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Romagnoli S, Krekeler N, de Cramer K, Kutzler M, McCarthy R, Schaefer-Somi S. WSAVA guidelines for the control of reproduction in dogs and cats. J Small Anim Pract 2024; 65:424-559. [PMID: 38804079 DOI: 10.1111/jsap.13724] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/25/2023] [Revised: 01/19/2024] [Accepted: 02/07/2024] [Indexed: 05/29/2024]
Affiliation(s)
- S Romagnoli
- Department of Animal Medicine, Production and Health, Viale dell'Università 16, University of Padova, Legnaro, 35020, Italy
| | - N Krekeler
- Department of Biomedical Sciences, Melbourne Veterinary School, Faculty of Science, Melbourne, VIC, Australia
| | - K de Cramer
- Department of Production Animals, Faculty of Veterinary Science, University of Pretoria, Onderstepoort, Pretoria, South Africa
| | - M Kutzler
- Dept of Animal and Rangeland Sciences, Oregon State University, 112 Withycombe Hall, Corvallis, OR, 97331, USA
| | - R McCarthy
- Department of Veterinary Clinical Sciences, Cummings School of Veterinary Medicine, Tufts University, North Grafton, MA, 01536, United States
| | - S Schaefer-Somi
- Center for Reproduction, Vetmeduni Vienna, Veterinärplatz 1, Vienna, 1210, Austria
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Gonzalez-Astudillo V, Schaffer-White A, Noble L, O’Hara P, Murray P, Barnes TS, Allavena R. Spontaneous Lesions of Endangered Geriatric Julia Creek Dunnarts ( Sminthopsis douglasi, Archer 1979) with Emphasis in Reproductive Pathology. Vet Sci 2024; 11:142. [PMID: 38668410 PMCID: PMC11054575 DOI: 10.3390/vetsci11040142] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/31/2023] [Revised: 02/22/2024] [Accepted: 03/13/2024] [Indexed: 04/29/2024] Open
Abstract
Julia Creek dunnarts are an endangered species of carnivorous marsupials and the focus of multiple conservation strategies involving significant resources such as captive breeding programs. Despite the relevance for conservation, no study to date has focused on evaluating geriatric diseases in dunnarts. This study describes the pathology findings in a group of one wild and thirty-five captive-born, mostly geriatric Julia Creek dunnarts that failed to produce offspring over multiple breeding periods. A total of 20 females and 16 males were submitted for a postmortem examination, with ages ranging from 9 to 42 and 12 to 42 months for females and males, respectively. Of these, 10 had unremarkable findings. The most common condition in females was cystic glandular hyperplasia (n = 8), typical of hormonal dysregulation profiles in senescence, particularly hyperestrogenism. Rarely, cutaneous disease represented by unidentified dermal round cell infiltrates was observed in females (n = 2). Primary reproductive hormonal dysregulation was also suspected in males diagnosed with testicular degeneration, aspermatogenesis and/or atrophy (n = 3). Cutaneous round cell infiltrates, possibly compatible with epitheliotropic lymphomas, were seen in males (n = 3), and 2/3 affected males also had concurrent testicular degeneration or atrophy, indicating male sex could be a predictor for lymphoid neoplasia in aged dunnarts, especially in individuals with concurrent testosterone-luteinizing hormone dysregulation as it occurs in gonadectomized animals. The role of an underlying viral etiology is also explored. This study is the first to describe major spontaneous diseases in endangered aged Julia Creek dunnarts, providing an important understanding of senescence and geriatric diseases within a conservation context.
