Haemato-biochemical and thyroxin status in Trypanosoma evansi infected dogs

Probiotics: an alternative anti-parasite therapy

This paper review about probiotic effects and mechanism of action against the gut and non-gut helminths and protozoan parasites. Gastrointestinal parasitic infections are considered a serious health problem and are widely distributed globally. The disease process which emanates from this parasite infection provides some of the many public and veterinary health problems in the tropical and sub-tropical countries. Prevention and control of the parasite disease is through antihelmintic and anti-protozoan drugs, but, due to the increasing emergence of such drug resistance, eradication of parasite infestation in human and livestock still lingers a challenge, which requires the development of new alternative strategies. The use of beneficial microorganisms i.e. probiotics is becoming interesting due to their prophylactic application against several diseases including parasite infections. Recent studies on the interactions between probiotics, parasites and host immune cells using animal models and in vitro culture systems has increased considerably and draw much attention, yet the mechanisms of actions mediating the positive effects of these beneficial microorganisms on the hosts remain unexplored. Therefore, the aim of the present review is to summarize the latest findings on the probiotic research against the gut and non-gut parasites of significance.

Radio Immune Assay (RIA) Enabled Total Triiodothyronine (TT3) and Total Thyroxine (TT4) in Canine Trypanosomiasis: First Case Report from Maharashtra (India)

Radio Immune Assay (RIA) is an extremely sensitive in vitro assay technique to measure concentrations of antigen viz. hormones in biological fluids using antibodies. The present study reports the status of total triiodothyronine (TT3) and total thyroxine (TT4) in Trypanosoma evansi infection in a dog, year 2022. An adult, non-descript, male dog was referred to the Department of Veterinary Nuclear Medicine, Mumbai Veterinary College, (MAFSU), Parel, Mumbai (India) with a history of inappetence, weakness, and ataxia of the hind limbs. Inspection revealed cachexia, anemia, bedsores, and mild mucopurulent ocular and nasal discharge. Clinical examination revealed pyrexia, polypnoea and tachycardia. There was an enlargement of popliteal, prescapular, and submandibular lymph nodes. The blood smear examination revealed severe infection of extracellular T. evansi. Laboratory investigations showed an altered haemato-biochemical profile. RIA-enabled thyroid hormone profile revealed a reduced concentration of TT3 (0.57 nmol/l) and TT4 (22.52 nmol/l). The present study reports a reduction in the concentration of TT3 and TT4 in a dog suffering from trypanosomiasis. The drop in TT4 concentration was within the normal limit, this could be a cause for the non-appearance of usual clinical symptoms of hypothyroidism in the present case.

A 5-Year Prospective Study on Incidence and Clinico-pathological Changes Associated with Naturally Occurring Trypanosomosis in Dogs of Mizoram, India

PURPOSE

The present research was taken to study the hospital-based incidence and clinico-pathological changes associated with naturally occurring trypanosomosis in dogs of Mizoram.

METHODS

A 5-year prospective study on hospital-based incidence and clinico-pathological changes associated with naturally occurring trypanosomosis in dogs of Mizoram was carried out during the study period from April, 2015 to March, 2020. Trypanosoma evansi infection was confirmed by microscopic examination and polymerase chain reaction (PCR). Non-infected clinically healthy dogs (n = 6) served as control. Blood samples were collected to study the haemogram and serum samples were used for the evaluation of serum biochemical parameters and oxidant-antioxidant parameters.

RESULTS

During the study period, an overall incidence of 0.25% was recorded for trypanosomosis in dogs. The most consistent clinical findings noticed were anorexia/inappetence, pyrexia, depression/lethargy, pale mucous membrane, dehydration and lymphadenomegaly. Anaemia, granulocytopenia, lymphocytosis and thrombocytopenia were the major findings noticed in trypanosomosis affected dogs. The profile of vital organ function revealed that the mean values of total protein, albumin and random blood glucose were significantly (P < 0.05) lower, whereas the mean values of alanine aminotransferase (ALT), aspartate aminotransferase (AST), alkaline phosphatase (ALP), total bilirubin, blood urea nitrogen (BUN) and creatinine were significantly (P < 0.05) higher in dogs affected with trypanosomosis. The mean value of lipid hydroperoxide (LPO) was significantly (P < 0.05) higher, whereas the mean values of glutathione (GSH), superoxide dismutase (SOD) and total antioxidant activity (TAOA) were significantly (P < 0.05) lower in trypanosomosis affected dogs. When total erythrocyte count (TEC) was correlated with LPO (r = - 0.631, P < 0.05), a negative correlation was found, while in case of GSH (r = 0.757, P < 0.05), SOD (r = 0.767, P < 0.05) and TAOA (r = 0.713, P < 0.05), it was positively correlated.

