Prevalence and risk factors for medical events following exercise at Australian Greyhound race meetings

AIM

A prospective, observational study to determine the prevalence of post-exercise conditions at Australian Greyhound race meetings and to assess association with race performance and other environmental, race- and dog-related factors was undertaken.

METHODS

A total of 4020 starters were observed (2813 Greyhounds, 1009 trainers, 536 races, 52 race meets, 48 race dates and 11 race tracks) following a race. The presence of diaphragmatic flutter (DF), ataxia, seizure, collapse or sudden death was recorded. Risk factors were screened by univariable logistic regression prior to multivariable backward stepwise model building.

RESULTS

In this study, 962 starters (n = 768 dogs) had DF (23.9%), 16 starters were ataxic (0.4%) and there were no observed cases of collapse, seizure or sudden death. Race track location, increasing race distance, race grade based on increasing 1st place prize value, lower (earlier) race number at the meeting, age, a previous observation of DF at the last start, females, colour (white) and better finishing position were all associated with an increased risk of a Greyhound being observed with DF. However, when logistic regression assessing the random effect of dog was performed, the presence of previous DF was not significant. In this cohort, DF was common following strenuous exercise in Greyhounds and on its own does not appear to result in reduced performance or distress to the animal.

CONCLUSION

The incidence of ataxia was low and collapse, seizure and sudden death were not observed. However, even though uncommon, ataxia has welfare concerns for racing Greyhounds that warrants further investigation.

Reference limits for urinary fractional excretion of electrolytes in adult non-racing Greyhound dogs

OBJECTIVE

To determine reference limits for urinary fractional excretion of electrolytes in Greyhound dogs.

METHODS

Urinary fractional excretion was calculated using a spot clearance method preceded by a 16 to 20 hour fast in 48 Greyhound dogs. Raw data analysed using the bootstrap estimate was used to calculate the reference limits.

RESULTS

The observed range for urinary fractional excretion in Greyhound dogs was 0.0 to 0.77% for sodium, 0.9 to 14.7% for potassium, 0 to 0.66% for chloride, 0.03 to 0.22% for calcium and 0.4 to 20.1% for phosphate. Expressed as percentages, the suggested reference limits for fractional excretion in Greyhound dogs are as follows: sodium < or = 0.72, potassium < or = 12.2, chloride < or = 0.55, calcium < or = 0.13 and phosphate < or = 16.5.

CLINICAL SIGNIFICANCE

Veterinary practitioners may use these reference limits for urinary electrolyte fractional excretion when investigating renal tubular disease in Greyhound dogs.

Primary hypoparathyroidism in dogs: a retrospective study of 17 cases

OBJECTIVE

To evaluate the clinico-pathological findings, response to treatment and prevalence of complications in dogs with primary hypoparathyroidism.

DESIGN

Retrospective study of 17 dogs presenting to the University of Melbourne Veterinary Clinical Centre and Murdoch University Veterinary Hospital over a 15 year period (1990 to 2004). Case records were evaluated for signalment, body weight, diet type, historical and clinical findings, serum total calcium, phosphate, albumin and parathyroid hormone concentrations, urinary fractional excretion ratios of calcium and phosphate, electrocardiogram (ECG) results, treatments administered, outcome and period of follow-up.

RESULTS

The most common breeds identified were St Bernard (three dogs), Chihuahua (two dogs), German Shepherd (two dogs) and Jack Russell Terrier (two dogs). Three dogs were cross bred. Seizures, muscle tremors and fasciculations, stiff gait, tetany, muscle cramping, behavioural change and hyperventilation were the most common clinical signs. Vomiting, inappetence, diarrhoea, abdominal pain, hyperthermia, facial pruritus, ataxia, weakness, cataracts, and circling also occurred with less frequency. The mean duration of observed clinical signs preceding diagnosis was 33 days (median 13 days, range 1 to 173 days). All dogs had marked hypocalcaemia with normal or mildly increased serum albumin concentrations. Mean phosphate concentrations were significantly higher in inappetent dogs (P = 0.049). Mean serum calcium concentrations were significantly lower in dogs with cataracts compared to those without (P = 0.046). There were no other significant relationships between serum calcium or phosphate concentrations and the clinical presentation or outcome. No significant correlations were identified between the presence of a particular clinical sign and the duration of clinical signs. ECGs were obtained in four dogs and all exhibited QT interval prolongation due to a ST-segment prolongation. Sixteen of 17 dogs were treated successfully for hypocalcaemia and discharged from hospital. Acute management included parenteral calcium gluconate (10 dogs) and intravenous anticonvulsants (five dogs). Chronic therapy included oral vitamin D analogues and calcium supplementation. Treatment complications occurred in two dogs and included acute renal failure (one dog) and iatrogenic tissue necrosis following subcutaneous calcium administration (one dog). The mean follow-up period was 14.5 months (median 13 months, range 0 to 39 months). Twelve dogs were alive at the last follow up and two dogs were euthanased for unrelated reasons. The type of vitamin D analogue used was not associated with outcome.

