C. Scott Bailey, DVM, MS, DACT
Consultant, Veterinary Answers
Veterinarians are often asked to perform pregnancy diagnosis and time a c-section with very little information from the owner. Often, the only information provided is the breeding-dates and occasionally even those are hard to come by. Consequently there is a need for veterinarians to be familiar different with methods of estimating gestational age. This is particularly important when an elective caesarean section is desirable. Elective c-sections can carry an excellent prognosis for maternal and fetal viability when timed correctly and may be less stressful to the bitch, puppies and attending veterinarian than waiting for a potential dystocia. Animals that are particularly good candidates are those with a history of dystocia or a c-section and animals that have small (less than 3 pups) or large (more than 8 pups) litter sizes. Dogs of certain breeds have a known predisposition to dystocia, such as Boxers, Bulldogs, Scottish Terriers, Great Danes and Bernese Mountain Dogs .
A number of factors play critical roles in the ultimate success-rate of elective c-sections, including fetal maturity, patient preparation, selection of anesthesia protocol and surgical technique as well as neonatal care of the pups. In this review we focus on only the first of these – Timing of c-section to maximize fetal maturity.
Three basic methods exist to predict parturition in the bitch:
While the easiest methods for timing involve breeding management, breeding dates provided by owners are notoriously unreliable. Parturition may occur anywhere from 57 to 72 days after a single observed breeding . On the contrary, the easiest and most accurate way to predict whelping is to diagnose or estimate the time of LH surge. Bitches reliably whelp 64-66 days post LH surge [2,3], which can be diagnosed by repeated LH assay (every 12 hours due to the short duration of the LH surge in the bitch). LH-peak may also be estimated by observing serum progesterone levels that achieve 2-3ng/ml and continue to rise thereafter [3,8]. Shortly after this period, vaginal cytology may be used to diagnose the onset of diestrus, occurring approximately 51-60 days before whelping .
Thereafter a variety of measures represent guides to estimate gestational stage within 2-3 days [4-6]. Further, equations have been developed to calculate gestational age in a variety of breeds [6,7].
A brief summary of useful ultrasonographic and radiographic markers of gestational age is listed below:
Ultrasonographic examination [5-8]
The fetal heartbeat is visible at approximately 22-26 days.
Limbuds, fetal movement and a fluid filled stomach may be seen on day 29, 30 and 33.
Fetal length exceeds chorionic width at approximately day 42.
Radiographic examination [5,7,9]
Pregnancy can first be reliably diagnosed radiographically day 45-48 post LH surge. More specific information is also available describing the appearance of specific structures in relation to whelping.
The scapula, humerus and femur are first detectable 17 days (15-18) prepartum.
The pelvis and 13 pairs of ribs are visible 11 days (9-13) prepartum.
Teeth are visible 4 days (3-8) prepartum.
During the final days of gestation, cortisol is produced and released from the maturing fetal adrenal gland in response to space-constraint and other physiologic stressors. This results in production of prostaglandin F2α in the placenta and endometrium, which in turn induces luteolysis and starts the cascade of events that ultimately result in fetal expulsion . At the same time the cortisol also has critical effects on the fetus, resulting in rapid maturation of vital organ systems, including the musculoskeletal system, gastrointestinal system and lungs. Prior to these final maturation processes, puppy survival may be decreased due to weakness, poor mobility and respiratory distress after removal from the uterus. On the contrary, if these processes have occurred and the bitch experiences a dystocia, survival may also be decreased. Consequently, the goal of gestational timing should be to predict whelping accurately enough to intervene after final maturation has occurred but before the bitch is in active labor. To do this, repeated monitoring of hormone levels during the final week of gestation, in combination with fetal monitoring via ultrasound or tocometry, may improve fetal viability and prevent dystocias [11-13].
Progesterone measures below 2ng/ml indicate imminent parturition within 18-36 hours.
A temperature drop by 1-3F from previous measures occurs in 75-85% of bitches within 8-18 hours prior to parturition.
Fetal heart-rate can accurately diagnose fetal distress during late gestation [12,13]
Normal late pregnancy: 200 beats/min
Fetal Stress: 180 beats/min – Values in this range indicate readiness for parturition
Fetal distress: 150 beats/min – values of 150 or below indicate the urgent need for emergency intervention to save the puppy.