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Affiliation(s)
- Viviana Gonzalez-Astudillo
- School of Veterinary Science, The University of Queensland, Gatton Campus, Gatton, QLD 4343, Australia; (L.N.); (P.M.); (T.S.B.); (R.A.)
| | - Andrea Schaffer-White
- Independent Veterinary Pathology, 3245 Logan Road, Underwood, Brisbane, QLD 4119, Australia;
| | - Lawrence Noble
- School of Veterinary Science, The University of Queensland, Gatton Campus, Gatton, QLD 4343, Australia; (L.N.); (P.M.); (T.S.B.); (R.A.)
| | - Patricia O’Hara
- School of Agriculture and Food Sustainability, The University of Queensland, Gatton Campus, Gatton, QLD 4343, Australia;
| | - Peter Murray
- School of Veterinary Science, The University of Queensland, Gatton Campus, Gatton, QLD 4343, Australia; (L.N.); (P.M.); (T.S.B.); (R.A.)
- Biological Resources, The University of Queensland, Brisbane, QLD 4072, Australia
- School of Agriculture and Environmental Science, University of Southern Queensland, Toowoomba, QLD 4350, Australia
| | - Tamsin S. Barnes
- School of Veterinary Science, The University of Queensland, Gatton Campus, Gatton, QLD 4343, Australia; (L.N.); (P.M.); (T.S.B.); (R.A.)
| | - Rachel Allavena
- School of Veterinary Science, The University of Queensland, Gatton Campus, Gatton, QLD 4343, Australia; (L.N.); (P.M.); (T.S.B.); (R.A.)
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Kutzler MA. Understanding the effects of sustained supraphysiologic concentrations of luteinizing hormone in gonadectomized dogs: What we know and what we still need to learn. Theriogenology 2023; 196:270-274. [PMID: 36459946 DOI: 10.1016/j.theriogenology.2022.11.007] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/29/2022] [Accepted: 11/04/2022] [Indexed: 11/11/2022]
Abstract
Removal of the gonads with surgical sterilization results in a loss of negative feedback to the hypothalamus and anterior pituitary. The sustained supraphysiologic luteinizing hormone (LH) concentrations in gonadectomized dogs can significantly alter organ function and even induce neoplastic changes. For example, gonad removal has a profound effect on thyroid function and is reported to be the most significant cause for the development of hypothyroidism in dogs. Thirty percent more gonadectomized dogs develop hypothyroidism compared with intact dogs. Within the canine thyroid, LH receptors are co-localized with thyroid stimulating hormone (TSH) receptors. Continuous LH receptor activation in gonadectomized dogs may interfere TSH receptor function by consuming second messengers involved in G-protein receptor cell signaling, preventing the action of TSH when it binds to its receptor in the thyroid, resulting in hypothyroidism. The incidence of anterior cruciate ligament ruptures is significantly increased following gonad removal independent of breed, sex, weight or body condition. Luteinizing hormone receptors are expressed in the cruciate ligament and continuous LH receptor activation may increase laxity in these ligaments, resulting in joint instability. Both male and female gonadectomized dogs are at a significantly increased risk for lymphoma and hemangiosarcoma. Luteinizing hormone receptors are also abundant in these tissues. Research in four canine hemangiosarcoma cell lines found that LH receptor activation induces cell proliferation. In addition, research in three canine T-cell lymphoma cell lines found that LH receptor activation induces cell proliferation, adhesion, and invasion as well as increases LH receptor expression. Research is needed to determine if LH reducing strategies using gonadotropin releasing hormone agonists will increase remission times in gonadectomized dogs with LH receptor-positive tumors. In conclusion, among the non-reproductive functions of gonads, suppression of LH secretion and resulting LH receptor overexpression appear necessary in maintaining endocrine, musculoskeletal, and anti-neoplastic health.
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Affiliation(s)
- Michelle Anne Kutzler
- Department of Animal and Rangeland Sciences, Oregon State University, 112 Withycombe Hall, Corvallis, OR, 97331, USA.
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Zwida KH, Kutzler MA. Canine splenic hemangiosarcoma cells express and activate luteinizing hormone receptors in vitro. Am J Vet Res 2022; 83:ajvr.22.07.0120. [DOI: 10.2460/ajvr.22.07.0120] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/06/2022]
Abstract
Abstract
OBJECTIVE
To determine luteinizing hormone receptor (LHR) expression and response to LHR activation in isolated canine splenic hemangiosarcoma cell lines in vitro.
