Acquired proximal renal tubulopathy in dogs exposed to a common dried chicken treat: retrospective study of 108 cases (2007-2009)

Biological variation of biochemical urine and serum analytes in healthy dogs

BACKGROUND

Biological variation (BV) of urinary (U) biochemical analytes has not been described in absolute terms, let alone as a ratio of the U-creatinine or fractional excretion in healthy dogs. These analytes are potential diagnostic tools for different types of kidney damage and electrolyte disorders in dogs.

OBJECTIVES

We aimed to investigate the BV of specific gravity, osmolality, creatinine, urea, protein, glucose, chloride, sodium, potassium, calcium, and phosphate in urine from healthy pet dogs.

METHODS

Blood and urine samples from 13 dogs were collected once weekly for 8 weeks. Samples were analyzed in duplicate and in randomized order. For each sample, U-analyte and serum concentrations were measured, and U-analyte/U-creatinine and fractional excretion (FE) were calculated. Components of variance, estimated by restricted maximum likelihood, were used to determine within-subject variation (CVI ), between-subject variation (CVG ), and analytical variation (CVA ). Index of individuality (II) and reference change values were calculated.

RESULTS

CVI for all urine analytes varied between 12.6% and 35.9%, except for U-sodium, U-sodium/U-Cr, and FE-sodium, which had higher CVI s (59.5%-60.7%). For U-protein, U-sodium, U-potassium, U-sodium/U-creatinine, FE-urea, FE-glucose, FE-sodium, FE-potassium, and FE-phosphate II were low, indicating that population-based RIs were appropriate. The remaining analytes had an intermediate II, suggesting that population-based RIs should be used with caution.

CONCLUSION

This study presents information on the biological variation of urinary and serum biochemical analytes from healthy dogs. These data are important for an appropriate interpretation of laboratory results.

Fanconi syndrome with hepatorenal karyomegaly in a young Sphynx cat

Case summary

A 3-year-old male neutered Sphynx cat was referred for history of chronically increased liver enzymes and lower urinary tract signs that were first reported when the cat was 5 months old. Urine metabolic profile revealed increased amino aciduria and glucosuria despite normoglycemia, suggesting Fanconi syndrome. Urine sodium dodecyl sulfate-polyacrylamide gel electrophoresis revealed a banding pattern suggestive of primary tubular damage. Serial blood work showed non-regenerative normocytic normochromic anemia, persistently elevated liver enzymes, worsening azotemia and progressive hyperchloremic metabolic acidosis. Ultrasound revealed irregular kidneys and bilaterally hyperechoic cortices and medullae with a loss of normal corticomedullary distinction. Laparoscopic kidney biopsy revealed a moderate-to-severe chronic interstitial fibrosis with chronic lymphoplasmacytic inflammation, tubular degeneration and atrophy, mild glomerulosclerosis and mild large vascular amyloidosis. Tubular epithelial cell karyomegaly was multifocally evident throughout the kidney. The liver had moderate diffuse zone 1 hepatocellular atrophy, periportal fibrosis, biliary hyperplasia, mild perisinusoidal amyloidosis and hepatocyte karyomegaly in zones 2 and 3. The patient continued to decline and developed polyuria, polydipsia, lethargy and hyporexia irrespective of rigorous management, which failed to curtail the progressive anemia and azotemia. The patient was euthanized 8 months from the onset of clinical signs.

Relevance and novel information

Fanconi syndrome in cats is a rare condition, with most reports occurring secondary to chlorambucil treatment. This is the first known case of Fanconi syndrome occurring with concurrent hepatorenal epithelial karyomegaly in a young Sphynx cat.

An investigation into an outbreak of pancytopenia in cats in the United Kingdom

BACKGROUND

In spring 2021 increasing numbers of cats presenting with severe pancytopenia were noted in United Kingdom (UK).

OBJECTIVE

To describe process and outcome of the investigation performed into the outbreak of pancytopenia in cats.

ANIMALS

Five hundred and eighty client owned cats that presented with severe bi- or pancytopenia of unknown cause.

METHODS

Real-time data collection was performed by an online registration forum available to all veterinary surgeons in UK. Data collected included demographics, clinicopathological findings, diagnostic testing, dietary and drug history, outcome and COVID household status. Mycotoxicological feed analysis was performed on feed samples of 3 diets frequently mentioned in the database and 3 control diets.

