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Hinderer J, Lüdeke J, Riege L, Bartel A, Kohn B, Müller E, Arlt SP. Thyroid hormones in canine pregnancy and lactation. Theriogenology 2023; 203:43-52. [PMID: 36966584 DOI: 10.1016/j.theriogenology.2023.03.005] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/03/2023] [Revised: 02/20/2023] [Accepted: 03/06/2023] [Indexed: 03/10/2023]
Abstract
It is believed that thyroid function has a significant effect on fertility and fetal development in mammals. So far, however, only few studies have been published about potential effects of the reproductive cycle stage on thyroid hormone concentrations in dogs. Therefore, over the course of 122 pregnant and non-pregnant cycles in healthy bitches, Thyroid stimulating hormone (TSH), free Thyroxine (fT4), total Thyroxine (tT4) and Progesterone (P4) were measured six times to assess the influence of the cycle stage and pregnancy on hormone concentrations. The aim was to evaluate established reference intervals for the thyroid hormones in a female study population. Of the 122 bitches, 98 became pregnant. Blood samples were collected during estrus, three times in pregnancy, during lactation and after weaning, or at equivalent times during and after estrus in non-pregnant dogs. No differences between pregnant and non-pregnant animals in any of the thyroid hormones were found. Hormone concentrations, however, differed significantly between the six samplings (p < .01). TSH initially declined during pregnancy, then rose again. The mean concentration of all dogs exceeded the overall upper reference limit of 0.70 ng/mL during lactation. Concentrations of tT4 and ft4 increased during the first third of pregnancy and then subsequently declined. The overall reference limits for tT4 were 0.47-3.20 μg/dL, and for fT4 4.86-29.60 pmol/L, but the reference intervals varied between the sampling dates. The observed patterns may reflect that maternal tT4 and fT4 seem to have important effects during early pregnancy, including a pronounced negative feedback effect on TSH. The initial increase and subsequent decline of tT4 and fT4 concentrations during the course of pregnancy is in accordance with findings in humans and may support the development of fetal thyroid function. The observed peak of TSH concentrations during lactation suggests that the demand for thyroid hormones in this phase is largest. Even if the underlying causes and mechanisms of thyroid regulation are not fully understood, the results of this study show relevant changes of hormone concentrations in the course of the sexual cycle and pregnancy. In that regard, cycle stage needs to be considered when assessing thyroid function in bitches.
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Laboratory Diagnosis of Thyroid and Adrenal Disease. Vet Clin North Am Small Anim Pract 2023; 53:207-224. [DOI: 10.1016/j.cvsm.2022.08.005] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/17/2022]
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Investigation of adrenal and thyroid gland dysfunction in dogs with ultrasonographic diagnosis of gallbladder mucocele formation. PLoS One 2019; 14:e0212638. [PMID: 30811473 PMCID: PMC6392329 DOI: 10.1371/journal.pone.0212638] [Citation(s) in RCA: 12] [Impact Index Per Article: 2.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/15/2018] [Accepted: 02/06/2019] [Indexed: 12/12/2022] Open
Abstract
Gallbladder mucocele formation is an emerging disease in dogs characterized by increased secretion of condensed granules of gel-forming mucin by the gallbladder epithelium and formation of an abnormally thick mucus that can culminate in obstruction of the bile duct or rupture of the gallbladder. The disease is associated with a high morbidity and mortality and its pathogenesis is unknown. Affected dogs have a significantly increased likelihood of concurrent diagnosis of hyperadrenocorticism, hypothyroidism, and hyperlipidemia. Whether these endocrinopathies represent coincidental primary disease processes that exacerbate gallbladder mucocele formation in predisposed dogs or reflect a concurrent disruption of endocrine and lipid metabolism is unclear. In this study, we investigated a hypothesis that dogs with gallbladder mucocele formation would have a high prevalence of occult and atypical abnormalities in adrenal cortical and thyroid gland function that would suggest the presence of endocrine disruption and provide deeper insight into disease pathogenesis. We performed a case-control study of dogs with and without ultrasonographic diagnosis of gallbladder mucocele formation and profiled adrenal cortical function using a quantitative mass spectrometry-based assay of serum adrenal-origin steroids before and after administration of synthetic cosyntropin. We simultaneously profiled serum thyroid hormone concentrations and evaluated iodine sufficiency by measurement of urine iodine:creatinine ratios (UICR). The studies were complemented by histological examination of archival thyroid tissue and measurements of thyroid gland organic iodine from dogs with gallbladder mucocele formation and control dogs. Dogs with gallbladder mucocele formation demonstrated an exaggerated cortisol response to adrenal stimulation with cosyntropin. A prevalence of 10% of dogs with gallbladder mucocele formation met laboratory-based criteria for suspect or definitive diagnosis of hyperadrenocorticism. A significantly greater number of dogs with gallbladder mucocele formation had basal serum dehydroepiandrosterone (DHEAS) increases compared to control dogs. A high percentage of dogs with gallbladder mucocele formation (26%) met laboratory-based criteria for diagnosis of hypothyroidism, but lacked detection of anti-thyroglobulin antibodies. Dogs with gallbladder mucocele formation had significantly higher UICRs than control dogs. Examination of thyroid tissue from an unrelated group of dogs with gallbladder mucocele formation did not demonstrate histological evidence of thyroiditis or significant differences in content of organic iodine. These findings suggest that dogs with gallbladder mucocele formation have a greater capacity for cortisol synthesis and pinpoint DHEAS elevations as a potential clue to the underlying pathogenesis of the disease. A high prevalence of thyroid dysfunction with absent evidence for autoimmune thyroiditis suggest a disrupted thyroid hormone metabolism in dogs with gallbladder mucocele formation although an influence of non-thyroidal illness cannot be excluded. High UICR in dogs with gallbladder mucocele formation is of undetermined significance, but of interest for further study.
