#&'$**)$"')*)""')*'*&)& >:?3 T+@T9::09?3 SPECIAL 2016 AAFP Guidelines for the Management of Feline Hyperthyroidism Clinical context: Since 1979 and 1980 when the first reports of clinical feline hyperthyroidism (FHT) appeared in the literature, our understanding of the disease has evolved tremendously. Initially, FHT was a disease that only referral clinicians treated. Hazel C Carney Now it is a disease that primary clinicians routinely manage. Inclusion of the DVM MS DABVP (Canine/Feline) Co-Chair measurement of total thyroxine concentration in senior wellness panels, as well as in WestVet Emergency diagnostic work-ups for sick cats, now enables diagnosis of the condition long before the and Specialty Center, 5019 North Sawyer Avenue, cat becomes the classic scrawny, unkempt, agitated patient with a bulge in its neck. However, Garden City, ID 83617, USA earlier recognition of the problem has given rise to several related questions: how to recognize the health Email: [email protected] significance of the early presentations of the disease; how early to treat the disease; whether to treat FHT Cynthia R Ward when comorbid conditions are present; and how to manage comorbid conditions such as chronic kidney VMD PhD DACVIM disease and cardiac disease with treatment of FHT. The 2016 AAFP Guidelines for the Management of Feline Co-Chair University of Georgia, Hyperthyroidism (hereafter referred to as the Guidelines) will shed light on these questions for the general College of Veterinary Medicine, practitioner and suggest when referral may benefit the cat. 2200 College Station Road, Athens, GA 30605, USA Scope: The Guidelines explain FHT as a primary disease process with compounding factors, and provide Email: [email protected] a concise explanation of what we know to be true about the etiology and pathogenesis of the disease. Steven J Bailey The Guidelines also: DVM DABVP (Feline) < Distill the current research literature into simple recommendations for testing sequences that will avoid Exclusively Cats Veterinary misdiagnosis and separate an FHT diagnosis into six clinical categories with associated management strategies. Hospital, 6650 Highland Road, Ste 116, Waterford, < Emphasize the importance of treating all hyperthyroid cats, regardless of comorbidities, and outline the MI 48327, USA currently available treatments for the disease. David Bruyette < Explain how to monitor the treated cat to help avoid exacerbating comorbid diseases. DVM DACVIM Dispel some of the myths surrounding certain aspects of FHT and replace them with an evidence-based VCA West Los Angeles < Animal Hospital, narrative that veterinarians and their practice teams can apply to feline patients and communicate to their 1900 South Sepulveda Blvd, owners. Los Angeles, CA 90025, USA Evidence base: To help ensure better case outcomes, the Guidelines reflect currently available, Sonnya Dennis evidenced-based knowledge. If research is lacking, or if a consensus does not exist, the expert panel DVM DABVP (Canine/Feline) Stratham-Newfields Veterinary of authors has made recommendations based on their extensive, cumulative clinical experience. Hospital, 8 Main Street, Newfields, NH 03856, USA Duncan Ferguson VMD PhD DACVIM DACVCP Feline hyperthyroidism: LRFJQSLT;QRIQNTRISTDMQOMTJSHPJSTLIO;SJTPT=SME College of Veterinary Medicine – an overview KO;TQNHQJSNHSTOCTRIEMOQJTPJSNOGPLTQNTHPRLA?