RESULTS

Five hundred and eighty cats presented to 378 veterinary practices were included for analysis. Case fatality rate was 63.3%. Dietary history was available for 544 (93.8%) cats, of which 500 (86%) were fed 1 of 3 diets (which were recalled midinvestigation). 54 (9.3%) cats were not fed a recalled product, with diet information unknown in 26 (4.5%) cats. Analysis of feed samples revealed concentrations of hematotoxic trichothecene T-2/HT-2 mycotoxins greater than recommended by the European Commission in 5/7 recalled diet samples but in none of control diet samples. The trichothecene mycotoxin diacetoxyscirpenol (DAS) was detectable in all recalled diet samples but not in any of control samples.

CONCLUSION AND CLINICAL IMPORTANCE

Contaminated-feed induced trichothecene mycotoxicosis should be considered as a differential diagnosis for pancytopenia in cats.

Outcome of Acquired Fanconi Syndrome Associated with Ingestion of Jerky Treats in 30 Dogs

Acquired canine proximal renal tubulopathy (Fanconi syndrome) related to excessive ingestion of jerky treats has been recognized since 2007. This study aimed to improve knowledge about the syndrome’s characteristics, especially long-term outcome. By reaching out to veterinarians and dog owners, dogs suspected of jerky induced Fanconi syndrome were identified. The dog’s medical records were reviewed, and owners interviewed. Data was analyzed using linear mixed models (p < 0.05 was considered statistically significant) and descriptive statistics are reported. Thirty dogs, median body weight 6.8 (range 1.2−59) kg and age 6.5 (0.5−14) years, were enrolled as suspected cases based on history of jerkey ingestion and confirmed normoglycemic/hypoglycemic glycosuria. Clinical signs included polydipsia (23/30), polyuria (21/30), lethargy (19/30), weight loss (15/30), hyporexia (11/30), vomiting (7/30), diarrhea (7/30) and no clinical signs (2/30). Para-clinical findings included azotemia (6/28), hypophosphatemia (9/25), metabolic acidosis (3/8), hypokalemia (6/20), proteinuria (13/26), aminoaciduria (4/4), hematuria (22/29) and ketonuria (7/27). Clinical signs resolved in 22/28 within 11 (0.3−52) weeks and glycosuria resolved in 28/30 within 6.5 (1−31) weeks. There were no associations between serum creatinine and urea and the amount/duration of jerky ingestion. Serum symmetric dimethylarginine concentrations were only available for a few dogs, therefore no conclusion was achieved on a possible association with duration of jerky ingestion. Apart from a larger percentage of dogs achieving complete recovery, the current findings are in agreement with previous reports.

Proceedings of the 2022 National Toxicology Program Satellite Symposium

The 2022 annual National Toxicology Program Satellite Symposium, entitled "Pathology Potpourri," was held in Austin, Texas at the Society of Toxicologic Pathology's 40th annual meeting during a half-day session on Sunday, June 19. The goal of this symposium was to present and discuss challenging diagnostic pathology and/or nomenclature issues. This article presents summaries of the speakers' talks along with select images that were used by the audience for voting and discussion. Various lesions and topics covered during the symposium included induced and spontaneous neoplastic and nonneoplastic lesions in the mouse lung, spontaneous lesions in the reproductive tract of a female cynomolgus macaque, induced vascular lesions in a mouse asthma model and interesting case studies in a rhesus macaque, dog and genetically engineered mouse model.

Acute kidney injury manifesting as renal tubular acidosis with proximal and distal renal tubular dysfunction in a dog with acute pancreatitis

Objective

To describe the clinical presentation and management of a critically ill dog with profound renal tubular acidosis (RTA) with proximal and distal renal tubular dysfunction.

Case Summary

A 3‐year‐old neutered female Border Terrier was presented with frequent regurgitation resulting from acute pancreatitis with severe ileus. Venous acid–base analysis and complete urinalysis confirmed the presence of normal anion gap metabolic acidosis with inappropriately alkaline urine (pH 8), consistent with distal RTA. Urinalysis, urine amino acids, and urinary fractional excretion of electrolytes revealed glycosuria (with normoglycemia), aminoaciduria, and increased fractional excretion of sodium, calcium, and phosphate consistent with generalized proximal renal tubulopathy or Fanconi syndrome. The dog responded well to supportive care and alkaline therapy and made a complete recovery.

