Frequency of Ticks and TBDs of Horses
Veterinarians were asked to rank concern regarding specific TBD conditions on a Likert scale, with 1 being the most concerning and 6 being the least concerning. Veterinarians were primarily concerned with Lyme disease and anaplasmosis (mean = 2.0 for each, respectively). There were no differences among regions for either tick-borne disease. There was less concern for piroplasmosis (mean = 4.0) and tick-associated skin conditions (mean = 3.0). There was a trend towards a higher concern of piroplasmosis in the northeastern states, but it was not statistically significant. There was less concern for tick-borne skin conditions in the Northeast than in other regions of the United States (P=0.016). Overall, most equine veterinarians removed three or more ticks from horses per year (81.7%, 49/60; Table 4) and only 5% (3/60) of veterinarians never removed a tick, although the “0 tick” response was exclusively from the Midwest region. Nearly 70% (15/22) of veterinarians removed six or more ticks in the Northeast region. This was significantly more than the combined responses of the remaining regions (Mann-Whitney U; P=0.030), where most veterinarians reported removing less than five ticks per year. However, the frequency of body checks for ticks did not differ between the Northeast and the combined responses from the remaining regions. Seventy-five percent (42/56) of responding veterinarians removed ticks from horses, and 51.8% (29/56) of veterinarians responded that clients had brought in ticks that had been removed from a horse. Interestingly, neither response differed among U.S. regions.
Equine veterinarians were asked to click on locations on an image representing an equine body that best represented where ticks were most frequently removed (Figure 6). Responses from the Northeast and Midwest were grouped and responses from the Southeast and South-Central were grouped; this was done to combine regions where tick species presence and abundance would be similar. Veterinarians in the Northeast and Midwest most frequently removed ticks from under the jaw, the hind legs, and by the elbow/between the front legs (Figure 6A). In the Southeast and South-Central regions (Figure 6B), ticks were commonly collected from the ears, between and on the front legs, on the flank, between the hind legs, and on the horse’s sides. In the West region, veterinarians removed ticks scattered on the ears, crest, under the jaw, limbs, flank, belly, and between the back legs (Figure 6C).
The frequency of diagnosis of any TBD (anaplasmosis and Lyme disease) in horses was higher in the Northeast than in other regions of the country (P=0.001). However, there were no differences in the confidence of veterinarians to accurately diagnose TBDs based on disease signs, tick identification, and knowing which tick transmits diseases in the Northeast versus other regions of the United States. Over 28% (16/57) of veterinarians responded that they had diagnosed a horse with tick-borne paralysis, and over 25% (15/59) for piroplasmosis. Cumulatively, most veterinarians have found a tick on a horse being treated for a tick-borne disease (75%; 42/56). Finding a tick was more frequent in the Northeast (90.5% of respondents) compared to other regions (65.7% of respondents) (P=0.038). Fewer veterinarians reported clients removed ticks and brought them to the provider (51.8%; 29/56) and this did not differ among regions. However, most veterinarians across all regions (73.7%; 42/57) responded that clients ask them for tick information, and even more veterinarians recommend tick control (79.7%; 47/59). Overall, veterinarians reported that clients were willing to spend an average of $141.53 a year on tick control for their horses, and this did not differ among regions.