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Hrovat A, De Keuster T, Kooistra HS, Duchateau L, Oyama MA, Peremans K, Daminet S. Behavior in dogs with spontaneous hypothyroidism during treatment with levothyroxine. J Vet Intern Med 2018; 33:64-71. [PMID: 30499213 PMCID: PMC6335523 DOI: 10.1111/jvim.15342] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/04/2018] [Accepted: 10/15/2018] [Indexed: 11/27/2022] Open
Abstract
Background Thyroid hormone supplementation anecdotally has been described as a valid treatment option for dogs with aggression‐related problems. However, prospective, controlled, and blinded trials evaluating behavior and neurohormonal status in hypothyroid dogs during treatment with levothyroxine are lacking. Objective Levothyroxine supplementation will have a significant influence on the behavior and neurohormonal status of dogs with spontaneous hypothyroidism. Animals Twenty client‐owned dogs diagnosed with spontaneous hypothyroidism. Methods This prospective study was to evaluate the behavior of dogs, which was screened at initial presentation, and after 6 weeks, and 6 months of treatment with levothyroxine (starting dosage 10 μg/kg PO q12h) using the standardized Canine Behavioral Assessment and Research Questionnaire (C‐BARQ). At each time period, circulating serotonin and prolactin (PRL) concentrations were evaluated using a commercially validated ELISA kit and heterologous radioimmunoassay, respectively. Results After 6 weeks of thyroid hormone supplementation, C‐BARQ scores demonstrated a significant increase in activity of hypothyroid dogs (P < .01). No significant change in any of the behavioral signs was observed after 6 months of treatment. No significant difference in circulating concentrations of serotonin (P > .99 and P = .46) and PRL (P = .99 and P = .37) were noted between the 6‐week and 6‐month periods compared with baseline. Conclusions and Clinical Importance The results of this study indicate increased activity of hypothyroid dogs after 6 weeks of thyroid hormone supplementation. None of the hypothyroid dogs in this cohort showed a significant change in any of the evaluated behavioral signs and neurohormonal status after 6 months of thyroid hormone supplementation.
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Affiliation(s)
- Alenka Hrovat
- Small Animal Department, Faculty of Veterinary Medicine, Ghent University, Merelbeke, Belgium
| | - Tiny De Keuster
- Small Animal Department, Faculty of Veterinary Medicine, Ghent University, Merelbeke, Belgium
| | - Hans S Kooistra
- Department of Clinical Sciences of Companion Animals, Faculty of Veterinary Medicine, Utrecht University, Utrecht, The Netherlands
| | - Luc Duchateau
- Biometrics Research Group, Faculty of Veterinary Medicine, Ghent University, Merelbeke, Belgium
| | - Mark A Oyama
- Department of Clinical Studies-Philadelphia, School of Veterinary Medicine, University of Pennsylvania, Philadelphia, Pennsylvania
| | - Kathelijne Peremans
- Department of Veterinary Medical Imaging and Small Animal Orthopedics, Faculty of Veterinary Medicine, Ghent University, Merelbeke, Belgium
| | - Sylvie Daminet
- Small Animal Department, Faculty of Veterinary Medicine, Ghent University, Merelbeke, Belgium
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Böhm T, Klinger C, Classen J, Udraite L, Linek M, Mueller RS. [Repeatability and variability of total T4 measurements at three German veterinary laboratories]. TIERARZTLICHE PRAXIS. AUSGABE K, KLEINTIERE/HEIMTIERE 2017; 45:161137. [PMID: 29099903 DOI: 10.15654/tpk-161137] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 12/20/2016] [Accepted: 08/02/2017] [Indexed: 11/13/2022]
Abstract
