Fabricio K. de L. Carvalho

Platynosomum fastosum-induced cholangiocarcinomas in cats

Platynosomum fastosum is a feline biliary tract trematode that generally causes asymptomatic infections. In the early 1980s in Brazil, P. fastosum was associated with cholangiocarcinomas, but this finding was not confirmed in the various publications on the parasite during the last 30 years. This study aims to report three cases of cholangiocarcinomas in cats associated with the presence of P. fastosum. From 2000 to 2011, in the Veterinary Hospital of the Federal University of Campina Grande in northeast Brazil, 348 cats were necropsied, 11 of which (3.16%) were parasitized by P. fastosum. Three cases that resulted in death were associated with cholangiocarcinomas that were found to be associated with P. fastosum. Histologically, the tumors consisted of acini composed of cells with pleomorphic nuclei, loose chromatin, evident nucleoli and lightly eosinophilic cytoplasm. Metastases were observed in two cases. The first case involved metastases to the lungs, kidneys, ovary and peritoneum, and in the second case, the lymph nodes, kidneys, heart and encephalon were involved. The other 8 cats died from other causes, and the parasite was an incidental finding. In those cases, the histologic lesions were nonsuppurative cholangiohepatitis and periductal fibrosis with P. fastosum present. Six animals also showed pre-neoplastic changes (hyperplasia and dysplasia) of the biliary duct epithelium. The study concluded that, as observed in other human biliary tract trematodes, P. fastosum causes cholangiocarcinomas in the liver of cats.

Intoxicação experimental por Ipomoea asarifolia (Convolvulaceae) em caprinos e ovinos

Ipomoea asarifolia causes a tremogenic syndrome in sheep, goats, cattle and buffaloes. The objectives of the experiments were (1) to determine the toxicity to goats of fresh I. asarifolia collected during the raining and the dry season, and the toxicity of the dried plant, and (2) to determine the toxicity of the plant to sheep, and if the active principle is eliminated through the milk. In the first experiment the plant collected in the dry season and in the raining season was fed to 16 goats. The plant collected during the dry season caused clinical signs at the daily doses of 5g and 10g/kg body weight. The plant collected during the raining season was toxic at daily doses of 20g and 30g/kg, indicating that the plant is more toxic during the dry season. The plant collected in the dry season and dried was fed to 9 goats at doses of 1.7g, 2.0g, 3.4g, and 5.1g per kg. Daily doses of 3.0g, 4.0g and 5.1g/kg caused clinical signs, showing that the plant maintains its toxicity after being dried. In the second experiment the fresh plant collected in the dry and in the raining season was fed to 10 sheep. The plant collected in the dry season was toxic at the dose of 5g/kg, and the plant collected in the raining season was toxic at the doses of 10g and 20g/kg. The experimental results suggest that sheep are more susceptible to the poisoning than goats. As some farmers mentioned that suckling non-grazing lambs are poisoned by milk ingestion, I. asarifolia was fed at daily doses of 2.5g, 5.0g and 10g/kg for variable periods to 5 sheep from the day of parturition (2 sheep), after the last day of pregnancy (1 sheep) and 60 days before parturition (2 sheep). The sheep but not the lambs showed clinical signs of intoxication suggesting that the active principle is not eliminated through the milk at doses toxic for the lambs. In one euthanized sheep no gross or histologic lesions were detected. The main ultra-structural findings were found in Purkinje cell dendrites and included swelling, decrease or absence of dendritic spines, decrease or absence of neurotubules and neurofilaments and vacuolation of the dendroplasm. Swelling of the smooth endoplasmic reticulum and granular eletrondense inclusions in dendroplasm was observed. Swelling of astrocyte foot processes was conspicuous. It is suggested that these alterations are a result of continuous tremors induced by the plant with liberation of glutamate causing excitotoxicity, which probably constitutes a neuronal mechanism of defense.

