Frequency of Animal Leptospirosis in the Southern United States and the Implications for Human Health.

Leptospirosis is a zoonotic disease with symptoms in humans and animals, ranging from subclinical to serious and fatal. The disease occurs worldwide, but there is limited recognition of the public and animal health risks it poses in the southern United States. A systematic review of the frequency of animal leptospirosis in 17 states and jurisdictions covering the southern continental United States was performed to advance our understanding of the pathogen's distribution and identify transmission patterns that could be targeted for prevention efforts. Fifty-two articles, spanning >100 years, met the analysis criteria. A wide range of techniques were used to measure seroprevalence and isolate the bacteria. The assessment identified exposure to Leptospira spp and Leptospira spp infection among a diverse range of species, spanning 22 animal families within 14 states, suggesting that the pathogen is distributed throughout the southern region. Disease frequency trends were assessed among animals in various habitats (all habitats, nonwild habitats, and wild habitats). The frequency of Leptospira spp detection in animals in wild habitats increased slightly over time (<0.2%/year). We identified reports of 11 human leptospirosis illness clusters and outbreaks in the southern United States. Exposure to potentially contaminated surface waters were documented for at least seven of the events, and interactions with infected or likely infected animals were documented for at least six of the events. This analysis highlights the need for stronger partnerships across the public and animal health fields to enhance diagnostics, surveillance, and reporting. The early identification of leptospirosis in animals may serve as an indicator of environmental contamination and trigger prevention measures, such as vaccinating companion animals and livestock, use of potable water, and the wearing of waterproof protective clothing near water that may be contaminated.

Integration of environmental stewardship and local economic development to enhance community health.

Environmental groups working to preserve natural ecosystems and groups working to enhance local economic development often find themselves on philosophically opposite sides of the negotiation table. Case histories of cooperative engagement are provided that serve as examples of how environmental stewardship is compatible with local economic development and community health.

Correlation of mannitol fermentation with virulence-associated genotypic characteristics in Vibrio vulnificus isolates from oysters and water samples in the Gulf of Mexico.

Vibrio vulnificus strains (n = 469) isolated from the Gulf of Mexico oysters and waters over a period of 2 years were subjected to phenotypic and genotypic characterizations. Of the strains that could be definitively genotyped (n = 465), 58% were classified as genotype A, 29% as genotype B, and 13% as genotype A/B by 16S rRNA genotyping. When the same strain bank was characterized by virulence-correlated gene (vcg) typing, 65% were genotype E while 35% were genotype C. Further analysis focusing on strains falling into typical genotype categories (i.e., 16S rRNA types A or B, excluding type A/B strains) showed a high degree of concordance (93%) when comparing the two genotyping methods. d-Mannitol fermentation was also predictive of genotype, with an 86% agreement between 16S rRNA genotype and mannitol fermentation patterns, and an 85% agreement between vcg genotype and mannitol fermentation patterns. d-Mannitol fermentation should be considered as a simple and less expensive alternative to screen V. vulnificus isolates for virulence potential, particularly when analyzing large strain banks.

Effects of opioids and anesthetic drugs on body temperature in cats.

