Bilirubin cholelithiasis and haemosiderosis in an anaemic pyruvate kinase-deficient Somali cat

Prevalence and clinical relevance of cholelithiasis in cats: A multicenter retrospective study of 98 cases

BACKGROUND

Cholelithiasis is an uncommon and mainly incidental finding in dogs; current literature on this topic is scarce in cats.

HYPOTHESIS

Report prevalence, clinical presentation, management, and outcome of cholelithiasis in cats.

ANIMALS

Ninety-eight cats with cholelithiasis.

METHODS

Retrospective multicenter case series. Electronic databases from 3 hospitals were searched for cats diagnosed with cholelithiasis by ultrasonography (US). Cholelithiasis was classified as incidental (IC) or symptomatic (SC) depending on clinicopathological signs, biliary tract US appearance, and presence of another disease potentially explaining the clinical presentation. Multivariate analysis was used to investigate factors associated with clinical expression of cholelithiasis and, within the SC group, survival.

RESULTS

The observed prevalence of cholelithiasis was 0.99% (95% confidence interval [CI], 0.79%-1.19%) among cats that underwent abdominal US. Cholelithiasis was classified as IC in 41% and SC in 59%. Choleliths found in multiple locations within the biliary tract (odds ratio [OR], 8.11; 95% CI, 2.32-34.15; P = .001) or associated with US signs of obstruction (OR, 18.47; 95% CI, 2.13-2413.34; P = .004) were significantly associated with SC. Concurrent hepatobiliary diseases were suspected or confirmed in 83% of cases with SC. Forty-three cats (74%) with SC survived to discharge. Biliary tract obstruction (BTO) was negatively associated with survival (OR, 13.87; 95% CI, 1.54-124.76; P = .001). None of the cats with IC that had available follow-up (47%) developed clinicopathological signs related to cholelithiasis.

CONCLUSIONS AND CLINICAL IMPORTANCE

Cholelithiasis is uncommon and can be asymptomatic in cats. Symptomatic cholelithiasis frequently is associated with another hepatobiliary disease or BTO or both. Biliary tract obstruction is associated with poorer outcome.

Intrahepatic cholelithiasis with gallbladder-like metaplasia of intrahepatic bile ducts associated with gallbladder agenesis in a wild boar

An unknown-aged adult female wild boar (Sus scrofa) was brought to Kyungpook National University for postmortem examination. Gross examination revealed gallbladder agenesis. Histologically, the liver was cirrhotic and had intrahepatic cholelithiasis, the choleliths were yellow, brown, gray, and black, and had coffin-lid and pyramidal appearances. Fourier-transform infrared spectroscopy analysis revealed that the components were 80% struvite and 20% calcium oxalate monohydrate. Chronic inflammatory cell infiltration was observed, with hyperplastic hepatocellular nodules characterized by large nuclei, prominent nucleoli, and scant cytoplasm with frequent binucleation, surrounded by thick fibrous septa. The epithelium of intrahepatic bile ducts that contained choleliths had undergone gallbladder-like metaplasia, which might have been induced by chronic irritation from the stones or by the accompanying chronic bacterial infection that was observed in Gram stains.

Clinical features, concurrent disorders, and survival time in cats with suppurative cholangitis-cholangiohepatitis syndrome

OBJECTIVE

To characterize clinical features, comorbidities, frequency of bacterial isolation, and survival time in cats with suppurative cholangitis-cholangiohepatitis syndrome (S-CCHS).

ANIMALS

168 client-owned cats with S-CCHS.

PROCEDURES

Data were prospectively (1980 to 2019) collected regarding clinical features, comorbidities, bacterial infection, illness duration, and treatments. Variables were evaluated for associations with survival time.

RESULTS

Median age of cats was 10.0 years, with no breed or sex predilection observed. Common clinical features included hyporexia (82%), hyperbilirubinemia (80%), lethargy (80%), vomiting (80%), jaundice (67%), weight loss (54%), and hypoalbuminemia (50%). Comorbidities included extrahepatic bile duct obstruction (53%), cholelithiasis (42%), cholecystitis (40%), and ductal plate malformation (44%) as well as biopsy-confirmed inflammatory bowel disease (60/68 [88%]) and pancreatitis (41/44 [93%]). Bacterial cultures were commonly positive (69%) despite prebiopsy antimicrobial administration in most cats. Of surgically confirmed choleliths, diagnostic imaging identified only 58%. Among 55 cats with "idiopathic pancreatitis," 28 (51%) were documented to have transiting choleliths, and 20 had pancreatic biopsies confirming pancreatitis. Cholelithiasis (with or without bile duct obstruction) and cholecystectomy were associated with survival advantages. Survival disadvantages were found for leukocytosis, ≥ 2-fold increased alkaline phosphatase, and hyperbilirubinemia. Cholecystoenterostomy had no survival impact. Cats with ductal plate malformations were significantly younger at diagnosis and death than other cats. Chronic treatments with antimicrobials, S-adenosylmethionine, and ursodeoxycholic acid were common postbiopsy.

