Mortality In Guinea Pigs Research Articles

Demography, commonly diagnosed disorders and mortality of guinea pigs under primary veterinary care in the UK in 2019-A VetCompass study.

Guinea pigs are popular as domestic pets but there is limited information on the health of the wider pet population. This study aimed to report demography, commonly diagnosed disorders and mortality of guinea pigs under UK primary veterinary care. Diagnosis and mortality information on guinea pigs was extracted from anonymised UK primary-care clinical records in VetCompass. From 51,622 guinea pigs under primary veterinary care during 2019, a specific breed was not recorded in 50,098 (97.05%). Of guinea pigs with information recorded, 23,206 (47.33%) were female and 25,828 (52.67%) were male. There were 1,020 (2.08%) neutered and 48,014 (97.92%) entire. Median adult bodyweight overall was 1.05kg (interquartile range [IQR] 0.90-1.19, range 0.40-2.66). From a random sample of 3,785/51,622 (7.33%) guinea pigs, the most prevalent disorders were overgrown nail(s) (n = 1,005, 26.55%, 95% confidence interval [CI] 25.15-27.99), dermatophytosis (228, 6.02%, 95% CI 5.29-6.83) and corneal ulceration (189, 4.99%, 95% CI 4.32-5.74). Among the 30 most common disorders, females showed predisposition for 3 disorders and males showed predisposition for 5 disorders. The disorder with the youngest age of affected animals was dermatophytosis (1.11 years) while weight loss had the oldest age of affected animals (4.64 years). From 757 recorded deaths, the median age at death overall was 4.03 years (IQR 2.56-5.44, range 0.17-10.00). Among deaths with a recorded cause, the most common causes of death were anorexia (n = 82, 13.87%, 95% CI 11.19-16.93), collapsed (58, 9.81%, 95% CI 7.54-12.50) and peri-anaesthetic death (20, 3.38%, 95% CI 2.08-5.18). These results can assist veterinarians and owners by providing demographic, disorder and mortality benchmarks that support improved clinical care and welfare outcomes in guinea pigs. Many common disorders in guinea pigs were husbandry related.

The moon cycle influences reproductive and productive traits in guinea pigs (Cavia porcellus) from a tropical Andean area

ABSTRACT There is currently innumerable evidence showing that the lunar cycle affects various reproductive aspects in farm animals. However, there is very little information on the effect of the lunar cycle on productive traits in these species. A retrospective study was conducted (2015–2018) to evaluate the influence of the lunar cycle on some reproductive and productive traits in a guinea pig (Cavia porcellus) production system in the southern Andean region of Ecuador. A total of 7352 productive and reproductive records of guinea pig females housed in 3 m2 cages with a breeding male were analyzed. The following variables were considered: offspring sex ratio, litter size per cage, number of weaned guinea pigs, mortality, individual and litter weaning weight of guinea pigs, and calving frequency. The lunar cycle was split into eight periods of ~3.7-d length each. Data were analyzed by logistic regression and general linear model, and means were compared by the least mean squares method of the SAS. The offspring sex ratio was not correlated to the lunar cycle. The lunar cycle at mating and calving influenced the litter size per cage, number of weaned, and mortality of guinea pigs. The individual and litter-weaning weights were influenced by the lunar cycle at calving. The frequency of calving was greater around the new and full moon than in the remaining periods of the lunar cycle. In conclusion, the lunar cycle influenced several productive and reproductive traits in guinea pigs, such as litter size, mortality, number of pups weaned, and individual and litter weaning weights. This valuable information may have practical applications in management of guinea pig production systems.

Cytomorphological characterization of lymphadenopathies in guinea pigs: study of 31 clinical cases

ABSTRACT Lymphadenopathy is a commonly found condition in guinea pigs that suffer diseases caused by bacterial organisms as Streptococcus zooepidemicus, Yersinia pseudotuberculosis, Bordetella, and Salmonellae (S. linate) which access cervical lymph nodes via an abraded oral mucosa. In this study, we investigate all possible alterations present in cytological smears obtained from cervical lymph nodes of guinea pigs with lymphadenopathy. Thirty-one clinical cases of guinea pigs with different grades of lymphadenomegaly and 10 clinically healthy guinea pigs were considered. The fine-needle nonaspiration cytology (FNNAC) provided an adequate quantity and quality of samples for cytological analysis. Air-dried FNNAC smears yielded excellent results with Wright stain. From 31 evaluated clinical cases, 64.5% were compatible with pseudoeosinophilic lymphadenitis, 22.6% compatible with reactive lymphatic node, 6.45% compatible with lymphoma, and 6.45% with Hodgkin's-like lymphoma. The findings revealed the usefulness of the FNNAC technique and Romanowsky stains as fast and easy methods for lymph node sampling and analysis, and also, the importance of recognizing various causes of lymphadenopathies associated with morbidity and mortality in guinea pigs which would influence treatment protocols and prognosis for patients.

