一株MDBK细胞的低血清悬浮驯化研究

研究选取一株背景清晰、纯净的MDBK贴壁细胞,通过直接驯化和逐级降低血清相结合的办法,获得了一株可以在低血清培养基中全悬浮培养的MDBK细胞。该细胞在含0.5%胎牛血清的培养基中悬浮培养48 h后的细胞密度稳定在5.0×10⁶/mL以上,培养72 h后细胞密度最高可达1.16×10⁷/mL,且细胞形态良好,活力在93%以上,具有良好的传代稳定性。应用筛选获得的悬浮培养MDBK细胞株分别接种伪狂犬病毒和传染性牛鼻气管炎病毒后,检测病毒敏感性。细胞在24 h均发生了皱缩,72 h大部分死亡。悬浮培养的MDBK细胞对传染性牛鼻气管炎病毒的滴度在24 h达到最大值107.6TCID50/mL,对伪狂犬病毒的滴度在48 h达到最大值107.6 TCID50/mL,说明虽然细胞的培养方式发生了改变,但并没有影响上述两种病毒在该细胞上的增殖特性。对MDBK细胞的全悬浮驯化研究可为相关病毒类疫苗规模化生产及工艺的升级改进提供细胞学基础资料。     

Communications: Protective Immunity Induced by a Commercial Vibrio Vaccine in Hybrid Striped Bass

Abstract

Commercial Vibrio anguiliarum-V. ordalii bacterin was used to vaccinate hybrid striped bass (Morone saxatilis ♀ × M. chrysops ♂) to test the vaccine efficacy against vibriosis. Vaccination by direct immersion of fish in diluted Vibrio vaccine for 20 s resulted in increased protective immunity. The relative percent survival of hybrid striped bass challenged 35 d after vaccination was 66.7% for those challenged by 1-h immersion exposure to 7.03 × 10⁷ V. anguillarum cells/mL, 75.0% for those challenged by injection with 3.51 × 10⁵ cells/fish, and 86.7% for those challenged by injection with 3.51 × 10⁴ cells/fish.     

The Lethal Dose of Largemouth Bass Virus in Juvenile Largemouth Bass and the Comparative Susceptibility of Striped Bass

Abstract

Largemouth bass virus (LMBV) is an iridovirus that was isolated from wild adult largemouth bass Micropterus salmoides in the southeastern United States in 1994. Although originally isolated from moribund wild fish, its virulence to juvenile largemouth bass is uncertain. To help clarify this point, two LMBV titrations were made in juvenile largemouth bass. Titers of LMBV in fathead minnow cells were 10^4.8 and 10^5.8 tissue culture infectious doses—50% cytopathic endpoint (TCID50) per milliliter, respectively. Tenfold serial dilutions of LMBV employed in each cell culture titration, injected intraperitoneally (0.1 mL/fish) into largemouth bass produced calculated lethal dose—50% mortality endpoints (LD50s) of 282 (10^2.45) and 288 (10^2.46) infectious doses in two consecutive infectivity trials. Virus yield of assayed infected fish averaged 10^8.5 TCID50/g and 10^7.7 TCID50/g in viscera of moribund and dead fish in the two trials and 10^6.5 TCID50/g in surviving exposed fish 14 d after infection. In a second experiment, largemouth bass had 100% mortality 5 d after injection while virus immersed fish had a significantly (P ≤ 0.005) lower mortality of 17% at 14 d. Similarly treated juvenile striped bass Morone saxatilis suffered 63% mortality after injection and significantly (P ≤ 0.005) lower mortality of 10% after immersion. In a third study of 25 d, 100% of injected largemouth bass died by 5 d after injection, and all of them were virus-positive. Injected striped bass had a significantly (P ≤ 0.005) lower mortality of 24%; all three fish were virus-positive initially, two fish were virus-positive at 18 d, and none were positive at 25 d. Juvenile largemouth bass were highly susceptible to LMBV injection and striped bass were moderately susceptible, but both species were only mildly susceptible when exposed by immersion.     