CLINICAL RELEVANCE

S-CCHS in cats was associated with bacterial infection and various comorbidities and may be confused with pancreatitis. Surgically correctable morbidities (ie, cholecystitis, cholecystocholelithiasis) and cholecystectomy provided a significant survival advantage.

Increased erythrocytic osmotic fragility in anemic domestic shorthair and purebred cats

OBJECTIVES

Increased erythrocytic osmotic fragility and splenomegaly have been reported in anemic Abyssinian and Somali cats. Here we report on this condition in anemic domestic shorthair cats and two other breeds, and describe common features of the clinicopathological profiles, management and outcomes.

METHODS

Anemic cats, other than Abyssinians and Somalis, were included. The erythrocytic osmotic fragility test was performed, known causes of anemia were excluded, the illness was followed and medical records were reviewed.

RESULTS

Twelve neutered cats were first found to be anemic between 0.5 and 9.0 years of age. Pallor, lethargy, inappetence, pica, weight loss and splenomegaly were commonly observed. A moderate-to-severe macrocytic and hypochromic anemia with variable regeneration was noted. Infectious disease screening, direct Coombs' and pyruvate kinase DNA mutation test results were negative. Freshly drawn blood did not appear hemolysed but became progressively lysed during storage at 4°C. The sigmoid osmotic fragility curves were moderately to severely right shifted, indicating erythrocytic fragility at 20°C. Cross-correction studies indicated an intrinsic red cell effect rather than plasma effect. Most cats were treated with immunosuppressive doses of prednisolone and doxycycline, with variable responses. Five cats with recurrent or persistent anemia responded well to splenectomy. However, two had occasional recurrence of severe anemia: one was found to be Bartonella vinsonii-positive during one episode and responded to azithromycin and prednisolone, while the other cat had two episodes of severe anemia of unknown cause. Finally, six cats were euthanized within 1 month and 7 years after initial presentation. Histopathology of six spleens revealed mainly congestion and extramedullary hematopoiesis.

CONCLUSIONS AND RELEVANCE

Similarly to Abyssinian and Somali cats, domestic shorthair and cats of other breeds can also develop severe erythrocytic osmotic fragility with anemia and splenomegaly, which should be considered as a differential diagnosis in anemic cats.

Erythrocyte pyruvate kinase deficiency in three West Highland white terriers in Ireland and the UK

Erythrocyte pyruvate kinase (PK) deficiency is described for the first time in three apparently unrelated West Highland white terriers (WHWT) from Ireland and the UK. All three dogs were diagnosed with markedly regenerative but persistent anaemia and had been treated for presumed immune-mediated haemolytic anaemia (IMHA) before hereditary erythrocyte PK-deficiency was confirmed by breed-specific DNA mutation analysis. This hereditary erythroenzymopathy causes haemolytic anaemia and affects several canine breeds with varying degrees of severity. Although eventually causing osteosclerosis, haemosiderosis and death, PK-deficient dogs can adapt to their anaemia for many years.PK-deficiency should be considered in anaemic WHWTs worldwide particularly in dogs with haemolytic anaemia where evidence for an immune-mediated, infectious or toxic underlying cause is lacking.

Mechanisms, causes, investigation and management of vomiting disorders in cats: a literature review

Vomiting is a common presenting complaint in feline practice. This article differs from previous reviews in that it is an evidence-based review of the mechanisms, causes, investigation and management of vomiting in the domestic cat. Published evidence was reviewed, and then used to make recommendations for clinical assessment, diagnosis, antiemetic drug treatment, dietary management and monitoring of cats presenting with vomiting. The strength of the evidence on which recommendations are made (and areas where evidence is lacking for cats) has been highlighted throughout.

Erythrocytic pyruvate kinase mutations causing hemolytic anemia, osteosclerosis, and secondary hemochromatosis in dogs

BACKGROUND

Erythrocytic pyruvate kinase (PK) deficiency, first documented in Basenjis, is the most common inherited erythroenzymopathy in dogs.

OBJECTIVES

To report 3 new breed-specific PK-LR gene mutations and a retrospective survey of PK mutations in as mall and selected group of Beagles and West Highland White Terriers (WHWT).

