Table 3.

Proportional fatality and relative risk for unassisted death (excluding euthanasia) in dogs recorded with specific clinical signs of heat-related illness cases presenting to primary-care veterinary practices in the UK between 2016 and 2018.

Presenting clinical sign	Clinical sign present			Clinical sign not present			Relative Risk	95% CI*	p -value
	n	Unassisted deaths	% Fatality Rate	n	Unassisted deaths	% Fatality Rate
Unresponsive	29	21	72.41	709	14	1.97	36.67	20.84 to 64.54	< 0.001
Coma	9	8	88.89	729	27	3.70	24.00	15.51 to 37.13	< 0.001
Stupor	12	5	41.67	726	30	4.13	10.08	4.74 to 21.47	< 0.001
Multiple seizures	7	3	42.86	731	32	4.38	9.79	3.90 to 24.57	< 0.001
Gastro- intestinal haemorrhage	15	2	13.33	723	33	4.56	2.92	0.77 to 11.07	0.115
Single seizure	29	3	10.34	709	32	4.51	2.29	0.75 to 7.05	0.148
Respiratory (excessive panting/ dyspnoea)	508	29	5.71	230	6	2.61	2.19	0.92 to 5.20	0.076
Ataxia	10	1	10.00	728	34	4.67	2.14	0.32 to 14.15	0.429
Petechiae/ Purpura	11	1	9.09	727	34	4.68	1.95	0.29 to 12.98	0.491
Hyper- salivation	31	2	6.45	707	33	4.67	1.38	0.35 to 5.50	0.646
Collapse—intermittent	231	8	3.46	507	27	5.33	0.65	0.30 to 1.41	0.276
Diarrhoea	69	2	2.90	669	33	4.93	0.59	0.14 to 2.40	0.459
Vomiting	176	5	2.84	562	30	5.34	0.53	0.21 to 1.35	0.185
Lethargy	363	5	1.38	375	30	8.00	0.17	0.07 to 0.44	< 0.001

Relative risk describes the risk ratio of death in heat-related illness cases recorded with this clinical sign compared to cases without this clinical sign. *CI confidence interval, n = 738.