CONCLUSION

Primary hypoparathyroidism was an uncommon diagnosis in dogs. Saint Bernards, cross bred dogs, German Shepherd dogs and Terrier breeds were most commonly affected. Neurological signs were the most common presenting clinical signs, although alimentary signs may have been more common than previously reported. Dogs with primary hypoparathyroidism appeared to have a good prognosis following initiation of calcium supplementation and vitamin D therapy. Complications of treatment were uncommon and could be minimised with regular monitoring.

Acquired myasthenia gravis associated with a non-invasive thymic carcinoma in a dog

An 8 1/2-year-old neutered male Beagle was diagnosed with acquired myasthenia gravis associated with a non-invasive thymic carcinoma. The thymic mass was surgically excised and the dog was treated with pyridostigmine, prednisolone and azathioprine. Serial acetylcholine receptor antibody titres were increased initially but slowly declined to normal values over a period of 24 weeks. Improved exercise tolerance was seen following therapy, however, oesophageal dysfunction persisted. The dog was euthanased 26 weeks after initial presentation due to a complicating illness. A necropsy showed no regrowth or metastasis of the thymic carcinoma.

Factor VIII activity in canine von Willebrand disease

This study was conducted to determine the relationship between factor VIII (FVIII) activity and von Willebrand factor antigen (vWf:Ag) concentration in canine von Willebrand Disease (vWD). In addition, the clinical utility of measuring FVIII activity in vWD was assessed. This was performed by the concurrent analysis of both FVIII activity and vWf:Ag concentration in three breeds of dogs, namely Dobermans (n=183), Scottish Terriers (n=169), and Labrador Retrievers (n=146). In the three breeds tested, linear regression analysis illustrated a positive relationship between FVIII activity and vWf:Ag concentration. This was reaffirmed in the Doberman and Scottish Terrier breeds, in which dogs with vWf:Ag concentrations < 50 CU/dL ("carriers") had lower median FVIII activities than dogs with vWf:Ag concentrations > 70 CU/dL ("normals"). The determination of various FVIII "cut-off" values was a poor test to separate Dobermans with and without clinical signs of hemorrhage attributable to vWD. In addition, the occurrence of hemorrhage in Dobermans with vWf:Ag concentrations < 50 CU/dL was not influenced by the FVIII activity. Various tests were performed to determine if the measurement of FVIII activity aided in the identification of "carriers" of the vWD gene in the Doberman and Scottish Terrier breeds. These included the use of optimal FVIII "cut-off" values for each breed and a FVIII "cut-off" value of 55 CU/dL; FVIII/vWf:Ag ratios and FVIII/vWf:Ag ratio "cut-off" values; and linear regression analysis of vWf:Ag concentration against FVIII activity. Of all these tests, only the determination of FVIII/vWf:Ag ratios appeared to have promise for "carrier" detection. The data in the present study indicated that routine FVIII assessment in vWD is not warranted; however, measurement of FVIII activity may be of use in confirming the "carrier" status of vWD.

