Table 1 Summary of the quality of evidence

American Journal of Veterinary Research/1984

Prospective with control group, single center

298

[8]

The Canadian Veterinary Journal/1996

Prospective with no control group, multi-center

27 and 14 respectively

[9]

The Canadian Veterinary Journal/1997

Prospective with no control group, single center

120

[10]

Veterinary Parasitology/2000

Prospective, blind, randomized, with control group, multi-center

42

[11]

Veterinary Parasitology/2000

Prospective, blind, randomized, with control group, multi-center

207

[12]

Veterinary Parasitology/2000

Prospective no control group, single center

41

[13]

Parasitology Research/2005

Prospective, blind, randomized, with control group, multi-center

53

[14]

Australian Veterinary Journal/2006

Prospective, blind, randomized, with control group, single center

30

[15]

Veterinary Research Communications/2011

Prospective with control group, single center

22

[16]

Veterinary Parasitology/2016

(1) Laboratory study, blind, randomized, placebo, with control group, single center

(2) Prospective, blind, randomized with control group, multi-center

(1) 44 and (2) 79 respectively

[17]

Parasite/2016

Prospective, randomized, with control group, single center

20

[18]

Veterinary Dermatology/2016

Prospective, no control group, single center

17

[4]

Parasites & Vectors/2016

Prospective, double-blind, randomized, with control group, single center

29

[19]

Parasite/2018

Prospective, double-blind, randomized, no control group, multi-center

80

[20]

Parasites & Vectors/2020

Prospective, single-blind, with control group, multi-center

135

[3]

The Canadian Journal of Veterinary Research/2020

Prospective, with control group, single center

142

[21]