Recurrent patent infections with Toxocara canis in household dogs older than six months: a prospective study

Parasites & Vectors

Table 2 Results of the final multivariable Cox proportional hazards regression model for “first” T. canis infection

	No. of dogs	No. of dog-months at risk	No. of observed FPIs	HR	95 % CI		P-value
Age group
0–12 months	202	636	42	Ref.
1–7 years	575	5,678	157	0.47	0.32	0.67	< 0.0001
> 7 years	250	2,469	60	0.40	0.26	0.61	< 0.0001
Sex
Male	362	3,702	113	Ref.
Female	481	5,081	146	0.93	0.72	1.20	0.580
Coprophagy
No	475	4,877	115	Ref.
Yes	400	3,906	144	1.36	1.05	1.77	0.021
Sampling season
Summer	655	2,332	38	Ref.
Winter	741	2,434	89	1.73	1.14	2.61	0.009
Autumn	564	1,978	76	1.62	1.05	2.50	0.030
Spring	603	2,039	56	1.28	0.81	2.01	0.287
Eating soil/sand
No	740	7,818	213	Ref.
Yes	106	965	46	1.62	1.12	2.35	0.011
Following a commercial diet
No	320	3,081	68	Ref.
Yes	567	5,702	191	1.47	1.08	2.00	0.014
Following a diet containing frozen raw meat
No	381	3,377	131	Ref.
Yes	494	5,406	128	0.68	0.52	0.89	0.005
Having respiratory conditions
No	822	8,456	244	Ref.
Yes	46	327	15	1.84	1.08	3.13	0.026
Having neurologic conditions
No	819	8,413	257	Ref.
Yes	40	370	2	0.21	0.06	0.82	0.024
Having urologic conditions
No	816	8,467	245	Ref.
Yes	41	316	14	1.79	1.12	2.86	0.015
Excreting worms in faeces
No	828	8,688	252	Ref.
Yes	10	95	6	2.26	1.16	4.42	0.017
Off-leash walking time (%)
≤ 20	131	1,325	29	Ref.
20–50	260	2,461	54	1.06	0.64	1.75	0.829
50–80	141	1,337	40	1.30	0.76	2.23	0.341
> 80	375	3,660	136	1.79	1.13	2.83	0.013
Time since last deworming (months)^a	–	–	–	1.002	1.000	1.003	0.024

^aContinuously time-varying variable let interact with the underlying time variable
Abbreviations: HR hazard ratio; 95 % CI, 95 % confidence interval; FPI “first” patent infection; Ref. reference category

ISSN: 1756-3305