1) Bergström A, Nødtvedt A, Lagerstedt AS, Egenvall A. Incidence and breed predilection for dystocia and risk factors for cesarean section in a Swedish population of insured dogs. Vet Surg 2006 Dec;35(8):786-91.
2) Concannon PW, Whaley S, Leid D, Wissler R. Canine Gestation length: vacioation related to time of mating and fertile life of sperm. Am J Vet Res 1983;44:1819-21.
3) Cohen JA, Holle DM, Meyers-Wallen VN. Accuracy of canine parturition date prediction from LH peak. Clin Theriogenology 2009;1:570
4) Holst PA, Phemister RD. Onset of diestrus in the Beagle bitch: definition and significance. Am J Vet Res 1974;35:401-6
5) Aissi A and Slimani C. Ultrasonographic appearance of the gestational structures throughout pregnancy in bitches. Am J Anim Vet Sciences 2008;3(1):32-35
6) Yeager AE and Concannon PW. Association between preovulatory LH surge and the early ultrasonographic detection of pregnancy and fetal hearteats in beagle dogs. Theriogenology 1990;34:655-665.
7) Lopate C. Estimation of gestational age and assessment of canine fetal marutation using radiology and ultrasonography: A review. Theriogenology 2008;70:397-402
8) Luvoni GC and Beccaglia M. The Prediction of Parturition Date in Canine Pregnancy. Reprod Dom Anim 2006;41:27-32.
9) Rendano VT. Radiographic evaluation of fetal development in the bitch and fetal death in the bitch and queen. In: Current veterinary therapy vol VIII. WB Saunders Co 1983; 947-52
10) Concannon PW, Butler WR, Hansel W, Knight PJ, Hamilton JM. Parturition and lactation in the bitch: serum progesterone, cortisol and prolactin. Biol Reprod 1978 Dec;19(5):1113-8.
11) Verstegen-Onclin K, Verstegen J. Endocrinology if pregnancy in the dog: A review. Theriogenology 2008;70:291-199.
12) Verstegen JP, Silvia LDM, Onclin K, Donnay I. Echocardiographic study of heart rate in dog and cat fetuses in utero. J Reprod Fertil Suppl 1993;47:174-80
13) Zone MA and Wanke MM. Diagnosis of canine fetal death by ultrasonography J. Reprod Fertil 2001;57:215-9.
Novel gastroretentive controlled-release drug delivery system for amoxicillin therapy in veterinary medicine
Evaluation of orally administered famciclovir in cats experimentally infected with feline herpesvirus type-1
J Small Anim Pract. 2011 Jan;52(1):32-7
OBJECTIVE: To report clinical findings and outcome in dogs and cats undergoing choledochotomy or primary repair of extrahepatic biliary duct rupture.
METHODS: Retrospective study of dogs (n=7) and cats (n=2) that had choledochotomy or primary bile duct repair.
RESULTS: Extrahepatic biliary obstruction was confirmed at surgery in all cases. The underlying cause in four dogs and both cats was choledocholithiasis, two dogs had gall bladder mucocoeles with associated bile duct rupture, and one dog had inspissated bile obstructing the bile duct secondary to gall bladder carcinoid tumour. Three dogs and both cats had choledochotomies performed to relieve extrahepatic biliary obstruction, and four dogs with bile duct rupture underwent primary repair of the defect. One dog with a bile duct rupture was re-explored four days postoperatively and had suffered dehiscence of the repair; this rupture was re-repaired. All animals were discharged from the hospital, and did not have clinical recurrence of extrahepatic biliary obstruction.
CLINICAL SIGNIFICANCE: Choledochotomy and primary repair of extrahepatic biliary duct rupture were associated with low perioperative morbidity and no mortality in this small cohort of cases. These techniques are reasonable options either alone or in conjunction with other procedures when bile duct patency cannot be re-established by catheterisation or bile duct discontinuity exists.
CASE DESCRIPTION: A 19-year-old neutered male domestic shorthair cat was evaluated because of signs of urinary tract obstruction.