OBJECTIVE: To determine which class of opioid alone or in conjunction with other anesthetic drugs causes post-anesthetic hyperthermia in cats. STUDY DESIGN: Prospective, randomized, crossover study. ANIMALS: Eight adult, healthy, cats (four spayed females and four castrated males weighing 3.8 +/- 0.6 kg). METHODS: Each cat was instrumented with a wireless thermistor in the abdominal cavity. Temperature in all phases was recorded every 5 minutes for 5 hours. Population body temperature (PBT) was recorded for approximately 8 days. Baseline body temperature is the final 24 hours of the PBT. All injectable drugs were given intramuscularly. The cats were administered drugs in four phases: 1) hydromorphone (H) 0.05, 0.1, or 0.2 mg kg(-1); 2) morphine (M) (0.5 mg kg(-1)), buprenorphine (BUP) (0.02 mg kg(-1)), or butorphanol (BUT) (0.2 mg kg(-1)); 3) ketamine (K) (5 mg kg(-1)) or ketamine (5 mg kg(-1)) plus hydromorphone (0.1 mg kg(-1)) (KH); 4) isoflurane in oxygen for 1 hour. Fifteen minutes prior to inhalant anesthetic, cats received either no premed (I), hydromorphone (0.1 mg kg(-1)) (IH), or hydromorphone (0.1 mg kg(-1)) plus ketamine (5 mg kg(-1)) (IHK). RESULTS: Mean PBT for all unmedicated cats was 38.9 +/- 0.6 degrees C (102.0 +/- 1 degrees F). The temperature of cats administered all doses of hydromorphone increased from baseline (p < 0.03) All four opioids (H, M, BUP and BUT) studied increased body temperature compared with baseline (p < 0.005). A significant difference was observed between baseline temperature values and those in treatment KH (p < 0.03). Following recovery from anesthesia, temperature in treatments IH and IHK was different from baseline (p < 0.002). CONCLUSIONS AND CLINICAL RELEVANCE: All of the opioids tested, alone or in combination with ketamine or isoflurane, caused an increase in body temperature. The increase seen was mild to moderate (<40.1 degrees C (104.2 degrees F) and self limiting.

Lack of influence by endosymbiont Wolbachia on virus titer in the common bed bug, Cimex lectularius.

BACKGROUND: The common bed bug, Cimex lectularius, is an obligatory blood-feeding ectoparasite that requires a blood meal to molt and produce eggs. Their frequent biting to obtain blood meals and intimate association with humans increase the potential for disease transmission. However, despite more than 100 years of inquiry into bed bugs as potential disease vectors, they still have not been conclusively linked to any pathogen or disease. This ecological niche is extraordinarily rare, given that nearly every other blood-feeding arthropod is associated with some type of human or zoonotic disease. Bed bugs rely on the bacteria Wolbachia as an obligate endosymbiont to biosynthesize B vitamins, since they acquire a nutritionally deficient diet, but it is unknown if Wolbachia confers additional benefits to its bed bug host. In some insects, Wolbachia induces resistance to viruses such as Dengue, Chikungunya, West Nile, Drosophila C and Zika, and primes the insect immune system in other blood-feeding insects. Wolbachia might have evolved a similar role in its mutualistic association with the bed bug. In this study, we evaluated the influence of Wolbachia on virus replication within C. lectularius. METHODS: We used feline calicivirus as a model pathogen. We fed 40 bed bugs from an established line of Wolbachia-cured and a line of Wolbachia-positive C. lectularius a virus-laden blood meal, and quantified the amount of virus over five time intervals post-feeding. The antibiotic rifampicin was used to cure bed bugs of Wolbachia. RESULTS: There was a significant effect of time post-feeding, as the amount of virus declined by ~90% over 10 days in both groups, but no significant difference in virus titer was observed between the Wolbachia-positive and Wolbachia-cured groups. CONCLUSIONS: These findings suggest that other mechanisms are involved in virus suppression within bed bugs, independent of the influence of Wolbachia, and our conclusions underscore the need for future research.

A Comparison of the chemical sensitivities between in vitro and in vivo propagated juvenile freshwater mussels: Implications for standard toxicity testing.

Unionid mussels are ecologically important and are globally imperiled. Toxicants contribute to mussel declines, and toxicity tests using juvenile mussels-a sensitive life stage-are valuable in determining thresholds used to set water quality criteria. In vitro culture methods provide an efficient way to propagate juveniles for toxicity testing, but their relative chemical sensitivity compared with in vivo propagated juveniles is unknown. Current testing guidelines caution against using in vitro cultured juveniles until this sensitivity is described. Our objective was to evaluate the relative sensitivity of juvenile mussels produced from both in vitro and in vivo propagation methods to selected chemicals. We conducted 96-h acute toxicity tests according to ASTM International guidelines with 3 mussel species and 6 toxicants: chloride, nickel, ammonia, and 3 copper-based compounds. Statistically significant differences between in vitro and in vivo juvenile 96-h median effect concentrations were observed in 8 of 17 tests, and in vitro juveniles were more sensitive in 6 of the 8 significant differences. At 96 h, 4 of the 8 statistically different tests for a given chemical were within a factor of 2, which is the intralaboratory variation demonstrated in a recent evaluation of mussel toxicity tests. We found that although differences in chemical sensitivity exist between in vitro and in vivo propagated juvenile mussels, they are within normal toxicity test variation. Therefore, in vitro propagated juvenile mussels may be appropriate for use in ASTM International-based toxicity testing. Environ Toxicol Chem 2018;37:3077-3085. © 2018 SETAC.