OBJECTIVE To evaluate the reproducibility of serum testing for total thyroxine (T4) in three German laboratories. MATERIALS AND METHODS Serum was taken from 53 dogs with suspected hypothyroidism and divided into five aliquots. Three aliquots of each sample were marked with different names and sent to one laboratory (two aliquots simultaneously and one aliquot 1-3 days later). The remaining aliquots were sent to two other laboratories. Laboratory 1 used an enzyme immunoassay for T4 measurements, whereas laboratories 2 and 3 used a chemiluminescence immunoassay. The agreement between the three laboratories (values within or below the reference interval) was determined using the Cohen's Kappa test. The intra- and interassay variability was calculated for each laboratory and the agreement between samples submitted to the same laboratory was also determined using the Cohen's Kappa test. RESULTS For n = 23/41 patients tested simultaneously in the three laboratories, all three values were either uniformly below, within or above the respective reference interval. The Cohen's Kappa value for intra- and interassay agreement was 1.0 in laboratory 2 (n = 15, complete agreement), 0.33 in laboratory 1 (n = 16) and 0.37 (intra-) and 0.19 (interassay agreement) in laboratory 3 (n = 16, low agreement). There was a low agreement between laboratories 1 and 2 and between laboratories 1 and 3 (κ = 0.30 and 0.25, respectively), while a high agreement was determined between laboratories 2 and 3 (κ = 0.68). The intrassay variability of laboratories 1, 2 and 3 was 13.6%, 5.0% and 10.4%, the interassay variability 17.2%, 5.1% and 17.4%, respectively. CONCLUSION AND CLINICAL RELEVANCE The differences in the measurement of thyroxine concentrations of the same serum sample in different laboratories and at different time points in the same laboratory underline the high relevance of interpreting laboratory results in context with the clinical signs of hypothyroidism as well as other laboratory values such as TSH concentration.
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Affiliation(s)
- Teresa Böhm
- Teresa Böhm, Medizinische Kleintierklinik, Ludwig-Maximilians-Universität München, Veterinärstraße 13, 80539 München, E-Mail:
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Anderson R, Mueller R, Reese S, Wehner A. Evaluation of an automated enzyme-linked fluorescent assay for thyroxine measurement in cat and dog sera. J Vet Diagn Invest 2017; 29:278-286. [PMID: 28355954 DOI: 10.1177/1040638717696442] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/15/2022] Open
Abstract
Measurement of total thyroxine (T4) is the first testing step in the work-up of thyroid disease in small animals. We evaluated an enzyme-linked fluorescent assay (ELFA) as an in-house method to measure T4 in cats and dogs. We compared the T4 concentration in sera of 122 cats and 176 dogs measured by the ELFA with an enzyme immunoassay (EIA) to assess the concordance of the 2 methods. Bias of the ELFA in cats was -11.4% and in dogs 1.4%. Using Bland-Altman plots, limits of agreement were -81.5 to 58.7% in cats and -71.4 to 74.4% in dogs. Imprecision was calculated for both methods. Intra- and interassay coefficients of variation (CVs) of the ELFA in feline sera were 0.7 and 3.4% and of the EIA 7.6 and 15.7%, respectively. Intra- and interassay CVs of both ELFA and EIA in canine sera were <9.5%. Reference intervals for the ELFA method were established and were 13.3-49.5 nmol/L for cats and 10.1-42.9 nmol/L for dogs. Accuracy of the EIA and ELFA was scored by assessing if the measured T4 value would identify the expected T4 range (low, normal, or elevated) of patients, based on history, clinical presentation, other diagnostic means, and response to therapy. This was possible for 75 cats and 50 dogs. Both methods yielded acceptable results, but the EIA was more accurate compared to the ELFA (percentage of true-positives in cats and dogs: EIA: 97% and 100%; ELFA: 92% and 94%).
