Duodenal perforation in a cat following the administration of nonsteroidal anti-inflammatory medication

Spontaneous cecal perforation in a cat diagnosed with ultrasonography

An 8-year-old cat was presented for an acute history of anorexia, marked abdominal pain, and hyperthermia. Ultrasonography showed a cecal perforation with focal steatitis and adjacent free gas bubbles, consistent with focal peritonitis. Surgery confirmed the imaging findings. An enterectomy was performed with the removal of the cecum and ileocolic valve, and anastomosis between the ileum and colon was performed. Histology revealed transmural enteritis and chronic severe pyogranulomatous peritonitis with intralesional plant fragments.

2024 ISFM and AAFP consensus guidelines on the long-term use of NSAIDs in cats

PRACTICAL RELEVANCE

Non-steroidal anti-inflammatory drugs (NSAIDs) are widely used and are effective for the management of pain in cats. These Guidelines will support veterinarians in decision-making around prescribing NSAIDs in situations of chronic pain, to minimise adverse effects and optimise pain management. Information is provided on mechanism of action, indications for use, screening prior to prescription, use in the presence of comorbidities, monitoring of efficacy, and avoidance and management of adverse effects.

CLINICAL CHALLENGES

The cat's unique metabolism should be considered when prescribing any medications, including NSAIDs. Chronic pain may be challenging to detect in this species and comorbidities, particularly chronic kidney disease, are common in senior cats. Management of chronic pain may be complicated by prescription of other drugs with the potential for interactions with NSAIDs.

EVIDENCE BASE

These Guidelines have been created by a panel of experts brought together by the International Society of Feline Medicine (ISFM) and American Association of Feline Practitioners (AAFP). Information is based on the available literature, expert opinion and the panel members' experience.

Surgical Anatomy of the Gastrointestinal Tract in Cats

In cats, the gastrointestinal tract is one of the regions in which surgical procedures are most frequently performed by veterinary surgeons; therefore, knowledge of the surgical anatomy of the feline gastrointestinal tract is of high importance. The main surgical procedures performed include gastrotomy, gastrectomy, enterotomy, and enterectomy, as well as procedures in the liver and pancreas. There are also anatomical differences between dogs and cats, increasing the need for deep knowledge of the anatomy treated in the different surgical approaches. The aim of the present review is to describe in detail the anatomy of the gastrointestinal tract in cats highlighting the anatomical regions of significant importance in different surgical procedures.

Unusual Case of Biliary Peritonitis in a Dog Secondary to a Gastric Perforation

Biliary peritonitis is a pathological condition representing a medical emergency with a high risk of mortality. This condition is reported in both human and veterinary medicine following biliary tract rupture, extrahepatic biliary obstructions, gallbladder rupture, trauma, or duodenal perforation. In this report, the first-ever case of biliary peritonitis due to gastric perforation in a Bobtail purebred dog is described, which was probably induced by the administration of nonsteroidal anti-inflammatory drugs (NSAIDs). After an elective splenectomy and castration, the dog was referred to our hospital for medical management for inappetence, mental depression, and multiple episodes of gastric vomits with traces of blood. Clinical diagnostic tests showed the presence of biliary peritonitis. Due to worsening clinical conditions, the patient was subjected to euthanasia. Macroscopic examination showed a free brownish abdominal effusion and the presence of perforating ulcer of the stomach pylorus region.

Gastroduodenal ulceration detected endoscopically in cats: retrospective study of 61 patients

OBJECTIVES

The aim of this study was to describe the endoscopic appearance of gastroduodenal ulcers (GDUs), and to assess the clinical, ultrasonographic and histological data, as well as long-term follow-up, in cats.

METHODS

The medical record databases of five veterinary endoscopists were evaluated between January 2016 and 2020, in a retrospective study. Cats with at least one gastric or duodenal ulcer detected by endoscopic examination were included. All the medical records of the selected cats were reviewed and information was collected regarding breed, age, sex, neuter status, medical history, clinical signs, and ultrasonographic, endoscopic and histological findings. The cats were evaluated at 6, 12 and 18 months.