New or Unique Information Provided

To the authors’ knowledge, this is the first description of RTA with proximal and distal renal tubular dysfunction in the veterinary literature. Furthermore, the authors hypothesize that the transient RTA was a manifestation of acute kidney injury secondary to acute pancreatitis, the first report of this in the literature.

[Acquired transient Fanconi syndrome after feeding jerky treats in dogs - A case series]

Between April 2018 and August 2019, 6 dogs with laboratory diagnostic evidence of Fanconi syndrome were presented to the Tierklinik Hofheim. The presumptive diagnosis was confirmed via urine amino acid analysis in all dogs. In 5 of the 6 dogs an alimentary origin was suspected, in 3 dogs the course of the disease could be followed. Supportive therapeutic measures and elimination of jerky treats from the dogs' diet improved the clinical symptoms in all dogs with known follow-up. This is the first case series of dogs with alimentary acquired Fanconi syndrome in Germany. The frequency of occurrence of the disease in that short period of time in only one small animal clinic suggests a significantly higher incidence than currently assumed.

A comparative analysis of two unrelated outbreaks in Latvia and Australia of acquired idiopathic megaesophagus in dogs fed two brands of commercial dry dog foods: 398 cases (2014-2018)

CASE DESCRIPTION

In Latvia in 2014, acquired idiopathic megaesophagus (AIME) was observed in increased numbers of dogs that consumed varieties of 1 brand of dog food. Within 2 years, 253 dogs were affected. In Australia in November 2017, 6 working dogs that consumed 1 diet of another brand of dog food developed AIME. In total, 145 Australian dogs were affected.

CLINICAL FINDINGS

AIME was diagnosed predominantly in large-breed male dogs (> 25 kg [55 lb]). Regurgitation, weight loss, and occasionally signs consistent with aspiration pneumonia (coughing, dyspnea, or fever) were noted. Most Latvian dogs had mild to severe peripheral polyneuropathies as evidenced by laryngeal paralysis, dysphonia, weakness, and histopathologic findings consistent with distal axonopathy. In Australian dogs, peripheral polyneuropathies were not identified, and histopathologic findings suggested that the innervation of the esophagus and pharynx was disrupted locally, although limited samples were available.

TREATMENT AND OUTCOME

Investigations in both countries included clinical, epidemiological, neuropathologic, and case-control studies. Strong associations between the dog foods and the presence of AIME were confirmed; however, toxicological analyses did not identify a root cause. In Latvia, the implicated dietary ingredients and formulations were unknown, whereas in Australia, extensive investigations were conducted into the food, its ingredients, the supply chain, and the manufacturing facilities, but a cause was not identified.

CLINICAL RELEVANCE

A panel of international multidisciplinary experts concluded that the cause of AIME in both outbreaks was likely multifactorial, with the possibility of individualized sensitivities. Without a sentinel group, the outbreak in Australia may not have been recognized for months to years, as happened in Latvia. A better surveillance system for early identification of pet illnesses, including those associated with pet foods, is needed.

Development of UHPLC/Q-TOF Analysis Method to Screen Glycerin for Direct Detection of Process Contaminants 3-Monochloropropane-1,2-diol Esters (3-MCPDEs) and Glycidyl Esters (GEs)

The U.S. Food and Drug Administration’s (FDA′s) Center for Veterinary Medicine (CVM) has been investigating reports of pets becoming ill after consuming jerky pet treats since 2007. Renal failure accounted for 30% of reported cases. Jerky pet treats contain glycerin, which can be made from vegetable oil or as a byproduct of biodiesel production. Glycidyl esters (GEs) and 3-monochloropropanediol esters (3-MCPDEs) are food contaminants that can form in glycerin during the refining process. 3-MCPDEs and GEs pose food safety concerns, as they can release free 3-MCPD and glycidol in vivo. Evidence from studies in animals shows that 3-MCPDEs are potential toxins with kidneys as their main target. As renal failure accounted for 30% of reported pet illnesses after the consumption of jerky pet treats containing glycerin, there is a need to develop a screening method to detect 3-MCPDEs and GEs in glycerin. We describe the development of an ultra-high-pressure liquid chromatography/quadrupole time-of-flight (UHPLC/Q-TOF) method for screening glycerin for MCPDEs and GEs. Glycerin was extracted and directly analyzed without a solid-phase extraction procedure. An exact mass database, developed in-house, of MCPDEs and GEs formed with common fatty acids was used in the screening.