CLINICAL FINDINGS: Physical examination findings were consistent with urethral obstruction, and a mass could be palpated in the region of the bladder neck. Abdominal ultrasonography and thoracic radiography revealed a mass in the trigone of the urinary bladder and a solitary mass in the left caudal lung lobe. Cytologic examination of the urine sediment, samples obtained by means of traumatic urethral catheterization, and fine-needle aspirates of the bladder mass did not result in a diagnosis.
TREATMENT AND OUTCOME: A balloon-expandable metallic stent was placed in the proximal portion of the urethra to relieve the malignant obstruction. After stent placement, the cat had signs of urinary incontinence and detrusor atony, both of which resolved with medical treatment. The cat was euthanized 1 month after stent placement because of progressive azotemia. Histologic examination of necropsy samples revealed grade III urothelial carcinoma and papillary pulmonary adenocarcinoma.
CLINICAL RELEVANCE: Findings suggested that stent placement may be a viable palliative treatment in cats with malignant urinary obstruction.
Intracranial Arachnoid Cysts in Dogs
from Compendium by Curtis W. Dewey – Veterinary Answers Consultant, Peter V. Scrivani, Ursula Krotscheck, Sofia Cerda-Gonzalez, Kerry Smith Bailey, Dominic J. Marino
Intracranial arachnoid cyst (IAC) is an infrequently reported developmental disorder seen primarily in small-breed dogs. It usually occurs in the caudal fossa, in the region of the quadrigeminal cistern. Although still considered uncommon, IAC is being recognized more frequently in veterinary medicine, coinciding with the increased availability of magnetic resonance imaging. In this article, clinical information from previously reported cases of canine IAC is combined with additional case information from our hospitals. Similar to IAC in people, it is thought that canine IAC is often an incidental finding. When IAC is responsible for neurologic disease in dogs, generalized seizures and cerebellovestibular dysfunction are the most common clinical presentations. Medical therapy of IAC focuses on management of increased intracranial pressure and seizures, if the latter are part of the clinical complaints. Surgical therapy of IAC involves either cyst fenestration or shunting the excess fluid to the peritoneal cavity.
from JVIM by I. Aroch, G. Segev, E. Loeb, Y. Bruchim
Heatstroke in dogs is often fatal and is associated with a high prevalence of secondary complications. Peripheral nucleated red blood cells (NRBC) occur in dogs with heatstroke, but their association with complications and the outcome is unclear. Peripheral NRBC are common in dogs with heatstroke and have prognostic significance. Forty client-owned dogs with naturally occurring heatstroke. Prospective, observational study. Dogs were followed from presentation to discharge or death. Serum biochemistry and coagulation tests were performed at presentation. CBC and evaluation of peripheral blood smears were performed at presentation and every 12 hours. The relative and the absolute NRBC numbers were calculated. Presence of NRBC was observed in 36/40 (90%) of the dogs at presentation. Median relative and absolute NRBC were 24 cells/100 leukocytes (range 0[ndash]124) and 1.48 × 103/[mu]L (range 0.0[ndash]19.6 × 103/[mu]L), respectively. Both were significantly higher in nonsurvivors (22) versus survivors (18) and in dogs with secondary renal failure and DIC versus those without these complications. Receiver operator curve analysis of relative NRBC at presentation as a predictor of death had an area under curve of 0.92. A cut-off point of 18 NRBC/100 leukocytes corresponded to a sensitivity and specificity of 91 and 88% for death. Relative and absolute numbers of peripheral NRBC are clinically useful, correlate with the secondary complications, and are sensitive and specific markers of death in dogs with heatstroke, although they should never be used as a sole prognostic indicator nor should they replace clinical assessment.