Seminal and endocrine characteristics of male Pallas' Cats (Otocolobus manul) maintained under artificial lighting with simulated natural photoperiods.

Pallas' cats (Otocolobus manul) have a pronounced reproductive seasonality controlled by photoperiod. Previous studies of reproduction in captive Pallas' cats exposed to natural light showed a breeding season of December-April. This study evaluated the impact of artificial lighting timed to simulate natural photoperiods on male reproductive seasonality of four Pallas' cats housed indoors. Semen evaluation, blood collection, and body weight measurements were conducted every 1-2 months from November 2000-June 2001. Fecal samples were collected from each male twice weekly to assess testosterone and corticoid concentrations. Mean values for reproductive traits (sperm attributes, testicular volume) were highest from February-April, the defined breeding season. Fecal testosterone concentrations were highest from mid-January to mid-March. Male Pallas' cats managed indoors under simulated photoperiods experienced a delayed onset of the breeding season by 1-2 months and a decreased length of the breeding season. Over the course of the study, fecal corticoid concentrations did not seem to differ among seasons. Although mating attempts during this study were unsuccessful, subsequent pairings of male and female Pallas' cats in the same research colony during the 2002 and 2003 breeding seasons produced viable offspring. These results suggest that male Pallas' cats, housed indoors under simulated photoperiods, exhibit distinct reproductive cyclic patterns, characterized by a delayed and truncated breeding season. Adrenocortical activity varied among individuals, but did not adversely affect reproductive parameters. Housing Pallas' cats indoors under simulated photoperiods may represent a viable strategy for maintaining breeding success while limiting disease exposure. Zoo Biol 0:1-13, 2007. (c) 2007 Wiley-Liss, Inc.

The dog as a sentinel for human infection: prevalence of Borrelia burgdorferi C6 antibodies in dogs from southeastern and mid-Atlantic States.

Lyme disease is the most frequently reported human vector-associated disease in the United States. Infection occurs after the bite of an Ixodid tick that is infected with Borrelia burgdorferi. Dogs have often been reported to serve as effective sentinel animals to assess the risk of human B. burgdorferi infection. Based on published data of human Lyme disease case numbers and our clinical impressions, we hypothesized that canine exposure to B. burgdorferi would be lower in North Carolina when compared to the exposure in Virginia, Maryland, and Pennsylvania. To address this hypothesis, we evaluated B. burgdorferi exposure status utilizing a specific and sensitive C6 peptide-based enzyme-linked immunosorbent assay. Our convenience sample included 1,666 canine serum samples submitted to the Vector-Borne Disease Diagnostic Laboratory from North Carolina (n = 987), Virginia (n = 472), Maryland (n = 167), and Pennsylvania (n = 40). Comparisons among states were made using the Chisquare test or the Fisher's exact test; p-values were adjusted for multiple comparisons using the Bonferroni correction. A Chi-square test for trend was used to determine if there was an increase in the frequency of seroreactors associated with the geographical origin of the samples. The proportion of seroreactive dogs in North Carolina was markedly lower (p < 0.008) than that observed in dogs from Virginia, Maryland, and Pennsylvania. These results support the hypothesis that B. burgdorferi transmission seems to occur infrequently in North Carolina dogs as compared to dogs residing in other southeastern and mid-Atlantic states. Furthermore, they support the utility of dogs as a sentinel to characterize the risk of B. burgdorferi transmission to humans in a defined geographical location.