Twelve previously healthy non-geriatric dogs present for acute kidney injury after general anaesthesia for non-emergency surgical procedures in the UK

OBJECTIVES

To characterise common factors after a suspected increase in the incidence of post-procedure acute kidney injury in healthy dogs presenting for non-emergency surgical procedures.

MATERIALS AND METHODS

Retrospective analysis of the medical records of 12 dogs that presented for acute kidney injury after general anaesthesia for non-emergency surgical procedures.

RESULTS

The 12 non-geriatric dogs re-presented with acute kidney injury at a median of 4 days after surgery to four different veterinary centres, including three multidisciplinary referral practices in the UK. All dogs in this case series weighed more than 20 kg and had a median age of 17 months. There was no apparent association with breed, type of surgery, duration of anaesthesia, perioperative drug choice or non-steroidal anti-inflammatory drug administration.

CLINICAL SIGNIFICANCE

Although well-defined in human medicine, there is very little information regarding the association between general anaesthesia and acute kidney injury in animals. No definitive causal link was found in this case series. Clinicians with similar cases are requested to contact the corresponding author so a more representative incidence rate can be obtained.

Transient Fanconi Syndrome After Treatment with Firocoxib, Cefadroxil, Tramadol, and Famotidine in a Maltese

Fanconi syndrome is a renal proximal tubulopathy characterized by excessive urinary loss of glucose, amino acids, several electrolytes, and bicarbonate. Here, we report the case of transient Fanconi syndrome in a dog following administration of firocoxib, cefadroxil, tramadol, and famotidine. A 10 mo old Maltese was presented with lethargy, anorexia, vomiting, and weight loss. Transient Fanconi syndrome without azotemia was associated with firocoxib, cefadroxil, tramadol, and famotidine treatment. The dog received supportive care including IV fluids, gastroprotectants, and oral nutritional supplements. Two months after initial diagnosis and treatment, the dog showed complete resolution of glucosuria and aminoaciduria. The unique features of Fanconi syndrome in this case emphasize the potential renal tubular toxicity of this widely used multiple-drug combination.

Fanconi Syndrome in Irish Wolfhound Siblings

Three juvenile male Irish wolfhound littermates presented with marked polyuria and polydipsia. The four female siblings were apparently unaffected. Diagnostic testing revealed glucosuria with normoglycemia, generalized aminoaciduria, hypokalemia and metabolic acidosis consistent with Fanconi syndrome. Renal ultrasonographic and histologic findings are presented. Cases were managed with a supplementation regimen based on a treatment protocol for Fanconi syndrome in basenjis. These dogs did not have angular limb deformities as documented previously in juvenile canine siblings with Fanconi syndrome. Fanconi syndrome has not been previously described in Irish wolfhound siblings.

Acquired Fanconi syndrome in two dogs following long-term consumption of pet jerky treats in Japan: case report

Renal Fanconi syndrome has recently been associated with the ingestion of pet jerky treats from China in mostly small breed dogs in North America, Australia and Europe. We report here about two dogs with Fanconi syndrome following pet jerky treats exposure in Japan. A mixed-breed dog and a French bulldog showed weight loss, polyuria and polydipsia. For years, the owners had been feeding large quantities of pet jerky treats containing chicken prepared in China. Diagnostics revealed glycosuria without hyperglycemia, severe aminoaciduria, and in one case also ketonuria, hypokalemia and metabolic acidosis. A diagnosis of Fanconi syndrome associated with long-term consumption of Chinese pet jerky treats was made. Both dogs recovered fully following withdrawal of the pet jerky treats and supportive care. Fanconi syndrome of dogs in association with the consumption of pet jerky treats of Chinese origin can cause a broad proximal tubular defect with glycosuria and generalized amino aciduria, and should be also considered in Asia. Jerky treats associated Fanconi syndrome can be completely reversible following withdrawal of the treats and supportive care to correct the metabolic abnormalities.