Iron accelerates hemoglobin oxidation increasing mortality in vascular diseased guinea pigs following transfusion of stored blood.

Non-transferrin-bound iron (NTBI) and free hemoglobin (Hb) accumulate in circulation following stored RBC transfusions. This study investigated transfusion, vascular disease, and mortality in guinea pigs after stored RBC transfusion alone and following cotransfusion with apo-transferrin (apo-Tf) and haptoglobin (Hp). The effects of RBC exchange transfusion dose (1, 3, and 9 units), storage period (14 days), and mortality were evaluated in guinea pigs with a vascular disease phenotype. Seven-day mortality and the interaction between iron and Hb as cocontributors to adverse outcome were studied. Concentrations of iron and free Hb were greatest after transfusion with 9 units of stored RBCs compared with fresh RBCs or stored RBCs at 1- and 3-unit volumes. Nine units of stored RBCs led to mortality in vascular diseased animals, but not normal animals. One and 3 units of stored RBCs did not cause a mortality effect, suggesting the concomitant relevance of NTBI and Hb on outcome. Cotransfusion with apo-Tf or Hp restored survival to 100% following 9-unit RBC transfusions in vascular diseased animals. Our data suggest that increases in plasma NTBI and Hb contribute to vascular disease-associated mortality through iron-enhanced Hb oxidation and enhanced tissue injury.

Effect of Ribavirin on Junin Virus Infection in Guinea Pigs

Junin virus (JUNV) is the aetiological agent of Argentine haemorrhagic fever. The pathogenesis of the infection is not well understood, no licensed vaccines exist and no specific antiviral therapy is available. Previous studies have demonstrated the ability of ribavirin to delay and reduce JUNV disease and virus burden in guinea pigs without preventing death. Based on available data, we performed three different studies to determine the efficacy of ribavirin against JUNV in the guinea pig model with a focus on survival. Different doses and treatment schedules of ribavirin were tested in a lethal model of JUNV infection. Our results show that prolonged treatment with high doses of ribavirin significantly reduces the mortality in guinea pigs infected with JUNV. These results may be useful in future experimental studies or clinical testing.

SIMVASTATIN REDUCES ENDOTOXIN-INDUCED NUCLEAR FACTOR κB ACTIVATION AND MORTALITY IN GUINEA PIGS DESPITE LOWERING CIRCULATING LOW-DENSITY LIPOPROTEIN CHOLESTEROL

Statins, which are effective lipid-lowering drugs, also possess anti-inflammatory potential. However, circulating lipoproteins may also play a protective role during acute inflammatory diseases because of their ability to bind bacterial toxins. Low cholesterol levels have been reported in inflammatory conditions, and plasma cholesterol concentrations inversely correlate with severity and clinical outcome in septic patients. It is thus paradoxical that statins, which drastically reduce circulating cholesterol levels, should be beneficial in patients with inflammatory disease who are already hypocholesterolemic. We investigated the effect of simvastatin on LPS-induced nuclear factor kappaB (NF-kappaB) activation, TNF release, and mortality in guinea pigs, an animal model with a lipoprotein profile and pattern similar to humans. In the present study, simvastatin reduced circulating total and low-density lipoprotein cholesterol levels by 68% and 76%, respectively, and LPS-induced mortality from 73% to 20%. This reduction was accompanied by a significant reduction of NF-kappaB activation in the liver tissue, splenocytes, and plasma TNF levels by about 80%, 50%, and 77%, respectively. Our data suggest that simvastatin, despite lowering circulating low-density lipoprotein cholesterol, decreased LPS toxicity by reduction of NF-kappaB activation and subsequent release of TNF by modulating 3-hydroxy-3-methylglutaryl coenzyme A reductase activity and therefore deserves consideration as a possible adjuvant therapy in acute inflammatory disease.

Antiasthmatic property of polyherbal preparation E-721 B.