DNA Vaccination Partially Protects Muskellunge against Viral Hemorrhagic Septicemia Virus (VHSV-IVb)

Abstract

A DNA vaccine containing the glycoprotein (G) gene of the North American viral hemorrhagic septicemia virus (VHSV) genotype IVb was developed to evaluate the immune response of fish following vaccination and evaluate its efficacy in protecting a susceptible species, the Muskellunge Esox masquinongy, against VHSV-IVb challenge. Seven weeks (539 degree-days) following vaccination with 10 μg of either pVHSivb-G or a control plasmid, Muskellunge were challenged by immersion with 10⁵ plaque-forming units (pfu)/mL of VHSV-IVb. Fish vaccinated with pVHSivb-G had a relative percent survival (RPS) of 45%. Vaccinated fish also had significantly lower mean viral titers in tissues (4.2 × 10² pfu/g) and viral prevalence (4%) than fish receiving the plasmid control vaccine (3.3 × 10⁵ pfu/g; 82%). Neutralizing antibodies were detected 28 d (308 degree-days) postchallenge (11 weeks postvaccination) in 100% of Muskellunge vaccinated with pVHSivb-G compared with only 12% of plasmid-control-vaccinated Muskellunge, suggesting robust induction of a secondary, adaptive immune response. In addition, pVHSivb-G–vaccinated Rainbow Trout Oncorhynchus mykiss challenged 7 d (100 degree-days) postvaccination with the heterologous novirhabdovirus, infectious hematopoietic necrosis virus (IHNV), experienced an RPS of 61%, compared to control fish, suggesting induction of an early and transient nonspecific antiviral immune response. This study provides an important starting point for VHSV-IVb vaccine development and useful information about the antiviral immune response elicited by DNA vaccination in a nondomesticated fish species.

Received May 1, 2016; accepted September 1, 2016     

Multiplication of Infectious Hematopoietic Necrosis Virus in Rainbow Trout following Immersion Infection: Organ Assay and Electron Microscopy

Abstract

Sequential spread of infectious hematopoietic necrosis virus (IHNV) to tissues of rainbow trout Oncorhynchus mykiss was examined following immersion infection with two different isolates of IHNV, a pathogenic strain and a nonpathogenic strain from rainbow trout. Virus strain 193–110 was highly pathogenic to 1-month-old rainbow trout and caused 100% mortality within 13 d, whereas strain RB-76 was much less virulent, causing 50% mortality by the 19th day. Virus titers of 1-month-old fingerling fish dying soon after infection were significantly higher than titers of those dying later. Assays of dissected tissues showed that gills of infected 2-month-old fingerlings contained virus as early as 16 and 20 h postinfection, with definite replication occurring at 48 h. The early presence of the virus in the gills followed shortly by appearance of the virus in the kidneys and spleen indicated that the virus spreads rapidly to the target organs. Virus was detected in many other organs at lower levels on the third day and increased to higher levels during the following days. Heart tissue had high titers later in the infection. When 4-month-old rainbow trout were infected with strain 193–110, the mortality was reduced and delayed, whereas those infected with strain RB-76 produced no mortality. Assays on the day of death of these older fingerlings infected with strain 193–110 revealed that fish dying soon after infection also had higher titers than those dying later. Electron microscopic examination offish organs showed the presence of typical IHNV particles budding off from various tissue cells of affected organs, including gill tissue. The destructive effect of the virus was particularly noticeable in the disarrangement of heart muscle organelles.     

Communications: Tolerance of Rainbow Trout to Dissolved Oxygen Supplementation and a Yersinia ruckeri Challenge

Abstract

Dissolved oxygen accounted for a significant proportion of the variation in mortality rate of rainbow trout Oncorhynchus mykiss acclimated for 10 weeks to a range of dissolved oxygen levels and challenged with Yersinia ruckeri. Moderate levels of oxygen supersaturation (150%) resulted in greater cumulative mortality (17.9%) among fish exposed to a 0.5-h static bath challenge with Y. ruckeri (1 × 10⁷ colony-forming units/mL). In contrast, hypoxic (70%) and normoxic (100%) levels of dissolved oxygen resulted in 12.8% and 10% cumulative mortality. Higher oxygen levels provided no additional “protection” against infection by Y. ruckeri in this study.     

