was identified during the growing process. Our results, showing changes in most parameters of mineral metabolism during growth, reinforce the need to use adequate age-related reference values for diagnostic purposes.

Diagnostic and prognostic value of serum creatine-kinase activity in ill cats: a retrospective study of 601 cases

In veterinary medicine, serum creatine-kinase (CK) activity is mostly used to assess skeletal muscle damage. This retrospective study aimed to evaluate the prevalence of increased CK activity in a large, ill-cat population and to characterise associated diseases, clinical and laboratory findings and its prognostic value. Cats with a complete serum biochemistry analysis were consecutively enrolled, divided into two CK activity-based groups (within and above reference interval) and compared. The study included 601 cats. Median serum CK was 402 U/l (range 16-506870). Increased CK (>250 U/l) was observed in 364 (60%) cats, and>30-fold its upper reference limit in 43 (7%). Cats with increased CK had greater (P < or = 0.05) body weight, and were more likely to have a history of collapse, dyspnoea, abnormal lung sounds, cyanosis, shock and paraplegia, higher median serum alanine aminotransferase, aspartate aminotransferase and lactate dehydrogenase activities and total bilirubin and triglyceride concentrations, but lower, median total protein, albumin, globulin and cholesterol concentrations and proportion of anorexia than cats with normal CK. Cardiac diseases, trauma, bite wounds, systemic bacterial infections, prior anaesthesia and intramuscular injections were more common (P < or = 0.05) in cats with increased compared to normal CK activity. The hospitalisation period was longer (P=0.007) and treatment cost and mortality were higher (P<0.005) in cats with increased CK activity. However, CK activity was an inaccurate outcome predictor (area under the receiver operator characteristics curve 0.58). Increased CK activity is very common in ill cats.

Alkaline phosphatase: beyond the liver

The alkaline phosphatases comprise a heterogeneous group of enzymes that are widely distributed in mammalian cells. They often are associated with cell membranes, but their exact physiologic function is unknown. Despite this, alkaline phosphatase activity is a very useful serum biochemical indicator of liver disease, particularly cholestatic disease. However, increases in the activity of alkaline phosphatase in serum and other body fluids may reflect physiologic or pathologic changes beyond those of hepatic origin. For example, nonhepatic increases in serum alkaline phosphatase activity are found in young animals, in pregnant and lactating females, and in association with high fat diets. Bone disease, endocrine disease, neoplasia, and other disorders can result in increased alkaline phosphatase activity. In addition, alkaline phosphatase activity may be increased due to induction by certain drugs such as glucocorticoids and anticonvulsants. In this article, we will review the physiologic and pathologic factors influencing the activity of alkaline phosphatase in serum and other body fluids, with an emphasis on disorders beyond liver disease.

Interpretation of liver enzymes

Abnormalities in liver enzymes are commonly encountered in clinical practice. Knowledgeable assessment requires a full understanding of their pathophysiology and provides an important means of detecting the earliest stage of many serious hepatobiliary disorders. The best interpretations are achieved using an integrated approach, combining historical and physical findings with routine and specialized diagnostic procedures and imaging studies. Information in this article provides the foundation, by example, for understanding the reliability of single time point enzyme measurements, the value of sequential measurements, the importance of interpreting the activity of enzymes in light of their half life and tissue of origin, and the influence of the induction phenomenon.

Evaluation of surrogate markers for passive transfer of immunity in kittens

OBJECTIVE

To identify surrogate markers of passive transfer of immunity in kittens.

DESIGN

Prospective clinical trial.

ANIMALS

55 kittens from 12 specific-pathogen-free queens.

PROCEDURE

Kittens were allocated at birth into colostrum-fed (n = 27) and colostrum-deprived (28) groups. Blood was collected at birth and on days 1, 2, 4, 7, 14, 28, and 56. Serum samples were analyzed for activities of alkaline phosphatase (ALP), alanine aminotransferase, aspartate aminotransferase, creatine kinase, lactate dehydrogenase, gamma-glutamyltransferase, amylase, and lipase and for concentrations of albumin, total protein, bilirubin, urea nitrogen, creatinine, cholesterol, glucose, calcium, phosphorus, and triglycerides by use of an automated analyzer. Total serum solids concentrations were estimated by use of refractometry. Serum IgG concentrations were quantified by use of radial immunodiffusion.

RESULTS

All kittens were agammaglobulinemic at birth. Colostrum-fed kittens had significantly higher IgG concentrations than did colostrum-deprived kittens from 1 though 28 days of age. Transient significant differences in serum biochemical variables between the colostrum-deprived and colostrum-fed groups were substantially resolved by day 4. Passive transfer of immunity could be reliably determined at 1 day of age and to a lesser extent at 2 days of age only by measurement of serum activity of ALP.

CONCLUSIONS AND CLINICAL RELEVANCE

Adequacy of passive transfer in kittens initially correlated with serum activity of ALP, but quantification of serum IgG concentration was necessary after 2 days of age.