Sodium cloprostenol administered at a continuous low dosage induces polydipsia and suppresses luteal function in early dioestrous bitches

The aim of this study was to determine whether sodium cloprostenol administered at a continuous low dosage induced luteolysis and polydipsia in early dioestrous bitches. Sodium cloprostenol was administered subcutaneously to greyhounds at doses of 4.04-5.19 microg/kg/day (treated group, n=5) or 0 microg/kg/day (control group, n=5) delivered by mini-osmotic pumps for 7 days. The treated bitches and two of the control bitches were in early dioestrus (Days 5-14, and 6 and 10, respectively) when the mini-osmotic pump was inserted (Day 0). Concentrations of plasmatic progesterone were measured in dioestrous bitches each day from Day -2 to 7, and then weekly until Day 90. Daily intake of water was ascertained in all bitches from Day -2 until Day 10, and their weight was measured on Days -2, 6 and 13. Biochemical analyses on plasma for concentrations of urea and glucose, and urinalyses were performed on all bitches before (Day -1), during (Day 4) and after treatment (Day 10). Concentrations of plasmatic progesterone declined dramatically and rapidly in treated bitches after Day 0 to <2.9 ng/ml but were not similarly affected in the dioestrous control bitches. However, in three of five treated bitches, concentrations of plasmatic progesterone increased to >1 ng/ml in the period from Day 10 to 90 indicating that luteolysis was incomplete. All treated bitches were polydipsic (intake of water >100 ml/kg/day) for 2-6 days during the period of treatment, and for 0-2 days immediately after treatment (Days 7 and 8). One control bitch was polydipsic on Days -2, -1 and 0. The treated bitches were also polyuric since they were hyposthenuric (<1.007, n=4) or isothenuric (1.010, n=1) on Day 4, their weight did not increase and no gastrointestinal or respiratory effects were observed. The control bitches were always hypersthenuric when measured during and after treatment (>1.021). Biochemical analyses of plasma and other data obtained from urinalyses did not reveal any differences between groups. This study indicated that sodium cloprostenol administered at a continuous low dosage induced polydipsia and suppressed luteal function in early dioestrous bitches.

Acute bronchopneumonia associated with Mycobacterium fortuitum infection in a dog

Mycobacterium fortuitum was isolated in a sample of bronchial fluid collected by transtracheal aspiration from a 1-year-old Corgi dog with a productive cough of 10 days' duration and with radiographic and cytological features of acute suppurative bronchopneumonia. The dog responded favourably to intravenous gentamicin and cephalexin for three days and a six week course of oral ciprofloxacin. Saprophytic mycobacterial pneumonia should be considered in cases of severe pulmonary consolidation in young dogs.

An interobserver and intraobserver study of buccal mucosal bleeding time in Greyhounds

Two observers experienced with the buccal mucosal bleeding-time technique using a standardised device (Surgicutt) performed the test on 20 Greyhounds, to evaluate interobserver and intraobserver repeatability. The interobserver and intraobserver repeatability were both about 2 minutes. The results indicated that, for any two readings within a dog, the buccal mucosal bleeding time may differ by up to +/- 2 minutes. A single reading was accurate to within +/- 80 seconds. Sixty-one Greyhounds were used to establish a reference interval for the buccal mucosal bleeding time, and to assess the relationship between the buccal mucosal bleeding time and plasma von Willebrand factor concentration. The mean was 129.5 (SD 44.2) seconds. The reference interval was 53 to 235 seconds, which was slightly lower than non-greyhounds. No significant correlation (r=-0. 18, P=0.17) between the buccal mucosal bleeding time and plasma von Willebrand factor concentration was found in the 61 Greyhounds, where plasma von Willebrand factor concentration was in the range 29 to 160 Canine Units dL(-1).

Streptococcal meningoencephalitis in a dog

A 5.5-year-old French bulldog was presented with acute neck pain and a short history of central vestibular syndrome. A marked neutrophilic pleocytosis and numerous gram-positive cocci were evident on cerebrospinal fluid (CSF) cytology. Streptococcus pneumoniae, a pathogen of humans, was isolated upon CSF microbiological culture. Treatment consisted of intravenous antibiotics, supportive care, and anticonvulsants for the generalized seizures which developed shortly after admission. The dog responded to therapy and two years later exhibited only a mild, residual head tilt. The pathogenesis and treatment of bacterial meningoencephalitis in dogs are reviewed.

Effect of desmopressin on plasma factor VIII and von Willebrand factor concentrations in Greyhounds

OBJECTIVE

To determine the effect of 1-Deamino-8-D-arginine vasopressin on plasma concentrations of von Willebrand factor and factor VIII in Greyhound blood donors, and to compare the response of 1-Deamino-8-D-arginine vasopressin injection on plasma concentrations of von Willebrand factor between groups with different resting plasma concentrations of von Willebrand factor.

