Practical information from ACVIM research: not yet in print (Proceedings)

Anemia predicts progression of chronic kidneydisease in newly diagnosed azotemic cats.

      S Chakrabarti, H Syme, J Elliott. Royal Veterinary College, London, UK.

Chronic Kidney Disease (CKD) is common in geriatric cats but often appears stable for long periods of time. Several studies have evaluated prognostic markers in cats with CKD, but few have identified which ones precede disease progression. The aim of this study was to find a marker which would predict deterioration of renal function in cats newly diagnosed with CKD.

Feline CKD cases were recruited between 1992 and 2009 through geriatric cat clinics held at two first opinion practices. Diagnosis was based on concurrent findings of plasma creatinine > 2 mg/dl and urine specific gravity (USG) < 1.035, with persistence of azotemia for 2 weeks. All cases were first screened using objective criteria and then classified by two clinicians. Renal function was approximated using the reciprocal of plasma creatinine concentration (1/creatinine) and linear regression was used to assess changes over time.

Cats which developed hyperthyroidism were excluded from the study and urine protein-to-creatinine ratios (UPCs) from urine samples with a positive urine culture outcome were not used in the analyses. Baseline variables at diagnosis were assessed for associations with progression using binary logistic regression.

In total, 52 progressive and 42 non-progressive cases were identified out of 118 cases which passed the initial screening criteria.

Lower packed cell volumes (PCVs) were associated with progression (OR: 0.916, 95%CI: 0.853–0.985, n 5 90, p 5 0.017). The median PCV for the progressive group was 32(IQR 29–36)% versus 36(IQR 34–41)% for the non-progressive group. The groups were matched for the degree of azotemia at diagnosis, with a median plasma creatinine concentration of 2.46 and 2.51 mg/dl for the non progressive group. Plasma creatinine, urea, USG, UPC , and potassium, did not predict CKD progression. The results of this study suggest that newly diagnosed cases of azotemic CKD which have low PCV values are more likely to progress. Thus, anemia may serve as a marker for cats which have more severe types of renal disease or may itself contribute to progression via hypoxic injury.

The effect of in vivo treatment with acetylsalicylic acid and meloxicam on platelet aggregation in cats.

      C Cathcart, BM Brainard, SC Budsberg. University of Georgia College of Veterinary Medicine, Athens, GA.

This study documents the effect of acetylsalicylic acid (ASA; 5 mg/kg PO q48 h) and meloxicam (0.05 mg/kg PO q24 h) on felineplatelet aggregation. Each medication was given to 8 cats for 14 days in a randomized, placebo controlled, cross-over design. It was hypothesized that both NSAIDs would decrease platelet aggregation. Outcome measures included oral mucosal bleeding time (OMBT) and whole blood (impedance) aggregometry (WBA) using adenosine diphosphate (ADP; 10 mM) and collagen (5 mg/mL) as agonists. WBA was performed before drug administration on days 0, 7, 15, and 17. OMBT was measured on days 0 and 15. study duration.

At the doses studied, neither meloxicam nor ASA had an inhibitory effect on WBA or OMBT in cats. The use of ASA at the testeddose for platelet inhibition in cats should be reconsidered.

Iatrogenic hypothyroidism (ih) contributes to the development of azotemia in hyperthyroid Cats.

      TL Williams, J Elliott, HM Syme. Royal Veterinary College, London, UK.

IH is reported to occur in some cats following treatment of hyperthyroidism (HTH). Hypothyroidism reduces GFR in other species,therefore IH could contribute to the development of azotemia in hyperthyroid cats with underlying mild chronic kidney disease. Our hypothesis was that the incidence of post treatment azotemia would be greater in cats with IH than euthyroid cats. Records from two London-based first opinion clinics between 1999 and 2009 were reviewed to identify cats diagnosed with HTH without pre-treatment azotemia. Baseline age and plasma creatinine concentration was recorded. HTH was treated using anti-thyroid medication alone or in combination with thyroidectomy. Cats were monitored for the development of azotemia over a six month follow up period, and at the final visit the following plasma biochemical and physical examination data were recorded; total thyroxine (TT4) concentration, cholesterol concentration, creatinine concentration, alanine aminotransferase and alkaline phosphatase activities, packed cell volume (PCV), heart rate and body weight. Only cats with a TT4 < 40 nmol/l (3.1 ng/dl) at the end of the follow up period were eligible for inclusion in the final analysis.