Induction and transfer of resistance to poisoning by Amorimia (Mascagnia) septentrionalis in goats

Amorimia septentrionalis contains sodium monofluoroactetate (MFA) and can cause acute heart failure in ruminants when ingested in toxic doses. In this study, we demonstrate that resistance to poisoning by A. septentrionalis can be improved in goats by the repeated administration of non‐toxic doses of A. septentrionalis. We also show that increased resistance to poisoning by A. septentrionalis can also be achieved by the transfaunation of ruminal content from goats previously conditioned to be resistant to naïve goats. These methods of improving resistance require further study, but appear to provide potential management solutions to mitigate toxicity problems from A. septentrionalis, and perhaps other plant species containing MFA. Copyright

Indução de resistência à intoxicação por Palicourea aeneofusca (Rubiaceae) mediante administração de doses sucessivas não tóxicas

Palicourea aeneofusca (Mull. Arg.) Standl. is a toxic plant which contains sodium monofluoroacetate (MFA). With the objective to investigate if repeated non-toxic doses of P. aeneofusca induce resistance to the intoxication by this plant, 12 goats were distributed in two similar groups. In Group 1, resistance was induced by the administration of the dry plant, during four alternate periods: 0.02g/kg during 5 days, 0.02g/kg during 5 days, 0.03g/kg during 5 days, and 0.03g/kg during 5 days. Between the first and second period of administration and between the second and the third period, the goats did not ingest P. aeneofusca for 10 days. Between the third and the fourth administration period the goats did not ingest the plant during 15 days. One goat died suddenly during the third administration period when was ingesting 0.03g/kg. The goats from Group 2 were not adapted to the consumption of P. aeneofusca. Fifteen days after the end of the adaptation period in Group 1, both groups ingested dry P. aeneofusca in the daily dose of 0.03g/kg during 19 days. From day 20 the daily dose was increased to 0.04g/kg, which was ingested for 12 days. The goats that showed clinical signs were removed from the experiment immediately after the observation of first signs. One goat from Group 2 showed clinical signs of poisoning and died on the 12th day of ingestion, and two showed clinical signs on day 24th; one recovered and the other died. At the end of the 31 days administration period, a new group (Group 3) with three goats was introduced in the experiment to investigate if the goats that did not become poisoned in Group 2 had acquired resistance. The three goats from Group 1, five goats from Group 1, and three from Group 2 started to ingest a daily dose of 0.06g/kg of dry P. aeneofusca. On the third day of ingestion the three goats from Group 3 showed clinical signs. Two died suddenly and another recovered 10 days after the end of ingestion. All goats of Groups 1 and 2 ingested 0.06g/kg/day during nine days without showing clinical signs. These results demonstrated that non-toxic repeated doses of P. aeneofusca increase significantly the resistance to the poisoning, and that this technique possibly could be used to control the poisoning by P. aeneofusca or other toxic Palicourea species. The results of previous research work suggest that resistance is due to the proliferation of MFA degrading bacteria in the rumen.

Estudo retrospectivo das neoplasias em ruminantes e equídeos no semiárido do Nordeste Brasileiro

In Brazil, data related to occurrence of tumors in livestock are scarce. The objective of this study was to determine the frequency of tumors diagnosed in equidae, cattle, sheep and goats in the Pathology Laboratory of the Federal University of Campina Grande, Patos, state of Paraiba, from 1983 to 2010, and to analyze the risk factors by the chi square test, considering variables such as species, breed, age and sex. During the period, 177 (5.6%) out of 3153 specimens from biopsies or necropsies were diagnosed as tumors. There were significant differences (p<0.001) in the frequency of tumors among different species; horses (10.6%) were more affected than cattle (6.8%), and cattle were more affected than goats (3.3%) and sheep (2.1%). Squamous cell carcinoma was most frequent tumor in cattle (58.3% of the tumors), sheep (80%) and goats (46.1%), and sarcoid (45.3%) was the most frequent in horses. Regarding the location, neoplasms were more common in the skin of horses (62.5%) and sheep (60%), in the eyes and periocular skin in cattle (36.1%), and un the female reproductive system (perineal region and vulva) of goats (34.6%). Regarding the sex of the animals, only cattle had significant prevalence (p<0.001). Regarding age only goats showed significant prevalence (p=0.015). There was no significant prevalence in any animal species in relation to race. We concluded that squamous cell carcinomas in ruminants and equine sarcoid are the most common tumors in livestock in the semiarid Brazilian Northeast, and the equidae were the most affected among the species studied.