SAMPLES
In vitro cultures of commercially available canine splenic hemangiosarcoma cell lines (EFS, GRACE-HSA, and DAL-4).
PROCEDURES
The percentage of each cell line expressing LHR was determined by immunocytochemistry. Cells were then treated with increasing doses (7.5 ng/mL, 75 ng/mL) of recombinant canine luteinizing hormone (cLH) for 48 hours and evaluated using a cell proliferation assay.
RESULTS
The percentage of cells expressing LHR was 17.2 ± 4.5%, 11.8 ± 3.1%, and 6.9 ± 2.5% in EFS, GRACE-HSA, and DAL-4, respectively. There was significant increase in cell count in the DAL-4 and EFS cell lines following a 48-hour incubation at the highest cLH concentration (P = .028 and P = .019, respectively). There was not a significant increase in cell count in the GRACE-HSA cell line at either cLH concentration.
CLINICAL RELEVANCE
Activation of LHR results in cell proliferation in some canine splenic hemangiosarcoma cell lines. These results may explain why spayed and castrated dogs with high circulating LH concentrations may develop hemangiosarcoma more frequently than intact dogs.
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Affiliation(s)
- Khawla H. Zwida
- Department of Animal and Rangeland Sciences, College of Agricultural Sciences, Oregon State University, Corvallis, Oregon, USA
| | - Michelle A. Kutzler
- Department of Animal and Rangeland Sciences, College of Agricultural Sciences, Oregon State University, Corvallis, Oregon, USA
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Anne Kutzler M, Moccia V, Zwida K, Verena Löhr C. Luteinizing Hormone Receptor Expression in Neoplastic Mast Cells Is Increased in Spayed and Neutered Dogs. J Am Anim Hosp Assoc 2022; 58:271-276. [PMID: 36315865 DOI: 10.5326/jaaha-ms-7150] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Accepted: 09/01/2021] [Indexed: 06/16/2023]
Abstract
Luteinizing hormone receptors (LHRs) are expressed in canine lymphoma and hemangiosarcoma. We hypothesized that LHR would be expressed in canine mast cell tumors (MCTs) and that more neoplastic mast cells would express LHR in gonadectomized dogs compared with intact dogs. Eleven archived formalin-fixed paraffin-embedded cutaneous MCT tissue sections were processed using routine immunohistochemistry. For both the KIT protein and LHR, the percentage of positive cells for each staining pattern (I-III) was calculated. A Student's t test was used to compare the total percentage of positive cells expressing LHR and KIT in intact and gonadectomized dogs. A one-way analysis of variance was used to compare the percentage of cells within each staining pattern for LHR and KIT in intact and gonadectomized dogs. All MCT expressed LHR. MCT from gonadectomized dogs had a significantly higher percentage of LHR-positive mast cells (84.2 ± 8.7%) compared with MCTs from intact dogs (64.3 ± 4.2%). This is the first study to demonstrate the expression of LHR in canine MCTs and to report that LHR expression is increased in neoplastic mast cells from gonadectomized dogs compared with intact dogs. Future studies are planned to evaluate the functionality of the LHR in canine neoplastic mast cells.
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Affiliation(s)
| | - Valerio Moccia
- Universita degli Studi di Bari Aldo Moro, Bari, Italy (V.M.)
| | - Khawla Zwida
- From Oregon State University, Corvallis, Oregon (M.A.K., K.Z., C.V.L.)