RESULTS

Sixty-one cats with a median age of 9.0 years (range 2.0-16.0) were included in the study. The most common complaints were vomiting (n = 55; 90%) and hyporexia (n = 40; 66%); haematemesis was reported in 12 (20%) cats. Endoscopy showed GDUs in the following locations: gastric body in 28 cats (46%), antropyloric area in 34 cats (56%), fundus in 13 cats (21%) and duodenum in eight cats (13%). A single GDU was found in 42 cats (69%) and multiple GDUs were seen in 19 cats (31%). Histopathological evaluation revealed benign lesions in 33 (54%) cats and malignant lesions in 28 (46%; 24 high-grade lymphoma, one low-grade lymphoma and three carcinoma). High-grade lymphoma was detected only in the stomach. Cats diagnosed with malignant GDUs (median 10.5, range 4-16) were significantly older than cats with benign lesions (P = 0.002).

CONCLUSIONS AND RELEVANCE

GDUs are common and were detected in 5.1% of cats undergoing an upper gastrointestinal endoscopy. The risk of a malignant ulcer increases proportionally with each year of increasing age. GDU location, number and morphological appearance do not provide any indication of the nature of the ulcer; however, duodenal ulcers are frequently benign. Endoscopic examination facilitates the early and minimally invasive detection of GDUs in cats.

Novel Multicentric Hepatic Lymphoma with Extrahepatic Biliary Obstruction Associated with Duodenal Perforation in a Cat

An 11-year-old male castrated domestic shorthair cat was presented for evaluation due to clinical deterioration and potential extrahepatic biliary obstruction (EHBO). Further investigations confirmed EHBO and revealed severe and previously unreported comorbidities. On initial examination, the cat was markedly icteric with a poor body condition score and severe muscle wasting. Serum chemistry and complete blood count showed evidence of cholestasis and anemia. Primary diagnostics and therapeutics targeted these abnormalities. Abdominal ultrasound revealed peritoneal effusion, multifocal mixed echogenic hepatic and splenic foci, small intestinal thickening, cholelithiasis, choledocholithiasis, and common bile duct and pancreatic duct dilation with evidence of obstruction. Peritoneal effusion cytology confirmed septic peritonitis. Hepatic and splenic cytology was consistent with lymphoma. Based on these results, euthanasia was elected by the owners of the animal. Necropsy confirmed the ultrasound diagnoses, septic peritoneal effusion associated with a duodenal perforation, multiorgan lymphoma, and common bile duct carcinoma. Flow cytometry classified the lymphoma as a double-negative phenotype of T-cell lymphoma (CD3+ and CD5+, but CD4- and CD8-) present in the duodenum and liver and suspected in the spleen which has previously not been reported in cats. This case report documents a cat with EHBO caused by multiple disease processes including a novel T-cell lymphoma phenotype, biliary carcinoma, duodenal perforation and septic abdomen, and choleliths, as well as inflammatory hepatobiliary disease.

Billroth II procedure for the treatment of spontaneous gastrointestinal perforation in two cats

CASE DESCRIPTION

A 9-year-old castrated male domestic shorthair cat (cat 1) and a 10-year-old castrated male Maine Coon cat (cat 2) were presented for recurrent feline lower urinary tract disease after receiving outpatient care from their primary veterinarians.

CLINICAL FINDINGS

Physical examination findings for both cats were initially within reference limits. After a short period of hospitalization, both cats developed peritoneal effusion; results of cytologic analysis of a sample of the fluid were consistent with septic peritonitis. During exploratory laparotomy, perforation of the pylorus or proximal portion of the duodenum secondary to ulceration was identified.

TREATMENT AND OUTCOME

Both cats underwent partial duodenectomy, partial gastrectomy (pylorectomy), and gastrojejunostomy (Billroth II procedure). The cats recovered from surgery and returned to a normal quality of life; however, each had mild episodes of anorexia but maintained a stable body weight. Cat 2 required additional surgery for trichobezoar removal 7 weeks later but recovered quickly. At 7 months after trichobezoar removal, cat 2 developed intermittent vomiting, but clinicopathologic, abdominal ultrasonographic, and upper gastrointestinal tract endoscopic findings were within reference limits. At 9 (cat 2) and 13 (cat 1) months after the Billroth II procedure, both cats were reported to be in good general health and without gastrointestinal signs.

CLINICAL RELEVANCE

In both cats, the Billroth II procedure was technically straightforward and associated with a full recovery and good medium- to long-term quality of life. A Billroth II procedure could be considered for treatment of cats with large mural lesions in the pyloroduodenal region.