Determination of toxicity in rabbits and corresponding detection of monofluoroacetate in four Palicourea (Rubiaceae) species from the Amazonas state, Brazil.

Numerous monofluoroacetate (MFA)-containing plants in Brazil cause sudden death syndrome precipitated by exercise in livestock, which is characterized by loss of balance, ataxia, labored breathing, muscle tremors, and recumbence leading to death. Four species of Palicourea collected at six farms were tested for the presence of MFA and their toxicity to rabbits. Palicourea longiflora and Palicourea barraensis contained MFA and caused sudden death in the rabbits. Palicourea croceoides and Palicourea nitidella did not contain MFA and were not toxic to rabbits. P. longiflora and P. barraensis were collected at three farms with a history of sudden death in their cattle. This is the first report of toxicity in regard to these two species.

Fatores de risco associados à ocorrência de carcinoma de células escamosas em ruminantes e equinos no semiárido da Paraíba

This paper describes the frequency of squamous cell carcinoma (SCC) diagnosed at the Laboratory (LPA) of Animal Pathology, Veterinary Hospital of the Federal University of Campina Grande (UFCG), in cattle, sheep, goats, and horses in the semiarid region of Paraiba, Brazil, from 1983 to 2010, analyzing epidemiological data and risk factors. We performed the analysis of risk factors, by the chi-square test, considering variables such as species, breed, sex, age and location of the tumor mass. During the period, 3153 diagnoses were recorded from biopsies and necropsies. From these, 81 cases (2.7%) were squamous cell carcinomas. The frequency by species was 4% (42/1052) in cattle, 2.5% (15/603) in horses, 1.7% (12/709) in sheep, and 1.5% (12/789) in goats, being significantly higher in cattle (p<0.001). All cases showed histological features of SCC, varying only the degree of cell differentiation. In cattle and goats, the frequency of SCC was significantly higher in adult animals (p<0.001 and <0.005, respectively). In cattle the preferred location was in the eyes and periocular region (p<0.001), in sheep in the skin (p=0.018), especially the head. In other species no significant differences were found in the tumor location. It is suggested that the higher frequency of SCC in cattle is due to the constitution of the herds, formed predominantly by females of the Holstein breed.

Utilização de vagens de Prosopis juliflora na alimentação de ovinos e caprinos

The ingestion of pods of Prosopis juliflora causes nervous signs in cattle due to lesions in the trigeminal nuclei, and colics in horses due to the formation of phytobezoars in the gut. The objective of this research was to study the toxicity for of P. juliflora pods in horses, and to establish if 30% of pods in the feed are not toxic for cattle. Three experiments were performed. In Experiment 1, two steers were fed, during one year, with food containing 30% of P. juliflora pods. None of the experimental animals showed nervous signs. In Experiment 2, two horses received pods of P. juliflora in amount equivalent to 1% of their bw during four months. For other 3 months this amount was increased to 1.5% bw. In Experiment 3, two horses received P. juliflora pods ad libitum during 30 days. None of the horses showed nervous signs or colic due to the presence of phytobezoars in the gut. These results suggest that P. juliflora pods, despite their toxicity, can be used to feed cattle at concentrations of 30% of the food during one year. There are no restrictions for the use of P. juliflora pods in horses in confined or semi-confined systems, but it is not recommended to maintain equidae grazing in areas where P. juliflora is fructificating. It is suggested that there is a loss in the capacity of the pods to form phytobezoars after harvesting. Cattle may be kept in areas invaded by P. juliflora, during fructification, for no more than 30 days.