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Affiliation(s)
- Rouven Anderson
- Clinic of Small Animal Medicine (Anderson, Mueller, Wehner), Faculty of Veterinary Medicine, Ludwig Maximilian University, Munich, Germany.,Institute of Veterinary Anatomy, Histology and Embryology (Reese), Faculty of Veterinary Medicine, Ludwig Maximilian University, Munich, Germany
| | - Ralf Mueller
- Clinic of Small Animal Medicine (Anderson, Mueller, Wehner), Faculty of Veterinary Medicine, Ludwig Maximilian University, Munich, Germany.,Institute of Veterinary Anatomy, Histology and Embryology (Reese), Faculty of Veterinary Medicine, Ludwig Maximilian University, Munich, Germany
| | - Sven Reese
- Clinic of Small Animal Medicine (Anderson, Mueller, Wehner), Faculty of Veterinary Medicine, Ludwig Maximilian University, Munich, Germany.,Institute of Veterinary Anatomy, Histology and Embryology (Reese), Faculty of Veterinary Medicine, Ludwig Maximilian University, Munich, Germany
| | - Astrid Wehner
- Clinic of Small Animal Medicine (Anderson, Mueller, Wehner), Faculty of Veterinary Medicine, Ludwig Maximilian University, Munich, Germany.,Institute of Veterinary Anatomy, Histology and Embryology (Reese), Faculty of Veterinary Medicine, Ludwig Maximilian University, Munich, Germany
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Zygner W, Gójska-Zygner O, Bąska P, Długosz E. Low T3 syndrome in canine babesiosis associated with increased serum IL-6 concentration and azotaemia. Vet Parasitol 2015; 211:23-7. [PMID: 25976636 DOI: 10.1016/j.vetpar.2015.04.023] [Citation(s) in RCA: 15] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/19/2014] [Revised: 04/13/2015] [Accepted: 04/26/2015] [Indexed: 01/31/2023]
Abstract
Low triiodothyronine (T3) syndrome, also named euthyroid sick syndrome or non-thyroidal illness syndrome, has been recognized in canine babesiosis caused by Babesia rossi, where it manifested by lowering of the serum thyrotropin (TSH), total thyroxin (TT4) and free thyroxin (FT4) concentrations. This syndrome has also been observed in critical diseases in humans and animals, and the severity of the disease is considered an important factor in lowering of thyroid hormone concentrations. Interleukin-6 (IL-6) plays a role in the development of low T3 syndrome by causing a decrease in deiodinases 1 and 2 activity and increased activity of deiodinase 3, enzymes involved in the conversion of thyroxin (T4) to T3. The purpose of this study was to compare the concentrations of serum thyroid hormones and TSH between healthy dogs and dogs with babesiosis, and to determine correlations between serum IL-6 concentration and serum total T3 (TT3), TT4, FT4, and TSH concentrations, and the level of azotaemia in dogs with babesiosis. The concentrations of IL-6, TT3, TT4, FT4, TSH, urea and creatinine were determined in 13 dogs with canine babesiosis caused by Babesia canis and in 10 healthy dogs. The results of this study showed decreases in TT3, TT4, FT4, and TSH and increases in IL-6, urea and creatinine concentrations in affected dogs in comparison to healthy dogs. The concentration of IL-6 was negatively correlated with TT3 and TSH concentrations and the TT3 concentration was negatively correlated with serum urea and creatinine concentrations. This study showed low T3 syndrome in canine babesiosis, which was confirmed by the determination of the T3 concentration, and demonstrates that in canine babesiosis the T3 concentration is associated with IL-6 concentration.
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Affiliation(s)
- Wojciech Zygner
- Division of Parasitology, Department of Preclinical Sciences, Faculty of Veterinary Medicine, Warsaw University of Life Sciences, Ciszewskiego 8, 02-786 Warsaw, Poland.
| | | | - Piotr Bąska
- Division of Pharmacology and Toxicology, Department of Preclinical Sciences, Faculty of Veterinary Medicine, Warsaw University of Life Sciences, Ciszewskiego 8, 02-786 Warsaw, Poland
| | - Ewa Długosz
- Division of Parasitology, Department of Preclinical Sciences, Faculty of Veterinary Medicine, Warsaw University of Life Sciences, Ciszewskiego 8, 02-786 Warsaw, Poland
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Randolph JF, Lamb SV, Cheraskin JL, Schanbacher BJ, Salerno VJ, Mack KM, Scarlett JM, Place NJ. Free thyroxine concentrations by equilibrium dialysis and chemiluminescent immunoassays in 13 hypothyroid dogs positive for thyroglobulin antibody. J Vet Intern Med 2015; 29:877-81. [PMID: 25858585 PMCID: PMC4895428 DOI: 10.1111/jvim.12573] [Citation(s) in RCA: 10] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/20/2014] [Revised: 01/29/2015] [Accepted: 02/19/2015] [Indexed: 11/28/2022] Open
Abstract
Objective To determine if concentrations of free thyroxine (FT4) measured by semi‐automated chemiluminescent immunoassay (CLIA) correspond to FT4 determined by equilibrium dialysis (ED) in hypothyroid dogs positive for thyroglobulin antibody (TGA). Animals Thirteen TGA‐positive dogs classified as hypothyroid based on subnormal FT4 concentrations by ED. Methods Qualitative assessment of canine TGA was performed using an enzyme‐linked immunosorbent assay. Serum total thyroxine and total triiodothyronine concentrations were measured by radioimmunoassay. Serum FT4 concentration was determined by ED, and also by semi‐automated CLIA for human FT4 (FT4h) and veterinary FT4 (FT4v). Canine thyroid stimulating hormone concentration was measured by semi‐automated CLIA. Results Each dog's comprehensive thyroid profile supported a diagnosis of hypothyroidism. For detection of hypothyroidism, sensitivities of CLIA for FT4h and FT4v were 62% (95% CI, 32–85%) and 75% (95% CI, 36–96%), respectively, compared to FT4 by ED. Five of 13 (38%) dogs had FT4h and 2 of 8 (25%) dogs had FT4v concentrations by CLIA that were increased or within the reference range. Percentage of false‐negative test results for FT4 by CLIA compared to ED was significantly (P < .0001 for FT4h and P < .001for FT4v) higher than the hypothesized false‐negative rate of 0%. Conclusions and Clinical Importance Caution should be exercised in screening dogs for hypothyroidism using FT4 measured by CLIA alone. Some (25–38%) TGA‐positive hypothyroid dogs had FT4 concentrations determined by CLIA that did not support a diagnosis of hypothyroidism.