Evaluation of a nonlethal technique for hemolymph collection in Elliptio complanata, a freshwater bivalve (Mollusca: Unionidae).

Hemolymph, the circulatory fluid of bivalves, transports nutrients, respiratory gases, enzymes, metabolic wastes, and toxicants throughout the body. Hemolymph can provide information pertinent to health assessment of animals or populations, but is not commonly used in freshwater bivalves partly because of the lack of tested, practical techniques for its nonlethal collection. The objective of this study was to evaluate the effect of hemolymph collection on the growth and survival of Elliptio complanata, a freshwater bivalve (Unionidae). We describe a simple technique for the collection of hemolymph from the anterior adductor muscle sinus of E. complanata. To evaluate the effect of hemolymph sampling on mussel survival and growth, 30 mussels sampled using the technique and 30 unsampled controls were followed for 3 mo post collection. Nine animals were sampled 3 times over 7 mo to monitor effects of repeated sampling. No negative impacts on survival or growth were observed in either the singly or repeatedly sampled animals. We also compared the composition of hemolymph collected from the adductor muscle sinus with that collected from the ventricle of the heart. Calcium levels and cell count of hemolymph obtained from the adductor sinus and ventricle were significantly different. There was no significant difference between collection sites for magnesium, phosphorus, ammonia, protein, sodium, potassium, or chloride. We conclude that collection of hemolymph from the adductor sinus is safe for sampled E. complanata and should be explored as a relatively non-invasive, and potentially useful, approach to the evaluation of freshwater mussel health.

Reference ranges for hemolymph chemistries from Elliptio complanata of North Carolina.

Hemolymph chemistries may be useful nonlethal measures of bivalve health. The prognostic value of hemolymph, however, depends on a comparison of chemistry results to reference ranges from healthy individuals. Currently, knowledge of expected hemolymph values in healthy and unhealthy freshwater mussels is extremely limited. The purpose of this study was to develop a set of reference ranges for clinical evaluation of hemolymph from a freshwater mussel species common to southeastern USA. We collected hemolymph from 380 Elliptio complanata from 19 apparently healthy populations from northwest of Raleigh, North Carolina, during May through July 2001. We present reference ranges for hemolymph parameters ammonia, glucose, calcium, magnesium, phosphorus, aspartate aminotransferase (AST), bicarbonate, protein and cell count, and for tissue glycogen. We compare the subpopulations of mussels from regions with an agricultural riparian buffer to those surrounded predominantly by forested lands. We further present correlations noted between hemolymph chemistries and physical or physiologic parameters. The only statistically significant differences between populations contiguous to agricultural and forested lands were in hemolymph calcium and glucose concentrations. Other statistically significant correlations identified were between gravidity and hemolymph protein concentration and tissue glycogen content, as well as between gravidity and parasite burden, and between shell length and hemolymph glucose, AST, calcium and bicarbonate concentrations. The results of this study will aid the interpretation of health measures from populations of E. complanata of similar geographic and seasonal origin.

Renal biopsy: a retrospective study of methods and complications in 283 dogs and 65 cats.

Renal biopsy often is required to establish a definitive diagnosis in dogs and cats with renal disease. In this retrospective study, we determined the complications of renal biopsy as well as factors that may be associated with development of complications and procurement of adequate renal biopsy specimens in 283 dogs and 65 cats. Data extracted from medical records at 4 institutions were evaluated using logistic regression. Proteinuria was the most common indication for renal biopsy in dogs. Complications were reported in 13.4 and 18.5% of dogs and cats, respectively. The most common complication was severe hemorrhage; hydronephrosis and death were uncommon. Dogs that developed complications after renal biopsy were more likely to have been 4 to < 7 years of age and > 9 years, to weigh < or = 5 kg, and to have serum creatinine concentrations > 5 mg/dL. The majority of biopsies from both dogs (87.6%) and cats (86.2%) were considered to be of satisfactory quality. Biopsies from dogs were more likely to be of high quality if they were obtained when the patient was under general anesthesia and more likely to contain only renal cortex if they were obtained by surgery. We concluded that renal biopsy is a relatively safe procedure, with a low frequency of severe complications. Hospital practices and patient variables have the potential to impact both the quality of the specimen obtained and the rate of complications.