@3@2 University of Illinois, Department of Comparative Biosciences, 7ISTDMS=PKSNHSTOCT(-7TIPLTLRSPJQKETQNHMSPLSJ 3840 Veterinary Medicine Basic (SKQNST IEDSMRIEMOQJQLGT (-7 T CQMLRT <SHPGS ;OMKJ;QJSTLQNHSTRIOLSTCQMLRTMSDOMRL@TPNJTRIS Sciences Bldg, 2001 South Lincoln Avenue, Urbana, S=QJSNRTP<OFRT68TESPMLTPBO@T;ISNTRISTQNQRQPK JQLSPLSTQLTNO;TJQPBNOLSJTQNT?A80??A9TOCTOKJSM ?@> 6@40?? IL 61802, USA MSDOMRLT PDDSPMSJT QNT RIST KQRSMPRFMSA *RT ;PL HPRLTPMOFNJTRIST;OMKJA (-7TQLTRISTGOLR Amy Hinc PDDPMSNRT RIPRT RIQLT ;PLT PT NS;@T NORT FLRT PN HOGGONTSNJOHMQNSTJQLOMJSMTQNTGQJJKS1PBSJTOM VMD DABVP (Feline) FNJQPBNOLSJ@T JQLSPLST <SHPFLST DPRIOKOBQHPK OKJSMTHPRLTQNTRIST+@6@?> ;ISMSTQRLTDMS=PKSNHSTQL Cosmic Cat Veterinary Clinic, FDTROT?:TOCTHPRLTOKJSMTRIPNT?:TESPMLA6 220 East Main Street, Branford, CT 06405, USA 'KQNQHPKT MSDOMRLT CMOGT RIST SPMKET ?54:L There are several excellent recent reviews of A Renee Rucinsky JSLHMQ<SJT;IPRTQLTNO;T)NO;NTPLTRISTHKPLLQH@ the history, pathogenesis, epidemiology and DVM DABVP (Feline) Mid Atlantic Cat Hospital, incidence of FHT.3–5 This ‘overview’ section of 201 Grange Hall Road, the Guidelines highlights information from these Queenstown, MD 21658, USA prior publications and other sources deemed most relevant to a practitioner today. "*/ ?:A??22?:543?> ?3396>8> 400 JFMS CLINICAL PRACTICE T7IST&FRIOML T>:?3 S P E C I A L / 2016 AAFP feline hyperthyroidism guidelines LIO;LTRIPRTGOLRTIEDSMRIEMOQJTHPRLTLFCCSMTCMOG CONTENTS page PT COMGT OCT ROQHT NOJFKPMT BOQRSM@T LQGQKPMT RO < Feline hyperthyroidism: an overview 400 %KFGGSMLT JQLSPLST LSSNT QNT GPNAT 7IQLT QLT P < Diagnosis 402 <SNQBNTHONJQRQONTQNT;IQHITBMO;RITPNJTCFNH1 – Presenting signs, differential RQONTPMSTPFRONOGOFLA?2@?4 7OTJPRSTRISMSTPMSTNO diagnoses and diagnostic confirmation 402 )NO;NT MSDOMRLT OCT HPRLT SIQ<QRQNBT RIEMOQJ – Signalment, history and physical PFROPNRQ<OJQSL@TPLTPMSTDMSLSNRTQNTMP=SLTJQL1 examination 402 SPLSTQNTIFGPNLAT – A systematic and categorical 7IST GPOMQRET OCT IEDSMRIEMOQJT HPRLT IP=S approach to diagnosis 403 <QKPRSMPKTJQLSPLSAT$PMKETSDSMQSNHSTQNJQHPRSJ < Managing hyperthyroid cats with RIPRTMSGO=PKTOCTPTCFNHRQONPKTPJSNOGPTGQBIRT<S concurrent CKD 405 Hyperthyroidism COKKO;SJT <ET JS=SKODGSNRT OCT PT HONRMPKPRSMPK – Managing the cat that is non-azotemic ONSAT*CTP<KPRQ=STLFMBSMETOMTMPJQOQOJQNST;PLTNOR at initiation of treatment for affects HIOLSNT COMT GPNPBSGSNRT OCT RIST QNQRQPKT GPLL@ hyperthyroidism 405 up to 10% of LHQNRQBMPDIQHT S=QJSNHST LFBBSLRSJT RIPRT RIS – Managing the cat that is azotemic PJSNOGPT HOFKJT HONRQNFST ROT BMO;@T DOLLQ<KE at initiation of treatment for North American KSPJQNBT ROT GPKQBNPNHE@T PLT OHHFMLT QNT IFGPN hyperthyroidism 405 6@?50>> cats older DPRQSNRLA CTQGDOMRPNHSTROTRISTDMPHRQRQONSM@ < Managing hyperthyroid cats with ONKET>TOCTIEDSMRIEMOQJTHPRLTIP=STGPKQBNPNR concurrent heart disease 406 than 10 years. HPMHQNOGPLTPRTRISTRQGSTOCTQNQRQPKTJQPBNOLQLA>6@>9 < Treatment modalities 406 