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Affiliation(s)
- J F Randolph
- Department of Clinical Sciences, College of Veterinary Medicine, Cornell University, Ithaca, NY, 14853
| | - S V Lamb
- The New York State Veterinary Diagnostic Endocrinology Laboratory, Animal Health Diagnostic Center, College of Veterinary Medicine, Cornell University, Ithaca, NY, 14853
| | - J L Cheraskin
- The New York State Veterinary Diagnostic Endocrinology Laboratory, Animal Health Diagnostic Center, College of Veterinary Medicine, Cornell University, Ithaca, NY, 14853
| | - B J Schanbacher
- The New York State Veterinary Diagnostic Endocrinology Laboratory, Animal Health Diagnostic Center, College of Veterinary Medicine, Cornell University, Ithaca, NY, 14853
| | - V J Salerno
- The New York State Veterinary Diagnostic Endocrinology Laboratory, Animal Health Diagnostic Center, College of Veterinary Medicine, Cornell University, Ithaca, NY, 14853
| | - K M Mack
- The New York State Veterinary Diagnostic Endocrinology Laboratory, Animal Health Diagnostic Center, College of Veterinary Medicine, Cornell University, Ithaca, NY, 14853
| | - J M Scarlett
- Department of Population Medicine & Diagnostic Sciences, College of Veterinary Medicine, Cornell University, Ithaca, NY, 14853
| | - N J Place
- Department of Population Medicine & Diagnostic Sciences, College of Veterinary Medicine, Cornell University, Ithaca, NY, 14853.,The New York State Veterinary Diagnostic Endocrinology Laboratory, Animal Health Diagnostic Center, College of Veterinary Medicine, Cornell University, Ithaca, NY, 14853
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Saridomichelakis MN, Xenoulis PG, Chatzis MK, Kasabalis D, Steiner JM, Suchodolski JS, Petanides T. Thyroid function in 36 dogs with leishmaniosis due to Leishmania infantum before and during treatment with allopurinol with or without meglumine antimonate. Vet Parasitol 2013; 197:22-8. [DOI: 10.1016/j.vetpar.2013.04.038] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/07/2012] [Revised: 04/15/2013] [Accepted: 04/19/2013] [Indexed: 10/26/2022]
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10
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Shiel RE, Sist M, Nachreiner RF, Ehrlich CP, Mooney CT. Assessment of criteria used by veterinary practitioners to diagnose hypothyroidism in sighthounds and investigation of serum thyroid hormone concentrations in healthy Salukis. J Am Vet Med Assoc 2010; 236:302-8. [DOI: 10.2460/javma.236.3.302] [Citation(s) in RCA: 20] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/20/2022]
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Espineira MD, Mol J, Peeters M, Pollak Y, Iversen L, Dijk J, Rijnberk A, Kooistra H. Assessment of Thyroid Function in Dogs with Low Plasma Thyroxine Concentration. J Vet Intern Med 2007. [DOI: 10.1111/j.1939-1676.2007.tb02924.x] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/28/2022] Open
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13
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Hegstad-Davies RL. A review of sample handling considerations for reproductive and thyroid hormone measurement in serum or plasma. Theriogenology 2006; 66:592-8. [PMID: 16828859 DOI: 10.1016/j.theriogenology.2006.05.004] [Citation(s) in RCA: 12] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/18/2022]
Abstract
Inappropriate sample handling of blood, serum or plasma collected for the determination of hormone concentration may lead to inaccurate endocrine data and diagnoses. Many useful studies have been conducted to determine the potential effects of sample handling on measured hormone concentration. Unfortunately, because reported results frequently differ according to assay method, species studied and parameters measured, it is not always possible to predict the effect of specific sample handling scenarios as they are presented in practice. The objective of this review is to provide a summary of what has been reported in the literature regarding sample-handling procedures that may affect the measurement of hormone concentration in plasma or sera from animals being evaluated for reproductive function.
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Affiliation(s)
- Rebecca L Hegstad-Davies
- Veterinary Diagnostic Laboratory, University of Minnesota, 1333 Gortner Avenue, St. Paul, MN 55108, USA.