Key metabolites in tissue extracts of Elliptio complanata identified using (1)H nuclear magnetic resonance spectroscopy.

We used (1)H nuclear magnetic resonance spectroscopy to describe key metabolites of the polar metabolome of the freshwater mussel, Elliptio complanata. Principal components analysis documented variability across tissue types and river of origin in mussels collected from two rivers in North Carolina (USA). Muscle, digestive gland, mantle and gill tissues yielded identifiable but overlapping metabolic profiles. Variation in digestive gland metabolic profiles between the two mussel collection sites was characterized by differences in mono- and disaccharides. Variation in mantle tissue metabolomes appeared to be associated with sex. Nuclear magnetic resonance spectroscopy is a sensitive means to detect metabolites in the tissues of E. complanata and holds promise as a tool for the investigation of freshwater mussel health and physiology.

The dog as a sentinel for human infection: prevalence of Borrelia burgdorferi C6 antibodies in dogs from southeastern and mid-Atlantic states.

Lyme disease is the most frequently reported human vector-associated disease in the United States. Infection occurs after the bite of an Ixodid tick that is infected with Borrelia burgdorferi. Dogs have often been reported to serve as effective sentinel animals to assess the risk of human B. burgdorferi infection. Based on published data of human Lyme disease case numbers and our clinical impressions, we hypothesized that canine exposure to B. burgdorferi would be lower in North Carolina when compared to the exposure in Virginia, Maryland, and Pennsylvania. To address this hypothesis, we evaluated B. burgdorferi exposure status utilizing a specific and sensitive C6 peptide-based enzyme-linked immunosorbent assay. Our convenience sample included 1,666 canine serum samples submitted to the Vector Borne Disease Diagnostic Laboratory from North Carolina (n = 987), Virginia (n = 472), Maryland (n = 167), and Pennsylvania (n = 40). Comparisons among states were made using the Chi-square test or the Fisher's exact test; p-values were adjusted for multiple comparisons using the Bonferroni correction. A Chi-square test for trend was used to determine if there was an increase in the frequency of seroreactors associated with the geographical origin of the samples. The proportion of seroreactive dogs in North Carolina was markedly lower (p < 0.008) than that observed in dogs from Virginia, Maryland, and Pennsylvania. These results support the hypothesis that B. burgdorferi transmission seems to occur infrequently in North Carolina dogs as compared to dogs residing in other southeastern and mid-Atlantic states. Furthermore, they support the utility of dogs as a sentinel to characterize the risk of B. burgdorferi transmission to humans in a defined geographical location.

Persistent urinary tract infections and reinfections in 100 dogs (1989-1999).

A retrospective study was performed of 100 dogs with persistent urinary tract infections (UTIs) or reinfections presenting to the North Carolina State University (Raleigh, NC) Veterinary Teaching Hospital between 1989 and 1999. Criteria for selection included > or = 2 positive urine cultures within a 6-month period. Signalment, presence of predisposing disorders, urinalysis and urine culture results, and treatment strategies were extracted from the medical records. Dogs were a median age of 7 years when the UTI was 1st diagnosed. Dogs younger than 3 and older than 10 years were at increased and decreased risks, respectively, for reinfections or persistent UTIs. Spayed females were more common in the UTI population. More than half of the dogs were asymptomatic for a UTI at 1st presentation. Urine sediment examinations identified hematuria, pyuria, and bacteriuria in 47, 72, and 85% of the samples, respectively. The most commonly isolated organisms were Escherichia coli and Streptococcus/Enterococcus spp.; multiple isolates also were common. Of the isolates, 29.5% were resistant to achievable serum concentrations of all antibiotics commonly prescribed for PO administration. Dogs with abnormal micturition were more likely to have infections by organisms resistant to commonly prescribed antibiotics. Potentially predisposing disorders were identified in 71 dogs. A correction of these disorders was accomplished in 35% of these 71 dogs. Dogs given standard antibiotic therapy without addressing predisposing disorders experienced poor control of their UTIs; 74.5% of these dogs had an apparent disease-free interval (ADFI) of < 8 weeks. By comparison, dogs in which predisposing disorders were corrected or those that were treated with low-dose, long-term antibiotic regimens subjectively had better control.