CONCLUSION

A negative correlation of TEC count with LPO, while a positive correlation with GSH, SOD and TAOA signify the role of oxidative stress in the pathogenesis of anaemia induced by T. evansi infection in dogs. The present study findings might be helpful to clinicians when treating clinical cases of this kind. Incorporation of organ protective drugs and antioxidants in the treatment schedule may result in better prognosis.

Hematobiochemical and Immunological Responses of Rats Treated with Multi-strain Probiotics and Infected with Trypanosoma brucei

The effects of treatment with probiotics on the immunological and hematobiochemical changes in Trypanosoma brucei infection were investigated. Probiotic strains used are Bifidobacterium BB-12, Lactobacillus acidophilus LA-5, Lactobacillus delbrueckii LBY-27, Lactobacillus paracasei LC-01, and Streptococcus thermophilus STY-31. Thirty rats randomly assigned to five groups were used in the experiment. Groups A to C received 1 × 10⁹ CFU, 5 × 10⁹ CFU, and 10 × 10⁹ CFU of the multi-strain probiotics daily and respectively from day 0 post-supplementation (PS) to termination. Group D and E were the infected and uninfected controls respectively. On day seven PS, groups A to D were challenged intraperitoneally with approximately 1 × 10⁶ trypanosomes. Parasitemia, nitric oxide level, hematobiochemical parameters, and antibody titer to heterologous antigen stimulation were monitored post-infection. By days 7 and 16 PS, probiotics-treated groups had significantly lower (p < 0.05) mean creatinine concentration than the controls; however, on day 7 PS, there were no significant variations in the leukocyte counts (LC), total erythrocyte counts (TEC), and the packed cell volume (PCV) in all experimental groups. Following infection, by day 16 PS, the pre-patent period, parasitemia levels, and antibody titer were similar in all infected groups. Furthermore, the probiotics-treated groups and the infected control had significantly lower PCV, TEC, and LC values when compared to the uninfected control, and probiotics treated groups (A and C) had only marginally lower nitric oxide levels than the infected control. Treatment with the probiotic strains gave a creatinine-lowering effect, was innocuous to the hematopoietic system, but was not sufficiently immunostimulatory in trypanosomosis.

A case of Trypanosoma evansi in a German Shepherd dog in Vietnam

A 2.5-year-old male German Shepherd was presented to a private veterinary clinic in Hanoi, Vietnam showing anorexia, weakness, lethargy, reluctant to go for walks with a recent history of intermittent fever. Clinical examination of the dog showed pale mucous membrane, impaired eyesight, edema of the back legs. Complete blood count revealed severe anemia; red blood cell 3.8 × 10¹²/l, hemoglobin 8.7 g/dl, hematocrit 26.4%, associated with thrombocytopenia 145 × 10⁹/l. Biochemical analysis showed a moderate increase of alanine transaminase (150.7 UI/l) and alkaline phosphatase activities (266 UI/I) with mild hypoglycemia (71.46 mg/dl). Trypanosoma evansi was observed in Giemsa-stained blood smears under microscopic observation which was confirmed by PCR. This is the first report of canine trypanosomiasis caused by T. evansi in Vietnam.

Systematic review and meta-analysis on the global distribution, host range, and prevalence of Trypanosoma evansi

BACKGROUND

Surra is an animal trypanosomosis, caused by infection with Trypanosoma evansi and leading to severe economic loss due to mortality and morbidity. Compared to tsetse-transmitted animal trypanosomoses, little attention is given to the epidemiology and control of surra. Understanding its epidemiology is a first step in local and global efforts to control the disease. We conducted a systematic review and meta-analysis of published studies on distribution, host ranges and prevalence of T. evansi infection.

METHODS

Four electronic databases were searched for publications on T. evansi that met our inclusion criteria for the systematic review. Subsets of publications were subjected to meta-analysis for the pooled prevalence of T. evansi in various hosts as determined by multiple detection methods.

RESULTS

A total of 272 references published between 1906-2017 were included. Trypanosoma evansi was reported from 48 countries; largely confined to Africa and Asia with publications on natural T. evansi infections from 77% (n = 48) of countries, contrasting with seven countries in South America, and four in Europe where T. evansi is not endemic but was imported with infected animals. Although surra is a notifiable disease, many countries do not report surra cases to OIE. Trypanosoma evansi was mainly reported from dromedary camels in Africa and the Middle East, water buffaloes, cattle, dogs and horses in East and Southeast Asia. In South America, the acute form of the disease was reported in horses and dogs. Surra was also reported in a wide range of wild animals. Some rare human cases occurred in India and Vietnam. Meta-analysis on a subset of 165 publications indicated pooled prevalence of T. evansi in domestic animals ranging from 14-31%, 6-28% and 2-9% using respectively antibody detection, molecular and parasitological tests, with camels as the most affected, followed by buffalo and cattle.