Proximal tubular nephropathy in two dogs diagnosed with lead toxicity

CASE REPORT

Lead toxicity was diagnosed in two dogs presenting with vague clinical symptoms. Complete blood count, biochemical testing and imaging changes showed a metarubricytosis in dog 1, but were largely normal in dog 2. Both dogs had glucosuria and proteinuria on urinalysis consistent with damage to the proximal renal tubules. Both animals returned elevated blood lead levels. A history of ingestion of lead was reported by the owner in one dog and elucidated from the second owner once the animal had recorded elevated blood lead levels.

CONCLUSION

Lead toxicity is rarely reported in the human literature as a cause of proximal tubular dysfunction. To the author's knowledge this is the first case report specifically examining this in the dog. The clinical awareness that lead is a potential cause of proximal renal tubular dysfunction offers another tool to assist the clinician in the diagnostic process. This is particularly important given that the clinical signs and minimum database findings in animals with lead toxicosis are highly variable. Evidence of proximal tubular dysfunction should trigger the clinician to closely examine the history for a potential source of lead exposure and consider submitting samples to test blood lead levels.

Acquired Fanconi syndrome in four cats treated with chlorambucil

Case series summary

Fanconi syndrome (FS) is well described in humans and dogs, but has not been reported in cats. This case series describes four cats with acquired FS. On the basis of clinical signs and intestinal biopsies, all cats were initially diagnosed with alimentary lymphoma or inflammatory bowel disease. Treatment with chlorambucil and corticosteroids was started at standard doses, based on published protocols. Within 2–26 months of the start of treatment, glucosuria, despite normoglycemia, was identified incidentally on routine biochemical screening; FS was diagnosed with urine metabolic assays, confirming aminoaciduria and glucosuria in all four cases. Neither polyuria nor polydipsia were noted in any case, and only 1/4 cats had any clinical signs at the time of diagnosis. Partial or complete resolution of FS was seen in 3/4 cases within 3 months of discontinuing chlorambucil therapy.

Relevance and novel information

This is the first case series to document acquired FS in the cat, and the first to suggest a possible association between chlorambucil and acquired FS. Cats treated with chlorambucil should be monitored for the development of glucosuria, and discontinuation of chlorambucil should be considered if FS is identified. Further study into the association between chlorambucil and acquired FS in cats is warranted.

Acquired Fanconi syndrome in a dog exposed to jerky treats in Japan

A 6-year-old spayed female Jack Russell Terrier presented with a 1-month history of lethargy, anorexia, vomiting and weight loss. The dog was fed beef and chicken jerky treats daily in addition to a commercial diet. Laboratory tests revealed azotemia, hypokalemia, hyperchloremia, metabolic acidosis and glucosuria with normoglycemia. Urine amino acid analysis showed significant amino acid loss into the urine. Thus, Fanconi syndrome was diagnosed, and based on the case history and extensive diagnostic testing, excessive consumption of jerky treats was strongly suspected as the cause. Glucosuria resolved 7 days after the withdrawal of jerky treats and fluid therapy. Aminoaciduria was substantially, but not completely, improved 3 months after diagnosis. Mild azotemia remained, suggesting chronic renal disease. To the best of our knowledge, this is the first reported case of Fanconi syndrome following the consumption of jerky treats in Japan.

Transient renal Fanconi syndrome in a Chihuahua exposed to Chinese chicken jerky treats

Transient Fanconi syndrome without azotemia was diagnosed in a dog and was associated with ingestion of Chinese chicken jerky treats. Fanconi syndrome is a proximal renal tubular defect and a diagnosis was made based upon severe glucosuria with normoglycemia, and severe generalized aminoaciduria. The clinical signs of polyuria and polydipsia as well as the massive urinary metabolic abnormalities resolved after jerky treat withdrawal. While frequently seen in North America and Australia, this is the first report of jerky treat induced Fanconi syndrome in continental Europe. Clinicians should be aware of this potential intoxication and be vigilant for a history of jerky treat consumption in a dog with glucosuria.