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Hoh WP, Oh TH. Circadian variations of serum thyroxine, free thyroxine and 3,5,3'triiodothyronine concentrations in healthy dogs. J Vet Sci 2006; 7:25-9. [PMID: 16434845 PMCID: PMC3242081 DOI: 10.4142/jvs.2006.7.1.25] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/04/2022] Open
Abstract
This study was to determine the daily fluctuation of serum thyroxine (tT4), free thyroxine (fT4), 3,5,3'-triiodothyronine (T3) concentrations in healthy dogs. Thyroid function of these dogs was evaluated on the basis of results of TSH response test. Samples for the measurement of serum tT4, fT4, and T3 concentrations were obtained at 3- hour intervals from 8 : 00 to 20 : 00. Serum tT4, fT4, and T3 concentrations were measured by the enzyme chemiluminescent immunoassay (ECLIA). Mean T3 concentrations had no significant differences according to the sample collection time during the day. Mean tT4 and fT4 concentrations at 11 : 00 were 3.28 +/- 0.86 microg/dl and 1.30 +/- 0.37 ng/dl, respectively and mean tT4 and fT(4) at 14:00 were 3.54 +/- 1.15 microg/dl and 1.35 +/- 0.12 ng/dl, respectively. These concentrations were significantly high compared with tT4 and fT4 concentrations at 8:00, which were 1.75 +/- 0.75 microg/dl and 0.97 +/- 0.25 ng/dl, respectively (p < 0.05). According to the sample collection time, mean tT4 and fT4 concentrations changed with similar fluctuation during the day. Based on these results, it was considered that measurement of serum tT4 and fT4 concentrations from 11 : 00 to 14 : 00 might more easily diagnose the canine hypothyroidism in practice.
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Affiliation(s)
- Woo-Pil Hoh
- Department of Veterinary Internal Medicine, College of Veterinary Medicine, Kyungpook National University, Daegu 702-701, Korea
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Schachter S, Nelson RW, Scott-Moncrieff C, Ferguson DC, Montgomery T, Feldman EC, Neal L, Kass PH. Comparison of Serum-Free Thyroxine Concentrations Determined by Standard Equilibrium Dialysis, Modified Equilibrium Dialysis, and 5 Radioimmunoassays in Dogs. J Vet Intern Med 2004. [DOI: 10.1111/j.1939-1676.2004.tb02543.x] [Citation(s) in RCA: 26] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/30/2022] Open
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Daminet S, Jeusette I, Duchateau L, Diez M, Van de Maele I, De Rick A. Evaluation of thyroid function in obese dogs and in dogs undergoing a weight loss protocol. JOURNAL OF VETERINARY MEDICINE. A, PHYSIOLOGY, PATHOLOGY, CLINICAL MEDICINE 2003; 50:213-8. [PMID: 12948159 DOI: 10.1046/j.1439-0442.2003.00534.x] [Citation(s) in RCA: 33] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 11/20/2022]
Abstract
Obesity and weight loss have been shown to alter thyroid hormone homeostasis in humans. In dogs, obesity is the most common nutritional problem encountered and weight loss is the cornerstone of its treatment. Therefore, it is important to clarify how obesity and weight loss can affect thyroid function test results in that species. The objectives of this study were to compare thyroid function in obese dogs and in lean dogs and to explore the effects of caloric restriction and weight loss on thyroid hormone serum concentrations in obese dogs. In the first experiment, 12 healthy lean beagles and 12 obese beagles were compared. Thyroid function was evaluated by measuring serum concentrations of total thyroxine (TT4), free thyroxine (FT4), total triiodothyronine (TT3), thyrotropin (TSH), and reverse triiodothyronine (rT3) as well as a TSH stimulation test using 75 microg i.v. of recombinant human TSH. In the second experiment, eight obese beagles were fed an energy-restricted diet [average 63% maintenance energy requirement (MER)] until optimal weight was obtained. Blood samples for determination of TT4, FT4, TT3, TSH and rT3, were taken at the start and then weekly during weight loss. Only TT3 and TT4 serum concentrations were significantly higher in obese dogs as compared to lean dogs. In the second experiment, weight loss resulted in a significant decrease in TT3 and TSH serum concentrations. Thus obesity and energy restriction significantly alter thyroid homeostasis in dogs, but the observed changes are unlikely to affect interpretation of thyroid function test results in clinics.
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Affiliation(s)
- S Daminet
- Department of Medicine and Clinical Biology of Small Animals, Ghent University, Belgium.