STJOTNORTESRTIP=STPTHKSPMTDQHRFMSTOCTRIS – Advantages and disadvantages of HPFLSLT OCT (-7T QNT QRLT HFMMSNRT DMSLSNRPRQONA feline hyperthyroidism treatments 407 .FKRQDKSTCPHROMLTDKPETPTMOKST<FRTRISTMSKPRQ=S < Radioactive iodine 407 QGDOMRPNHST OCT SPHIT QLT FN)NO;NA>:@>80>2 FM < Medical therapy 408 HFMMSNRTFNJSMLRPNJQNBTHPNT<STLFGGPMQ!SJTPL < Surgical thyroidectomy 409 COKKO;LATSNSRQHLTGPETQNCKFSNHSTLFLHSDRQ<QKQRE/ < Dietary therapy 410 QNTONSTLRFJE@T+QPGSLSTPNJTFMGSLST<MSSJLTIPJ < Monitoring hyperthyroid patients 410 PTJSHMSPLSJTMQL)TOCTJS=SKODQNBTRISTJQLSPLSA>3 < Prognosis 410 'IPNBSLTQNTHPRTIFL<PNJMETLQNHSTRIST?52:LTRO < Myths and realities of hyperthyroidism RISTDMSLSNRTJPE@TQNHKFJQNBTPTIQBISMTDSMHSNRPBS treatment 411 OCT QNJOOMT HPRL@T QNHMSPLSJT FRQKQ!PRQONT OC < Summary points 412 HOGGSMHQPKTHPRTCOOJLTPNJTKONBSMTKQCSTLDPNL@ < Appendix: Client brochure 415 GPETQNCKFSNHSTRISTDMS=PKSNHSA>80>2 &BSTIPLTKONB <SSNTFNJSMLROOJTROT<STPTMQL)TCPHROMTCOMTRIEMOQJ NOJFKST JS=SKODGSNRT QNT IFGPNLAT QKPRSMPK LS=SMSKETIEDSMGSRP<OKQHTHKQNQHPKTDMSLSNRPRQON JQLSPLSTLRMSNBRISNLTRISTIEDORISLSLTOCTJQSRPME (QBFMST? AT7ISTGOLRTQGDOMRPNRTHOGOM<QJQRQSL PNJT SN=QMONGSNRPKT SRQOKOBQSLT MPRISMT RIPN ;SMST HPMJQOMSLDQMPROMET JQLSPLSLA?6 *NT RIS GFRPRQONPKTHPFLSLTPKONSA?4 ?54:L@TRISTBMSPRSLRTPJ=PNHSLT;SMSTQNTKP<OMPRO1 $DQJSGQOKOBQHTLRFJQSLTIP=STDMOJFHSJTPTKQLRTOC ME@TMPJQOTBMPDIQHTPNJTSHIOHPMJQOBMPDIQHTS=PKF1 BFQKRT <ET PLLOHQPRQONT HOGDOFNJL@T GPNET OC PRQONTOCTRISTJQLSPLS@TPNJTRMSPRGSNRTCOHFLSJTON ;IQHIT PMST DISNOKLT OMT IPKOBSNPRSJT IEJMOHPM1 PNRQRIEMOQJT JMFBLT PNJT LFMBSMEAT*NT RIST ?55:L@ <ONLAT .OMST IEDSMRIEMOQJT HPRLT FLST JSOJOMQ!SJ MSDOMR LTOCTPDPRISRQH@TOHHFKRTSFRIEMOQNSGQH )QRRETKQRRSMTPNJOMTSPRTCOOJTCMOGTHPNLTRIPRTGPE 6@>4066T BOQRSM T PNJT LF<HKQNQHPKT IEDSMRIEMOQJQLG Figure 1 Severely HONRPQNT <QLDISNOKT &T PNJT DIRIPKPRSLA +OE SGSMBSJAT7ISTQNHKFLQONTOCTRORPKTLSMFGTRIEMO1 debilitated hyperthyroid cat: QLOCKP=ONSL@T PT HOGDONSNRT OCT GPNET HPRT COOJL@ this was a very common QNSTHONHSNRMPRQONTP<<MS=QPRSJTROT79TQNTRISLS clinical presentation in PNJT RIST HOGGONT SN=QMONGSNRPKT HONRPGQNPNR FQJSKQNSL TQNTCSKQNSTBSMQPRMQHTLHMSSNQNBTDPNSKL the 1980s and early 1990s. CQMS1MSRPMJPNRT%"$LTDOKE<MOGQNPRSJTJQDISNEK IPLTQNHMSPLSJTRISTMSHOBNQRQON Courtesy of Dr Hazel Carney SRISML T GPET PHRT PLT BOQRMOBSNL OCT RISLST ORISMT COMGLA =QPT RIEMOQJ1LRQGFKPRQNBT IOM1 SLSPMHIT HSNRSMLT <SBPNT MOF1 GONST7+- TLRQGFKPRQONTOMTPL RQNSKET OCCSMQNBT MPJQOPHRQ=S JQMSHRT GQROBSNLA6?069 PMQP<KS QOJQNST ?6?* T RISMPDET QNT RIS QOJQNSTHONRSNRTOCTHPRTCOOJLTPKLO SPMKET?55:L@T;QRITRISTCQMLRTLQB1 LSSGLTROTIP=STPNTQNCKFSNHSTON NQCQHPNRT MSDOMRT JSLHMQ<QNB RIST JS=SKODGSNRT OCT RIST JQL1 RIQLTRISMPDET<SQNBTDF<KQLISJ SPLSA68062 SHPFLST NOT LRFJQSL QNT ?558@?9 ;IQHIT HOQNHQJSJ IP=ST DMOLDSHRQ=SKET S=PKFPRSJ ;QRIT RIST SGSMBSNHST OCT DMQ1 KQCSKONBTSDOLFMSTROTPTLDSHQCQH =PRSTRMSPRGSNRTHSNRSMLA HOGDOFNJT QNT IEDSMRIEMOQJ +OGST HPRLT IP=ST PT HELRQH HPRL@TPJ=QLSTHPFRQOFLTHPRTO;N1 SNKPMBSGSNRT OCT RIST RIEMOQJ SMLT RIPRT PKKT PLLOHQPRQONLT PMS BKPNJT ;QRIOFRT IEDSMRIEMO1 HONSHRFMS@T PNJT NORT DMO=SN SGQPA?8@?3 -QLRODPRIOKOBE CPHRA JFMS CLINICAL PRACTICE 401 S P E C I A L / 2016 AAFP feline hyperthyroidism