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2013). Glucose and bicarbonate are the most commonly affected, but loss of amino acids, phosphate, sodium, potassium, calcium, magnesium, uric Fanconi acid, lactate, ketones, carnitine and protein can also occur. The condition can be congenital or acquired as a result SYNDROME of proximal tubule insult, and, if left untreated, can progress to renal failure Cases of acquired Fanconi syndrome are on the rise in parts (Jamieson and Chandler, 2001). of New Zealand. Julie Tomlinson of Gribbles Veterinary, HEREDITARY FANCONI SYNDROME Auckland, outlines the presenting signs to be aware of. The hereditary form is well described in Basenjis (10% incidence) but can be seen in other breeds including Norwegian Elkhounds, Cairn Terriers, Schnauzers, and Shetland Sheepdogs (Giger et al., 2015; Hostutler et al., 2004). It is associated with a mutation in the FAN1 gene with an autosomal recessive inheritance pattern (Giger et al., 2015; Johnson et al., 2012). Clinical signs typically develop in middle age (four to seven years) (Giger et al., 2015). One study of 60 dogs with idiopathic or hereditary Fanconi syndrome found that lifespan was not significantly reduced, and owners reported a good quality of life (Yearly et al., 2004).

ACQUIRED FANCONI SYNDROME The acquired form can occur with any injury to the proximal renal tubular epithelium due to certain antibiotics, infectious agents, heavy metals or other toxins – see Table 1 (Riordan and Schaer, 2005; Hooper and Roberts, 2011; Reinert and Feldman, 2015). Cases of acquired Fanconi syndrome have also been described in dogs with copper-associated hepatitis (Langlois et al., 2013) and there is a single case report of transient Fanconi syndrome in a dog with primary hypoparathyroidism DISEASES OF THE proximal tubule of overt Fanconi syndrome. Proximal (Freeman et al., 1994). are fairly rare in veterinary medicine. renal tubular acidosis is characterised In 2007, reports of acquired Fanconi- Primary renal glucosuria, proximal by reduced bicarbonate reabsorption. like syndrome in association with renal tubular acidosis and Fanconi Fanconi syndrome is a more generalised Chinese-origin chicken jerky treats syndrome have been described. Primary loss of proximal tubular reabsorptive began to occur. renal glucosuria may occur as a sole function, resulting in excessive loss of From 2007 to 2015, the US Food and reabsorptive defect, or may be the water and multiple solutes from the Drug Administration (FDA) received initial finding prior to development glomerular filtrate (Langlois et al., approximately 5,200 complaints of