ANIMALS

Fifteen Greyhound blood donors were used. Dogs were grouped into three categories depending on their von Willebrand factor concentrations.

PROCEDURE

Desmopressin was administered subcutaneously at 1 microgram/kg [corrected] to all dogs. Plasma von Willebrand factor and factor VIII concentrations were measured before and 10, 20, 30, 45, 60, 90 and 120 min after desmopressin injection.

RESULTS

The von Willebrand factor and factor VIII concentrations in all dogs increased significantly and remained higher than base-line throughout the 2 h period.

CONCLUSION

Desmopressin is useful in increasing von Willebrand factor concentrations in Greyhound blood donors, including those with low resting concentrations.

The use of recombinant ovine IL-1beta and TNF-alpha as natural adjuvants and their physiological effects in vivo

In the present study we have investigated the use of recombinant ovine IL-1beta and TNF-alpha both alone and in combination, as natural adjuvants in vaccination trials in sheep. Initial experiments were conducted to investigate the physiological effects of the cytokines in vivo and determine what dose could be administered without adverse pyrogenic effects. Even at the maximum dose tested (100 microg) the only significant physiological effect was a transient increase in body temperature of approximately 2 degrees C in sheep injected with TNF-alpha. Administration of either cytokine had profound effects on the levels of circulating leucocytes for up to 5 days postinjection. The incorporation of either IL-1beta or TNF-alpha in aqueous or Al(OH)3 vaccine formulations enhanced antibody responses to a recombinant antigen from the cestode parasite Taenia ovis. The addition of IL-1beta to aqueous vaccine formulations increased antibody responses 15-20-fold and in Al(OH)3 formulations by three to six fold. TNF-alpha stimulated 1.5 to six-fold and 2.5 to seven-fold increases in antibody levels in aqueous and Al(OH)3-based formulations, respectively, in a dose-dependent manner. The addition of either cytokine to Quil A or IFA vaccines did not enhance the antibody levels elicited. When 10 microg of both IL-1beta and TNF-alpha were incorporated in the aqueous or Al(OH)3 vaccine formulations, increases of 21-fold and 25-fold, respectively, were observed in antibody levels. The adjuvant activity of IL-1beta and TNF-alpha in combination in the Al(OH)3-based vaccine resulted in antibody levels commensurate with those obtained using Quil A or IFA.

Pharmacokinetics of von Willebrand factor and factor VIII in canine von Willebrand disease and haemophilia A

The pharmacokinetics of von Willebrand factor antigen (vWf:Ag) and factor VIII coagulant (FVIII:C) activity in dogs with von Willebrand Disease (vWD) and haemophilia A, respectively, were assessed after the administration of fresh frozen plasma (FFP) and cryoprecipitate. Loading doses necessary to attain target plasma concentrations of each factor were estimated to be 63 U kg-1 BW for FFP and 13 U kg-1 BW for cryoprecipitate to reach 35 U dl-1 vWf:Ag in vWD and 23 U kg-1 BW for FFP and 4 U kg-1 BW for cryoprecipitate to reach 30 U dl-1 FVIII:C in haemophilia A. The estimated volumes of FFP required to attain these target concentrations (49 ml kg-1 BW for vWD and 20 ml kg-1 BW for haemophilia A) are approximately 10-fold higher than the volumes of cryoprecipitate required (4 ml kg-1 BW for vWD and 2 ml kg-1 BW for haemophilia A). This indicates that cryoprecipitate is a more efficient and practical means of treating or preventing haemorrhage in these two haemostatic disorders.

Studies to detect carriers of haemophilia A in German shepherd dogs using diagnostic DNA polymorphisms in the human factor VIII gene

The current study investigated whether the DNA polymorphisms in the human FVIII gene, that are used for the diagnosis of carriers of haemophilia A, were diagnostically useful in dogs. Genomic DNA from 20 German Shepherd dogs (13 females, three normal males and four haemophilic males) was tested using five restriction site polymorphisms [HindIII/F8 (exon 17-18), Taq I/ST14.1, BclI/ST14.1, BclI F8 (exon 17-18) and Bgl II/DX13]. The DNA probes (with the exception of DX13) all hybridized to the canine DNA at high stringency, indicating significant homology between the human and canine FVIII gene. A BclI polymorphism (13.5/13.5 + 12.8 kb) was detected with the ST14.1 probe.