Assessment of the Risk of White Sturgeon to become Infected and Potential Carriers of Infectious Pancreatic Necrosis Virus

Abstract

Little scientific information is available to assess whether White Sturgeon Acipenser transmontanus can become infected and potential carriers of infectious pancreatic necrosis virus (IPNV). To assess this risk, monitoring results of adult and progeny White Sturgeon were examined from waters historically stocked with salmonid fish known to be IPNV carriers. From 1999 through 2004 White Sturgeon from a total of 30 separate families whose parentage came from waters historically stocked with IPNV carrier fish were tested. Duplicate groups of 25 juvenile Snake River White Sturgeon were waterborne exposed to 1.0×10⁴ 50% tissue culture infective dose (TCID50)/mL of water for 1 h and an additional group was injected intraperitoneally with 1.0×10⁵ TCID50/fish. A negative control group was handled similarly but was not exposed to the virus. No morbidity was detected in any of the treatment groups or the negative control. At 34, 40, 47, and 54 d postexposure to IPNV, virus reisolation was attempted on five fish from each group, and an additional five fish from each group were examined for histological changes consistent with an IPNV infection. At 34 and 40 d postinjection with IPNV, 20% (one of five) of the fish tested positive for the virus per sample interval; however, fish from groups that were waterborne-exposed to IPNV were all negative. At 47 and 54 d after exposure or injection with IPNV an additional five fish from each group were tested at each sample interval and all results were negative. Histological analysis of target tissue obtained from five fish per group at 34 and 54 d postinfection also failed to detect any consistent change associated with an IPNV infection. These results suggest that the risk of White Sturgeon to become infected and develop into potential carriers of IPNV is negligible.

Received May 21, 2013; accepted July 8, 2013     

Supplementing Propionibacterium acidipropionici P169 does not affect methane production or volatile fatty acid profiles of different diets in in vitro rumen cultures from heifers

Abstract

Effects of Propionibacterium acidipropionici P169 on gas, methane (CH₄) production and volatile fatty acids in in vitro rumen cultures were studied. Ground barley (Experiment 1), mixed forage (Experiment 2) or mixed concentrate-forage (Experiment 3) served as substrates. Three doses of P169 were used in Experiments 1 and 2 [1.2 × 10⁴; 1.2 × 10⁶; 1.2 × 10⁸ colony forming unit (CFU)/mL], while two doses (2.4 × 10⁶; 2.4 × 10⁸ CFU/mL) were used in Experiment 3. In Experiment 1, P169 increased (P < 0.05) gas production at 6–12 h and CH₄ (mL/g diet dry matter) at all times. In Experiment 2, CH₄ was increased at 6 h (P < 0.01). At 12 h, propionate declined (P < 0.01) in Experiment 1 and increased at 48 h in Experiment 3. The inability of P169 to increase propionate and its lack of persistence in mixed ruminal cultures may account for its inability to alter CH₄ production.     

Survivability of Infectious Hematopoietic Necrosis Virus in Fertilized Eggs of Masu and Chum Salmon

Abstract

The possibility of vertical transmission of infectious hematopoietic necrosis virus (IHNV) was studied with the eggs of masu (cherry) salmon Oncorhynchus masou and chum salmon O. keta. The surfaces of eggs and sperm were contaminated with IHNV (10^3.8-10^4.8 50% tissue culture infective dose [TCID50]/egg) and then the eggs were fertilized. Eggs just after fertilization and embryonated eggs also were infected by injection with IHNV (10^3.8 TCID50/egg) directly into the yolk. During incubation, eggs were held in running water at 10°C. Mortality of the eggs or hatched progeny was determined and isolation of IHNV on the surface or inside of the eggs was determined during the incubation period. No mortality occurred and no virus was detected in fertile eggs from contaminated gametes. For injected eggs, IHNV was not detected on the surface of masu and chum salmon eggs after 1 d of incubation. Infectivity of IHNV inside the eggs decreased gradually and could not be detected after 1 month of incubation. This rate of IHNV reduction in the fertilized egg was similar to that found in a mixture of IHNV and homogenized yolk contents. Several individual yolk components also showed anti-IHNV activity. When eyed eggs were injected with IHNV, the embryos of both masu and chum salmon became infected, and the concentration of virus increased rapidly and reached more than 10^6.5 TCID50/fish. The cumulative mortality of eggs injected at the eyed stage for both masu and chum salmon was 90%. The susceptibilities of hatched-out larvae of masu and chum salmon to IHNV were different; cumulative mortality was more than 90% in masu salmon and 20–30% in chum salmon artificially infected with the virus. We concluded that vertical transmission of IHNV is doubtful because the virus is apparently unable to survive in eggs before the eyed stage.     