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Fontes GS, McCarthy RJ, Kutzler MA, Zitek-Morrison E. The effects of sex and neuter status on trauma survival in dogs: A Veterinary Committee on Trauma registry study. J Vet Emerg Crit Care (San Antonio) 2022; 32:756-763. [PMID: 35522236 PMCID: PMC9637234 DOI: 10.1111/vec.13210] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/27/2020] [Revised: 03/22/2021] [Accepted: 03/27/2021] [Indexed: 11/30/2022]
Abstract
OBJECTIVE To determine the effect of sex and neuter status on trauma survival in dogs. DESIGN Multi-institutional prospective case series, September 2013 to March 2019, retrospectively analyzed. SETTING Level I and II Veterinary Trauma Centers. ANIMALS Consecutive sample of 2649 dogs in the American College of Veterinary Emergency and Critical Care Veterinary Committee on Trauma patient registry meeting inclusion criteria. For inclusion, dogs had to have complete data entries, be postpubertal (≥7 months age in females and ≥10 months age in males), and have sustained moderate to severe trauma (animal trauma triage [ATT] score ≥5/18). Dogs that were dead upon arrival, euthanized for financial or unknown reasons alone, or that were presented by a Good Samaritan but subsequently humanely euthanized were excluded. MEASUREMENTS AND MAIN RESULTS Data collected included age, sex, neuter status (intact, neutered), trauma type (blunt, penetrating, both), outcome (survived to hospital discharge, died, euthanized), and reason for euthanasia (grave prognosis, financial reasons, or both). Of 2649 eligible dogs, 56% survived to hospital discharge (n = 1469). Neutered females had a significantly higher survival rate (58.3% vs 51.3%; P = 0.03) compared to intact females, and neutered males had a significantly higher survival rate (56.6% vs 50.7%; P = 0.04) compared to intact males. There was no significant difference in survival between intact females and intact males (P = 0.87) or between neutered females and neutered males (P = 0.46). Mean cumulative ATT score was higher in intact groups and was found to be a significant predictor of survival (P < 0.01). Based on logistic models, overall odds of survival were 20.7% greater in neutered dogs. CONCLUSIONS Gonadectomy is associated with lower ATT scores and improved survival after moderate to severe trauma in both female and male dogs.
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Affiliation(s)
- Gabrielle S Fontes
- Department of Veterinary Clinical Sciences, Tufts University Cummings School of Veterinary Medicine, North Grafton, Massachusetts, USA
| | - Robert J McCarthy
- Department of Veterinary Clinical Sciences, Tufts University Cummings School of Veterinary Medicine, North Grafton, Massachusetts, USA
| | - Michelle A Kutzler
- Department of Animal and Rangeland Sciences, Oregon State University, Corvallis, Oregon, USA
| | - Emily Zitek-Morrison
- Department of Population and Quantitative Health Sciences, University of Massachusetts Medical School, Worcester, Massachusetts, USA
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Schäfer-Somi S, Kaya D, Aslan S. Prepubertal Use of Long-Term GnRH Agonists in Dogs: Current Knowledge and Recommendations. Animals (Basel) 2022; 12:ani12172267. [PMID: 36077986 PMCID: PMC9454922 DOI: 10.3390/ani12172267] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/11/2022] [Revised: 08/22/2022] [Accepted: 08/27/2022] [Indexed: 11/16/2022] Open
Abstract
The search for an alternative approach of estrus control (induction or suppression) in dogs is an important issue and the use of slow GnRH agonist-releasing implants has been the subject of frequent research in recent years. Studies to date demonstrate that the short- and long-term effects of deslorelin implants applicated at different time points of the prepubertal period are similar to those of adult dogs; however, there are important differences. The age of the prepubertal bitch and the dosage appear to be the main determinants of the response to deslorelin, as well as the individual metabolism of the bitch. Recent studies reported that the deslorelin-mediated long-term delay of puberty does not have negative carry-over effects on subsequent ovarian functionality, serum steroid hormone concentrations, uterine health, and fertility; however, more molecular studies are needed to determine the effects of application time of GnRH agonists on hormone concentrations and peripheral receptor expression. Furthermore, the long-term effects of delay of puberty with deslorelin on joint health, tumor development, the immune system, and social behavior deserve further investigations.