Use of intravenous lipid therapy in a cat with carprofen overdose

Intravenous lipid emulsion (ILE) was administered to a cat with no adverse effects. This case report postulates that ILE can be used for the treatment of carprofen toxicity in cats and supports the lipid sink theory as the main mechanism of action.

Gastroduodenal Ulceration in Small Animals: Part 1. Pathophysiology and Epidemiology

Gastroduodenal ulceration in small animals is a complex and important comorbidity that occurs when the physiological homeostasis of the gastrointestinal tract is disrupted secondary to administration of medications or the presence of local or systemic diseases. The aim of this article is to provide a comprehensive review of the veterinary literature regarding the pathophysiology, epidemiology, and risk factors associated with gastroduodenal ulceration in small animals. Pertinent concepts from the human literature will be integrated into the discussion. This article serves as an introduction to the second part of this series, which will review current evidence regarding the use of H2-receptor antagonists and proton pump inhibitors in small animals.

Pain management in cats—past, present and future. Part 2. Treatment of pain—clinical pharmacology

Opioids have an unjustified reputation for causing mania in cats, but with refinements in dosing they are now used successfully in this species. The mu-opioid agonists are generally considered the best analgesics. Morphine (0.1–0.3 mg/kg) is effective in a clinical setting. Methadone (up to 0.5 mg/kg) has a similar profile to morphine. Pethidine (Demerol, meperidine; 2–5 mg/kg) is a useful analgesic with a faster onset but shorter duration of action than morphine. Oxymorphone and hydromorphone (0.05–0.1 mg/kg) are widely used in the USA. These opioids are more potent (up to 10 times), and longer acting than morphine in cats. Butorphanol (0.1–0.4 mg/kg) is a mu-opioid antagonist that produces its analgesic actions through kappa agonist activity. It rapidly reaches a ceiling effect, is short acting and is a weaker analgesic than pure mu opioids. Buprenorphine (0.01–0.02 mg/kg), a partial mu-agonist, is the most popular opioid used in small animal practice in the UK, other parts of Europe, Australia and South Africa. In clinical studies it has produced better analgesia than several other opioids and appears to be highly suitable for perioperative pain management in cats. NSAIDs are also used in cats for pain management, although cats metabolise these differently from other species. With appropriate dosing, carprofen (1–4 mg/kg) and meloxicam (0.3 mg/kg) have proved highly effective with few side effects. The use of ketoprofen (2 mg/kg), tolfenamic acid (4 mg/kg) and vedaprofen (0.5 mg/kg) has been reported in cats. Other less traditional analgesics such as ketamine, medetomidine and local anaesthetics are also used for clinical pain management. The transmucosal, transdermal and epidural routes offer novel methods for administration of analgesic drugs and have considerable potential for improving techniques in feline pain management.

Spontaneous gastrointestinal perforation in cats: a retrospective study of 13 cases

Objectives

The aim of this study was to describe the clinical characteristics and the frequency of malignant vs non-malignant causes for spontaneous gastrointestinal perforation in cats.

Methods

The medical records of cats diagnosed as having gastrointestinal perforation between August 2010 and July 2013 were reviewed. Diagnosis was confirmed by exploratory surgery. Patients with incomplete records, perforation due to external trauma, leakage at previous enterotomy or anastomotic sites, or foreign bodies were excluded. Each record was examined for different information pertaining to signalment, medical history, clinical and clinicopathological data, imaging findings, abdominal fluid examination, surgical findings, histopathological examination, treatment received after surgery and outcome.

Results

Thirteen cats were included. Five of these cats had concurrent illnesses, including viral upper respiratory tract disease, pancreatitis and chronic kidney disease. Two cats had previously received non-steroidal anti-inflammatory drugs and four had received corticosteroids. Clinical signs and clinicopathological abnormalities were not specific. Six of 13 patients were diagnosed during surgery with gastric perforations, four patients with duodenal perforations and three patients with jejunal perforations. Histopathological examination of the ulcerated wall was performed in 11/13 cats. Alimentary lymphoma was diagnosed in six cats. Non-neoplastic lesions (lymphocytic– plasmacytic inflammatory bowel disease, necrotic suppurative enteritis) were observed in the other five cats. The major limitation of the study was the small sample size.

Conclusions and relevance

Lymphoma may be a frequent cause of spontaneous perforation in cats. Therefore, histological examination of ulceration is essential in all cases. The direct and sole implication of anti-inflammatory administration in a gastrointestinal perforation is not clearly established in this study.

