Serum proteome profiles in cats with chronic enteropathies.

BACKGROUND: Serum protein biomarkers are used to diagnose, monitor treatment response, and to differentiate various forms of chronic enteropathies (CE) in humans. The utility of liquid biopsy proteomic approaches has not been examined in cats. HYPOTHESIS/OBJECTIVES: To explore the serum proteome in cats to identify markers differentiating healthy cats from cats with CE. ANIMALS: Ten cats with CE with signs of gastrointestinal disease of at least 3 weeks duration, and biopsy-confirmed diagnoses, with or without treatment and 19 healthy cats were included. METHODS: Cross-sectional, multicenter, exploratory study with cases recruited from 3 veterinary hospitals between May 2019 and November 2020. Serum samples were analyzed and evaluated using mass spectrometry-based proteomic techniques. RESULTS: Twenty-six proteins were significantly (P < .02, ≥5-fold change in abundance) differentially expressed between cats with CE and controls. Thrombospondin-1 (THBS1) was identified with >50-fold increase in abundance in cats with CE (P < 0.001) compared to healthy cats. CONCLUSIONS AND CLINICAL IMPORTANCE: Damage to the gut lining released marker proteins of chronic inflammation that were detectable in serum samples of cats. This early-stage exploratory study strongly supports THBS1 as a candidate biomarker for chronic inflammatory enteropathy in cats.

Serum proteome of dogs with chronic enteropathy.

BACKGROUND: Chronic enteropathy (CE) is common in dogs and can occur with multiple etiologies including food-responsive enteropathy (FRE) and idiopathic inflammatory bowel disease (IBD). HYPOTHESIS/OBJECTIVE: To study the protein profile and pathway differences among dogs with FRE, IBD, and healthy controls using serum proteome analysis. ANIMALS: Nine CE dogs with signs of gastrointestinal disease and histologically confirmed chronic inflammatory enteropathy and 16 healthy controls. METHODS: A cross-sectional study with cases recruited from 2 veterinary hospitals between May 2019 and November 2020 was performed. Serum samples were analyzed using mass spectrometry-based proteomic techniques. RESULTS: Proteomic profiles showed marked variation in relative protein abundances. Forty-five proteins were significantly (P ≤ .01) differentially expressed among the dogs with CE and controls with ≥2-fold change in abundance. The fold change of dogs with IBD normalized to controls was more pronounced for the majority of proteins than that seen in the dogs with FRE normalized to control dogs. Proteins involving reactive oxygen species, cytokine activation, acute phase response signaling, and lipid metabolism were altered in dogs with CE. CONCLUSIONS AND CLINICAL IMPORTANCE: Cytokine alterations, acute phase response signaling, and lipid metabolism are likely involved in pathogenesis of CE. Although there are insufficient current data to justify the use of proteomic biomarkers for assessment of CE in dogs, our study identifies potential candidates.

Candidate causative variant for xanthinuria in a Domestic Shorthair cat.

Xanthinuria is a clinically significant form of urolithiasis in cats with poor clinical outcomes and limited treatment options. In humans, xanthinuria has an autosomal recessive mode of inheritance, with variants in xanthine dehydrogenase (XDH) and molybdenum cofactor sulfurase (MOCOS) responsible for cases. While causative genetic variants have not been identified in the domestic cat, a recessive mode of inheritance has been suggested. DNA was extracted from EDTA-stabilised blood obtained from a Domestic Shorthair cat with clinically confirmed xanthinuria. Whole-genome sequencing and variant assessment in XDH and MOCOS identified XDH:c.2042C>T (XDH:p.(A681V)) as a candidate causative variant for xanthinuria in this cat. The variant is located in a highly conserved part of the molybdenum-pterin co-factor domain, responsible for catalysing the hydroxylation of hypoxanthine to xanthine and uric acid. Variants in this domain of XDH have been shown to disrupt enzyme function and to cause xanthinuria in other species. When assessed in the wider cat population, the variant had an allele frequency of 15.8%, with 0.9% of the animals assessed homozygous for the alternative allele. Cats diagnosed with xanthinuria should be tested for this variant to validate its clinical relevance in the wider population.

Zinc toxicosis in a cat associated with ingestion of a metal screw nut.