E-721B and its aqueous extract were studied for its antiasthmatic effect in various experimental models using rats and guinea pigs. E-721B produced significant and dose-dependent inhibition of peritoneal mast-cell degranulation induced by compound 48/80 and egg-albumin in sensitised rats. The inhibition was comparable to that with disodium cromoglycate, ketotifen, and prednisolone. E-721B administered 2 h before the experiment and once daily for seven days significantly increased the preconvulsion time of acetylcholine and histamine aerosol-induced bronchospasm. It also significantly reduced mortality in guineapigs produced by egg albumin-induced anaphylactic shock and also reduced bronchoalveolar fluid eosinophil count in the same animals. E-721B significantly inhibited the acetylcholine and histamine-induced contraction of different isolated smooth muscle preparations from rats and guinea pigs. Contrary to these findings E-721B produced dose-dependent contraction of the rat anococcygeus muscle which was blocked by prazosin. Thus our observations establish the antiasthmatic potential of this herbal formulation.

Protective role for neuropeptides in acute pulmonary response to acrolein in guinea pigs.

To determine the potential role of neuropeptides in acrolein-induced airway responses, capsaicin-treated guinea pigs were exposed to acrolein aerosol in a regimen causing increased airway sensitivity to substance P. Acrolein exposure resulted in 100% mortality after capsaicin pretreatment compared with only 14% mortality in guinea pigs not pretreated with capsaicin. Acrolein exposure by itself caused marked pulmonary inflammation and large airway epithelial necrosis and denudation. Pretreatment with capsaicin exacerbated these responses throughout the lung. Intravenous acrolein caused an acute dose-related bronchoconstriction in naive guinea pigs that was diminished by capsaicin treatment and potentiated by thiorphan pretreatment, which suggests that arolein exposure causes an acute release of capsaicin-sensitive C-fiber neuropeptides. To determine whether acrolein-induced C-fiber release altered neuronal viability, either rhodamine or Fast Blue dye was instilled intratracheally into vehicle- or acrolein-exposed guinea pigs. Acrolein exposure did not reduce the neuronal uptake or retrograde transport of these dyes, as indicated by the number of fluorescent cell bodies in the nodose ganglia. To determine the functional state of airway neurons, the dose response to intravenous capsaicin was measured in vehicle-exposed and acrolein-exposed guinea pigs; no differences were observed. Thus, acrolein appears to activate airway C-fibers, which release neuropeptides that are protective against this insult, with no suggestion of an accompanying reduction in C-fiber function.

ATTENUATION OF ANAPHYLACTIC SHOCK AND RELATED MORTALITY IN GUINEA-PIGS AFTER ADMINISTRATION OF A POTENT PROTEIN KINASE INHIBITOR, K252A

We examined whether protein kinases have a role in the expression of anaphylactic shock (AS). Guinea-pigs sensitized to ovalbumin were administered i.p. saline (control) or 10 micrograms/kg K252a, a potent protein kinase inhibitor, 30 min before challenge. The development of AS and mortality was observed for the next 2 h. In the K252a-treated group the incidence of AS fell to 53% from 100%, the maximum intensity was 62% less than the control, and mortality dropped to 16% from 50% of the animals. We suggest that protein kinases are involved in the expression of AS, and that inhibitors of these enzymes may protect against the symptoms of AS and allergy.

Biological Effects of Short-Term, High-Concentration Exposure to Methyl Isocyanate. I. Study Objectives and Inhalation Exposure Design

Early reports from India indicated that humans were dying within minutes to a few hours from exposure to methyl isocyanate (MIC). Attempts to explain the cause(s) of these rapid mortalities is where Union Carbide Corporation concentrated its post-Bhopal toxicologic investigations. The MIC studies involving rats and guinea pigs focused primarily on the consequences of acute pulmonary damage. All MIC inhalation exposures were acute, of short duration (mainly 15 min), and high in concentration (ranging from 25-3506 ppm). MIC vapors were statically generated in a double chamber exposure design. Precautionary measures taken during exposures are discussed. Guinea pigs were more susceptible than rats to MIC exposure-related early mortality. A greater than one order of magnitude difference was observed between an MIC concentration that caused no early mortality in rats (3506 ppm) and an MIC concentration that caused partial (6%) early mortality in guinea pigs (225 ppm) for exposures of 10 to 15 min duration. For both species, the most noteworthy clinical signs during exposure were lacrimation, blepharospasm, and mouth breathing. Fifteen minute LC50 tests with 14-day postexposure follow-up were conducted, and the LC50 (95% confidence limit) values were 171 (114-256) ppm for rats and 112 (61-204) ppm for guinea pigs. Target exposure concentrations for the toxicologic investigations of MIC-induced early mortality were established. A short summary of pertinent results of Union Carbide Corporation's post-Bhopal toxicologic investigations is presented.

Biological effects of short-term, high-concentration exposure to methyl isocyanate. I. Study objectives and inhalation exposure design.