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Affiliation(s)
- Sabine Schäfer-Somi
- Platform for Artificial Insemination and Embryo Transfer, Vetmeduni Vienna, 1210 Vienna, Austria
- Correspondence:
| | - Duygu Kaya
- Department of Obstetrics and Gynecology, Faculty of Veterinary Medicine, University of Kafkas, 36100 Kars, Turkey
| | - Selim Aslan
- Department of Obstetrics and Gynecology, Veterinary Faculty, Near East University, 99138 Nicosia, Cyprus
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Driancourt MA, Briggs JR. Gonadotropin-Releasing Hormone (GnRH) Agonist Implants for Male Dog Fertility Suppression: A Review of Mode of Action, Efficacy, Safety, and Uses. Front Vet Sci 2020; 7:483. [PMID: 32923467 PMCID: PMC7456901 DOI: 10.3389/fvets.2020.00483] [Citation(s) in RCA: 9] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/17/2020] [Accepted: 06/29/2020] [Indexed: 11/18/2022] Open
Abstract
At present, only surgical sterilization is available for veterinarians and pet owners seeking suppression of fertility in male dogs, in most countries. An alternative contraceptive alternative approach is GnRH releasing implants that desensitize the pituitary to the stimulatory effects of GnRH and thereby block testicular function (testosterone and sperm production). Two GnRH agonists (deslorelin and azagly-nafarelin) have been researched in controlled release formulations for this purpose. A deslorelin-releasing biodegradable implant, marketed under the name Suprelorin®, has been available in Australia and New Zealand since 2007, the European Union (EU) since 2008, and received regulatory approval in China and Mexico in late 2019. Two versions of the implant are available, one labeled for a minimum of 6 months of fertility suppression in male dogs, and the other for a minimum of 12 months in male dogs. Another GnRH agonist (azagly-nafarelin) was also included in a solid implant (Gonazon®). Research results showed it delivered 6-months to 1 year of suppressed fertility; however, it is not commercialized. This review paper summarizes research on the mechanism of action for these technologies and compiles and interprets the research on efficacy and safety. New findings on usage of the deslorelin releasing implant in countries where veterinarians and pet owners have this option is shared. Research on off-label use of the product in male dogs is also reviewed. This review aims to aid in the evaluation of the deslorelin releasing implant as an adjunct or alternative for surgical sterilization of male dogs.
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Affiliation(s)
| | - Joyce R Briggs
- Alliance for Contraception in Cats and Dogs, Portland, OR, United States
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Kutzler MA. Possible Relationship between Long-Term Adverse Health Effects of Gonad-Removing Surgical Sterilization and Luteinizing Hormone in Dogs. Animals (Basel) 2020; 10:E599. [PMID: 32244716 PMCID: PMC7222805 DOI: 10.3390/ani10040599] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/10/2020] [Revised: 03/30/2020] [Accepted: 03/31/2020] [Indexed: 01/14/2023] Open
Abstract
Spaying and neutering dogs is commonly used to prevent the birth of unwanted animals and eliminate the risk of reproductive diseases. However, removal of the gonads prevents the feedback of estrogen and testosterone on the pituitary and hypothalamus. As a result, luteinizing hormone (LH) is continuously elevated at supraphysiologic concentrations. Although the main role of LH is for reproductive function (e.g., ovulation), there are LH receptors present in several normal tissues including the thyroid and adrenal glands, gastrointestinal tract, cranial cruciate ligament and round ligament, and lymphocytes. In addition, there are LH receptors present in several neoplastic tissues (e.g., lymphoma, hemangiosarcoma, mastocytoma, transitional cell carcinoma, and osteosarcoma). The role of LH receptors in non-reproductive normal and neoplastic tissues is not known but may stimulate nitric oxide release and induce cell division. The precise etiology of the increased incidence of several non-reproductive long-term health complications following spaying and neutering is not known but may be related to LH receptor activation in these non-reproductive target tissues. How these effects may be mediated is described in this review.
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Affiliation(s)
- Michelle A Kutzler
- Department of Animal and Rangeland Sciences, Oregon State University, 112 Withycombe Hall, Corvallis, OR 97370, USA
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