Case number 1
In January 2014, an 8-year-old neutered female indoor domestic cat, Sphynx breed, was evaluated at a private veterinary clinic for gastrointestinal signs, namely anorexia with recent weight loss, vomiting and diarrhoea. The signs had began 10 days earlier with lethargy/weakness and malaise; the cat had a history of gastrointestinal and hepatic problems. For most of the cat’s adult life, her body weight had been consistent at approximately 4 kg. The cat was housed with one other cat, her daughter, which reported no signs. At the first visit, the owner reported giving the animals the same diet, namely homemade and commercial dry pet food.
On physical examination, the cat weighed 2.8 kg, the rectal temperature was 39.5 °C, pulse rate was 180 beats/min, and respiratory rate was 36 breaths/min; abnormalities on physical examination included fluid-splashing sounds in the abdomen, about 8% dehydration, left retromandibular lymph node enlargement, and the oral examination showed gingivitis, plaque and halitosis. The cat appeared otherwise normal.
Faecal examination showed a mucoid and bloody diarrhoea and the faecal flotation test and SNAP faecal enzyme-linked immunosorbent assay (ELISA) Giardia test (SNAP Giardia test, IDEXX Laboratories, Maine, USA) were negative. A complete geriatric haemobiochemical profile was sent to Idexx Laboratory; results of the cell blood count (CBC), venous haemogas analysis, serum biochemical analysis and assessment of serum total thyroxine concentration were within reference intervals except for leukocytes (23.6 G/l, reference interval, 6–11 G/l), absolute segmented neutrophils (19,030/ul, reference intervals 3000-11,000/ul), absolute monocytes (1676/ul reference intervals 0-500/ul); ALT (256 U//l, reference interval, < 175 U/l), AST (118 U/l, reference intervals <71 U/l) serum albumin concentration (17 g/l, reference intervals 27–44 g/l), calcium (1.9 mmol/l, reference interval, 2.2-2.9 mmol/l), and folate (7.9 ng/ml, reference interval 11.1 - 21.6 ng/ml).
A diagnosis of generic enteritis, hepatopathy with probable intestinal infection, was made. The cat was hospitalized for 6 days and treated intravenously with: fluid therapy (Ringer’s acetate), Metronidazole antibiotic (10 mg/kg bid - Deflamon 500 mg/100 mL), Enrofloxacin antibiotic (5 mg/kg sid - Baytril 50 mg/ml), S-Adenosylmethionine (20 mg/kg sid - Samyr 400 mg/5 ml). The cat was fed with a gastrointestinal diet (Prescription Diet i/d Feline, Hill’s) and lactobacillus (Florentero, Candioli Pharma), and treated with milbemycin oxime and praziquantel (Milbemax®, Novartis).
Case number 2
Four days after case number 1 was seen for the first time, a 6-year-old female cat from the same household was referred to the same veterinary clinic for the same signs previously reported for case number 1, 3 days of vomiting and diarrhoea and 1 day of anorexia, but milder than case 1. For most of the cat’s adult life, her body weight had been approximately 3 kg.
During the clinical visit and considering the anamnesis of case number 2, the veterinarian suspected the same infection. Investigating the infection and the possible sources of contamination more deeply, the owner specified that the homemade food given to both animals was a frozen commercial poultry RMBD bought on the internet.
On physical examination, the cat weighed 2.5 kg, the rectal temperature was 38.3 °C, pulse rate was 180 beats/min, and respiratory rate was 40 breaths/min; abnormalities included only about 7% dehydration. Faecal examination showed a mucoid diarrhoea and the faecal flotation test was negative.
Clinicopathologic findings (procyte Idexx, catalyst Idexx), CBC and restricted serum biochemical analysis were within reference intervals except for leukocytes (22.14 K/ul, reference interval, 2.87-17.02 K/ul), absolute segmented neutrophils (18.2 K/ul, reference intervals 1.48-10.29 K/ul), absolute monocytes (0.72 K/ul reference intervals 0.05-0.67 K/ul); ALT (132 U//l, reference interval, < 130 U/l), AST (57 U/l, reference intervals <48 U/l) and GGT (4 U/l, reference intervals 0–1 U/l).
Based on the information acquired during anamnesis of the second case and the fact that both cats had received the same raw food diet, fresh faeces of case number 2 were collected and sent to IDEXX Laboratories for a real-time PCR assay evaluating a panel of 8 enteropathogens (Feline Diarrhoea RealPCR™ Panel) including feline panleukopenia virus, feline coronavirus, Tritrichomonas foetus, Giardia sp., Toxoplasma gondii, Cryptosporidium sp., Salmonella sp. and the detection of Clostridium perfringens toxin A gene (cpa) and Clostridium perfringens enterotoxin gene (cpe). The PCR assays detected Salmonella sp. and 1,300,000 copies/g of cpa were quantified; no other enteropathogens were detected. The cat was hospitalized for 4 days and treated as reported for case number 1.
At the time of writing, a diagnosis of inflammatory bowel disease was made for case number 1 and the cat reports several daily episodes of diarrhoea, whereas case number 2 is healthy and never showed any recurrence of gastrointestinal signs.
Analysis of commercial frozen poultry RMBD and commercial dry pet food
On the basis of the Salmonella sp. and C. perfringens positive faeces, the owner of the two cats was advised by the veterinarian to discontinue the practice of feeding raw meat-based diets and the commercial poultry RMBD was suspected as a possible source of infection. The owner submitted specimens of both diets, namely commercial prepared bowl of frozen poultry RMBD and commercial dry pet food, to the Experimental Institutes for Zooprophylaxis in Veneto for bacteriological culture: the diets were analyzed for the detection of Salmonella sp. with real-time PCR (iQ-Check® Salmonella, Bio-Rad) validated by AFNOR (BRD 07/06-07/04) and also using the official International Organization for Standardization (ISO) cultural methods, ISO 6579:2002/Cor 1:2004, and using the ISO 7937:2004 for the count of C. perfringens. The RMBD results disclosed the presence of Salmonella spp. DNA by real-time PCR and the isolation of Salmonella spp., that was serotyped as Salmonella Typhimurium Group B 1,4,(5),12:i:1,2, whereas C. perfringens was counted as <10 colony forming units (cfu)/g. Salmonella spp. was not detected by real-time PCR in the commercial dry pet food, and C. perfringens was counted as <10 cfu/g.