Eighty-one cats were eligible for the study, of which 28 were classified with IH and 48 as euthyroid. Five cats were excluded as they were of uncertain thyroid status. No significant difference in age (P 5 0.063) or plasma creatinine concentration (P 5 0.963) at baseline was present between the two groups. Sixteen cats with IH and fourteen euthyroid cats developed azotemia. The proportion of cats with azotemia in the IH group was significantly greater than the euthyroid group. Cats with IH had significantly lower plasma alkaline phosphatase activity, PCV and than euthyroid cats. Cats with IH also had significantly higher plasma creatinine concentrations No other parameters were significantly different between the two groups.

The incidence of post treatment azotemia was significantly higher in cats with IH. Clinicopathological changes in cats with IH were consistent with those that occur in naturally occurring hypothyroidismin other species.

Glargine administered intramuscularly is effective for treatment of feline diabetic Ketoacidosis.

      RD Marshall1,2, JS Rand1, MN Gunew2, VH Menrath2. 1Centre for Companion Animal Health, Uni of Queensland, Australia, 2The Cat Clinic, Brisbane, Australia.

Therapies recommended for treatment of DKA (diabetic ketoacidosis) in cats and the reported survival rates (78–82%) have not changed substantially in 20 years. There is no short-acting insulin registered for feline use and historically regular (crystalline) insulin is used for DKA. The glucose lowering effects of intravenous glargine and regular insulin in human patients are similar. The aim of this report is to describe outcome of administering glargine intramuscularly (IM) with or without subcutaneous (SC) glargine for initial stabilization of DKA in cats. The study involved a retrospective case series presented to an exclusively feline veterinary clinic. Included cases had a diagnosis of DKA and were initially treated with IM glargine with or without SC glargine.

The protocol for insulin therapy using glargine was adapted from published protocols using regular insulin IM for managing DKA in cats, but substituting glargine. Initial IMand SC doses of glargine were calculated on a per cat basis rather than per kg or on the degree of hyperglycemia. All cats were initially administered intramuscular glargine (1–2 U) and in 12/15 cats this was combined with SC glargine (1–3U); in 3/15 cats SC glargine was begun later. Intermittent IM glargine was administered as required 2–22 hours later and SC glargine (1–2U) every 12 hrs.

Cats were managed with subcutaneous glargine alone once appetite returned and dehydration had resolved. The outcome of using glargine IM in the initial stabilization of DKA cats was considered successful if ketosis resolved, appetite returned and the cat was discharged from hospital on SC glargine and survived for more than two weeks without requiring re-admission to hospital for management of DKA or related complications.

All 15 cats survived and were discharged from hospital (median 4 days; range 2–5 days) and one third (5/15) of cats surviving to discharge subsequently achieved remission (median time 20 days;range 15–29 days). Of the 12 cats treated with intermittent IM and SC glargine from the outset, half (6/12) were managed with SC glargine as their sole insulin therapy within 18 hrs.

This study demonstrates that glargine administered intramuscularly is an effective treatment for DKA in cats, and thus provides an alternative to regular insulin. It may also be more cost effective for owners because the same vial used for initial treatment of DKA can then be used for later management with subcutaneous glargine injections.

An intermittent insulin protocol improves metabolic acidosis faster than a continuous rate infusion of regular insulin in feline diabetic ketoacidosis.

      S Buob, OM Mahony, EA Rozanski, LM Freeman. Tufts Cummings School of Veterinary Medicine,North Grafton, MA.

The purpose of this study was to compare a simplfied regimen of intramuscular regular insulin and SQ insulin glargine to a CRI regular insulin protocol in cats with DKA.

Cats were randomized to receive insulin therapy with either a CRI of regular insulin adjusted via a sliding scale (CRI group) or a simplified protocol which included glargine insulin SQ twice daily and intramuscular regular insulin up to every 8 hours (Intermittent group). The primary endpoint was defined as time to resolution of metabolic acidosis, with secondary objectives including 1) Duration of hospitalization, 2) Nadir of hematocrit, 3) Hours until resolution of ketonemia

Sixteen cats were enrolled (n 58/group). There was no significant difference in age, weight, sex, pH at admission, ketonemia, or chemistry profile and complete blood count results between the two groups at baseline.

Eleven of the sixteen cats enrolled in the study survived to discharge . Cats in the intermittent group had a significantly faster time to resolution of metabolic acidosis compared to the CRI No significant differences were detected between the two groups for hospitalization time, nadir of the hematocrit , or resolution of ketonemia.