Early reports from India indicated that humans were dying within minutes to a few hours from exposure to methyl isocyanate (MIC). Attempts to explain the cause(s) of these rapid mortalities is where Union Carbide Corporation concentrated its post-Bhopal toxicologic investigations. The MIC studies involving rats and guinea pigs focused primarily on the consequences of acute pulmonary damage. All MIC inhalation exposures were acute, of short duration (mainly 15 min), and high in concentration (ranging from 25-3506 ppm). MIC vapors were statically generated in a double chamber exposure design. Precautionary measures taken during exposures are discussed. Guinea pigs were more susceptible than rats to MIC exposure-related early mortality. A greater than one order of magnitude difference was observed between an MIC concentration that caused no early mortality in rats (3506 ppm) and an MIC concentration that caused partial (6%) early mortality in guinea pigs (225 ppm) for exposures of 10 to 15 min duration. For both species, the most noteworthy clinical signs during exposure were lacrimation, blepharospasm, and mouth breathing. Fifteen minute LC50 tests with 14-day postexposure follow-up were conducted, and the LC50 (95% confidence limit) values were 171 (114-256) ppm for rats and 112 (61-204) ppm for guinea pigs. Target exposure concentrations for the toxicologic investigations of MIC-induced early mortality were established. A short summary of pertinent results of Union Carbide Corporation's post-Bhopal toxicologic investigations is presented.

Generation, behavior, and toxicity of ammonium sulfite aerosols.

Ammonium sulfite aerosols were continuously generated for periods up to 6 h by gas phase reaction of sulfur dioxide, ammonia, and water vapor in nitrogen carrier gas. Concentrations from 1 to 500 mg/m3 were obtained. Aerosol leaving the generator was greater than 90% sulfite, but when diluted with air preparatory to animal exposures, the aerosol was rapidly oxidized. Sulfite concentrations in a large exposure chamber with a long residence time were consistently less than 25 percent of the aerosol mass. Sulfite concentrations in a nose-only or head-only inhalation chamber 1 ft downstream from a radial air injection system ranged from 10 to 80 percent sulfite. The latter system, with a short residence time, was used to expose animals to aerosols. Effects of the mixed sulf ite/sulfate aerosol on acute mortality of guinea pigs and tracheal mucous clearance of dogs were measured and no effects were observed.

Effect of detergent on protease-induced mortality and pulmonary histopathology.

Adddition of an anionic detergent to aerosols of Bacillus subtilis protease markedly increased mortality in guinea pigs following a single aerosol exposure and altered the nature of the lung pathology after exposure. It was observed that the detergent inhibited in vitro activity of serum protease inhibitors and it is suggested that such impairment may be, in part, responsible for the observed in vivo effects of detergent on protease-induced mortality and pulmonary pathology.

Fascioloides magna: Development in selected nonruminant mammalian hosts

Metacercariae of Fascioloides magna were inoculated per os into selected nonruminant animals to evaluate them as laboratory hosts for this trematode. Immature F. magna were recovered from 36 of 52 guinea pigs, 6 of 15 mice, 2 of 3 rabbits, and 16 of 25 domestic swine. The parasite was not recovered from two beavers ( Castor canadensis), two ferrets ( Mustela putorius), one red fox ( Vulpes fulva), one Shetland pony ( Equus caballus) and two Rhesus monkeys ( Macaca mulatta). Mortality in guinea pigs inoculated with 10 metacercariae each, occurred 56 to 116 (mean of 80) days after inoculation. Trematodes were in the liver up to 69 days after inoculation and usually free in the peritoneal cavity after 69 days after inoculation. Swine 2 weeks of age when inoculated were more susceptible to infection (5.6% trematode recovery rate) than were those inoculated at 4 weeks of age (1.9% trematode recovery rate) or 10 weeks of age (0.4% trematode recovery rate), indicating an age resistance to infection.

Effects on experimental animals of long-term continuous inhalation of nitrogen dioxide

One preliminary acute 8-hour study at a concentration of 123 mg/m 3 of nitrogen dioxide, and one 30-day repeated study at a level of 67 mg/m 3 were conducted. Both exposures produced marked lung irritation and high mortality in all species. The gross pathologic findings in the lungs of surviving animals indicated hemorrhagic pulmonary edema in the 123 mg/m 3 study, and vascular congestion and focal hemorrhage in the 67 mg/m 3 study. Five 90-day continuous studies were run at 0.9, 1.0, 9.2, 21.3, and 21.6 mg/m 3 of nitrogen dioxide. Except for a possible slight weight loss, there were no effects noted at 0.9 and 1.0 mg/m 3. At 9.2 mg/m 3 there was a significant increase of mortality in guinea pigs and rabbits, and at the 21.3 and 21.6 mg/m 3 levels there was a significant increase in mortality in all species except the dog. Minimal pathologic lung changes were seen at the highest concentrations. Cumulative 30−, 60−, and 90-day mortality data for the continuous exposure studies indicate that one cannot safely extrapolate from the 30-day results to anticipate the effects which may occur after 90 days. Care should also be taken in extrapolating continuous-exposure guidelines from data obtained in repeated-exposure studies. It is believed that the submarine guideline of 0.5 ppm (0.9 mg/m 3) will not cause any untoward effects in personnel exposed continuously for 60 days. The choice of analytical procedure is critical in measuring the concentration to which animals are exposed. Absorption of samples in 0.1 N NaOH is not satisfactory. Absorption directly into the nitriting reagent is the method of choice.

