Serum concentrations of thyroxine, 3,5,3'-triiodothyronine, thyrotropin, and prolactin in dogs before and after thyrotropin-releasing hormone administration

Serum concentrations of thyrotropin (TSH), prolactin, thyroxine, and 3,5,3'-triiodothyronine in 15 euthyroid dogs and 5 thyroidectomized and propylthiouracil-treated dogs after thyrotropin-releasing hormone (TRH) administration were measured. Although thyroidectomized and propylthiouracil-treated dogs had higher (P less than 0.01) base-line concentrations of TSH in serum than did euthyroid dogs, concentrations of TSH after TRH administration varied at 7.5, 15, and 30 minutes with 14 of 45 samples obtained from healthy dogs having lower TSH concentrations than before TRH challenge. Similarly, concentrations of 3,5,3'-triiodothyronine in the serum of euthyroid dogs 4 hours after TRH administration were similar (P less than 0.05) to concentrations before TRH challenge. Although the mean concentration of thyroxine in serum was elevated (P less than 0.05) 4 hours after administration of TRH to euthyroid animals, as compared with base-line levels, the individual response was variable with concentrations not changing or decreasing in 4 dogs. Therefore, the TRH challenge test as performed in the current investigation was of limited value in evaluating canine pituitary gland function. Although mean concentrations of TSH in serum were higher (P less than 0.05) in euthyroid dogs after TRH administration, the response was too variable among individual animals for accurate evaluation of pituitary gland function. Concentrations of prolactin in the sera of dogs after TRH administration, confirmed previous reports that exogenously administered TRH results in prolactin release from the canine pituitary and indicated that the TRH used was biologically potent.     

Cryosurgery for treatment of recurrent proliferative keratoconjunctivitis in five dogs

Cryosurgery was used for treatment of recurrent proliferative keratoconjunctivitis in 5 dogs that had been treated with combined medical and surgical procedures without success. Four dogs recovered completely after one application of cryosurgery. The fifth dog did not respond to cryosurgery until after oral administration of corticosteroids was stopped, indicating a possible immune-mediated mechanism of action of cryosurgery on proliferative keratoconjunctivitis.     

Continuous positive airway pressure therapy for aspiration pneumonia in a dog

A 14-year-old mixed-breed dog aspirated a large amount of liquid barium sulfate. Calculation of the alveolar arterial oxygen tension difference (34 mm of Hg; normal, less than 7.5 mm of Hg) from the alveolar gas equation and the arterial blood gas analysis indicated impaired pulmonary gas exchange. The dog was treated for 5 days with continuous positive airway pressure and supplemental oxygen administered by a simple apparatus connected to a tracheostomy tube. Continuous positive airway pressure was believed to improve gas exchange and to increase pulmonary compliance by decreasing alveolar collapse in this dog.     

Lumbosacral disease.

Careful clinical and neurologic evaluations are the foundation on which a diagnosis of lumbosacral disease is based. Appropriate use of ancillary diagnostic aids will confirm the diagnosis and allow appropriate treatment to be instituted.     

Potato growth in response to relative humidity

Potato plants (Solanum tuberosum L. cvs. Russet Burbank, Norland, and Denali) were grown for 56 days in controlled-environment rooms under continuous light at 20C and 50% or 85% RH. No significant differences in total plant dry weight were measured between the humidity treatments, but plants grown under 85% RH produced higher tuber yields. Leaf areas were greater under 50% RH and leaves tended to be larger and darker green than at 85% RH.