Case summary: A 3-year-old female neutered domestic shorthair cat was presented for vomiting, inappetence and weight loss. The cat developed moderately regenerative anaemia, moderately increased alanine transaminase and alkaline phosphatase activities, hyperbilirubinaemia and prolonged activated partial thromboplastin time. Abdominal ultrasound identified gastric wall thickening and changes suggestive of pancreatitis. Gastroduodenoscopy identified a metal screw nut in the pylorus, which was removed with rat tooth forceps. Metal analysis and serum zinc concentration using leftover serum collected at admission were performed after screw nut removal. Serum zinc concentration was markedly elevated, confirming a diagnosis of zinc toxicosis. Metal analysis of the screw nut showed that the major metal component was zinc. The cat recovered after screw nut removal and supportive care. Clinical signs resolved and the serum zinc concentration reduced significantly after screw nut removal. Relevance and novel information: Reports of zinc toxicosis in cats are scarce, possibly due to the more discriminating eating habits of this species. To our knowledge, this is the first report of zinc toxicosis causing haemolytic anaemia, liver enzyme activity increases, gastrointestinal signs and pancreatitis in a cat associated with ingestion of a zinc-containing metal object.

Gynaecomastia in a male neutered cat with an adrenal tumour and associated hyperprogesteronism, hypercortisolism and hyperaldosteronism.

CASE SUMMARY: A 7-year-old male neutered domestic longhair cat was presented with chronic progressive gynaecomastia, polydipsia, polyphagia, weight loss and poor fur regrowth. Sexualised behavioural changes were not reported and virilisation was not present on physical examination. Pertinent haematology, biochemistry and urinalysis findings at the time of referral included mild hypokalaemia. Left adrenomegaly and mild prostatomegaly were identified on a CT scan. Evaluation of adrenal hormones with a low-dose dexamethasone suppression test, serum progesterone, testosterone, oestradiol, plasma aldosterone, renin, plasma metanephrine and normetanephrine measurement supported a diagnosis of hyperprogesteronism, hyperaldosteronism and hypercortisolism. Adrenalectomy was performed and histopathology was consistent with an adrenocortical tumour. Clinical signs and hormone elevations resolved postoperatively. RELEVANCE AND NOVEL INFORMATION: To our knowledge, this is the second report of gynaecomastia secondary to an adrenal tumour in a male neutered cat and the first associated with hyperprogesteronism.

Complete clinical response to combined antifungal therapy in two cats with invasive fungal rhinosinusitis caused by cryptic Aspergillus species in section Fumigati.

Cryptic species in Aspergillus section Fumigati are increasingly reported to cause invasive aspergillosis in humans and animals. These infections are often refractory to treatment because of intrinsic antifungal resistance. We report two cases of invasive fungal rhinosinusitis in domestic cats caused by A. udagawae and A. felis. Clinical signs resolved after combined therapy including posaconazole, caspofungin and terbinafine. Both cases remained asymptomatic more than 2 years from initial presentation.

A shift towards early-age desexing of cats under veterinary care in Australia.

The global problem of unowned domestic cats, driven by their phenomenal reproductive success, carries significant economic, animal welfare and biodiversity costs. Desexing owned cats prior to puberty prevents unwanted litters that contribute to unowned cat populations. The prevalence and predictors of desexing, and the age at which surgery was carried out were investigated using anonymized electronic patient records in the VetCompass Australia database of cats presented to veterinary practices. Of 52,941 cats born between 2010 and 2017, 83.6% were desexed. Among 7463 desexed females, 21.5% had been desexed by 4 months of age, 59.8% by 6 months and 85.4% by 1 year. Sex, breed, location and socioeconomic indices significantly influenced desexing status and age at surgery. Cats born between 2010 and 2017 had greater odds of being desexed than cats born between 1995and 2009 at each age cut-off (≤ 4 months [OR 1.76, CI95 1.58-1.97], ≤ 6 months [OR 1.50, CI95 1.38-1.62] and ≤ 1 year [OR 2.33, CI95 2.11-2.57] p < 0.001). Most cats presented to veterinarians in Australia are desexed. Compared with cats born before 2010, cats born later are significantly younger at desexing but, even so, many cats would have reached sexual maturity before surgery. These findings will inform the design of front-line strategies promoting prepubertal desexing and they demonstrate, for the first time, a shift towards desexing younger cats.

Successful tracheoscopy-assisted reconstruction of traumatic tracheal avulsion in a cat.

OBJECTIVE: To outline the clinical findings, surgical management, complications, and outcomes in a case of intrathoracic, traumatic, tracheal avulsion. CASE SUMMARY: A 2-year-old domestic shorthair cat presented with respiratory distress 18 days after a motor vehicle accident. A tracheal avulsion was diagnosed and treated by surgical anastomosis. The initial anastomosis failed. The subsequent tracheoscopic-assisted tracheal anastomosis was successful. The cat had no further episodes of respiratory distress following the second surgery in a 9-month follow-up period. UNIQUE INFORMATION PROVIDED: This communication describes a complication of intrathoracic, traumatic, tracheal avulsion repair that has not previously been described and the use of tracheoscopy during the subsequent surgical procedure to ensure accurate suture placement.