Successful surgical management of spontaneous gastric perforations in three cats

BACKGROUND

In the veterinary literature, feline gastroduodenal ulcer disease has been described only in individual case reports or retrospective studies reporting small numbers of cats. Although its canine counterpart is commonly encountered, less is known about factors predisposing cats to gastroduodenal ulceration and potentially perforation. Similarly the outcome following treatment is not well reported in this species.

REPORTED RISK FACTORS

In dogs, hepatic disease and administration of non-steroidal anti-inflammatory drugs (NSAIDs) have been reported as the two most common causes of gastroduodenal ulceration. In cats, only one clinical report so far has implicated an NSAID as a risk factor for spontaneous gastroduodenal perforation.

FINDINGS AND PRACTICAL RELEVANCE

This report describes the historical and physical findings, as well as the treatment and outcome, in three cats with spontaneous gastric perforation that were receiving anti-inflammatory medication immediately prior to presentation. It highlights the importance of thorough patient evaluation in any cat presenting with non-specific clinical signs and a history of anti-inflammatory drug administration.

Recent developments in nonsteroidal antiinflammatory drugs in cats

Pain, particularly chronic pain, is an underestimated ailment in cats. Veterinarians tend to under-diagnose and under-treat pain in this aloof and stoic species. Until recently, there was only one analgesic (i.e., butorphanol) approved in the United States for use in cats; but many analgesics, particularly opioids, have been used extra-label for this purpose. Nonsteroidal antiinflammatory drugs (NSAIDs) have been used sparingly in cats because of safety concerns, which are less of an issue with the newer agents. Meloxicam is the only NSAID labeled for use in cats in the United States, but other agents are available in this country and are labeled for use in cats in other countries.

Dose-related thermal antinociceptive effects of intravenous hydromorphone in cats

OBJECTIVE

To describe the dose-related thermal antinociceptive effects of intravenous (i.v.) hydromorphone in cats.

STUDY DESIGN

Randomized, blinded, crossover design.

ANIMALS

Seven adult cats (3.5-7.4 kg), two spayed females, and five neutered males.

METHODS

Hydromorphone (0.025, 0.05, or 0.1 mg kg(-1)) was administered i.v.. Skin temperature and thermal threshold were measured before and at selected time points to 720 minutes post-administration. Statistical analysis of mean thermal threshold and skin temperatures over time for each dose and between doses was by way of a split-plot model and post hoc Bonferroni t-tests. p < 0.05 was considered significant.

RESULTS

A significant difference from baseline for mean thermal threshold was identified for the 0.05 mg kg(-1) dose (5-80 minutes, peak thermal threshold 46.9 +/- 6.2 degrees C) and 0.1 mg kg(-1) dose (5-200 minutes, peak thermal threshold 54.9 +/-0.2 degrees C). The thermal threshold was significantly greater after the 0.1 mg kg(-1) dose from 5 to 200 minutes compared to the 0.025 mg kg(-1) and 0.5 mg kg(-1) doses. The thermal threshold was significantly greater from 35 to 80 minutes for the 0.05 mg kg(-1) dose when compared with the 0.025 mg kg(-1) dose. Skin temperature was significantly increased from 35 to 140 minutes following the 0.1 mg kg(-1) dose.

CONCLUSIONS

A dose-related antinociceptive effect was demonstrated for i.v. hydromorphone in cats.

CLINICAL RELEVANCE

Hydromorphone at doses less than 0.1 mg kg(-1) has a modest antinociceptive effect and a short duration of action. At a dose of 0.1 mg kg(-1) i.v., onset of analgesia is rapid with a clinically useful duration of effect, but is associated with a rise in skin temperature.

Nonsteroidal anti-inflammatory drugs in cats: a review

OBJECTIVE

To review the evidence regarding the use of nonsteroidal anti-inflammatory drugs (NSAIDs) in cats.

DATABASES USED

PubMed, CAB abstracts.

CONCLUSIONS

Nonsteroidal anti-inflammatory drugs should be used with caution in cats because of their low capacity for hepatic glucuronidation, which is the major mechanism of metabolism and excretion for this category of drugs. However, the evidence presented supports the short-term use of carprofen, flunixin, ketoprofen, meloxicam and tolfenamic acid as analgesics in cats. There were no data to support the safe chronic use of NSAIDs in cats.

