Table 5 Significant results of the binomial generalized linear model and pairwise comparison analysis of potential risk factors for positive status for the three most common co-infections noted in this study among 3750 dogs from shelters in 19 states in the Eastern United States

Dirofilaria immitis + Ehrlichia spp.

 Age group

  ≥ 1 year old/< 1 year old

9.3

1.3–67.3

0.0269

 Intact status

  Intact–Non-intact

2.1

1.1–3.9

0.0185

 Region

  Southeast–Midwest

3.6

1.2–11.1

0.0042

Borrelia burgdorferi + Ehrlichia spp.

 Breed group

  Hound–Sporting

7.0

2.1–23.6

0.0272

  Hound–Terrier

4.1

2.1–8.2

0.0013

 Region

  Northeast–Midwest

4.4

1.4–13.5

0.0275

Borrelia burgdorferi + Anaplasma spp.

 Breed group

  Sporting–Terrier

3.8

1.8–8.3

0.0131

 Region

  Northeast–Southeast

2.6

1.4–4.7

0.0072