Pharmacokinetics and pharmacodynamics of furosemide after oral administration to horses.

Furosemide is the most common diuretic drug used in horses. Furosemide is routinely administered as IV or IM bolus doses 3-4 times a day. Administration PO is often suggested as an alternative, even though documentation of absorption and efficacy in horses is lacking. This study was carried out in a randomized, crossover design and compared 8-hour urine volume among control horses that received placebo, horses that received furosemide at 1 mg/kg PO, and horses that received furosemide at 1 mg/kg IV. Blood samples for analysis of plasma furosemide concentrations, PCV, and total solids were obtained at specific time points from treated horses. Furosemide concentrations were determined by reversed-phase high-performance liquid chromatography with fluorescent detection. Systemic availability of furosemide PO was poor, erratic, and variable among horses. Median systemic bioavailability was 5.4% (25th percentile, 75th percentile: 3.5, 9.6). Horses that received furosemide IV produced 7.4 L (7.1, 7.7) of urine over the 8-hour period. The maximum plasma concentration of 0.03 microg/mL after administration PO was not sufficient to increase urine volume compared with control horses (1.2 L [1.0, 1.4] PO versus 1.2 L [1.0, 1.4] control). There was a mild decrease in urine specific gravity within 1-2 hours after administration of furosemide PO, and urine specific gravity was significantly lower in horses treated with furosemide PO compared with control horses at the 2-hour time point. Systemic availability of furosemide PO was poor and variable. Furosemide at 1 mg/kg PO did not induce diuresis in horses.

Hypomagnesemia in hospitalized horses.

This study was initiated to identify the signalment and clinical variables potentially associated with hypomagnesemia in horses evaluated at the North Carolina State University, College of Veterinary Medicine (NCSU-CVM) veterinary teaching hospital between January 1999 and May 2001. A nested case reference study (nested case-control study) was conducted to examine the potential relationship between hypomagnesemia and signalment, serum chemistry panel analyses, number of hospitalization days, discharge status, and diagnosis. A series of independent and multivariable logistic regression models were used to assess the potential association of each variable with low total serum magnesium concentrations. Four hundred one of 823 (48.7%) horses had serum total magnesium concentrations below the normal reference range. Hypomagnesemia was more likely to occur in horses older than I month of age. Colic (odds ratio [OR]: 2.96, 95% confidence intervals [CI]: 2.14-4.08), acute diarrhea (OR: 5.91, 95% CI: 2.32-15.06), other gastrointestinal disease (OR: 2.07, 95% CI: 1.15-3.71), infectious respiratory disease (OR: 5.07, 95% CI: 2.09-12.28), and multiorgan system disease (OR: 2.31, 95% CI: 1.24-4.28) were associated with hypomagnesemia in adult horses, whereas foals with diarrhea (excluding septic foals) (OR: 0.11, 95% CI: 0.01-0.84) were less likely to have hypomagnesemia. Overall, there was no relationship between hypomagnesemia and mortality (OR: 1.00, 95% CI: 0.72-1.41), but horses with colic and hypomagnesemia were less likely to die than horses with colic and normal or high total magnesium (OR: 0.53, 95% CI: 0.30-0.95). Among horses that survived, hypomagnesemia at admission was associated with a longer hospitalization period (OR: 1.45, 95% CI: 1.00-2.11).

Furosemide continuous rate infusion in the horse: evaluation of enhanced efficacy and reduced side effects.