These data support the use of an intermittent protocol with a long-acting insulin for cats with DKA. The intermittent protocol resulted in faster resolution of metabolic acidosis and was simple, likely requiring less technical time and supplies than the CRI protocol.

These results support amore simplified but effective approach totreating cats with DKA that may be more cost-efficient for owners.

Obesity in physically inactive domestic shorthaired cats is associated with a hypercoagulable State.

      CR Bjornvad, B Wiinberg, ST Traberg, AT Kristensen. Department of Small Animal Clinical Sciences, University of Copenhagen, Denmark.

Obesity predisposes to a prothrombotic state in humans, but whether obesity affect hemostasis in animals is unknown. The purposeof this study was to examine differences in hemostatic parameters including thromboelastography (TEG) between lean, overweight and obese client owned indoor confined physically inactive cats.

Following health screening by physical examination, urinalysis, hematology,coagulation and biochemical profiles, 73 cats (35males and 38 females) were included in the study and informed consents were obtained. All cats were anaesthetized and body fat percentage (BF) was measured. The correlation between BF and individual TEG and traditional coagulation parameters (platelet count, PT, APTT, fibrinogen and D-dimer) was evaluated.

In conclusion, Obesity in cats is associated with a hypercoagulable state as measured by TEG and it is defined by both faster clot formation and increased clot strength. This may be linked to obesity- related low grade inflammation.

Subclinical airway inflammation despite oral corticosteroid therapy in cats with lower

      Airway disease. CGCocayne AEDeClue, CR Reinero. University of Missouri, College of Veterinary Medicine, Columbia, MO.

Recommendations for tapering of glucocorticoid therapy in cats with lower airway disease (eosinophilic or neutrophilic inflammation) have traditionally been based on resolution of clinical signs and radiographic abnormalities. In people, resolution of clinical signs is a poor predictor of airway inflammation. In cats, there are no reports on the sensitivity of clinical signs in predicting airway inflammation, in particular while receiving glucocorticoid treatment. Since assessment of the presence of clinical signs is often the driving force behind recommendations to alter therapy in cats with lower airway disease, it is essential to determine if they can reliably predict the presence of airway inflammation. We hypothesized that subclinical inflammation is present in cats with lower airway disease being treated with oral glucocorticoids.

Cats with clinical signs of lower airway disease (cough, wheeze, or expiratory respiratory distress) and a definitive diagnosis of lower airway disease diagnosed using bronchoalveolar lavage fluid (BALF) cytology (defined as eosinophils 4 17% or neutrophils 45%) and no evidence of pulmonary infection were enrolled. Cats were required to have complete resolution of clinical signs and BALF collected while asymptomatic and still receiving glucocorticoid therapy (minimum of 3 weeks in duration). Data were analyzed using a paired t-test with p o 0.05 considered significant and presented as mean_SE. Nine cats were included in the study. The group percentage of BALF eosinophils and neutrophils prior to treatment were 25±7% and 28 ±9%, respectively. After the baseline BAL, variable treatments with antibiotics and bronchodilators were initiated by preference of the attending clinician and all cats had oral glucocorticoid therapy. Cats were treated with prednisolone (n = 8) or prednisone (n = 1) at a dose of 1.8 - 0.2mg/kg/day. There was no significant difference before and after treatment between the percent of BALF eosinophils or neutrophils despite complete resolution of clinical signs.After treatment, only 3/9 asymptomatic cats had complete resolution of airway inflammation based on BALF. The remaining 6/9 cats had persistent airway inflammation (eosinophils, 29 ±11%; neutrophils, 43 ± 12%) despite resolution of their clinical signs.

Two-thirds of pet cats with lower airway disease treated with steroids had subclinical airway inflammation as determined by BALF cytology. Since persistent airway inflammation can lead to permanent structural and functional changes in the lungs, therapeutic decisions based solely on the resolution of clinical signs in cats receiving glucocorticoids should likely not be made. We conclude there is a need to reassess how we monitor efficacy of therapy in these cats. Future studies should focus on developing more comprehensive schemes of airway pathology including lung function testing and other, ideally less invasive tests of airway inflammation and remodeling.

Nebulized acetylcysteine in cats with experimental asthma.

      C Reineroa, T Lee-Fowlera, V Gunturb, A DeCluea, L Cohna, J Dodama. aCollege of Veterinary Medicine and bCollege of Medicine, University of Missouri, Columbia MO.