Seroprevalence and Risk Factors for Toxoplasma gondii Infection in Owned Domestic Cats in Australia.

Ongoing surveillance of Toxoplasma gondii seroprevalence and exposure risks in owned cats is important to identify effective mechanisms to decrease the prevalence of this global zoonotic parasite. We aimed to determine the seroprevalence of T. gondii and risk factors for seropositivity in owned domestic cats in Australia. Sera, signalment data, postcode, and completed owner-questionnaires surveying diet composition and lifestyle factors were collected for cats presenting to 18 veterinary clinics across Australia. T. gondii-specific IgG was measured by enzyme-linked immunosorbent assay. Data were analyzed using univariable and multivariable logistic regression to evaluate risk factors associated with positive T. gondii IgG serology. Among 417 cats, T. gondii seroprevalence was 39%. More than two-thirds of cats tested (69%) had outdoor access and 59% were fed a diet containing raw meat. Univariable analyses identified, age (>1 year, p < 0.001), a diet containing any raw meat (p = 0.001), raw kangaroo (p = 0.008), raw chicken (p = 0.012), or raw beef (p = 0.017), and hunting (p = 0.049) as risk factors for T. gondii infection. Age (>1 year, odds ratio [OR]: 7.15) and feeding of raw meat (OR: 2.23) remained significant risk factors (p < 0.001) in multivariable analyses. T. gondii seroprevalence did not differ between cats domiciled in urban and semiurban or rural areas. Pet cats in Australia are commonly infected with T. gondii. Feeding raw meat to cats, a common practice in Australia, is associated with T. gondii infection, highlighting the need for education about the health implications for cats from feeding a diet containing raw meat.

Colonic malignant peripheral nerve sheath tumour in a cat.

CASE SUMMARY: A 14-year-old male neutered domestic mediumhair cat presented with a 4 month history of inappetence and weight loss. Pertinent abnormalities on haematology and biochemistry included a mild microcytic regenerative anaemia (packed cell volume [PCV] 24% [reference interval (RI) 30-45%], mean cell volume 30.8 fl [RI 40-45 fl], absolute reticulocyte count 326.8 × 1012) and increased alkaline phosphatase activity (76 IU/l; RI <50 IU/l). Abdominal ultrasound and CT scan revealed masses in the transverse colon (2.0 cm × 1.2 cm) and right medial liver lobe (5.0 cm diameter). Thoracic radiographs were unremarkable. Right medial liver lobe resection and colectomy were performed. Immunohistochemistry was positive for S-100 protein, vimentin and glial fibrillary acidic protein, very weakly positive for c-kit and negative for muscle-specific actin and CD18, consistent with a colonic malignant peripheral nerve sheath tumour (MPNST) with a hepatic metastasis. Postoperative treatment with metronomic cyclophosphamide was well tolerated. Eighteen months postoperatively the cat re-presented after 3 days of progressive lethargy and inappetence. Haematology revealed a marked non- or pre-regenerative anaemia (PCV 10%). Coagulation times were prolonged (prothrombin time 39 s [RI 15-22 s] and activated partial thromboplastin time >300 s [RI 65-119 s]). Abdominal ultrasound identified multiple renal and hepatic nodules. Euthanasia was performed and post-mortem examination confirmed metastasis of the MPNST. RELEVANCE AND NOVEL INFORMATION: This report describes the treatment of a metastatic colonic peripheral nerve sheath tumour in a cat. Feline visceral MPNSTs are rare and little is known about prognosis or optimal treatment.

Acute adrenal haemorrhage in two cats with aldosterone-secreting adenocarcinomas.

CASE SUMMARY: Two 13-year-old domestic shorthair cats were diagnosed with unilateral right adrenocortical carcinomas (ACCs) and primary hyperaldosteronism (PHA). Both had polyuria, polydipsia and weight loss, and developed severe anaemia from an episode of acute adrenal haemorrhage. In one case, this occurred during hospitalisation and treatment of severe muscle weakness with cervical ventroflexion, while the other cat had acute collapse at home. A diagnosis of PHA was confirmed in both cases based on measurement of plasma aldosterone and renin activity. In one case, basal progesterone was also measured and was elevated. On ultrasonography and CT in one case, haemorrhage into the right retroperitoneal space was identified. Unilateral adrenalectomy was performed in both cases and there was no evidence of venous tumoral invasion in either. On histopathology of the excised adrenal glands both were ACCs with tumour necrosis, and one had extensive intratumoral haemorrhage. Both cats were diagnosed with International Renal Interest Society stage 2 or 3 chronic kidney disease postoperatively; one survived for 18 months and the other was well 8 months postoperatively. RELEVANCE AND NOVEL INFORMATION: Acute adrenal haemorrhage secondary to adrenal neoplasia has been reported in only one other cat, in which tumour type and function were not specified. Acute adrenal haemorrhage can occur as a consequence of tumour necrosis and rupture and can cause severe hypovolaemia and anaemia in cats with primary hyperaldosteronism.