CONCLUSIONS

This study illustrates that T. evansi affects a wide range of domestic and wild animals in Africa, Asia and South America with highest prevalence observed in dromedary camels. For successful control of T. evansi, both locally and globally, the role of wild animals in the epidemiology of surra needs further investigation.

VALORES HEMATOLÓGICOS DE LOBINHOS (Cerdocyon thous) DO PANTANAL, MATO GROSSO DO SUL, BRASIL NATURALMENTE INFECTADOS E NÃO INFECTADOS POR Trypanosoma cruzi e T. evansi

Resumo O objetivo do trabalho foi avaliar a influência do sexo, da sazonalidade e de infecções por Trypanosoma cruzi e Trypanosoma evansi nos valores hematológicos de lobinhos (Cerdocyon thous) que habitam o Pantanal Sul-Mato-Grossense. Entre novembro de 2015 e outubro de 2016, foram amostrados 48 lobinhos. Os valores hematológicos mensurados foram as contagens de eritrócitos e leucócitos, volume globular e volume corpuscular médio. Consideramos como parasitados os animais positivos para T.cruzi e T. evansi em qualquer um dos testes diagnósticos utilizados. Observamos que sete (14.5%) lobinhos encontraram-se parasitados somente por T.cruzi, sete por T. evansi, e nove (19%) estavam coinfectados. Os animais parasitados por T.cruzi mostraram um aumento significativo das contagens de leucócitos (14.7 x 103) em relação aos animais não parasitados (10.4 x 103), parasitados por T. evansi (12.4 x 103) e coinfectados (12.9 x 103). Observamos diferença significativa em relação aos valores médios de eritrócitos e volume corpuscular médio entre os períodos de cheia e seca: 2.6 x 106 e 165, e 3.4 x 106 e 132, respectivamente. Todos apresentaram macrocitose não confirmada morfologicamente.

Rare report of orchitis in a bull due to Trypanosoma evansi infection

A 9 years old bull was presented to the hospital with a history of scrotal swelling for a period of 12 days and progressive emaciation with intermittent fever. Clinical examination revealed the swollen and painful scrotum with fluid thrill, mild abduction and disorientation of hindlimbs were noticed. Ultrasonography of the testes revealed the anechoic fluid in between the visceral and parietal layers of tunica vaginalis of testis with variation in the echogenicity of the testes. Stained peripheral blood smear examination revealed the presence of Trypanosoma evansi organisms. The bull was administered with diminazene aceturate, enrofloxacin, flunixin meglumine, multivitamin injections and dextrose normal saline. Uneventful recovery was noticed following the therapy.

Outcomes of Trypanosoma cruzi and Trypanosoma evansi infections on health of Southern coati (Nasua nasua), crab-eating fox (Cerdocyon thous), and ocelot (Leopardus pardalis) in the Brazilian Pantanal

The occurrence of Trypanosoma spp. in wild carnivore populations has been intensively investigated during the last decades. However, the impact of these parasites on the health of free-living infected animals has been largely neglected. The Pantanal biome is the world’s largest seasonal wetland, harboring a great diversity of species and habitats. This includes 174 species of mammals, of which 20 belong to the order Carnivora. The present study aimed to investigate the effect of Trypanosoma evansi and Trypanosoma cruzi infections and coinfections on the health of the most abundant carnivores in the Pantanal: coati (Nasua nasua), crab-eating fox (Cerdocyon thous), and ocelot (Leopardus pardalis). We captured 39 coatis, 48 crab-eating foxes, and 19 ocelots. Diagnostic tests showed T. cruzi infection in 7 crab-eating foxes and 5 coatis. Additionally, 7 crab-eating foxes, 10 coatis, and 12 ocelots were positive for T. evansi. We observed coinfections in 9 crab-eating foxes, 8 coatis, and 2 ocelots. This is the first report of T. evansi and T. cruzi infection on the health of free-living ocelots and crab-eating foxes. We showed that single T. evansi or T. cruzi infection, as well as coinfection, caused some degree of anemia in all animals, as well as an indirect negative effect on body condition in coatis and crab-eating foxes via anemia indicators and immune investment, respectively. Furthermore, the vigorous immune investment observed in sampled coatis, crab-eating foxes and ocelots infected by T. evansi, T. cruzi and coinfected can be highly harmful to their health. Overall, our results indicate that single and combined infection with T. evansi and T. cruzi represent a severe risk to the health of wild carnivores in the Pantanal region.