Introduction

Babesiosis is an important tropical tick-borne protozoal infection of domestic and wild animals. The disease occurs in the southern USA, Central and South America, Africa, Asia and Southern Europe. Out of the hundred species, three Babesia species are known to cause natural infection to dogs. Babesia canis, Babesia gibsoni and Babesia vogeli ¹. The disease is transmitted by ticks among which, Dermacentor reticulatus in Europe, Rhipicephalus sanguineus in tropical and sub-tropical regions, Haemaphysalis leachi in South-Africa². Once infected, the Babesia organisms multiply within erythrocytes. The infection has been associated with the “fading puppy syndrome”. The infected erythrocytes are destroyed this causes acute onset anemia along with fever and lethargy. Although chronic infections occur, they are uncommon. Sudden death is a possible consequence of acute onset Babesia infection associated with low blood pressure shock and hypoxia. The wide variety of additional clinical signs depends on the tissues affected by the infection. Mild to severe pulmonary disease, diarrhea, vomiting, muscle pain, yellow-colored urine, rapid weight loss, eye discharge, and neurological signs are reported³.

Dogs are common sight within Makurdi metropolis, where they are kept as guard dogs and pets (to a lesser degree). The climatic and topographic characteristics of the area are such that ectoparasites which harbor and transmit viral, bacterial and protozoan pathogens could thrive. Thus, in order that dogs function effectively and people enjoy the companionship derived from living with them, it is of utmost importance that their health is maintained optimally and that zoonotic transmissions are kept in check. As such, this study was carried out to determine the disease pattern of canine babesiosis in relation to various parameters (age, sex, breed of dogs and degree of restriction) for future prophylaxis and to identify responsible vector species.

Materials and Methods

Study Area

Study Population

Laboratory Analysis

Statistical Analysis

Results

The report showed that Rhipicephalus sanguineus was the most prevalent tick species on dogs despite the presence of an infested dog with the tropical bont tick Amblyomma variegatum. The preferred site of attachment is shown in Table 1. 89 dogs (82.41%) had tick infestation, distribution of ticks on dogs’ body was not significantly different though most ticks preferred the paws (86 dogs, 96.3%) and the back (82 dogs, 92.1%).

Figure 1

Table 1: Preferred site of attachment of ticks on dogs in Makurdi

A total of 11 dogs (10.2%) were positive for Babesia canis infection, out of which 8 (13.8 %) were males and 3 (6.0%) were females (Table 2). Prevalence of infection among sexes was not significantly different (X² = 2.59, P > 0.05).

Figure 2

Table 2: Prevalence of in relation to sex

Table 3 shows the occurrence of canine babesiosis with respect to degree of restriction. Dogs were grouped based on their degree of restriction (information obtained from interview with owners) as follows: free-roaming, semi-confined (restricted then released) and confined. Only free-roaming and semi-confined were found to be infected with babesiosis, (9.3%) and 18.2% respectively. A significant difference in infection was observed between the free-roaming, semi-confined and the confined dogs(X² = 1.32, P < 0.05).

Figure 3

Table 3: Occurrence of canine babesiosis with respect to degree of restriction

The occurrence of canine babesiosis in relation to breed of dogs is given in Table 4. Three breeds of dogs were identified, these include foreign breed, local breed and hybrid/croosbred. The highest prevalence of babesiosis was found in the hybrid dogs 18.8%, followed by the foreign 9.1% and the local 8.6% respectively. No significant difference was observed in the occurrence of babesiosis between the breeds (X² = 12.52, P > 0.05).

Figure 4

Table 4: Occurrence of canine babesiosis in relation to breed of dogs

Discussion

The results show a relatively high prevalence of canine babesiosis and tick infestation in Makurdi. R. sanguineus was found to be the tick commonly infesting dogs, this corroborates with the findings of a study conducted on ectoparasites of dogs in Calabar, Nigeria⁷. This also agrees with a similar study performed in Mozambique where out of the 89 ticks collected from dogs, R. sanguineus recorded the highest rate of infestation among the two species of ticks that were observed⁸. Although, preferred sites of tick attachment to dogs’ body differs according to the environment, in Makurdi ticks appear to prefer the paws, this could be due to the fact that these sites are less accessible compared with locations such as the neck and head. This disagrees with a study carried out in Mexico where the authors found the ears, interdigital spaces and back as preferred sites for ticks⁹. Free roaming dogs were more infected than semi-confined and confined dogs, this could be attributed to the non- development of immune responses due to continuous exposure to ticks. The result, however, contrasts the findings observed in other works^10,11. However, the high rate of babesiosis observed among male dogs than their female counterparts could be the cause of their frequent roaming to look for mates and establishing territories thereby picking the ticks^{12, 13, 7.} Based on breed, more local breeds were infected than foreign and hybrid, this must be due to the care free attitude of their owners. Such dogs are often not cared for, hardly ever washed and treated and even not immunized. Moreover, the fact that these dogs are exposed to all manners of environmental hazard, are easier to get contaminated by communicable diseases that could be easily transmitted to man, this observation was also reported in other works.^{14, 15,9, 10}

Public health awareness on the care for dogs and dangers associated with their indiscriminate roaming is thus necessary to prevent and check the possibility of babesiosis and other zoonotic infections occurring in humans living in Makurdi and other such towns. Prevention and control can only be achieved through administration of prophylaxis, weekly bathing, monitoring and grooming of dogs, regular deticking of dogs, regulation of children and adults interaction with dogs, fumigation of kernels and houses and above all, provision of laws to enforce a high standard of public and veterinary health.