The Clinical Pharmacology of Cyclooxygenase-2–Selective and Dual Inhibitors

Over the past decade, there have been several nonsteroidal anti-inflammatory drugs (NSAIDS) introduced in veterinary medicine with an increased gastrointestinal safety profile consistent with a cyclooxygenase (COX)-1-sparing effect. More recently, an NSAID with additional 5-lipoxygenase (5-LOX) activity has also been approved for use. Although it is tempting to equate in vitro COX-2/COX-1 and 5-LOX inhibition to overall in vivo safety, the data do not support this approach. The true overall safety for any individual compound is based on its evaluation in laboratory margin-of-safety studies, reproductive safety studies, and blind multicenter field studies in client-owned animals. Therefore, when choosing a COX-2-selective or dual-inhibitor NSAID for clinical use, all in vivo data must be taken into account to understand comparative safety, and continued use must be based on the drug's performance in the individual being treated. Until head-to-head trials in multicenter blind studies are published, comments on comparative safety and effectiveness must be reserved.

Effects of intravenous administration of lidocaine on the thermal threshold in cats

OBJECTIVE

To determine the effects of IV administration of lidocaine on thermal antinociception in conscious cats.

ANIMALS

6 cats.

PROCEDURE

2 experiments were performed in each cat (interval of at least 2 months). In experiment 1, lidocaine pharmacokinetics were determined for each conscious cat following IV administration of a bolus of lidocaine (2 mg/kg). In experiment 2, data from experiment 1 were used to calculate appropriate doses of lidocaine that would achieve predetermined plasma lidocaine concentrations in the cats; lidocaine (or an equivalent volume of saline [0.9% NaCl] solution as the control treatment) was administered IV to target pseudo-steady-state plasma concentrations of 0, 0.5, 1, 2, 5, and 8 microg/mL. Skin temperature and thermal threshold were determined at the start of the experiment (baseline) and at each concentration. Samples of venous blood were obtained at each target concentration for plasma lidocaine concentration determination.

RESULTS

In experiment 2, actual plasma lidocaine concentrations were 0.00 +/- 0.00 microg/mL, 0.25 +/- 0.18 microg/mL, 0.57 +/- 0.20 microg/mL, 1.39 +/- 0.13 microg/mL, 2.33 +/- 0.45 microg/mL, and 4.32 +/- 0.66 microg/mL for target plasma concentrations of 0, 0.5, 1, 2, 5, and 8 microg/mL, respectively. Compared with baseline values, no significant change in skin temperature or thermal threshold was detected at any lidocaine plasma concentration (or saline solution equivalent). Skin temperature or thermal threshold values did not differ between lidocaine or control treatments.

CONCLUSIONS AND CLINICAL RELEVANCE

Results indicated that these moderate plasma concentrations of lidocaine did not affect thermal antinociception in cats.

Megaesophagus was complicated with Billroth I gastroduodenostomy in a cat

A seven-year-old, female, domestic short hair cat was presented with a history of chronic anorexia. Radiographic examination revealed a large space-occupying calcified mass in the abdominal cavity. The mass was located in pylorus and did not extend into the duodenum and surrounding tissues. Billroth I gastroduodenostomy was conducted to remove the mass. Histopathological examination of the mass showed a lymphoma. Although Recovery following the operation was excellent, the patient showed intermittent vomiting unrelated to feeding. Radiographical examination revealed a megaesophagus, which was assumed to be a complication of the Billroth I procedure, since the condition was not observed before the procedure.

Managing pain in feline patients

In the past 10 years, great strides have been made in the field of feline analgesia. A better understanding of the cat's unique metabolism has led researchers to realize that extrapolation across species boundaries is unwise,and this has resulted in feline-specific studies. The opioids are now used more commonly in cats, with good analgesic effect and few side effects. Excellent acute pain management is achievable in cats by using opioids, NSAIDs, alpha2-agonists, and local anesthetics. Although much of the research data has compared the use of single drugs, a multimodal approach using agents that work at different parts of the pain pathway is commonly used in clinical settings, with added benefit. Compared with dogs, few pain-scoring systems have been developed for cats, and this remains an important goal. Management of chronic pain in cats is a challenge because of the potential problems with long-term NSAID use; however, reports of low doses given at extended intervals are encouraging. As we gain experience with less traditional analgesics, such as amitriptyline, amantadine, and gabapentin, and critically evaluate complimentary therapies, our ability to provide comfort to this population of cats will improve.