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Gulikers KP, Panciera DL. Evaluation of the Effects of Clomipramine on Canine Thyroid Function Tests. J Vet Intern Med 2003. [DOI: 10.1111/j.1939-1676.2003.tb01322.x] [Citation(s) in RCA: 11] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/28/2022] Open
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Hill RC, Fox LE, Lewis DD, Beale KM, Nachreiner RF, Scott KC, Sundstrom DA, Jones GL, Butterwick RF. Effects of racing and training on serum thyroid hormone concentrations in racing Greyhounds. Am J Vet Res 2001; 62:1969-72. [PMID: 11763190 DOI: 10.2460/ajvr.2001.62.1969] [Citation(s) in RCA: 22] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/20/2022]
Abstract
OBJECTIVES To determine the effects of racing and training on serum thyroxine (T4), triiodothyronine (T3), and thyroid stimulating hormone (TSH) concentrations in Greyhounds. ANIMALS 9 adult racing Greyhounds. PROCEDURE Serum thyroid hormone concentrations were measured before and 5 minutes after a race in dogs trained to race 500 m twice weekly for 6 months. Resting concentrations were measured again when these dogs had been neutered and had not raced for 3 months. Postrace concentrations were adjusted relative to albumin concentration to allow for effects of hemoconcentration. Thyroid hormone concentrations were then compared with those of clinically normal dogs of non-Greyhound breeds. RESULTS When adjusted for hemoconcentration, total T4 concentrations increased significantly after racing and TSH concentrations decreased; however, there was no evidence of a change in free T4 or total or free T3 concentrations. Resting total T4 concentrations increased significantly when dogs had been neutered and were not in training. There was no evidence that training and neutering affected resting TSH, total or free T3, or free T4 concentrations. Resting concentrations of T3, TSH, and autoantibodies against T4, T3, and thyroglobulin were similar to those found in other breeds; however, resting free and total T4 concentrations were lower than those found in other breeds. CONCLUSIONS AND CLINICAL RELEVANCE Except for total T4, thyroid hormone concentrations in Greyhounds are affected little by sprint racing and training. Greyhounds with low resting total and free T4 concentrations may not be hypothyroid.
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Affiliation(s)
- R C Hill
- Department of Small Animal Clinical Sciences and the Center for Veterinary Sports Medicine, College of Veterinary Medicine, University of Florida, Gainesville 32610-0126, USA
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19
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Kemppainen RJ, Behrend EN. Diagnosis of canine hypothyroidism. Perspectives from a testing laboratory. Vet Clin North Am Small Anim Pract 2001; 31:951-62, vii. [PMID: 11570134 DOI: 10.1016/s0195-5616(01)50007-8] [Citation(s) in RCA: 21] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/22/2022]
Abstract
The most common sample received by our endocrine testing laboratory is submitted for the diagnosis of hypothyroidism in a dog. The current tests most frequently employed in our laboratory for thyroid evaluation in dogs are total T4, free T4 by dialysis, and canine TSH measurement. Each test has strengths and weaknesses and suffers from the possibility of both false positive and false negative results. This article provides a working description of each test and an approach to interpretation of results. Other tests that are less commonly used are also discussed. Examples of interpretation of test results in individual hypothyroid-suspect dogs are presented for illustration.
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Affiliation(s)
- R J Kemppainen
- Department of Anatomy, Physiology and Pharmacology, Auburn University College of Veterinary Medicine, Endocrine Diagnostic Service, Auburn, Alabama, USA.
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20
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Kooistra HS, Diaz-Espineira M, Mol JA, van den Brom WE, Rijnberk A. Secretion pattern of thyroid-stimulating hormone in dogs during euthyroidism and hypothyroidism. Domest Anim Endocrinol 2000; 18:19-29. [PMID: 10701761 DOI: 10.1016/s0739-7240(99)00060-0] [Citation(s) in RCA: 22] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 11/23/2022]
Abstract
In as many as one third of dogs with primary hypothyroidism a plasma thyrotropin (TSH) concentration within the reference range for euthyroid dogs is found. To determine whether this is due to fluctuations in the release of TSH, the plasma profiles of TSH were analyzed in 7 beagle bitches by collecting blood samples every 10 min for 6 hr, both before and after induction of primary hypothyroidism. After induction of primary hypothyroidism, a 37-fold increase in mean basal plasma TSH concentration and a 34-fold increase in mean area under the curve for TSH were found. Analysis by the Pulsar program demonstrated pulsatile secretion of TSH in the hypothyroid state, characterized by relatively low amplitude pulses (mean [+/-SEM]) amplitude 41 +/- 3% of basal plasma TSH level) and a mean pulse frequency of 2.0 +/- 0.5 pulses/6 hr. In the euthyroid state, significant TSH pulses were identified in only 2 dogs. The mean basal plasma TSH level correlated positively (r = 0.84) with the mean amplitude of the TSH pulses, and correlated negatively (r = -0.88) with the TSH pulse frequency. The results of this study demonstrate pulsatile secretion of TSH in dogs during hypothyroidism and only small fluctuations in plasma TSH concentrations during euthyroidism. The findings also suggest that the low TSH values occasionally found in dogs with spontaneous primary hypothyroidism may in some cases in part be the result of ultradian fluctuations.
