Thyroid function testing in Greyhounds.
OBJECTIVE
To evaluate thyroid function in healthy Greyhounds, compared with healthy non-Greyhound pet dogs, and to establish appropriate reference range values for Greyhounds.


METHODS
98 clinically normal Greyhounds and 19 clinically normal non-Greyhounds.


METHODS
Greyhounds were in 2 groups as follows: those receiving testosterone for estrus suppression (T-group Greyhounds) and those not receiving estrus suppressive medication (NT-group Greyhounds). Serum thyroxine (T4) and free thyroxine (fT4) concentrations were determined before and after administration of thyroid-stimulating hormone (TSH) and thyroid-releasing hormone (TRH). Basal serum canine thyroid stimulating hormone (cTSH) concentrations were determined on available stored sera.


RESULTS
Basal serum T4 and fT4 concentrations were significantly lower in Greyhounds than in non-Greyhounds. Serum T4 concentrations after TSH and TRH administration were significantly lower in Greyhounds than in non-Greyhounds. Serum fT4 concentrations after TSH and TRH administration were significantly lower in NT-group than T-group Greyhounds and non-Greyhounds. Mean cTSH concentrations were not different between Greyhounds and non-Greyhounds.


CONCLUSIONS
Previously established canine reference range values for basal serum T4 and fT4 may not be appropriate for use in Greyhounds. Greyhound-specific reference range values for basal serum T4 and fT4 concentrations should be applied when evaluating thyroid function in Greyhounds. Basal cTSH concentrations in Greyhounds are similar to non-Greyhound pet dogs.
Gaughan
K R
KR
Veterinary Medical Teaching Hospital, Kansas State University, Manhattan 66506-5701, USA.
Bruyette
D S
DS
D000818:Animals; D004285:Dogs / Q000097:blood / Q000502:physiology*; D005260:Female; D008297:Male; D012016:Reference Values; D013960:Thyroid Function Tests / Q000662:veterinary*; D013961:Thyroid Gland / Q000502:physiology*; D013972:Thyrotropin / Q000008:administration & dosage / Q000502:physiology; D013973:Thyrotropin-Releasing Hormone / Q000008:administration & dosage / Q000502:physiology; D013974:Thyroxine / Q000097:blood
D013973:Thyrotropin-Releasing Hormone; D013972:Thyrotropin; D013974:Thyroxine