N-acetylcysteine (NAC) is a mucolytic and antioxidant which is thought to cause bronchoconstriction in cats when delivered byaerosol. A recent abstract reported no adverse effects or alterations in enhanced pause (Penh) after delivery of 150mg of NAC into a barometric whole body plethysmography chamber in 27 pet cats.

However, delivery of NAC by nebulizing into a 38L chamber likely resulted in minimal distribution to lower airways. Moreover, Penh is an indirect measure of airway resistance and may be insensitive to some changes in airway function. We hypothesized that in experimentally asthmatic cats aerosol delivery of NAC into an endotracheal tube with direct ventilator acquired mechanics would allow detection of airflow limitation.

The first 3 study cats at least one adverse effect was noted in each cat. Subjectively excessive tenaciousoral secretions, increased lower airway secretions (crackles), and transient unilateral strabismus, respectively. The fourth cat died during anesthetic recovery immediately post-NAC challenge (necropsypending).

Results of this pilot study are in contrast to the previous study which did not report changes in airflow limitation or other perceivableadverse reactions. It is unclear if the NAC caused or contributed to death in one asthmatic cat. We used a direct measure of airway resistance and used a higher dose of NAC (extrapolated from the human infant dosage of 200–400 mg) through the endotracheal tube. Extreme caution should be taken if using this drug in cats with airway disease, if at all.

Effects of high versus normal salt diets on renal variables in aged cats: a 6-month blinded Randomized prospective study.

      BS Reynolds1, P Nguyen2, V Chetboul3, V Biourge4, I Testault5, H Dumon2, C Carlos-Sampedrano3, E Trehiou3, J Abadie6, HP Lefebvre1. 1Clinical Sciences, National Veterinary School (NVS), Toulouse. 2Nutrition/Endocrinology, NVS, Nantes. 3Cardiology, NVS, Alfort. 4Royal Canin, Research Center, Aimargues. 5Atlantia, Nantes. 6Pathology, NVS, Nantes, France.

Concerns have been expressed about adverse renal effects of high salt diets. The objective of this blinded study was to compare the effects of normal versus high salt diets on renal variables in aged cats.

Twenty healthy neutered cats (10.1 _ 2.4 y.) were included. Following baseline measurements, cats were randomly allocated in 2groups according to their glomerular filtration rate (GFR), gender, age and body weight. One group was fed a high salt diet (1.30%sodium, 2.27% chloride as fed basis (4000 kcal ME/kg)) and the other one a control diet (0.35% sodium, 0.70% chloride). Bodyweight, urine specific gravity and protein/creatinine ratio, plasmaurea, creatinine, electrolytes, calcium, phosphate, total proteins,systolic/diastolic arterial blood pressures and GFR were measuredbefore, and again 3 and 6 months after diet implementation. Statisticalanalysis was performed using a general linear model. None of the variables was affected by the dietary treatment.

In conclusion, over a six month period, a high salt diet has noadverse effects on renal function in healthy aged cats. Cardiac parameters checked in parallel study: In conclusion, over a 6-month period a high-salt diet has no adverse effects on ABP and cardiac function in aged healthy cats.

Efficacy of a diet designed with a relative super saturation o 1 to dissolve struvite stonesin the feline bladder.

      D. Houston1 , H. Weese1, M. Evason1, I. van Hoek2. 1Medi-Cal Royal Canin, Guelph, ON, 2Royal Canin Research Center, Aimargues, France.

Previous studies have shown the efficacy of canned and dry magnesium- restricted, urine acidifying diets in dissolving struvite stones in cats; the mean times to dissolution in these studies were 26–36 days (canned food) and 34 days (dry food), respectively. Studies have shown that urine supersaturation is primarily responsible for the formation and dissolution of crystals within the urinary tract. The present study was undertaken to determine if a diet with efficacy for dissolving struvite stones in vitro also had efficacy of dissolving struvite stones in vivo.

Ten privately owned cats suspected of struvite urolithiasis based on radiographs taken by local practitioners were initially included. Cats were kept in their home environment and owners were instructed to feed Royal Canin Urinary S/O either wet (5 cases) or dry (5 cases) as the exclusive diet for the duration of the study.

Eight spayed female and 2 neutered male cats with a mean age of 7.05 - 3.34 years were included. Struvite stones dissolved in a median of 24 days (range 14–56 days) and of 19 days (range 10–39 days) in cats fed wet or dry food respectively.

Our preliminary results suggest that a diet designed to create urine undersaturated for struvite (RSS o 1) is effective both in vivo and in vitro in dissolution of struvite bladder stones. These results suggest that in vitro studies might be sufficient to predict dissolution times in vivo.

