Exercise induced hypercoagulability, increased von Willebrand factor and decreased thyroid hormone concentrations in sled dogs

BACKGROUND: Sled dogs performing endurance races have been reported to have a high incidence of gastric erosions or ulcerations and an increased risk of gastro intestinal bleeding leading to death in some cases. In addition, these dogs also become hypothyroid during training and exercise. Canine hypothyroidism has been shown to correlate with decreased von Willebrand factor antigen and potentially increased bleeding tendency. Whether increased gastro intestinal bleeding risk is exacerbated due to changes in the hemostatic balance is unknown. The aim of this study was to investigate the hemostatic balance in sled dogs before and after exercise and in addition evaluate any correlation to thyroid status. Twenty sled dogs have been assessed in untrained and trained condition and immediately after exercise. The first sample was collected in the autumn following a resting period, and subsequently the dogs were exposed to increased intensity of training. After four months the peak of physical condition was reached and a 68 km long sled pulling exercise was performed. Samples were collected before and immediately after the exercise. Evaluated parameters were: plasma thromboelastographic (TEG) R, SP, α and MA, activated partial thromboplastin time (aPTT), prothrombin time (PT), fibrinogen, von Willebrand factor (vWf), D-dimer, platelet number, thyroid hormones, hematocrit and C-reactive protein (CRP). RESULTS: Exercise induced an overall hypercoagulable state characterized by significant decreases of TEG R and SP and an increase of α, increased concentrations of plasma vWf and decreased aPTT. In addition, a proinflammatory status was seen by a significant increase of serum CRP concentrations. Thyroid status was confirmed to be hypothyroid as training and exercise induced significant decrease of thyroxin (T4), free thyroxin (fT4) and thyroxin stimulating hormone (TSH) concentrations. Fibrinogen decreased significantly and PT increased. The training-induced changes showed correlation between T4, fT4 and aPTT and correlation between TSH and fibrinogen. Exercise-induced changes showed correlation between T4 and PT. CONCLUSIONS: Exercise was associated with a hypercoagulable state and an increase of vWf concentration in this group of sled dogs. Decreased thyroid hormone concentrations after training and exercise were confirmed, but were associated with increased and not decreased vWf in this group of sled dogs

QimmeqHealth—thyroid status of Greenland sled dogs (<i>Canis lupus familiaris borealis</i>)

BACKGROUND: Greenland sled dogs (GSD) are a unique, genetically isolated population of dogs living under exceptional environmental conditions. Metabolism, and thereby thyroid hormones are affected by multiple factors. Among other activity, energy balance and environmental conditions are important. A breed-specific reference interval (RI) can be useful for diagnostics of potential thyroid-related pathologies. The aim of this study was to establish RIs of the thyroid hormones thyroxin (T4), free thyroxin (fT4), and thyroid stimulating hormone (TSH) in GSD. In addition to evaluate the effect of sex, age, season, management, and body condition score (BCS) in GSD. Physical exams and cephalic venous blood sampling were performed in the period of 2018–2019 from 265 GSD managed either privately or by the Danish navy. Serum biochemical analyses, including C-reactive protein, were performed and RIs were determined for TSH, T4 and fT4 in only healthy dogs. The RIs were determined using American Society for Veterinary Clinical Pathology guidelines and the effect of varying factors were evaluated by linear regression and further tested by Mann–Whitney test. RESULTS: 144 GSD were included in the reference group resulting in RIs: T4: 6.44–48.65 nmol/L; fT4: 3.91–18.51 pmol/L; and TSH: 0.04–0.55 ng/mL. Female GSD had significantly higher concentrations of T4 (P = 0.039) and fT4 (P = 0.015) compared to males; a positive correlation between TSH and aging was found; T4 concentrations were significantly higher (P = 0.003) during summer; and TSH concentrations were lower in GSD managed by the navy (P < 0.0001). BCS was higher (P < 0.0001) in Sirius GSD compared to civilian GSD, and BCS was positively correlated with T4 and negatively correlated with TSH. CONCLUSIONS: Reference intervals for T4, fT4 and TSH in GSD were established. The RI for T4 and fT4 was lower compared to other breeds. In addition, sex, age, season, management and BCS demonstrated variable effects on thyroid hormones. Our results can be used as a foundation for improving management and further research of GSD. SUPPLEMENTARY INFORMATION: The online version contains supplementary material available at 10.1186/s13028-021-00617-8

Ethylene glycol toxicosis in milk-fed dairy calves

BACKGROUND: Ethylene glycol (EG) (antifreeze) toxicosis has mostly been reported in dogs and cats, while reports on EG toxicosis in cattle are sparse. We report EG toxicosis in 25 milk-fed calves associated with a leak in the cooling pipes in a milk taxi. The milk taxi was connected to a geothermal heating system in which EG was used as antifreeze. CASE PRESENTATION: Although the assistant responsible for feeding milk to the calves observed a few blue-colored droplets of liquid on the surface of the milk in the milk taxi and suspected EG contamination, the milk was fed to the calves. Within hours, the calves became depressed and some died within the next 2 days. Necropsy and histopathology revealed widespread severe acute renal tubular necrosis with numerous birefringent crystals in the tubular lumen. Biochemical analysis of serum showed severe damage to the kidneys (marked azotemia) and hypochloremia, hyponatremia and hyperkalemia; findings consisting with metabolic acidosis. After feeding the calves, the assistant inspected the milk taxi and found a leaking cooling pipe. CONCLUSIONS: The suspected EG toxicosis was confirmed by the observation of renal tubular necrosis, numerous intratubular crystals, and metabolic acidosis. EG toxicosis due to leaking pipes connected to a geothermal heating system has not been reported previously. Alternative antifreeze products that are less toxic than EG are recommended for use if there is a risk of contamination of human and animal foodstuffs in case of a leak in the system