von Willebrand's disease in Scottish Terriers in Australia

Over a 5-year period (1988-92), von Willebrand factor antigen (vWf:Ag) assays were performed on plasma samples from 207 Scottish Terriers. Based on these tests, 47 dogs (23%) had vWf:Ag concentrations < 50 canine units (CU)/dL and were classified as heterozygous carriers of the von Willebrand's disease (vWD) gene, while 9 (4%) had concentrations below the sensitivity of the assays and were classified as homozygous. There was thus an overall prevalence of 27% for the vWD gene in the Scottish Terriers tested. The homozygous dogs (median age 0.6 years at diagnosis) consisted of 7 males and 2 females. Eight of these had haemorrhage attributable to the disease, mostly spontaneous and from the oral mucosa. Other signs included haemorrhage induced by trauma or surgery, easy bruising and epistaxis. Many haemorrhagic episodes were severe enough to warrant therapeutic intervention and there was a single fatality. Pedigree analysis, possible in 7 of the dogs, revealed that each was the progeny of a mating between dogs with vWf:Ag concentrations < 50 CU/dL, which supported an autosomal recessive mode of inheritance. A single heterozygous carrier suffered haemorrhage after surgery that, in contrast to the homozygotes, was mild and did not require therapy. The data indicate that vWD is a significant problem in Scottish Terriers in Australia. Accordingly, we recommend that steps be taken to reduce the prevalence of the disease and thereby the number of clinically affected dogs, such as the establishment of a national testing scheme to determine the vWD status of all breeding dogs.

Stability of canine factor VIII and von Willebrand factor antigen concentration in the frozen state

The stability of factor VIII and von Willebrand factor antigen concentration in the frozen state was assessed. Citrated plasma was obtained from 10 healthy, mixed breed dogs and separated into 300 microliters aliquots. One aliquot was assayed immediately and the others were frozen at either -20 degrees C or -70 degrees C. The activity of factor VIII and the concentration of von Willebrand factor antigen were measured after one week and one, two, three, four, five, six, eight and 10 months of storage. There were minor changes in both variables, particularly after four months, resulting in a decrease in the activity of factor VIII and an increase in the concentration of von Willebrand factor antigen. The changes were more pronounced at -20 degrees C. However, both factors remained relatively stable for the whole period.

Stability of von Willebrand factor and factor VIII in canine cryoprecipitate under various conditions of storage

The stability of factor VIII and von Willebrand factor antigen in canine cryoprecipitate obtained from seven greyhound donors was determined after storage under various conditions, including twice freezing at -70 degrees C and thawing at 37 degrees C, slow thawing at 4 degrees C, refreezing the slowly thawed cryoprecipitate at -20 degrees C and thawing at 37 degrees C and maintaining the thawed cryoprecipitate at room temperature for 24 hours. The results indicated that factor VIII and von Willebrand factor antigen were effectively concentrated during the initial cryoprecipitation procedure. The cryoprecipitate which had been thawed and refrozen under the above conditions maintained factor VIII activities and concentrations of von Willebrand factor antigen similar to those in the original thawed cryoprecipitate. Furthermore, there was no significant loss of either of the coagulation factors in cryoprecipitate which was thawed in a warm water bath and stored for 24 hours at room temperature.

von Willebrand's disease in Dobermann dogs in Australia

Over a 5-year period (1988-92), von Willebrand factor antigen (vWf:Ag) concentrations were determined on plasma samples from 614 Dobermanns. The vWf:Ag concentration was < 50 canine units (CU)/dL in 373 dogs (61%); these dogs were classified as carriers of the von Willebrand's disease (vWD) gene. In order to identify which dogs were at risk of haemorrhage due to vWD, we determined a cut-off vWf:Ag concentration below which dogs could be considered at risk. This cut-off was chosen in order to minimise the number of dogs genuinely at risk of haemorrhage, being wrongly classified as not at risk. This was done without sacrificing the specificity of the cut-off to any great extent. A vWf:Ag concentration of < 36 CU/dL was empirically chosen as the optimum cut-off concentration. In 282 dogs (76% of the carriers), the vWf:Ag concentration was below this cut-off and these dogs were, thus, classified as being at risk of haemorrhage due to vWD. Haemorrhage attributable to vWD was seen in 107 dogs (29% of the carriers, or 17% of all the dogs). Haemorrhage mostly followed trauma or surgery, but spontaneous genito-urinary and gastrointestinal haemorrhages were also frequent. Of these dogs, 92 were of known age, with a median of 3 years, and 102 were of known sex, with 61% being female. In 89 dogs in which the severity of haemorrhage was subjectively assessed, mild and moderate bleeding occurred with similar frequency (48% and 43%, respectively). There were 8 cases of severe haemorrhage, with two deaths.(ABSTRACT TRUNCATED AT 250 WORDS)