Recanalisation of a congenital extrahepatic portosystemic shunt previously attenuated with cellophane banding in a cat.

CASE SUMMARY: A congenital extrahepatic portosystemic shunt was attenuated with commercial roll cellophane banding in a cat and postoperative liver changes were monitored using CT angiography (CTA). The patient clinically improved after cellophane banding, characterised by resolution of hepatic encephalopathy, weight gain, reference interval (RI) bile acid stimulation tests, as well as CTA-documented increased liver size, increased hepatic vasculature and shunt attenuation. Six months later the cat re-presented with recurrence of clinical signs and increased bile acids. CTA confirmed recanalisation of the shunt. Shunt attenuation was repeated using pure cellophane banding and nearly complete closure of the shunt was later documented by CTA. Seven months later, recanalisation was again documented via CTA and associated with clinical signs and increased bile acids. Complete ligation of the shunt was achieved using a polypropylene ligature and a titanium ligating clip. At long-term follow-up, the cat was clinically well, and bile acids and biochemistry were within the RIs. RELEVANCE AND NOVEL INFORMATION: This is the first report of CTA-documented recanalisation of an extrahepatic portosystemic shunt previously attenuated with cellophane banding. Recanalisation should be considered as a differential for recurrence of hepatic encephalopathy following cellophane banding.

Peculiarities of feline hyperadrenocorticism: Update on diagnosis and treatment.

Practical relevance: Hyperadrenocorticism (HAC) is a relatively uncommon endocrinopathy of older cats, with a mean age at diagnosis of 10 years. In addition to pituitary-dependent and adrenal-dependent hypercortisolism, clinical signs of HAC can result from adrenal sex steroid-producing tumours. Clinical challenges: While HAC in cats has many similarities to canine HAC, there are key differences in presentation, diagnosis and response to therapy. Most, but not all, cats with HAC have concurrent diabetes mellitus, which is often insulin resistant. Up to a third of cats with HAC have extreme skin fragility and are at high risk of debilitating iatrogenic skin tears during diagnostic or therapeutic interventions. Infections of the skin and nail beds, and urinary, respiratory and gastrointestinal tract, secondary to cortisol-induced immune suppression, are also common. Cats respond differently to dogs to adrenal function tests including adrenocorticotropic hormone (ACTH) stimulation and dexamethasone suppression tests; a 10-fold higher dose of dexamethasone is recommended in cats to screen for HAC. Curative treatment options include adrenalectomy or transsphenoidal hypophysectomy. Radiation or medical treatment may improve clinical signs. The response to mitotane therapy is poor. While trilostane is the medical treatment of choice based on retrospective studies, investigations into the pharmacokinetics of this drug in cats are lacking. Global importance: Feline HAC occurs worldwide and is not associated with any purebreed predisposition. Although uncommon, adrenal sex steroid-producing tumours have a higher prevalence in cats than in dogs. Evidence base: The information in this review is drawn from over 180 reported cases of feline HAC. Reports investigating clinical presentation, clinicopathological findings and treatment outcomes are observational, retrospective multiple case series (EBM grade III) or single case reports (EBM grade IV). While most endocrine testing studies for diagnosis are cohort controlled analytical studies (EBM grade III), prospective, randomised, placebo-controlled studies have been performed (EBM grade I).

Caecocolic intussusception associated with a caecal polyp and concurrent hepatocellular carcinoma in a cat.