Aversão alimentar condicionada para o controle da intoxicação por Ipomoea carnea subsp. fistulosa em caprinos

Conditioned food aversion is a technique that can be used to train livestock to avoid ingestion of poisonous plants. This study tested the efficacy and durability of conditioned food aversion to eliminate goats consumption of Ipomoea carnea subsp. fistulosa. We used 14 young Moxoto goats, which were initially adapted to the consumption of the plant by offering dried I. carnea subsp. fistulosa with their concentrate diet for 30 days, and then subsequently providing green plant for another 10 days. To confirm the spontaneous consumption of the plant, the goats were allow to graze in a paddock of 510m2 where I. carnea subsp. fistulosa had been planted in an area of 30m2 (10 plants/m2). On day 42, 12 goats were offered fresh green plant individually in a pen for a few minutes, and after the consumption of any amount of the plant they were treated orally with a solution of LiCl at a dose 175mg per kg of body weight. This procedure was repeated for two more consecutive days. Thereafter, the goats were divided into two groups: Group 1 with four averted and two non-averted goats; and Group 2 with eight averted goats. To verify the efficacy and duration of aversion, both groups were introduced into the paddock with I. carnea subsp. fistulosa three days a week for two hours daily. In Group 1, with two non-averted and four averted goats, all animals started to ingest the plant after 1-6 weeks of grazing. They continually increased their consumption of the plant, but never consumed the plant exclusively. None of the goats of Group 2 goats started eating the plant during the 12 months of observation. After this period the area of the paddock planted with I. carnea subsp. fistulosa was expanded to 80 m2 and grazing time was increased to four hours per day for five days a week. At this stage all the goats in Group 1 ingested the plant in large quantities. The goats from Group 2 gradually started to eat the plant and aversion was extinguished in all animals after two months. Swainsonine concentration of I. carnea subsp. fistulosa was 0.052±0.05% (mean ±SD). It was concluded that conditioned food aversion was effective in reducing goat consumption of I. carnea subsp. fistulosa, but the duration of aversion depends on the time of grazing and amount of plant available. However, the aversion was quickly extinguished by social facilitation when averted animals grazed with non-averted animals.

Intoxicação experimental por Passiflora foetida (Passifloraceae) em caprinos

Passiflora foetida is mentioned as a toxic plant by farmers in northeastern Brazil. This research aimed to establish the toxicity of P. foetida for goats, in different seasons of the year, and to determine its toxic compound. Initially, the plant collected two days before administration was non toxic at the daily dose of 40g per kg of body weight (g/kg) given during two days. Furthermore, the plant was administered immediately after collection at a dose of 4-8g/kg to four goats. The animal that ingested 8g/kg showed severe clinical signs, but recovered after treatment with sodium thiosulfate. The other three goats showed mild signs of poisoning and recovered spontaneously. The plant was then administered during different seasons to 23 goats at the dose of 10g/kg. The plant was significantly (P<0.05) more toxic during the dry season than during the rainy season; 11 out of 14 goats that received the plant in the dry season showed clinical signs, but only 3 out of 13 goats that ingested the plant during the rainy season had signs. All goats with clinical signs recovered after the administration of sodium thiosulfate. Clinical signs were apathy, tachycardia and tachypnea, jugular venous pulse, incoordination, bellowing, mydriasis, and sternal recumbence followed by lateral recumbence. Before each administration the plant was tested for cyanide by the picric acid paper test to estimate the cyanide concentration in the plant, which was defined as slight, moderate, high, and very high. Samples with slight reaction were not toxic, those with moderate reaction induced mild signs of poisoning, and those with high reaction induced severe clinical signs. Samples with very high concentrations of cyanide were not observed. The results demonstrated that P. foetida is a cyanogenic plant, which causes poisoning after the ingestion of fresh leaves, mainly during the dry period.