Experimental Infection of Brook Trout with Infectious Hematopoietic Necrosis Virus Types 1 and 2

Abstract

Fry of brook trout Salvelinus fontinalis became infected and diseased after immersion exposure to infectious hematopoietic necrosis virus (IHNV), but a long-lasting IHNV carrier state was not induced. Duplicate groups of 100 fish were immersed for 6 h in baths containing a type 1 (Round Butte, RB) or a type 2 (Rangen, RA) IHNV isolate at a high or low dose. Brook trout mortalities induced by immersion in a bath of the RB or RA IHNV isolate at 10² plaque-forming units (pfu) per milliliter were equivalent (1 and 0%), but fish were more susceptible to infection with RA IHNV. Only the single dead fish in the RB group was infected, but 24% of the RAexposed fish were infected 1 week after exposure. At a dose of 10⁶ pfu/mL, exposure to RB IHNV resulted in a higher mortality (35%) and prevalence of infection (89% of live fish sampled at 1 week postexposure), but no infectious virus was detectable by 5 weeks after exposure. In contrast, RA IHNV exposure at a dose of 10⁴ pfu/mL resulted in only 5% mortality, and live fish killed at 1 week postexposure had a 22% prevalence of infection, but infectious virus was not detectable by week 3. Although brook trout have been previously considered to be resistant to IHNV, this study has shown that brook trout become diseased and die after exposure to a high dose of one type I IHNV isolate and can be infected after immersion exposure to even a low dose of type 1 or type 2 IHNV.     

A Strain of Siniperca chuatsi Rhabdovirus Causes High Mortality among Cultured Largemouth Bass in South China

Abstract

In April 2011, 40% mortality of Largemouth Bass Micropterus salmoides juveniles occurred at a farm of Zhongshan City, Guangdong Province, China. Infected fish became lethargic, exhibited corkscrew and irregular swimming, and developed a distended abdomen and crooked body. Fish began to die within 2 d after the appearance of clinical signs. In order to analyze the pathogeny and diagnose the disease earlier, observation of clinical signs, cell infection, titer calculation, electron microscopy, immersion infection assay for fish, and nucleotide sequence analysis were carried out. Fathead minnow (FHM) cell cultures, inoculated with filtrate of liver and spleen homogenates from the diseased fish, developed the obvious cytopathic effect 46 h after inoculation in the primary culture and 24 h at the first passage. Typical rhabdovirus particles, 115–143 nm in length and 62–78 nm in diameter, were observed in infected FHM cells by direct transmission electron microscopy. The isolated virus produced a titer of 10^7.15 TCID50/mL. Immersion-Fish infected with the virus had similar clinical signs and 80% mortality with 10^2.5 LD50/mL. The data indicated that the rhabdovirus was the lethal pathogeny of the current disease. Based on nucleoprotein-gene nucleotide sequence multiple alignment analysis, the newly isolated virus is a strain of Siniperca chuatsi rhabdovirus (SCRV) under family Rhabdoviridae, which was initially isolated from Mandarin Fish Siniperca chuatsi. Up to the present, at least four virus strains have been isolated from diseased Largemouth Bass, which have had different clinical signs. Comparison of the clinical signs can help in an early diagnosis of the disease.

Received October 30, 2012; accepted April 19, 2013     

无血清全悬浮PK15细胞培养猪圆环病毒2型的研究

为改进猪圆环病毒2型的培养工艺,驯化了一株可无血清培养的全悬浮PK15细胞用于培养猪圆环病毒2型,并对病毒的敏感性、接毒时间、接毒量、收获方法进行了试验.结果表明,用该细胞培养猪圆环病毒2型,如果采用批次收获,接毒时细胞密度为0.5×106/mL,接毒量为0.1 MOI,接毒72 h后收毒,病毒滴度能达到106.4 T...     