ANIMALS

Labrador Retrievers (2 siblings, 5 unrelated), Pugs (2 siblings, 1 unrelated), Beagles (39 anemic, 29 other),WHWTs (22 anemic, 226 nonanemic), Cairn Terrier (n = 1).

METHODS

Exons of the PK-LR gene were sequenced from genomic DNA of young dogs (<2 years) with persistent highly regenerative hemolytic anemia.

RESULTS

A nonsense mutation (c.799C>T) resulting in a premature stop codon was identified in anemic Labrador Retriever siblings that had osteosclerosis, high serum ferritin concentrations, and severe hepatic secondary hemochromatosis. Anemic Pug and Beagle revealed 2 different missense mutations (c.848T>C, c.994G>A, respectively) resulting in intolerable amino acid changes to protein structure and enzyme function. Breed-specific mutation tests were developed. Among the biased group of 248 WHWTs, 9% and 35% were homozygous (affected) and heterozygous, respectively, for the previously described mutation (mutant allele frequency 0.26). A PK-deficient Cairn Terrier had the same insertion mutation as the affected WHWTs. Of the selected group of 68 Beagles, 35% were PK-deficient and 3% were carriers (0.37).

CONCLUSIONS AND CLINICAL IMPORTANCE

Erythrocytic PK deficiency is caused by different mutations in different dog breeds and causes chronic severe hemolytic anemia, hemosiderosis, and secondary hemochromatosis because of chronic hemolysis and, an as yet unexplained osteosclerosis. The newly developed breed-specific mutation assays simplify the diagnosis of PK deficiency.

Trace elements and metallothionein in liver and kidney of Felis catus

Trace metals such as Zn, Cu, and Fe are essential for life; differently, no biochemical function is known for Cd. Changes in dietary metal concentrations can cause deficiency or toxicity. Studies on trace elements in cat are lacking. This paper aimed to analyze Zn, Cu, Fe and Cd concentrations in liver and kidney of pathological domestic cat and to isolate metallothionein (MT) in these tissues. It was not possible to explore a possible correlation between metal concentrations and pathologies because the incidence for each of them was too low. Fe was the most abundant metal; in particular, the liver accumulates average Fe concentrations one order of magnitude higher than Zn and Cu, ranging from 66.75 and 1,444.23 microg/g. Significantly, higher levels of Fe were found in the liver of elder animals. Zn concentrations varied between 26.31 and 84.78 microg/g in the liver whereas in the kidney, ranged between 7.69 and 71.15 microg/g. Cu concentrations were between 2.37 and 112.91 microg/g in liver and between 2.12 and 9.85 microg/g in kidney. Cd was the least abundant metal with the exception of the kidney of the oldest cats where it reached a maximum of 13.71 microg/g. Gel-filtration metal distribution profiles from cytosolic extracts revealed the presence of Cd, Cu, Zn thioneins either in the liver or in the kidney. Because tissue samples were taken from pathological cats from different breed and age, care must be taken to use these data as a baseline profile of trace elements in healthy animals. Our results are indicative that for some specimens the feed levels of Fe and Cu could be higher than the optimal dietary intake and in few cats, there was also an exposure to Cd that was counteracted by MT biosynthesis.

Erythrocytic pyruvate kinase deficiency and AB blood types in Australian Abyssinian and Somali cats

OBJECTIVE

To determine the frequency of the mutant pyruvate kinase (PK) allele, haematological parameters and AB blood types of Abyssinian and Somali cats in Australia.

DESIGN

Complete blood cell and reticulocyte counts, DNA PK mutation testing and blood typing were performed in all cats.

RESULTS

A total of 60 cats (36 Abyssinians, 24 Somalis) were included (37 females, 23 males). For the mutant PK allele, three female Somalis were homozygous (affected, 5%), 17 cats were heterozygous (carrier, 28%) and 40 cats tested negative (normal, 67%). Pedigree analysis revealed common ancestry of affected and many carrier cats. Of affected cats, two had regenerative anaemias and all had reticulocytosis (range 64-390 x 10(9)/L; P < 0.001 compared with normal or carrier cats). The only consistent historical sign was lethargy. One affected cat was euthanased 18 months after testing, because of anaemia, neutropenia, anorexia and weight loss. The mutant allele frequency was 0.19 overall (0.29 in Somalis, 0.13 in Abyssinians). All cats had blood type A. The commercial blood typing card method incorrectly identified 12 cats as having type AB blood.

CONCLUSIONS

The frequency of the mutant PK allele is high in Australia. Screening for PK deficiency is indicated before mating and in individual cats of these breeds, even in the absence of anaemia and especially when there is reticulocytosis. Although all cats in the present study had blood type A, blood type B is common in these breeds worldwide. Retyping of any AB typed cats by a laboratory technique is recommended.