Nonsteroidal anti-inflammatory drugs in veterinary ophthalmology

Uveitis is a common sequela to many ocular diseases. Primary treatment goals for uveitis should be to halt inflammation, prevent or control complications caused by inflammation, relieve pain, and preserve vision. Systemic and topical NSAIDs are essential components of the pharmaceutic armamentarium currently employed in the management of ocular inflammation by general practitioners and veterinary ophthalmologists worldwide. NSAIDs effectively prevent intraoperative miosis; control postoperative pain and inflammation after intraocular procedures, thus optimizing surgical outcome; control symptoms of allergic conjunctivitis;alleviate pain from various causes of uveitis; and circumvent some of the unwanted side effects that occur with corticosteroid treatment. Systemic NSAID therapy is necessary to treat posterior uveitis, because therapeutic concentrations cannot be attained in the retina and choroid with topical administration alone, and is warranted when diseases, such as diabetes mellitus or systemic infection, preclude the use of systemic corticosteroids. Risk factors have been identified with systemic and topical administration of NSAIDs. In general, ophthalmic NSAIDs may be used safely with other ophthalmic pharmaceutics; however, concurrent use of drugs known to affect the corneal epithelium adversely, such as gentamicin, may lead to increased corneal penetration of the NSAID. The concurrent use of NSAIDs with topical corticosteroids in the face of significant preexisting corneal inflammation has been identified as a risk factor in precipitating corneal erosions and melts in people and should be undertaken with caution[8]. Clinicians should remain vigilant in their screening of ophthalmic and systemic complications secondary to drug therapy and educate owners accordingly. If a sudden increase in patient ocular pain (as manifested by an increase in blepharospasm, photophobia, ocular discharge, or rubbing)is noted, owners should be instructed to contact their veterinarian promptly.

Comparison of preoperative carprofen and postoperative butorphanol as postsurgical analgesics in cats undergoing ovariohysterectomy

OBJECTIVE

To compare carprofen to butorphanol, with regard to postsurgical analgesic effects, duration of analgesia, and adverse side effects.

STUDY DESIGN

Blinded, randomized clinical study.

ANIMALS

Seventy-one cats, 0.5-5 years of age, weighing 3.24 +/- 0.61 kg, undergoing ovariohysterectomy (OHE).

METHODS

Cats were premedicated with subcutaneous atropine (0.04 mg kg(-1)), acepromazine (0.02 mg kg(-1)), and ketamine (5 mg kg(-1)). Anesthesia was induced with ketamine (5 mg kg(-1)) and diazepam (0.25 mg kg(-1)) given intravenously, and maintained with isoflurane. There were three treatment groups: group C (4 mg kg(-1) carprofen SC at induction), group B (0.4 mg kg(-1) butorphanol SC at end of surgery), and group S (0.08 mL kg(-1) of sterile saline SC at induction and end of surgery). Behavioral data were collected using a composite pain scale (CPS), prior to surgery (baseline) and 1, 2, 3, 4, 8, 12, 16, 20, and 24 hours post-surgery. Interaction scores were analyzed separately. Cats with CPS scores >12 received rescue analgesia (meperidine, 4 mg kg(-1), intramuscular).

RESULTS

Sixty cats completed the study. The CPS scores did not differ significantly between groups C and B at any time period. CPS scores for groups B and C were significantly increased for 12 hours post-surgery, and in group S for 20 hours. Both group C and B CPS scores were significantly lower than group S in this 20-hour postoperative period, except at 4 hours (B and C) and at 3 and 8 hours (B alone). Interaction scores for group C returned to preoperative baseline 4 hours after surgery, while both groups B and S remained increased for at least 24 hours post-surgery. Nine cats required meperidine.

CONCLUSION

In this study, carprofen provided better postsurgical analgesia than butorphanol. Clinical relevance Neither drug completely abolished pain, however preoperative carprofen provided better pain control compared with postoperative butorphanol in the 24-hour period following OHE surgery in cats.