Feline herpesvirus-1 and mycoplasma spp. Infections in cats with acute conjunctivitis in an Animal shelter.

      D. Zirofsky1, C.C. Powell1, W. Rekers2, M. Brewer1, M.R. Lappin1. 1Colorado State University, Fort Collins, CO. 2Cat Adoption Team, Sherwood OR.

In previous studies, DNA of feline herpesvirus 1 (FHV-1) and Mycoplasma spp. were the most likely to be amplified by PCR assaysfrom nasal discharges of cats with rhinitis and ocular discharges of cats with conjunctivitis. However, both organisms can colonizehealthy cats and in the previous studies, only small numbers of samples from normal cats were included as controls. Thus, the significance of positive PCR test results for FHV-1 and Mycoplasma spp. in samples from clinically ill cats is unclear.

The purpose of this study is to compare the prevalence rates for FHV-1 DNA and Mycoplasma spp. DNA in samples from cats with and without conjunctivitis.

Cats housed in two animal shelters in Oregon were used for the study. Cats with conjunctivitis with no obvious exogenous cause,with or without rhinitis were included in the study. For every two cats with conjunctivitis, samples were to be collected from a cathoused in the shelter without conjunctivitis.

Overall, samples were collected from 69 cats with conjunctivitis and 30 cats without conjunctivitis. The results of the PCR assays are shown in the following table.

Table [Abstract 113]

Results of Mycoplasma spp. and FHV-1 PCR assay results do not always document a disease association. However, while both organisms can be amplified from cats with and without conjunctivitis, Mycoplasma spp. were amplified from a greater percentage of cats with conjunctivitis suggesting that this microbial group may be common primary pathogens in cats with this syndrome.

Feline hyperbilirubinemia: a retrospective study of 180 cases.

      A Bradley, K McCord, J Quimby, D Twedt. Colorado State University College of Veterinary Medicine and Biomedical Sciences, Fort Collins, CO.

A retrospective study was conducted to characterize the diseases, clinicopathologic findings, and outcomes associated with hyperbilirubinemia in cats presented to Colorado State University Veterinary Teaching Hospital over a 39-month period.

Criteria for inclusion were a serum total bilirubin (TB, mg/dl) concentration > 0.2 on presentation and a complete medical record.

History, physical exam findings, laboratory data, imaging, cytology, and histopathology were analyzed to identify the cause of hyperbilirubinemia.

The mean TB concentration for all 180 cats was 1.93 (range 0.3–24.9). Diagnoses were categorized as shown in the table. Non-survivors either died or were euthanized due to their disease. Patients that recovered orwere lost to follow-up were counted as survivors. Overall survival rate was 62% (survivor TB = 1.64, non-survivor TB 5= 2.41). Survival rate was assessed for three TB levels: mild (TB < 0.5, 73% survival), moderate (TB > 0.5–1.9, 60%survival), and severe (TB_> 2.0, 45%survival).

Mildly elevated TB in cats with identifiable non-hepatic disease is likely clinically insignificant, whereas severely elevated TB was associated with primary causes of hyperbilirubinemia and lower survival rates.

Safety and palatability of polyethylene gycol 3350 (miralax) as an oral laxative in cats

      FM Tam, AP Carr, SL Myers. Western College of Veterinary College, Saskatoon,Saskatchewan.

Recurrent constipation is a common problem in cats. These cats often require long-term laxatives as part of their medical management to improve their quality of life. Despite the common use of these medications, there is very limited data in veterinary medicineregarding the efficacy, dosage and safety of different oral laxatives.

The aim of this study was to evaluate the safety and palatability of PEG for long term use in cats.

Six (6) healthy, research cats were included in this study. PEG3350 with electrolytes was administered by adding it to a commercial diet (canned and dry) and the dosage was titrated in each cat to achievesoft, but formed stool. A complete blood count and serum biochemistry panel with electrolytes were obtained prior to administration of PEG, as well as two and four weeks after PEG administration was initiated.

All cats completed the study with no significant side-effects. Sporadic vomiting was observed in one cat during the treatment. Soft tovery soft stools were achieved in all animals. Food intake, and body weight was not significantly influenced by PEG. Mild erythrocytosis was found in 1 of 6 cats, before and after the treatment. No changes in serum sodium were found in any of the cats, however, 3 cats developed mild hyperkalemia. The change in potassium was not statistically significant between any time points. The cause was unknown, but may have been secondary to mild non-clinical dehydration. No clinical signs of hyperkalemiawere observed in any of the cats.