Effects of growth factors (EGF,PDGF-BB and TGF-beta 1) on cultured equine epithelial cells and keratocytes: implications for wound healing

Objective The physiologic mechanisms involving growth factors, including PDGF‐BB, EGF, and TGF‐β1, as potent mediators of fibroblasts and epithelial cells in corneal wound healing remain unknown. The goal of this study was to determine culture methods for equine epithelial cells and keratocytes and to investigate how exogenous growth factors influence proliferation of both cell types. Procedures Cell cultures were established from healthy corneas harvested from horses immediately following euthanasia and maintained using standard tissue culture protocols. To determine the effects of PDGF‐BB, EGF, TGF‐β1, keratocytes (1 × 10⁵/well) and epithelial cells (2 × 10⁵/well) were each cultured in 12 well plates and exposed separately to the growth factors. The cells were exposed to concentrations of EGF between 0 and 50 ng/mL; PDGF‐BB between 0 and 75 ng/mL; and TGF‐β1 between 0 and 10 ng/mL. Cell proliferation was measured using ³H‐thymidine assay and differences in growth determined using anova and Tukey's HSD test (P < 0.05). Results Epithelial cell and keratocyte cultures were successfully established. EGF maximally stimulated keratocyte and epithelial cells at 25 ng/mL and 5 ng/mL, respectively. PDGF‐BB maximally stimulated keratocytes and epithelial cells at 50 ng/mL and 5 ng/mL, respectively. TGF‐β1 inhibited keratocytes at 5 ng/mL and 10 ng/mL, and epithelial cells at 1 ng/mL and 2 ng/mL. Conclusions Methods were established to maintain epithelial cells and keratocytes in vitro. PDGF‐BB and EGF stimulate, while TGF‐β1 inhibits the proliferation of epithelial cells and keratocytes. These growth factors may play a role in maintenance and repair of the equine cornea.     

Influence of environmental temperature on experimental infection of redfin perch (Perca fluviatilis) and rainbow trout (Oncorhynchus mykiss) with epizootic haematopoietic necrosis virus, an Australian iridovirus

SUMMARY Experimental transmission of epizootic haematopoietic necrosis virus (EHNV) to adult redfin perch Perca fluviatilis and juvenile rainbow trout Oncorhynchus mykiss was undertaken at different water temperatures using intraperitoneal (IP) and bath inoculation. Redfin perch were highly susceptible to EHNV by both routes of infection. Bath inoculation with as few as 0.08 TCID₅₀. _mL^-1 was lethal. The incubation period in redfin perch was about 11 days at a water temperature of 19–21°C but was longer at colder temperatures and disease did not occur at temperatures below 12°C. The longest incubation period recorded in redfin perch was 28 days. Rainbow trout were not susceptible to infection by bath inoculation but the disease was reproduced after IP inoculation with 10^5.6 TCID₅₀ at water temperatures ranging from 8–21°C. The incubation period was 3–10 days at 19–21°C, but was up to 32 days at 8–10°C. Persistent infection with EHNV was detected by virus isolation in a clinically unaffected rainbow trout after 63 days. The implications of these findings in the understanding of the epidemiology of EHNV infection are discussed.     

Production of Ban miniature pig embryos by in vitro fertilization: A comparative study with Landrace

Ban is an endangered miniature pig breed in Vietnam. This study aimed to set up an in vitro embryo production (IVP) system for this breed. Ban's epididymal sperm concentration (1240 ± 35 × 10⁶/mL) was lower (P < 0.01) compared with Landrace (4160 ± 42 × 10⁶/mL). However, sperm characteristics before and after freezing in Ban and Landrace were similar. The numbers of follicles with diameter larger than 2 mm per ovary in Ban females treated with equine chorionic gonadotropin and human chorionic gonadotropin (27.1 ± 1.3) were higher (P < 0.05) than those in Landrace (12.9 ± 2.0) and in non‐hormone stimulated Ban (no > 2 mm follicles). After in vitro maturation, the percentages of oocytes with expanded cumulus cells and the first polar body (matured oocytes) were not different among Ban, hormone‐stimulated Ban and Landrace. The percentages of two‐cell embryos and morulae derived from oocytes collected from three sources did not differ. However, the rate of blastocysts derived from oocytes in non‐stimulated Ban (4.0 ± 3.8%) was lower (P < 0.05) than that in Landrace (15.3 ± 1.8%). In conclusion, an effective IVP system for good quality embryos in Ban, that is essential for genetic conservation of this breed, was established.     

Characterization of the Largemouth Bass Virus in Cell Culture

Abstract

The largemouth bass virus (LMBV) was characterized in cell culture, by infectivity in five cell lines of fish origin, optimum replication temperature, and ether and pH sensitivity. Viral induced cytopathic effect (CPE) appeared most rapidly in bluegill fry-2 (BF-2) and fathead minnow (FHM) cell lines where the optimum temperature for LMBV replication was 30°C. In a one-step growth curve in BF-2 cells, LMBV reached 10^8.6 TCID50/mL (±0.12 log SD) in 24 h. The virus showed reduced infectivity when treated with ether but was stable when held in medium with a pH 3–9 for 12 h at 4°C. These characteristics further support the classification of LMBV in the family Iridoviridae.     