Relationships between Low Serum Cobalamin Concentrations and Methlymalonic Acidemia in Cats
from JVIM by C. G. Ruaux, J. M. Steiner, D. A. Williams
Serum cobalamin concentrations below reference range are a common consequence of gastrointestinal disease in cats. Serum cobalamin [le] 100 ng/L is associated with methylmalonic acidemia. To determine the prevalence of cobalamin deficiency, defined by elevated serum methylmalonic acid (MMA), in cats with serum cobalamin [le] 290 ng/L, and the optimum serum cobalamin concentration to predict cobalamin deficiency in cats. Residual serum samples (n = 206) from cats with serum cobalamin [le] 290 ng/L. Retrospective, observational study. Serum cobalamin and folate were measured with automated assays. Serum MMA was determined by gas chromatography-mass spectrometry. Cobalamin deficiency was defined as serum MMA > 867 nmol/L. Sensitivity and specificity of serum cobalamin concentrations [le]290 ng/L for detecting MMA > 867 nmol/L were analyzed using a receiver-operator characteristic curve. There was a negative correlation between serum cobalamin and MMA concentrations (Spearman’s r=[minus]0.74, P 867 nmol/L. No significant difference in serum folate concentrations was detected between affected and unaffected cats. Elevated MMA concentrations, suggesting cobalamin deficiency, are common in cats with serum cobalamin [le] 290 ng/L. Cobalamin deficiency is clinically significant, and supplementation with parenteral cobalamin is recommended for cats with gastrointestinal disease and low serum cobalamin concentrations.
For more on MMA in human beings, click here.
From AJVR by James W. Carpenter, MS, DVM; Christal G. Pollock, DVM (VETERINARY ANSWERS CONSULTANT); David E. Koch, MS; Robert P. Hunter, PhD
Objective—To determine the pharmacokinetics of marbofloxacin after oral administration every 24 hours to rabbits during a 10-day period.
Animals—8 healthy 9-month-old female New Zealand White rabbits.
Procedures—Marbofloxacin (5 mg/kg) was administered orally every 24 hours to 8 rabbits for 10 days. The first day of administration was designated as day 1. Blood samples were obtained at 0, 0.17, 0.33, 0.5, 0.75, 1, 1.5, 2, 3, 4, 5, 6, 8, 12, and 24 hours on days 1 and 10 of marbofloxacin administration. Plasma marbofloxacin concentrations were quantitated by use of a validated liquid chromatography–mass spectrometry assay. Pharmacokinetic analysis of marbofloxacin was analyzed via noncompartmental methods.
Results—After oral administration, mean ± SD area under the curve was 10.50 ± 2.00 μg·h/mL and 10.90 ± 2.45 μg·h/mL, maximum plasma concentration was 1.73 ± 0.35 μg/mL and 2.56 ± 0.71 μg/mL, and harmonic mean terminal half-life was 8.0 hours and 3.9 hours for days 0 and 10, respectively.
Conclusions and Clinical Relevance—Marbofloxacin administered orally every 24 hours for 10 days appeared to be absorbed well and tolerated by rabbits. Administration of marbofloxacin at a dosage of 5 mg/kg, PO, every 24 hours is recommended for rabbits to control infections attributable to susceptible bacteria.
from JVIM by S. Torfs, C. Delesalle, J. Dewulf, L. Devisscher, P. Deprez
Postoperative ileus (POI) is a frequent and often fatal complication of colic surgery. Reliably effective treatments are not available. To determine risk factors and protective factors associated with POI, and to assess the effect of lidocaine IV on short-term survival. One hundred and twenty-six horses that underwent small intestinal colic surgery and that survived for at least 24 hours postoperatively. Retrospective cross-sectional study. The association of 31 pre-, intra-, and postoperative variables with POI and the association of lidocaine treatment with short-term survival were investigated. Associations were evaluated with univariable logistic regression models, followed by multivariable analysis. Significant associations of high heart rate (odds ratio [OR] = 1.05, 95% confidence interval [CI] 1.03[ndash]1.08), the presence of more than 8 L of reflux at admission (OR = 3.02, 95% CI 1.13[ndash]8.02) and the performance of a small intestinal resection (OR = 2.46, 95% CI 1.15[ndash]5.27) with an increased probability of POI were demonstrated. Prophylactic lidocaine treatment was significantly associated with a reduced incidence of POI (OR = 0.25, 95% CI 0.11[ndash]0.56). Lidocaine treatment was also significantly associated with enhanced short-term survival (OR = 0.30, 95% CI 0.09[ndash]0.98). The variables associated with an increased risk of POI can be useful in identifying horses at risk of POI and in providing a more accurate prognosis. The results are supportive for lidocaine IV as an effective prokinetic treatment after small intestinal colic surgery.
