Clinical Effects of Mixed Infection of Trypanosomes and Ancylostoma caninum in Dogs and Treatment with Diminazene and Mebendazole (Nigeria)

Trypanosomosis is one of the major diseases ravaging animals in Nigeria especially within Nsukka
area in Enugu State. All species of trypanosomes, with the exception of some strains of T. vivax which
produce a hyper acute and acute infection, are characterized by high parasitaemia, pyrexia, severe
anaemia and haemorrhages on the mucosal and serosal surfaces. The socio-economic importance of
trypanosomosis and ancylostomosis in both humans and animal necessitated the investigation of the
clinical signs of single and conjunct infection of both parasites in dogs. Sixteen dogs grouped into 4 of
4 members each were used in the study. GROUP I was uninfected dogs (control), GROUP II was
infected with Ancylostoma caninum GROUP III was infected with Trypanosoma brucei (T. brucei),
GROUP IV was mixed infections of Trypanosoma brucei and Ancylostoma caninum (T. brucei/A.
caninum). Post acclimatization, Ancylostoma caninum infection was done on GPII and GPIV. Two
weeks later Trypanosoma brucei infections was done on GPIII and superimposed on GPIV. Three
weeks post trypanosome infection; GPIII and GPIV were treated with 7 mg/kg diminazene aceturate
(Veribin®, CEVA Sante Animale- La Ballasteiére 33501 Libourne Cedex, France) x intramuscularly x
once. Mebendazole (Vermin®, Janssen-Cilag Ltd 50 - 100 Holmers Farm Way, High Wycombe, Bucks,
HP12 4EG UK) at 100 mg x per os twice daily for 3 days was used only on GPII and GPIV and a
repeat treatment given 2 weeks later. Prepatent period of T. brucei infection was 5.00±1.30 days in
single infection and 3.00±1.40 days in conjunct infection of T. brucei and A. caninum. Persistent
parasitaemia resulted in repeated treatment with diminazene aceturate at 7 mg/kg and mebendazole
at 100 mg twice daily for 3 days. The predominant signs revealed include; fluctuation in weight,
lethargy, vomition, enlargement of popliteal lymphnodes, pyrexia, oedema of lower jaw and ocular
discharges, enlarged abdomen, anaemia, cornea opacity and slight emaciation. The clinical signs
were most severe in GPIV compared to GPIII. The egg per gram of faeces (EPG) in GPII was
significantly higher than the mixed infection (GPIV). Treatment only slightly improved clinical
manifestations.
In conclusion, most signs shown were consistent with trypanosomosis in dogs except abdominal
enlargement which is a complication of A. caninum. Clinical signs therefore could serve as a
diagnostic tool in the treatment of both conditions in dogs. The severity of the disease conditions was
more in the conjunct group compared to the single infection. Treatment of the diseases with
diminazene aceturate and mebendazole caused slight improvement in the clinical condition due to the
resistant strain of T. brucei used in the study.