This study showed that polyethylene glycol is a safe and palatable oral laxative in cats for long term use. Potential side effects may include hyperkalemia. Subclinical dehydration may also occur.

Constipation resolution with administration of polyethylene-glycol solution in cats.

      AP Carr, MC Gaunt. Western College of Veterinary Medicine, Saskatoon,askatchewan.

This retrospective study describes the use of PEG 3350 (Colytes)infusions as the predominant therapy resulting in the resolution of constipation in 9 cats. PEG 3350 is commonly used in cats for colonoscopy preparation where dosages of 50 to 125 ml/kg have been recommended.

All 9 cats were admitted to the University of Saskatchewan VeterinaryTeaching Hospital and received intravenous fluid therapy aswell as various supportive care measures. If cats were on laxatives, these were continued at previously used dosages. All cats had clinicalsigns consistent with clinical constipation/impaction. Seven of the cats had multiple previous episodes of constipation.

PEG 3350 (Colytes) was administered via naso-esophageal tube at rates between 6 and 10 ml/kg/hr. The median total dose given was 80 ml/ kg (range 40–156 ml/kg). Median time to significant defecation was 8 hours (range 5 to 24). All cats had either radiographs or palpation to confirm that all firm feces had been passed. Side effects were limitedto vomiting in one cat, however the cat had been vomiting priorto presentation. Hyponatremia was not noted in 5 cats where blood work after administration was obtained. Use of PEG 3350 solution (Colytes) appears to be an effective alternative or adjunctive therapy for the treatment of constipated/ impacted cats.

Comparison of models for predicting renal disease following i-131 therapy for feline hyperthyroidism.

      J Morrison1, A Jergens1, K Deitz1, K Miles1, R King1, C Wang1, M Winter2, C Flatjord1, A Hodnefield1. 1Iowa State University, College of Veterinary Medicine, Ames, IA. 2University of Florida, College of Veterinary Medicine, Gainesville, FL.

Hyperthyroidism is a common endocrine disorder in middle aged to older cats. Therapy with I-131 is considered to be curative for 90% of affected cats. However, the hyperthyroid state may mask underlying renal insufficiency and rates of subsequent renal disease following I-131 therapy approach 30%. Initial prospective analysisof a population of hyperthyroid cats identified pre-treatment serum creatinine concentration and glomerular filtration rate (GFR, as determined by nuclear scintigraphy) to be significantly associated with the development of renal disease following I-131 therapy.

The results of this analysis demonstrated the model based on both pre-treatment serum creatinine concentration and GFR affordedthe best predictive power for the development of renal disease following I-131 treatment. This model was superior to models thatevaluated the variables independently.

Investigation of prognostic factors for the development of renal disease following i-131 Therapy in feline hyperthyroidism.

      J Morrison1, A Jergens1, K Deitz1, K Miles1, R King1, C Wang1, M Winter2, C Flatjord1, A Hodnefield1. 1Iowa State University, College of Veterinary Medicine, Ames, IA. 2University of Florida, College of Veterinary Medicine, Gainesville, FL.

Fifty-two hyperthyroid cats were evaluated prior to I-131 therapy over a 48 month period.

Forty-six cats completed I-131 therapy with 13/46 (28%) determined to have renal disease at the time of follow up. Pre-treatmentserum creatinine levels were significantly (p o0.02) associated with the development of renal disease as determined by logistic regression analysis. The predicted chance for renal disease in a cat with a pre-treatment creatinine of 1.6 mg/dl and GFR of 2.25 ml/min/kg was 67%. No other patient factors were significantly associated with the development of renal disease post I-131 therapy. The data of the present study confirms a 30% incidence of renal disease following radioactive iodine therapy of feline hyperthyroidism. Pre-treatment serum creatinine concentration was the variable most highly correlated with a negative outcome of renal disease.

Intestinal tritrichomonas foetus infection in cats: a retrospective study of 104 cases.

      PG Xenoulis, DJ Lopinski, LC Doyal, SA Read, JS Suchodolski, JM Steiner. Gastrointestinal Laboratory, Texas A&M University,College Station, TX.

Tritrichomonas foetus (T. foetus) is a flagellated protozoan parasite that has been recently recognized as an important cause ofdiarrhea in cats. It primarily colonizes the surface of the distal ileal and colonic mucosa, leading to chronic or intermittent diarrhea.Although many studies have confirmed the existence and pathogenicityof T. foetus in cats in many countries around the world, thehistory, clinical presentation, and response to treatment have not been described in a large number of naturally infected cats. The aim of this study was to collect and analyze clinical data from cats that were diagnosed with intestinal T. foetus infection.

