Table 2 Significant results of bivariable generalized linear model and pairwise comparison analysis of potential risk factors for seropositive status for vector-borne pathogens among 3750 dogs from shelters in 19 states in the Eastern United States

Dirofilaria immitis

 Age group

  ≥ 1 year old vs. < 1 year old

12.2

5.4–27.4

 < 0.0001

 Sex

  Male–Female

1.2

1.0–1.5

0.0418

 Intact status

  Intact–Non-intact

2.0

1.6–2.5

 < 0.0001

 Breed group

  Herding–Toy

3.2

1.7–5.9

0.0032

  Hound–Toy

3.2

1.8–5.8

0.0020

  Non-sporting–Toy

3.4

1.7–7.0

0.0120

  Sporting–Toy

4.0

2.2–7.1

0.0001

  Terrier–Toy

4.4

2.6–7.6

 < 0.0001

 Region

  Midwest–Northeast

3.4

1.8–6.4

0.0005

  Southeast–Midwest

3.7

2.8–5.1

 < 0.0001

  Southeast–Northeast

12.7

7.1–22.7

 < 0.0001

Ehrlichia spp.

 Age group

  ≥ 1 year old vs. < 1 year old

3.7

2.1–6.5

 < 0.0001

Breed group

  Herding–Toy

3.2

1.7–6.2

0.0073

  Hound–Herding

2.1

1.4–3.2

0.0060

  Hound–Non-sporting

3.6

1.8–7.4

0.0067

  Hound–Sporting

3.0

1.9–4.6

 < 0.0001

  Hound–Terrier

3.5

2.5–4.8

 < 0.0001

  Hound–Toy

6.8

3.7–12.4

 < 0.0001

  Hound–Working

2.9

1.7–4.8

0.0013

 Region

  Southeast–Midwest

2.3

1.7–3.2

 < 0.0001

  Southeast–Northeast

2.5

1.7–3.6

 < 0.0001

Anaplasma spp.

 Breed group

  Sporting–Terrier

4.1

2.2–7.6

0.0002

  Sporting–Toy

24.5

3.3–181.3

0.0288

 Region

  Northeast–Midwest

3.1

1.8–5.3

0.0002

  Northeast–Southeast

4.2

2.6–6.8

 < 0.0001

Borrelia burgdorferi

 Age group

  ≥ 1 year old vs. < 1 year old

3.5

2.0–5.9

 < 0.0001

 Breed group

  Herding–Toy

3.8

2.0–7.4

0.0014

  Hound–Non-sporting

3.0

1.5–6.2

0.0388

  Hound–Terrier

2.3

1.7–3.2

 < 0.0001

  Hound–Toy

6.1

3.3–11.5

 < 0.0001

  Sporting–Toy

4.2

2.2–8.0

0.0002

  Terrier–Toy

2.6

1.4–4.9

0.0336

  Working–Toy

4.4

2.2–8.8

0.0004

 Region

  Northeast–Midwest

3.3

2.4–4.5

 < 0.0001

  Northeast–Southeast

3.8

2.9–4.9

 < 0.0001