Effect of acepromazine, xylazine and thiopentone on factor VIII activity and von Willebrand factor antigen concentration in dogs

The effect of acepromazine maleate, xylazine and thiopentone on the packed cell volume, plasma protein content, factor VIII activity and von Willebrand factor antigen concentration of blood was studied in normal dogs. The same variables were measured in dogs with haemophilia A given acepromazine maleate and thiopentone. Both the packed cell volume and plasma protein content decreased after the administration of either acepromazine maleate or xylazine. Values were not changed further after administration of thiopentone. Changes in the haemostatic variables measured were generally small. Consequently, blood samples collected from dogs under the influence of premedicant doses of acepromazine maleate or xylazine, and when subsequently anaesthetised with thiopentone, are adequate for the assay of factor VIII activity and von Willebrand factor antigen concentration for establishing an animal's haemophilia A and von Willebrand's disease status.

Changes in factor VIII activity and von Willebrand factor antigen concentration with age in dogs

The factor VIII activity of 38 German shepherd puppies, 6-12 weeks old, submitted for diagnosis of haemophilia A was measured. Eight of these puppies had values higher than would be expected for haemophiliacs, but less than the reference range for adult dogs. A further sequential study of 21 puppies (6-26 weeks of age) indicated that the factor VIII activity of puppies is generally less than that of adult dogs until about 14 weeks of age. Changes in the concentration of von Willebrand factor antigen in the puppies were irregular. These variations are probably not sufficient to interfere with accurate diagnosis of haemophilia A in most affected young dogs, but may interfere with the detection of heterozygotes in young bitches.

Stability of canine factor VIII activity and von Willebrand factor antigen concentration in vitro

The in vitro stability of canine factor VIII activity, von Willebrand factor antigen concentration and the ratio of these two factors was studied. Samples were stored for up to 48 hours, either as plasma or as whole blood, at 4 degrees, 20 degrees and 37 degrees C. Factor VIII activity was generally stable in both plasma and whole blood samples for up to 48 hours at 4 degrees or 20 degrees C. The concentration of von Willebrand factor antigen was more stable in samples stored as plasma than whole blood, and for a shorter time than factor VIII activity. Consequently, the stability of the ratio of these two factors was relatively poor in vitro.

Changes in factor VIII: coagulant activity and von Willebrand factor antigen concentration after subcutaneous injection of desmopressin in dogs with mild hemophilia A

Four German Shepherd dogs with mild hemophilia A were given Desmopressin (Minirin intranasal solution, Ferring, Malmo, Sweden) subcutaneously at a range of doses in a controlled blind study. No substantial change in plasma FVIII activity was observed 0.5, 1, 2, 4, or 6 hours after administration of Desmopressin. Plasma von Willebrand factor antigen concentrations increased rapidly after doses of 0.4, 1.0, 2.0, and 5.0 micrograms/kg to mean values of 140%, 127%, 120%, and 140% of baseline, respectively. The duration of this increase was dependent on the dose of Desmopressin injected.

Pleural effusion secondary to thoracic metastatic mammary adenocarcinoma in a mare

A 17-year-old Quarter Horse mare was examined nearly 3 years after excision and cryotherapy of a papillary mammary gland adenocarcinoma. The mare had been used for pleasure riding since surgery, but had recently developed progressive dyspnea. The mare had clinical evidence of pleural effusion, but died before further clinical examination and treatment were instituted. Necropsy revealed deep mammary masses with similar nodules in the deep inguinal, renal, and mediastinal lymph nodes and in the lungs, pericardium, visceral and parietal pleurae, and left ovary. The masses were identified as papillary mammary gland adenocarcinoma. Large volumes of free pleural and peritoneal fluid were detected. The pleural fluid contained similar neoplastic cells that could have been readily detected by exfoliative cytologic examination had the mare survived.