Questionnaires for 104 cats living in North America were completed. A total of 24 breeds were represented and the median age ofthe cats was 12 months (range: 1–195 months). The most common clinical sign was diarrhea (98.1%) with a median durationof 135 days (range: 1–2,880 days) and a fecal quality ranging from soft (40.9%) to watery (33.0%). Fifty-nine percent of cats hadmucus in the feces, 45.5% had hematochezia, 42.9% had tenesmus,and 7% had melena. Forty-nine (59.0%) of 83 cats had diarrhea since adoption. Other clinical signs included anorexia (27.2%), depression (23.5%), weight loss or failure to gain weight (19.8%), vomiting (19.4%), fecal incontinence (14.9%), hyperthermia (13.8%), abdominal pain (8.9%), and increased appetite (2.9%).Fecal flotation had been performed in 85 cases, 3 (3.5%) of which were reported to be positive for coccidia. Of the 67 cats that weretested for Giardia spp., 15 (22.4%) were positive. A total of 49 catshad completed treatment with ronidazole, 29 of which (59.2%) showed clinical response to treatment. Sixteen (32.7%) cats had either partial or no improvement, or a relapse shortly afterdiscontinuation of treatment; 10 (62.5%) of these cats had beentreated with dosages of ronidazole of 30 mg/kg, q24h, for 2 weeks (n5 4) or lower (n 5 5), while one cat had been treated for only 1 week. In 4 (8.1%) cats, the treatment was discontinued due to neurologic signs (n 5=3) and/or anorexia (n = 3). In this study, diarrhea was the predominant clinical sign of naturalintestinal T. foetus infection in cats. Other clinical signs, such as anorexia, depression, and weight loss, were also commonly present. Most treatment failures were associated with the use of lower dosages of ronidazole.

Detection of bartonella henselae igm in serum of naturally exposed cats.

      J Ficociello, C Bradbury, A Morris, MR Lappin. Department of Clinical Sciences, Colorado State University, College of Veterinary Medicine and Biomedical Sciences, Fort Collins, CO.

Bartonella henselae has been associated with illness in cats and people. However, results of blood culture, PCR on blood, or B. henselaeIgG in serumhave not correlated to the presence or absence of clinicaldisease. In addition, results of B. henselae IgG in serum is poorly predictiveof bacteremia. We recently validated a Bartonella spp. IgM ELISA using serum collected sequentially from cats experimentally infected by exposure to B. henselae infected Ctenocephalides felis. The purpose of this study was to determine whether B. henselae IgM resultscan be used to predict clinical bartonellosis or bacteremia.

Paired samples from cats with and without fever (n=184), paired samples from cats with and without stomatitis (n = 108), and samples from healthy shelter cats (n = 51) that had been used in previous studies of Bartonella spp. IgG antibodies and Bartonellaspp. PCR had been stored at – 80 C were used.

Results from the analyses revealed no statistical association between Bartonella spp. IgM (positive or negative) or IgM titer magnitude and the presence of fever or stomatitis. The PPV and NPV of Bartonella spp. IgM and disease were approximately 40% in all analyses. ThePPV andNPV of Bartonella spp. IgM and bacteremia based on PCR results were approximately 15%and 85%, respectively. Bartonella spp. IgM antibodies do not correlate with the presence of fever or stomatitis and are not accurate for the prediction of the Bartonella spp. bacteremia.

Prevalence of bartonella spp. Dnainconjunctival cells collected from shelter cats with and without conjunctivitis.

      CL McInnis1, L Clark1,M Brewer1, CC Powell1, W Rekers2, P Dingman3, MR Lappin1. Colorado State University, Fort Collins, CO. 2Cat Adoption Team, Sherwood, OR. 3University of Florida, Gainesville, FL.

Bartonella spp. have been implicated as a cause of a variety of feline ocular abnormalities including conjunctivitis. However, studies definitively confirming the association between feline conjunctivitis and Bartonella are lacking. The primary purpose of the study was to determine the prevalence of Bartonella spp. DNA in conjunctival cells collected from cats with and without conjunctivitis.