Continuous rate infusion (CRI) of furosemide in humans is considered superior to intermittent administration (IA). This study examined whether furosemide CRI, compared with IA, would increase diuretic efficacy with decreased fluid and electrolyte fluctuations and activation of the renin-angiotensin-aldosterone system (RAAS) in the horse. Five mares were used in a crossover-design study. During a 24-hour period, each horse received a total of 3 mg/kg furosemide by either CRI (0.12 mg/kg/h preceded by a loading dose of 0.12 mg/kg IV) or IA (1 mg/kg IV q8h). There was not a statistically significant difference in urine volume over 24 hours between methods; however, urine volume was significantly greater after CRI compared with IA during the first 8 hours ([median 25th percentile, 75th percentile]: 9.6 L [8.9, 14.4] for CRI versus 5.9 L [5.3, 6.0] for IA). CRI produced a more uniform urine flow, decreased fluctuations in plasma volume, and suppressed renal concentrating ability throughout the infusion period. Potassium, Ca, and Cl excretion was greater during CRI than IA (1,133 mmol [1.110, 1,229] versus 764 mmol [709, 904], 102.7 mmol [96.0, 117.2] versus 73.3 mmol [65.0, 73.5], and 1,776 mmol [1,657, 2.378] versus 1,596 mmol [1,457, 1,767], respectively). Elimination half-lives of furosemide were 1.35 and 0.47 hours for CRI and IA, respectively. The area under the excretion rate curve was 1,285.7 and 184.2 mL x mg/mL for CRI and IA, respectively. Furosemide CRI (0.12 mg/kg/h) for 8 hours, preceded by a loading dose (0.12 mg/kg), is recommended when profound diuresis is needed acutely in horses.

Evaluation of T lymphocytes in captive african lions (Panthera leo) infected with feline immunodeficiency virus.

OBJECTIVE: To determine whether FIV infection in captive African lions is associated with changes in immune cell variables similar to those detected in domestic cats infected with FIV. ANIMALS: 5 captive African lions naturally infected with FIV (FIV+) and 5 lions not infected with FIV (FIV-). PROCEDURE: Peripheral blood samples were collected from FIV+ lions during annual examinations conducted during a 7-year period and at a single time point from the FIV- lions. From results of CBC and flow cytometry, lymphocyte subsets were characterized and compared. RESULTS: Flow cytometric analysis revealed that the percentage and absolute number of CD4+ and CD8+ T cells were significantly lower in FIV+ lions, compared with these values in FIV- lions. In FIV+ lions, severe depletion in the absolute number of CD4+ and CD8+ T cells was detected, although this did not correlate with clinical signs. Muscle wasting was the most consistent clinical sign of infection. CONCLUSIONS AND CLINICAL RELEVANCE: Results suggest that FIV+ African lions develop lymphocyte deficiencies, including significant decreases in the absolute number of CD4+ and CD8+ T cells; these findings of immune dysfunction are similar to those defined for FIV+ domestic cats. It is important to monitor the number of CD4+ T cells in infected animals as a measure of disease progression.

Reproductive capacity of free-roaming domestic cats and kitten survival rate.

OBJECTIVE: To determine reproductive capacity of naturally breeding free-roaming domestic cats and kitten survival rate. DESIGN: Prospective cohort and retrospective cross-sectional study. ANIMALS: 2,332 female cats brought to a trap-neuter-return clinic for neutering and 71 female cats and 171 kittens comprising 50 litters from a cohort study of feral cats in managed colonies. PROCEDURE: Data collected for all cats included pregnancy, lactation, and estrus status and number of fetuses for pregnant cats. Additional data collected for feral cats in managed colonies included numbers of litters per year and kittens per litter, date of birth, kitten survival rate, and causes of death. RESULTS: Pregnant cats were observed in all months of the year, but the percentage of cats found to be pregnant was highest in March, April, and May. Cats produced a mean of 1.4 litters/y, with a median of 3 kittens/litter (range, 1 to 6). Overall, 127 of 169 (75%) kittens died or disappeared before 6 months of age. Trauma was the most common cause of death. CONCLUSIONS AND CLINICAL RELEVANCE: Results illustrate the high reproductive capacity of free-roaming domestic cats. Realistic estimates of the reproductive capacity of female cats may be useful in assessing the effectiveness of population control strategies.