Changes in thermal threshold response in eight cats after administration of buprenorphine, butorphanol and morphine

Thermal thresholds were measured in eight cats after the intramuscular administration of morphine (0.2 mg/kg), buprenorphine (0.01 mg/kg) or butorphanol (0.2 mg/kg), doses commonly used in clinical practice; 0.9 per cent saline (0.3 ml) was injected as a control. Groups of six cats were used and each cat participated in at least two treatments, according to a randomised design. The investigator was blinded to the treatments. The thermal thresholds were measured with a testing device developed specifically for cats, and measurements were made before and five, 30, 45 and 60 minutes and two, four, six, 12 and 24 hours after the injections. There was no significant change in thermal threshold after the injection of saline. With butorphanol, the threshold was increased only at five minutes after the injection and was decreased two hours after the injection; with morphine it was increased from between four and six hours after the injection, and with buprenorphine it was increased from between four and 12 hours after the injection.

Plasma fentanyl concentrations in awake cats and cats undergoing anesthesia and ovariohysterectomy using transdermal administration

OBJECTIVE

To measure the plasma fentanyl concentrations achieved over time with transdermal fentanyl patches in awake cats and cats undergoing anesthesia and ovariohysterectomy.

STUDY DESIGN

Randomized prospective experimental study.

ANIMALS

Twenty-four purpose-bred cats.

METHODS

Cats were randomly assigned to three groups for Part I of a larger concurrent study. Group P received only a 25 micro g hour-1 transdermal fentanyl patch. Group P/A received the patch and anesthesia. Group A received only anesthesia. After a minimum 1-week washout period, the cats were randomly reassigned to two groups for Part II of the larger study. Group P/A/O received the patch, anesthesia and ovariohysterectomy. Group A/O received anesthesia and ovariohysterectomy. Patches were left in place for 72 hours and plasma samples were obtained for fentanyl analysis while the patches were in place, and for 8 hours after patch removal for cats in Group P, P/A, and P/A/O.

RESULTS

The 25 micro g hour-1 transdermal fentanyl patches were well tolerated by the cats in this study (mean body weight of 3.0 kg) and no overt adverse effects were noted. Mean plasma fentanyl concentrations over time, mean plasma fentanyl concentrations at specific times (8, 25, 49, and 73 hours after patch placement), time to first detectable plasma fentanyl concentration, time to reach maximum plasma fentanyl concentration, maximum plasma fentanyl concentration, mean plasma fentanyl concentration from 8 to 73 hours, elimination half-life, and total area under concentration (AUC) were not statistically different among the groups.

CONCLUSIONS

Halothane anesthesia and anesthesia/ovariohysterectomy did not significantly alter the plasma fentanyl concentrations achieved or pharmacokinetic parameters measured, when compared with awake cats. There was a high degree of individual variability observed both within and between groups of cats in parameters measured.

CLINICAL SIGNIFICANCE

The high degree of variability observed suggests that careful observation of cats with fentanyl patches in place is required to assess efficacy and any potential adverse effects. Anesthesia and anesthesia/ovariohysterectomy do not appear to alter plasma fentanyl concentrations achieved by placement of a 25 micro g hour-1 transdermal fentanyl patch when compared to cats not undergoing these procedures.

Spontaneous pneumoperitoneum in two cats

Spontaneous pneumoperitoneum is an infrequently observed presentation in cats. This report details two cases of pneumoperitoneum in the cat. The first case was suspected to have been caused by a gastric perforation secondary to gastric lymphoma. The second case was caused by a perforated gastric ulcer in a cat that had been recently treated with corticosteroids and a non-steroidal anti-inflammatory drug.

Gastroduodenal ulceration in cats: eight cases and a review of the literature

Gastroduodenal ulceration (GU) and blood loss was diagnosed in eight cats and compared with 25 previously reported cases of feline GU. Cats with GU presented in a critical condition. Clinical signs consistent with gastrointestinal bleeding were infrequently identified although anaemia was a common finding. Non-neoplastic causes of feline GU tended to have a shorter clinical course with ulcers confined to the stomach. Conversely, cats with tumour-associated GU usually had a more protracted clinical course, weight loss, and ulcers located in the stomach for gastric tumours and the duodenum for extra-intestinal tumours. In this series, definitive diagnosis was possible for cats with neoplasia (gastric tumours and gastrinoma), however, it was difficult to precisely identify the underlying aetiology in cats with non-neoplastic GU. Prompt stabilisation with a compatible blood transfusion, surgical debridement or resection, antibiotic and antiulcer therapy, and treatment of the underlying disease, if identified, was successful in the majority of cases. The prognosis for cats with appropriately managed GU depended on the underlying aetiology, but even cats with neoplasia could be successfully palliated for prolonged periods.