SYNERGISTIC ACTIVITY BETWEEN PR8 INFLUENZA VIRUS AND STAPHYLOCOCCUS AUREUS IN THE GUINEA PIG1

Abstract : The synergistic interaction of influenza virus (Type A, PR8 strain) and Staphylococcus aureus in guinea pigs was studied by aerosol exposures to mixtures of the organisms. The reaction of the host was a toxic death occurring within 48 hours. Quantitative studies of this phenomenon have shown that the concentration of virus ad ministered was critical. On the other hand, in activated or partially inactivated staphylococci, in combination with the virus, were capable of inducing high mortality in guinea pigs. No significant differences were observed between the multiplication of either organism and the corresponding single-agent controls. Evidence suggesting a possible mechanism of toxic action is discussed.

Pharmacological Studies on Irradiated Animals: V. The Effects of Postirradiation Administration of Vitamin K on X-Ray-Induced Mortality

Although there are numerous ways to reduce the lethal effect of ionizing radiation by the administration of chemicals, drugs, hormones, etc., prior to exposure (1, 2), only a small number of agents have so far been found to be effective when given after irradiation. In the course of systematic studies in this field, we found that vitamin K is an agent which reduces the X-ray mortality in guinea pigs by postirradiation administration. Pertinent observations are reported in the present paper.

Relationships among Hematopoiesis, Blood Coagulation, Hemorrhage and Mortality in the Guinea Pig after Total Body X-Irradiation

Abstract Studies have been presented on blood, bone marrow, coagulation and their relation to mortality in guinea pigs exposed to 200, 400 and 600 r total body x-irradiation. The initial responses of the blood and bone marrow were remarkably similar for the 3 doses of x-irradiation (ranging from LD10 to LD100). Marked differences among the dosages were noted in regeneration which occurred earliest after 200 r, later after 400 r and not at all after 600 r. Once started, regeneration was equally active after 200 and 400 r. A coagulation defect, closely related to thrombocytopenia, was observed in the 6 to 13 day period following all doses of irradiation. An additional clotting defect, characterized by increases in the prothrombin time and heparin clotting time, was noted at 4 and 24 hours following all 3 doses of irradiation. The etiology of this defect requires further evaluation. The pattern of hemorrhage, evaluated in various tissues by a semiquantitative scoring method, revealed that hemorrhage was most prominent in the 9 to 13 day period after exposure, and was closely related to thrombocytopenia. As the dose of x-ray increased, hemorrhage tended to become more protracted and severe and involved more organs. Hemorrhage disappeared rapidly as platelet formation returned in the recovery period. Hemorrhage was the chief factor in the severity and incidence of anemia after irradiation.

Inability of flavonoids to modify roentgen ray irradiation mortality in guinea pigs.

SummaryIt has been shown that rutin, hesperidin, hesperidin methylchalcone, and naringin were ineffective in modifying Roentgen ray irradiation lethality in guinea pigs. There was an indication that post-irradiation medication with rutin may have increased the rate of mortality.

Allergy and Immunity in Coccidial Infections.

Immunity to the several species of coccidia which occur in chickens has been thoroughly demonstrated by Tyzzer1 and by Henry.2 A similar host response has been shown to occur in rabbits (Bachman3) and in cats and dogs (Andrews4).The purpose of this paper is to report the development of a similar immunity in guinea pigs infected with Eimeria caviae, together with the appearance of degenerate forms of the parasite in partially immune animals, observations on the production of hypersensitivity to the protein of the infecting organism, and a cutaneous hypersensitivity to E. caviae in this host.The reinoculation of 35 previously infected guinea pigs has in all cases shown the presence of some immunity. In most cases the resistance has been sufficient to completely prevent the occurrence of clinical symptoms, which are invariably present in initial infections. While the mortality in guinea pigs upon infection with E. caviae for the first time has been found to be 40%, not one of the guinea pigs infected 2 or mo...