Assessment of efficacy of a bivalent BTV-2 and BTV-4 inactivated vaccine by vaccination and challenge in cattle

The efficacy of a bivalent inactivated vaccine against bluetongue virus (BTV) serotypes 2 (BTV-2) and 4 (BTV-4) was evaluated in cattle by general and local examination, serological follow-up, and challenge. Thirty-two 4-month-old calves were randomly allocated into 2 groups of 16 animals each. One group was vaccinated subcutaneously (s/c) with two injections of bivalent inactivated vaccine at a 28-day interval, and the second group was left unvaccinated and used as control. Sixty-five days after first vaccination, 8 vaccinated and 8 unvaccinated calves were s/c challenged with 1 mL of 6.2 Log10 TCID50/mL of an Italian field isolate of BTV serotype 2, while the remaining 8 vaccinated and 8 unvaccinated animals were challenged by 1 mL of 6.2 Log10 TCID50/mL of an Italian field isolate of BTV serotype 4. Three additional calves were included in the study and used as sentinels to confirm that no BTV was circulating locally. At the time of the challenge, only one vaccinated animal did not have neutralizing antibodies against BTV-4, while the remaining 15 showed titres of at least 1:10 for either BTV-2 or BTV-4. However, the BTV-2 component of the inactivated vaccine elicited a stronger immune response in terms of both the number of virus neutralization (VN) positive animals and antibody titres. After challenge, no animal showed signs of disease. Similarly, none of the vaccinated animals developed detectable viraemia while bluetongue virus serotype 2 and 4 titres were detected in the circulating blood of all unvaccinated animals, commencing on day 3 post-challenge and lasting 16 days. It is concluded that administration of the bivalent BTV-2 and BTV-4 inactivated vaccine resulted in a complete prevention of detectable viraemia in all calves when challenged with high doses of BTV-2 or BTV-4.     

Hematology and Serum Biochemistry of Feline Immunodeficiency Virus-Infected and Feline Leukemia Virus-Infected Cats

Background: Hematological and biochemical values in cats naturally infected by feline immunodeficiency virus (FIV) or feline leukemia virus (FeLV) are not completely documented. Objective: Report differences in laboratory values between FIV‐ or FeLV‐infected and noninfected and between FIV‐ and FeLV‐infected cats. Animals: Three thousand seven hundred and eighty client‐owned cats tested for FIV and FeLV. Methods: Retrospective study. Evaluation of clinicopathologic changes in cats with defined FIV and FeLV status and for which laboratory data were available. Results: FIV‐infected cats were more likely to be neutropenic (odds ratio [OR]=3.6, 95% confidence interval [95% CI] 2.1–6.2, P < .0001) and had lower serum activities of aspartate aminotransferase and glutamate dehydrogenase than control cats; serum total protein (8.1 ± 1.1 versus 7.6 ± 1.3 g/dL, P < .001) and γ‐globulin concentrations (2.2 ± 1.1 versus 1.7 ± 1.3 g/dL, P < .001) were higher than in uninfected cats. Compared with controls, FeLV‐infected cats had a higher risk of anemia (OR = 3.8, 95% CI 2.4–6.0, P < .0001), thrombocytopenia (OR = 5.0, 95% CI 3.0–8.4, P < .0001), neutropenia (OR = 3.6, 95% CI 2.1–6.1, P < .0001), lymphocytosis (OR = 2.8, 95% CI 1.6–4.8, P= .0002), and lower erythrocyte counts (6.13 ± 2.95 × 10³ versus 8.72 ± 2.18 × 10³/μL, P < .001), thrombocyte counts (253.591 ± 171.841 × 10³ versus 333.506 ± 156.033 × 10³/μL, P < .001), hematocrit (28.72 ± 12.86 versus 37.67 ± 8.90%, P < .001), hemoglobin and creatinine concentration. Conclusions and Clinical Importance: Hematologic abnormalities are common in FeLV‐infected but not in FIV‐infected cats. Clinicopathologic abnormalities are less frequent in FIV‐infected cats and might reflect an unspecific immunologic response.