Spontaneous gastroduodenal perforation in 16 dogs and seven cats (1982-1999)

The records of 23 dogs and cats diagnosed with spontaneous gastroduodenal perforation (GDP) were retrospectively reviewed. Survival was 63% in dogs and 14% in cats. Rottweilers <5 years of age were overrepresented. Clinical evidence of gastrointestinal bleeding was common in dogs but not in cats. Shock was an uncommon presenting condition in dogs and was not closely linked to outcome. In fact, progression of an ulcerating lesion to GDP was not associated with marked changes in symptoms exhibited by many patients in this study. Most GDPs were associated with histopathological evidence of subacute or chronic peritoneal reaction at the time of diagnosis. This suggests that diagnostic methods employed lacked sensitivity in identifying early perforating lesions, and that dramatic signs of acute abdomen following gastroduodenal perforation may not be as common as was previously thought.

Evaluation of the clinical efficacy of meloxicam in cats with painful locomotor disorders

The ability of two non-steroidal anti-inflammatory drugs to modify the clinical manifestations of pain associated with locomotor disease was assessed. Sixty-nine cats with acute or chronic locomotor disorders were recruited from 14 first opinion UK veterinary practices and randomly allocated to one of two treatment groups. Group A received meloxicam drops (0.3 mg/kg orally on day 1 followed by 0.1 mg/kg daily for four more consecutive days) and group B received ketoprofen tablets (1.0 mg/kg orally once daily for five days). Each cat underwent a full clinical examination before treatment, 24 hours after initiation of treatment and 24 hours after completion of treatment. General clinical parameters (demeanour and feed intake) and specific locomotor parameters (weightbearing, lameness, local inflammation and pain on palpation) were scored using a discontinuous scale scoring system. The two groups did not differ in terms of age, weight, gender distribution or duration of clinical signs; nor did they differ in terms of general clinical or specific locomotor scores pretreatment. Both treatment regimens resulted in a significant improvement in demeanour, feed intake and weightbearing, and a significant reduction in lameness, pain on palpation and inflammation. No significant difference was observed between the two treatment groups with respect to any of the parameters measured and both treatments were associated with minimal observed side effects. Meloxicam and ketoprofen were found to be effective analgesics and well tolerated in cats with acute or chronic locomotor disorders when administered for short-term treatment (five days) in such cases. However, meloxicam was assessed to be significantly more palatable than ketoprofen.

Comparison of pharmacokinetics of fentanyl after intravenous and transdermal administration in cats

OBJECTIVE

To compare pharmacokinetic and pharmacodynamic characteristics of fentanyl citrate after IV or transdermal administration in cats.

ANIMALS

6 healthy adult cats with a mean weight of 3.78 kg.

PROCEDURE

Each cat was given fentanyl IV (25 mg/cat; mean +/- SD dosage, 7.19 +/- 1.17 mg/kg of body weight) and via a transdermal patch (25 microg of fentanyl/h). Plasma concentrations of fentanyl were measured by use of radioimmunoassay. Pharmacokinetic analyses of plasma drug concentrations were conducted, using an automated curve-stripping process followed by nonlinear, least-squares regression. Transdermal delivery of drug was calculated by use of IV pharmacokinetic data.

RESULTS

Plasma concentrations of fentanyl given IV decreased rapidly (mean elimination half-life, 2.35 +/- 0.57 hours). Mean +/- SEM calculated rate of transdermal delivery of fentanyl was 8.48 +/- 1.7 mg/h (< 36% of the theoretical 25 mg/h). Median steady-state concentration of fentanyl 12 to 100 hours after application of the transdermal patch was 1.58 ng/ml. Plasma concentrations of fentanyl < 1.0 ng/ml were detected in 4 of 6 cats 12 hours after patch application, 5 of 6 cats 18 and 24 hours after application, and 6 of 6 cats 36 hours after application.

CONCLUSIONS AND CLINICAL RELEVANCE

In cats, transdermal administration provides sustained plasma concentrations of fentanyl citrate throughout a 5-day period. Variation of plasma drug concentrations with transdermal absorption for each cat was pronounced. Transdermal administration of fentanyl has potential for use in cats for long-term control of pain after surgery or chronic pain associated with cancer.