Exercise-induced hyperthermia syndrome (canine stress syndrome) in four related male English springer spaniels

Abstract

Objective: This retrospective study describes the signalment, clinical presentation, diagnostic findings, and mode of inheritance in four young male English springer spaniel dogs with presumptive canine stress syndrome.

Materials and methods: Appropriate cases were located through medical searches of medical records of two large private referral centers. Inclusion criteria comprised of English springer spaniel dogs with tachypnea and hyperthermia that subsequently developed weakness or collapse, with or without signs of hemorrhage, soon after a period of mild-to-moderate exercise. The pedigrees of the four affected dogs, as well as eleven related English springer spaniels, were then analyzed to determine a presumptive mode of genetic inheritance.

Results: Four dogs met the inclusion criteria. All four were male, suggesting the possibility of a recessive sex-linked heritable disorder. Pedigree analysis suggests that more dogs may be potentially affected, although these dogs may have never had the concurrent triggering drug/activity/event to precipitate the clinical syndrome. There was complete resolution of clinical signs in three of the four dogs with aggressive symptomatic and supportive therapy, with one dog dying during treatment.

Conclusion: Dogs with canine stress syndrome have the potential for rapid recovery if treated aggressively and the complications of the disease (eg, coagulopathy) are anticipated. All four dogs were male, suggesting the possibility of a recessive sex-linked mode of inheritance. Further genetic analyses should be strongly considered by those involved with the English springer spaniel breed, either with a genome-wide association study using canine single-nucleotide polymorphism arrays or whole-genome sequencing of affected and closely related dogs.

Keywords: English springer spaniel; canine stress syndrome; coagulopathy; dog; malignant hyperthermia.

Figure 1

Multigenerational pedigree representing affected males segregating for canine stress syndrome. Notes: Circles represent female and squares represent males. Solid symbols represent the affected dogs included in the study. (A) Pedigree representing the relationship between the four affected males and 37 additional related individuals. (B) Pedigree hypothesizing the inheritance of the disease allele under a recessive X-linked transmission. Half-filled circles represent the hypothesized inheritance of mutated allele from the maternal side.