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Affiliation(s)
- H S Kooistra
- Department of Clinical Sciences of Companion Animals, Faculty of Veterinary Medicine, Utrecht University, The Netherlands.
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21
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Abstract
A definitive diagnosis of hypothyroidism can be difficult because of the many clinical abnormalities associated with thyroid hormone deficiency, and the lack of readily available diagnostic tests with high sensitivity and specificity. Thyroid function tests should be performed only in dogs with clinical findings consistent with hypothyroidism. Measurement of serum total thyroxine (T4) concentration is a useful initial screening test since most hypothyroid dogs have values below the reference range. Serum free T4 concentration measured by equilibrium dialysis is a more sensitive and specific test of thyroid function than total T4 and is particularly useful in dogs with non-thyroidal illness or atypical clinical signs. Measurement of serum endogenous thyroid-stimulating hormone concentration is also helpful, but many hypothyroid dogs have normal results. The gold standard for diagnosis of hypothyroidism remains the thyroid-stimulating hormone response test. It should be used to confirm hypothyroidism when other tests do not agree with the clinical impression or if atypical signs or non-thyroidal illness exist or there has been administration of drugs known to alter thyroid function tests. Ultimately, a positive response to treatment is expected in hypothyroid dogs treated appropriately with levothyroxine.
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Affiliation(s)
- D L Panciera
- Department of Small Animal Clinical Sciences, Virginia-Maryland Regional College of Veterinary Medicine, Virginia Tech University, Blacksburg 24061-0442, USA
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22
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Ramsey IK, Evans H, Herrtage ME. Thyroid-stimulating hormone and total thyroxine concentrations in euthyroid, sick euthyroid and hypothyroid dogs. J Small Anim Pract 1997; 38:540-5. [PMID: 9444634 DOI: 10.1111/j.1748-5827.1997.tb03313.x] [Citation(s) in RCA: 39] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/05/2023]
Abstract
Canine thyroid-stimulating hormone (cTSH) was measured in a variety of clinical cases (n = 72). The cases were classified as euthyroid, sick euthyroid, hypothyroid or hypothyroid on nonthyroidal therapy on the basis of their history, clinical signs, laboratory results (including total thyroxine concentrations and, where indicated, thyroid-releasing hormone [TRH] stimulation tests) and response to appropriate therapy. Additional samples were taken during some of the TRH stimulation tests to measure the response of cTSH concentrations following TRH administration. A reference range (0 to 0.41 ng/ml) was calculated from the basal concentrations of cTSH in a group of 41 euthyroid dogs. Six of nine cases of confirmed hypothyroidism had basal cTSH concentrations above the reference range, whereas the remainder were within the normal range. One of these three remaining cases was a pituitary dwarf and did not show a rise in cTSH concentration following TRH stimulation. In contrast, only one of a group of six hypothyroid dogs that had been on non-thyroidal treatment within the previous four weeks had increased concentrations of basal cTSH. This study also found that five of a group of 16 dogs with sick euthyroid syndrome had increased cTSH concentrations. It was concluded that cTSH measurements are a useful additional diagnostic test in cases of suspected hypothyroidism in dogs but that dynamic testing is still required to confirm the diagnosis of hypothyroidism.
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Affiliation(s)
- I K Ramsey
- Department of Clinical Veterinary Medicine, University of Cambridge
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23
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Dixon RM, Graham PA, Mooney CT. Serum thyrotropin concentrations: a new diagnostic test for canine hypothyroidism. Vet Rec 1996; 138:594-5. [PMID: 8799987 DOI: 10.1136/vr.138.24.594] [Citation(s) in RCA: 15] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/02/2023]
Affiliation(s)
- R M Dixon
- Department of Veterinary Clinical Studies, University of Glasgow Veterinary School, Bearsden, Glasgow
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24
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Kaptein EM, Hays MT, Ferguson DC. Thyroid hormone metabolism. A comparative evaluation. Vet Clin North Am Small Anim Pract 1994; 24:431-66. [PMID: 8053105 DOI: 10.1016/s0195-5616(94)50051-2] [Citation(s) in RCA: 43] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/28/2023]
Abstract
Knowledge of thyroid hormone and iodide metabolism is derived from a combination of in vivo and in vitro studies in a variety of mammalian species including cats, dogs, and humans. Each species provides a unique opportunity to investigate various aspects of normal or altered thyroid hormone physiology. Availability of sensitive and specific human TSH assays has allowed detailed studies of the human hypothalamic-pituitary-thyroid axis which have not been possible in cats and dogs to date. Similarities and differences of thyroid hormone metabolism in dogs, cats, and humans provide the basis for a better understanding of normal physiology as well as shedding light on the significance of changes induced by spontaneous or induced thyroidal and nonthyroidal disorders.
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Affiliation(s)
- E M Kaptein
- Department of Medicine, University of Southern California, Los Angeles
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