Of the 70 cats with conjunctivitis, 0 had Bartonella DNA amplified from conjunctival swabs, but 10 of the 41 cats tested (24.4%)had Bartonella DNA amplified from blood and 23 of the 41 cats tested (56.1%) had Bartonella spp. IgG in serum. Of the 43 control cats, 0 had Bartonella DNA amplified from conjunctival swabs, but 10 of the 27 cats tested (37.0%) had Bartonella DNA amplified fromblood and 22 of the 27 cats tested (81.5%) had Bartonella spp. IgG in serum. There were no significant differences in the prevalence of Bartonella spp. DNA amplified from conjunctival swab samples or from whole blood samples (p 5 1.0, p 5 0.115, respectively). Cats without conjunctivitis were significantly more likely to have Bartonella spp. IgG detected in their serum than cats with conjunctitis. The results of this study indicate that while Bartonella spp. Infection was common based on the blood results, there was no association between Bartonella DNA in blood and conjunctivitis and Bartonella DNA was not amplified from conjunctival cells. These results fail to confirm an association between Bartonella spp.and feline conjunctivitis and suggest that Bartonella may not be a cause of this syndrome.

Feline herpesvirus-1 and feline calicivirus molecular diagnostic assay results in adult cats after booster vaccination with modified live products.

      R Ruch-Gallie, JK Veir, MR Lappin. ColoradoState University, Fort Collins, CO.

Molecular diagnostic assays (PCR) are now commonly being offered by veterinary diagnostic laboratories. Cats with respiratory diseases thought to be from feline herpesvirus-1 (FHV-1) and feline calicivirus (FCV) are being tested, but current molecular assays do not differentiate vaccine strains from natural strains. The purpose of this study is to determine the impact vaccination has on FHV-1 and FCV molecular diagnostic assay results from nasal and pharyngeal samples collected from healthy cats after inoculation.

Nasal and pharyngeal samples were collected on days -7, -3, 0, 3, 7, 10, 14, 17, 21 and 28 from 12, young adult, previously vaccinated, apparently healthy, mixed sex cats housed in two groups in separate research wards On day 0, six cats were administered a modified live FVRCP vaccine intranasally (Feline UltraNasals. HESKA Corporation) and six cats were administered a modified live FVRCP vaccine SQ (Purevax Feline 3RCP; Merial). FHV-1 DNA and FCV RNA can be amplified from samples collected from apparently healthy, vaccinated cats and which could represent current subclinical infection or shedding of vaccine strains. These findings should be considered when attempting to interpret results of molecular diagnostic assay results from clinically ill cats.

The pharmacokinetics of mirtazapine in cats with chronic kidney disease.

      JM Quimby, DL Gustafson, KF Lunn. Department of Clinical Sciences, Colorado State University, Fort Collins, CO.

This study was designed to determine the pharmacokinetics of mirtazapine, an appetite stimulant, in cats with chronic kidney disease (CKD) and age-matched controls (AMC) after administration of a single oral 1.88mg dose. Two cats with stable CKD from each IRIS Stage (II, III and IV) were utilized. Six age-matched cats with normal CBC, chemistryand urinalysis served as controls.

Increased vocalization and affection were the only side effects noted. Mean half-life was 16.4 1/_ 5.1 hours (CKD) and 12.3 1/_ 1.8 hours (AMC). CKD delays the clearance of mirtazapine. A single low dose of mirtazapine was well tolerated and resulted in a half-life that is compatible with 48 hour dosing intervals in cats with CKD.

Age associated diminishing urine concentrating ability in apparently healthy cats.

      S Yu.Hill's Pet Nutrition, Inc., Topeka, KS.

Feline chronic kidney disease is a slowly progressive disease with a high prevalence in older cats. Oftentimes, it is not diagnosed until cats become azotemic. The objective of the present study was to investigateage associated changes in clinical markers associated withkidney function in apparently healthy cats.

A cross sectional study was conducted with 96 apparently healthy American domestic shorthair cats, 29 males and 67 females. Cats used in the study were either castrated or spayed except two intact female cats. The age of cats ranged from 1.7 to 15.9 years. Both urine specific gravity and urine creatinine were inversely associated with age in cats. Urine specific gravity had a significantdrop after cats were 9.8 years old. Urine creatinine was positively associated with urine specific gravity. Age had little effect on serum creatinine, urea nitrogen, and phosphorus. Urine microalbumin was not affected by age either. These data show that urine concentrating ability diminishes with age as indicated by decreasing urine specific gravity. The diminishing urine concentrating ability escalated after about 10 years of age in cats, suggesting that urine specific gravity might be an early marker for kidney disease in apparently healthy cats.