There are ulcerated lesions starting on ear margins, later involving lip margins and periocular area as well as neck. Pruritus started after ulcerated lesions appeared. Skin scraping – neg., DTM – neg., Cytology – PMN’s and bacteria, C&S – pending, Dermohistopathology – pending, Bloodwork – normal. She is an outside cat, in a multicat household with no other pets involved. There are no external parasites, owner is not pruritic, no change in diet, on commercial pet food. Gave depo-medrol injection 10 days prior to biopsy. Expect biopsy results in 7 days.
This consultation is based on our phone consultation, submitted history and clinical photos. Thank you for the clinical photos which were helpful. I agree with your suspicion that immune-mediated disease is most likely. Differential diagnoses would include: Erythema multiforme (drug-induced, paraneoplastic, idiopathic) and pemphigus foliaceus (drug-induced, paraneoplastic are possible causes). Lupus erythematosus less commonly occurs in cats so is considered less likely. A cutaneous drug reaction also appears less likely in this case given the cat’s lack of drug history (no medications were being administered prior to the onset of skin disease). Although severe allergic dermatitis can sometimes mimic immune-mediated disease in the cat, the severity of the clinical presentation also makes this less likely. I would also make sure to closely examine mucosal surfaces (perianal, oral)- mucosal surfaces are involved it could indicate vesicular auto-immune disease (pemphigus vulgaris, Stevens-Johnson Syndrome, epidermolysis bullosa acquisita). Immunosuppressive therapy will likely be required to control this disease process. Pending skin biopsies, I would recommend starting this cat on immunosuppressive doses of glucocorticoids (typically 2-3 mg/kg of Prednisolone [over prednisone] divided BID). I start to taper after there has been 75-80% improvement (often within 2 weeks). New lesions should not be developing & older lesions regressing. I would not recommend adding in an additional immunomodulatory agent at this time until after the biopsy results have been reviewed.
Additional follow-up is requested on this case: biopsy report, response to initial therapeutic recommendations, etc. Addendum comments and additional therapeutic recommendations can be made at that time.
Per our phone conversation, the dermatopathology report is consistent with feline pemphigus foliaceus. Pemphigus foliaceus (PF) is a cutaneous auto-immune disease which most commonly occurs in middle aged to older cats. Another consideration would be paraneoplastic pemphigus; I would be suspicious of this if the skin lesions are not responding to appropriate therapy (this is typically more difficult to treat). Treatment for PF is often life-long, however some cats will go into extended periods of remission (without maintenance medications). Immunosuppressive therapy is required to control this disease. I recommend immunosuppressive doses of glucocorticoids (typically 2.2 mg/kg of Prednisolone [over prednisone] divided BID). I start to taper after there has been 75-80% improvement (often within 2 weeks). New lesions should not be developing & older lesions regressing. I often recommend a second immunosuppressive agent to control the disease and allow for lower doses of glucocorticoids to be used. Options include Chlorambucil or Atopica (Cyclosporine). Most commonly chlorambucil (0.1-0.2 mg/kg qd-qod) is used; tapered further over time. Monitor for myelosuppression. Obtain a baseline CBC, Chemistry profile & UA prior to initiating therapy. Recheck CBC values every 2 weeks for the first 6-8 weeks; then every 3-6 months. Although PF is often responsive to therapy, it can be a difficult auto-immune disease to manage. If remission is not initially achievable, I recommend referral to a veterinary dermatologist if possible.
Please contact me if this report is inconsistent with your clinical findings or you have additional questions. Please contact me at PetRays phone number listed below.
Terri Bonenberger, DVM
Diplomate, American College Veterinary Dermatology
3 week Update
The ulcerated lesions have healed and scabs have fallen off. The cat is doing very well.
Edited by Jennifer S. Fryer, DVM
The influence of crystalloid type on acid-base and electrolyte status of cats with urethral obstruction
Drobatz KJ, Cole SG. JVECCS 2008; 18: 355 – 361.