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illness associated with consumption TABLE 1: REFERENCES: of chicken, duck or sweet potato jerky Differentials for acquired , FDA Annual Update, Jerky Pet Treats, treats, most of which involved products Anonymous Fanconi syndrome www.fda.gov/AnimalVeterinary/SafetyHealth/ imported from China. The reports ProductSafetyInformation/ucm360951.htm involved more than 6,200 dogs, 26 cats Carmichael N, Lee J, Giger U. Fanconi syndrome in Antibiotics Gentamicin and three people and included more Cephalosporins dog in the UK. Veterinary Record 174, 357–8, 2014 than 1,140 canine deaths (FDA Annual High doses of amoxicillin Freeman LM, Breitschwerdt EB, Keene BW, Degraded tetracyclines* Update). Cases have also been reported Hansen B. Fanconi syndrome in a dog with primary Other drugs Cisplatin hypoparathyroidism. Journal of Veterinary Internal in Australia, Canada, Japan and Streptozotocin Medicine 8, 349–54, 1994 Europe (Thompson et al., 2013; Igase Chlorambucil (cat) Giger U, Brons A, Mizukami K, Slutsky J, Raj K, et al., 2015; Carmichael et al., 2014; Salicylates* Fitzgerald CA, Strickland S, Sewell AC, Henthorn Hooijberg et al., 2015). Heavy metals Copper PS. Update on Fanconi syndrome and cystinuria. Lead WSAVA World Congress Proceedings, 2015 In 2013, an Australian paper provided Mercury Hooijberg EH, Furman E, Leidinger E, a summary of 102 cases of kidney Cadmium* Brandstetter D, Hochleithner C, Sewell AC, disease in dogs exposed to a Chinese- Other toxins Chinese-origin jerky treats Leidinger E, Giger U. Transient renal Fanconi origin chicken jerky treat. The majority Melamine/Cyanuric acid syndrome in a Chihuahua exposed to Chinese chicken Ethylene glycol jerky treats. Tieraerztliche Praxis Kleintiere 43, 188–92, of the dogs affected were small or toy 2015 Infectious agents Leptospirosis breeds, and six of the 102 died or were Pyelonephritis Hooper AN, Roberts BK. Fanconi syndrome in four euthanased due to the illness. Follow-up non-Basenji dogs exposed to chicken jerky treats. Hypoparathyroidism data was available for 35 survivors, for Journal of American Animal Hospital Association 47, 178–87, 2011 which the time to resolution of clinical Hypovitaminosis D Hostutler RA, DiBartola SP, Eaton KA. Transient signs ranged from humans tilmicosin and enrofloxacin) has been Veterinary Medical Science 77, 1507–10, 2015 reported, although there is no evidence Jamieson PM, Chandler ML. Transient renal linking these contaminants to clinical tubulopathy in a Labrador Retriever. Journal of Small Animal Practice 42, 546–9, 2001 cases of renal tubular injury (Sheridan et in ALT (Thompson et al., 2013). Johnson GS, Farias FH, Mhlanga-Mutangadura T, al., 2014). Treatment involves elimination of Taylor JF, O’Brien DP, Schnabel RD. Whole genome the underlying aetiology (if possible), sequencing shows a deletion of the last exon of Fan1 in CLINICAL FINDINGS electrolyte/bicarb supplementation and Basenji Fanconi syndrome. Proceedings from the Advances in Canine and Feline Genomics and Inherited Diseases Polyuria and polydipsia are the supportive care. Prognosis depends on Conference. Visby, Sweden, 2012 most common presenting signs. the underlying etiology, the degree of Langlois DK, Smedley RC, Schall WD, Kruger JM. Others may include dehydration, renal injury and response to treatment. Acquired proximal renal tubular dysfunction in nine weakness, lethargy and weight loss. At Gribbles Veterinary, we have Labrador Retrievers with copper-associated hepatitis (2006–2012). Journal of Veterinary Internal Medicine 27, Dogs with the hereditary form may recently seen an increased number of 491–9, 2013 have a poor haircoat (Yearly et al., acquired Fanconi syndrome cases in Reinert NC, Feldman DG. Acquired Fanconi syndrome 2004). Laboratory abnormalities the Auckland and Northland regions. in four cats treated with chlorambucil. Journal of Feline include normoglycemic glucosuria, Clinical histories were available for Medicine and Surgery 18, 1034–40, 2015 a normal anion gap hyperchloremic several cases in which the dogs were Riordan L, Schaer M. Renal tubular acidosis. Compendium of Continuing Education for the Practising metabolic acidosis, hypokalaemia, fed chicken, duck or sweet potato Veterinarian 27, 513–28, 2005 hypophosphatemia and aminoaciduria. jerky products. However, we do not Sheridan R, Mirabile J, Hafler K. Determination of Ketonuria, mild proteinuria and have feedback to know whether the six illegal antibiotics in chicken jerky dog treats. Journal azotemia may also be found (Hostutler dogs improved after discontinuation of Agricultural and Food Chemistry 62, 3690–6, 2014 et al., 2004). Other clinical signs and of the jerky product. Please be aware Thompson MF, Kessel AE, Steenhard LA, Foster SF. Acquired proximal renal tubulopathy in dogs exposed laboratory abnormalities may depend of this condition, the hallmark finding to a common chicken treat: Retrospective study of 108 on the underlying aetiology. For of glucosuria with normoglycemia, cases (2001–2009). Australian Veterinary Journal 91, example, dogs that have consumed the possible link to Chinese-origin 368–73, 2013 Chinese-origin jerky treats may exhibit jerky treats and the importance of Yearly JH, Hancock DD, Mealey KL. Survival time, lifespan and quality of life in dogs with Fanconi GI signs (anorexia, vomiting and performing a urinalysis and obtaining syndrome. Journal of American Veterinary Medical diarrhoea) and have a mild elevation a diet history in sick patients. Association 225, 377–83, 2004

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