Table 2 Descriptive and univariable logistic regression results for risk factors associated with patellar luxation diagnosis in dogs attending primary-care veterinary practices in England

Purebred status

Crossbred

174 (20.4)

46291 (22.5)

Base

Purebred

680 (79.6)

159205 (77.5)

1.1

1.0–1.3

0.133

Common breed-types

Crossbred

174 (20.4)

46291 (22.5)

Base

Yorkshire Terrier

116 (13.6)

6481 (3.2)

4.8

3.8–6.0

<0.001

Chihuahua

70 (8.2)

4323 (2.1)

4.3

3.3–5.7

<0.001

Jack Russell Terrier

70 (80.2)

13097 (6.4)

1.4

1.1–1.9

0.013

Cavalier King Charles Spaniel

52 (6.1)

4183 (2.0)

3.3

2.4–4.5

<0.001

West Highland White Terrier

40 (4.7)

5025 (2.5)

2.1

1.5–3.0

<0.001

Bichon

33 (3.9)

2686 (1.3)

3.3

2.2–4.8

<0.001

Staffordshire Bull Terrier

26 (3.0)

16458 (8.0)

0.4

0.3–0.6

<0.001

Pug

22 (2.6)

1933 (0.9)

3.0

1.9–4.7

<0.001

Pomeranian

21 (2.5)

951 (0.5)

5.9

3.7–9.3

<0.001

Lhasa Apso

20 (2.3)

1605 (0.8)

3.3

2.1–5.3

<0.001

Shih-tzu

18 (2.1)

4053 (2.0)

1.2

0.7–1.9

0.501

Bulldog

16 (1.9)

1728 (0.8)

2.5

1.5–4.1

0.001

French Bulldog

16 91.9)

1230 (0.6)

3.5

2.1–5.8

<0.001

Other breed-types

160 (18.7)

95452 (46.5)

0.4

0.4–0.6

<0.001

Kennel Club Breed Groups

Not Kennel Club recognised

251 (29.4)

62010 (30.2)

Base

Toy

354 (41.5)

23937 (11.6)

3.7

3.1–4.3

<0.001

Utility

107 (12.5)

16872 (8.2)

1.6

1.2–2.0

<0.001

Terrier

89 (10.4)

28772 (14.0)

0.8

0.6–1.0

0.030

Gundog

26 (3.0)

38001 (18.5)

0.2

0.1–0.3

<0.001

Hound

13 (1.5)

9134 (4.4)

0.4

0.2–0.6

<0.001

Pastoral

7 (0.8)

15403 (7.5)

0.1

0.1–0.2

<0.001

Working

7 (0.8)

11367 (5.5)

0.2

0.1–0.3

<0.001

Adult (>18 months) bodyweight (kg)

<10.0

473 (55.4)

32,604 (15.9)

2.8

2.3–3.3

<0.001

10.0–19.9

167 (19.6)

32,218 (15.7)

Base

20.0–20.9

39 (4.6)

27,233 (13.2)

0.3

0.2–0.4

<0.001

30.0–30.9

11 (1.3)

19,384 (9.4)

0.1

0.1–0.2

<0.001

≥40.0

11 (1.3)

9,409 (4.6)

0.2

0.1–0.4

<0.001

Not recorded

153 (17.9)

84,780 (41.2)

0.4

0.3–0.4

<0.001

Breed relative bodyweight^a

Equal/Higher

283 (33.1)

55,494 (27.0)

Base

Lower

418 (49.0)

65,355 (31.8)

1.3

1.1–1.5

0.003

Not recorded

153 (17.9)

84,779 (41.1)

0.4

0.3–0.4

<0.001

Age category (years) (pre-existing cases included as non-recorded)

<3.0

287 (33.6)

85665 (41.7)

Base

3.0 – 5.9

200 (23.4)

42541 (20.7)

1.4

1.2–1.7

<0.001

6.0 – 8.9

137 (16.0)

32179 (15.7)

1.3

1.0–1.6

0.021

9.0 – 11.9

84 (9.8)

23819 (11.6)

1.1

0.8–1.3

0.680

≥12.0

41 (4.8)

20901 (10.2)

0.6

0.4–0.8

0.001

Not recorded

105 (12.3)

523 (0.3)

59.9

47.2–76.1

<0.001

Sex

Male

385 (45.1)

106869 (52.2)

Base

Female

468 (54.8)

97768 (47.8)

1.3

1.2–1.5

<0.001

Neuter status

Entire

70 (8.2)

20650 (10.0)

Base

Neutered

513 (60.1)

73594 (35.8)

2.1

1.6–2.6

<0.001

Not recorded

271 (31.7)

111384 (54.2)

0.7

0.6–0.9

0.014

Insurance

Non-insured

269 (31.5)

70794 (34.4)

Base

Insured

375 (43.9)

47507 (23.1)

2.1

1.8–2.4

<0.001

Not recorded

210 (24.6)

87327 (42.5)

0.6

0.5–0.8

<0.001