To compare the effect of a balanced isotonic crystalloid solution with that of 0.9% sodium chloride on the acid[ndash]base and electrolyte status of cats with urethral obstruction. Randomized prospective clinical trial. Academic veterinary emergency room.
Sixty-eight cats with naturally occurring urethral obstruction. Cats were randomized to receive either a balanced isotonic crystalloid solution (Normosol-R, n=39) or 0.9% sodium chloride (n=29) for fluid therapy. Baseline venous blood gas and blood electrolyte values were obtained at the time of admission and at intervals during the course of therapy. Baseline values were similar between groups.
Cats receiving Normosol-R had a significantly higher blood pH at 12 hours, a significantly greater increase in blood pH from baseline at 6 and 12 hours, as well as a significantly higher blood bicarbonate concentration at 12 hours and a significantly greater increase in blood bicarbonate from baseline at 6 and 12 hours. Conversely, the increase in blood chloride from baseline was significantly higher at 2, 6, and 12 hours in cats receiving 0.9% sodium chloride. There were no significant differences in the rate of decline of blood potassium from baseline between groups. Subgroup analysis of hyperkalemic cats (K+>6.0 mmol/L) and acidemic cats (pHEfficacy and tolerability of once-daily cephalexin in canine superficial pyoderma: an open controlled study
Toma S, Colombo S, Cornegliani L, Persico P, Galzerano M, Gianino MM, Noli C. Journal of Small Animal Practice 2008; 49: 384 – 39.
Objectives: The aims of this study were to evaluate the efficacy and tolerability of oral cephalexin given at 30 mg/kg once daily in dogs with superficial pyoderma and to compare them with those of oral cephalexin given at 15 mg/kg twice daily.
Methods: Twenty dogs with superficial pyoderma were treated with cephalexin at 30 to 60 mg/kg orally once daily (group A) and compared with 20 dogs treated at a dose of 15 to 30 mg/kg orally twice daily (group B). Dogs were treated until 14 days after clinical remission. Type and distribution of lesions, pruritus and general health status were assessed every 14 days using a numerical scale until 14 days after treatment discontinuation. Total scores for each evaluation day were compared between the two groups as well as time to obtain resolution and percentage of relapses.
Results: Resolution of superficial pyoderma was obtained in all dogs in 14 to 42 days (median 28 days for both groups), with no difference between groups. Six dogs experienced vomiting or diarrhoea but did not require discontinuation of the treatment. Only one dog (in group A) relapsed nine days after treatment discontinuation.
Clinical Significance: Once-daily cephalexin is as effective as twice-daily cephalexin in the treatment of canine superficial pyoderma.
Evaluation of antibodies against feline coronavirus 7b protein for diagnosis of feline infectious peritonitis in cats
Kennedy MA, Abd-Eldaim M, Zika SE, Mankin JM, Kania SA. AJVR 2008; 69: 1179-1182.
Objective—To determine whether expression of feline coronavirus (FCoV) 7b protein, as indicated by the presence of specific serum antibodies, consistently correlated with occurrence of feline infectious peritonitis (FIP) in cats.
Sample Population—95 serum samples submitted for various diagnostic assays and 20 samples from specific-pathogen–free cats tested as negative control samples.
Procedures—The 7b gene from a virulent strain of FCoV was cloned into a protein expression vector. The resultant recombinant protein was produced and used in antibody detection assays via western blot analysis of serum samples. Results were compared with those of an immunofluorescence assay (IFA) for FCoV-specific antibody and correlated with health status.
Results—Healthy IFA-seronegative cats were seronegative for antibodies against the 7b protein. Some healthy cats with detectable FCoV-specific antibodies as determined via IFA were seronegative for antibodies against the 7b protein. Serum from cats with FIP had antibodies against the 7b protein, including cats with negative results via conventional IFA. However, some healthy cats, as well as cats with conditions other than FIP that were seropositive to FCoV via IFA, were also seropositive for the 7b protein.
Conclusions and Clinical Relevance—Expression of the 7b protein, as indicated by detection of antibodies against the protein, was found in most FCoV-infected cats. Seropositivity for this protein was not specific for the FCoV virulent biotype or a diagnosis of FIP.