CASE SUMMARY: A 17-year-old female neutered domestic shorthair cat presented for several days of reduced faecal volume and a rectal prolapse. Physical examination revealed a 2 cm rectal prolapse, hepatomegaly and a low body condition score of 3/9. Haematology and biochemistry revealed a mild non-regenerative anaemia (haematocrit 24.5%; reference interval [RI] 30.3-52.3%), a mild mature neutrophilia (16.21 × 109/l; RI 1.48-10.29 × 109/l) and a mild increase in alanine aminotransferase activity (222 IU/l; RI 12-130 IU/l). Abdominal radiographs identified hepatomegaly. The rectal prolapse was reduced under general anaesthesia. Abdominal ultrasound identified a caecocolic intussusception and a large hepatic mass. Thoracic radiographs were unremarkable. Hepatic fine-needle aspirate cytology revealed well-differentiated hepatocytes. A typhlectomy was performed and the quadrate liver lobe, with mass, was resected. Gross examination of the caecum identified a focal polyp; histopathology showed moderate plasmacytic-lymphocytic typhlitis and reactive mucosal-associated lymphoid tissue. The hepatic mass was diagnosed as a well-differentiated hepatocellular carcinoma. Six weeks postoperatively the cat had gained 0.5 kg, had an improved body condition score of 5/9 and resolution of clinical signs. The cat died acutely 1 year later from an unknown cause. RELEVANCE AND NOVEL INFORMATION: Caecocolic intussusception is rare in cats and uncommon in dogs. This is the third report in a cat and the first associated with a caecal polyp. As reported in dogs, the outcome following surgery was good. Hepatocellular carcinoma is a rarely reported feline neoplasm, which may have a good prognosis with surgical resection.

Feline Cholangitis.

Cholangitis is common in felines, including neutrophilic, lymphocytic, and chronic cholangitis (liver fluke). History, physical examination, laboratory testing, and abdominal ultrasound support a diagnosis. Diagnosis using hepatic histopathology and/or bile analysis is ideal but not always practical. Neutrophilic cholangitis is associated with bacterial cholecystitis, pancreatitis, and inflammatory bowel disease. The typical presentation is a short illness with lethargy, inappetence, pyrexia, and jaundice. Lymphocytic cholangitis, suspected to be immune-mediated, can have a prolonged clinical course with weight loss and ascites as the predominant features. The prevalence of liver fluke infestation in cats varies worldwide and clinical manifestations are uncommonly reported.

A survey of owners' perceptions and experiences of radioiodine treatment of feline hyperthyroidism in the UK.

The efficacy of radioiodine treatment of feline hyperthyroidism is well established; however, limited information is known about owners' perceptions or experiences of radioiodine. This study aimed to examine factors that influence owner treatment choices and their opinions following radioiodine. Surveys were sent to owners of cats referred for radioiodine treatment between 2002 and 2011 (radioiodine group; 264 cats) and owners of non-radioiodine-treated hyperthyroid cats seen at first-opinion practices (control group; 199 cats). The response rate was 67.0% (310 returned: 175 radioiodine, 135 control). Of 135 controls, 72 (53.3%) were unaware of radioiodine as a treatment option. Owners of cats ⩾15 years old and uninsured cats were less likely to pursue radioiodine. Cost of treatment, travel distance, potential human or animal health risks and waiting periods for radioiodine had a low impact on owners' treatment choice. Owners reported a moderate level of concern about treatment hospitalisation length, which included (158 respondents) the possibility of the cat being unhappy 130 (82.3%), owner missing the cat 102 (64.6%), inappetence 50 (31.6%), other pets missing the cat 32 (20.3%), development of co-morbid disease 28 (17.7%) and side effects 25 (15.8%). Owners assessed their cat's quality of life on a scale of 1 (very poor) to 10 (excellent), as 4 (4) (median [interquartile range]) pre-radioiodine (134 respondents) and 9 (2) post-radioiodine (131 respondents). Of 132 respondents, 121 (91.7%) were happy with their decision to choose radioiodine. The results of this questionnaire may assist veterinarians in addressing common owner concerns when discussing radioiodine as a treatment option for hyperthyroidism.

Feline permethrin toxicity: retrospective study of 42 cases.

Forty-two cases of feline permethrin toxicity treated at a referral hospital in Sydney, Australia were retrospectively reviewed. In most cases canine permethrin spot-on (PSO) flea products had been directly applied to affected cats. Most presented during summer and there was an increase in cases during the 2007/2008 period. Clinical signs included; tremors/muscle fasciculations (86%), twitches (41%), hyperaesthesia (41%), seizures (33%), pyrexia (29%), ptyalism (24%), ataxia (24%), mydriasis (19%) and temporary blindness (12%). Treatment involved decontamination, anticonvulsants and supportive care. Methocarbamol was not used. Complications occurred in 33% of cats and included: hypothermia (29%), electrolyte abnormalities (26%), aspiration pneumonia (12%), hypoproteinaemia (12%), anaemia (5%), apnoea (7%), respiratory arrest (5%), cardiorespiratory arrest (2%), pleural effusion (2%), urinary tract infection (2%) and corneal ulceration (2%). One cat was euthanased. Feline permethrin toxicity may result in severe clinical signs requiring intensive treatment. Despite prominent label warnings, cases of feline permethrin toxicity continue to occur in Australia and may be fatal.