Observations on blood coagulation after snakebite in dogs and cats

Blood samples from 13 cases of snakebite, 6 in dogs and 7 in cats, were tested for activated partial thromboplastin time (APTT), prothrombin time (PT) and fibrin/fibrinogen degradation products (FDP). Four cases were tested for fibrinogen concentration. Based on the results of a commercially available ELISA test, 9 cases were caused by tiger snakes (Notechis scutatus) and 1 case by a brown snake (Pseudonaja textilis). Three other cases had clinical signs and increased creatine phosphokinase values which suggested tiger snake envenomation. Although the period post-envenomation varied, results indicated a marked prolongation of the APTT and PT in 5 of 6 dogs. Three of these 5 dogs also had increased FDP values and 3 (of 3 examined) were hypofibrinogenaemic. Clinical manifestations of this coagulopathy were: haematoma formation after venepuncture (3 cases), gingival petechiae (1 case) and hyphaema (1 case). In contrast, there was minimal or no prolongation of the APTT and PT values, and no increase in FDP, in all 7 cats. Furthermore, no cat exhibited clinical signs of a coagulopathy.

Cytology of the canine reproductive system

The methods for semen collection, its laboratory examination, and the interpretation of findings are presented in this article. The lack of comprehensive data for normal dogs and the lack of data associating actual percentages of spermatozoa with specific abnormalities with fertility or infertility are highlighted. Consequently, there is a need for standardization and completeness of semen examination procedures, especially in studies destined for publication. Collection and analysis of prostatic samples then is discussed, and the distinguishing cytological features of benign prostatic hyperplasia, prostatic adenocarcinoma, prostatis (including prostatic abscessation), and prostatic cysts are presented. This is followed by an assessment of the clinical usefulness of vaginal cytology, particularly to assist in the management of normal canine reproduction and in the diagnosis of reproductive disorders. The ways in which vaginal smears can facilitate the diagnosis of the stage of the estrous cycle and the diagnosis of abnormalities of the cycle and other disorders of reproduction are presented. Further consideration is given to its use to estimate the time of ovulation retrospectively and estimate the time of whelping prospectively. Finally, two specific diseases that can affect dogs and bitches are reviewed, namely, canine brucellosis and transmissible venereal tumor.

Laboratory evaluation of hemorrhagic coagulopathies in small animal practice

Assessment of animals with a suspected hemorrhagic diathesis of unknown cause(s) should be methodical. Most acquired coagulopathies result from thrombocytopenia. A platelet estimate (from a blood smear) and/or a platelet count on a fresh blood sample therefore are useful first steps in case evaluation. If thrombocytopenia is present, the most likely causes are immune-mediated destruction of platelets, DIC, or megakaryocytic hypoplasia. These diagnoses can be pursued by further test, including antiplatelet antibody assays (for example, the platelet factor 3 tests or an ELISA test), measurement of FDP, and bone marrow biopsy, respectively. If the platelet count is normal, a buccal mucosa bleeding time test is a useful second step. If this is prolonged, most likely causes are vWD or a thrombocytopathy (functional platelet defect). von Willebrand's disease can be diagnosed by measurement of vWf concentration or activity. A normal bleeding time does not exclude a diagnosis of vWD, but suggests that the functional activity of vWf is not compromised markedly. If the bleeding time is normal, APTT and PT should be measured. A prolonged APTT with normal PT, in the clinical setting, implies a deficiency of factor XI, IX, or VIII. A prolonged PT with normal APTT indicates factor VII deficiency. Prolongation of both APTT and PT usually is caused by a deficiency of several factors and is seen most often in cases with vitamin K deficiency or antagonism. Obviously, if a particular cause is suspected from the case history or for other reasons, appropriate tests should be evaluated at the beginning. If these do not confirm the provisional diagnosis, the just-described protocol might be a useful one to follow.

Diagnosis of feline leukemia virus and feline immunodeficiency virus infections

Feline leukemia virus is an oncogenic retrovirus that can result in a wide variety of neoplastic and non-neoplastic diseases, including immunosuppression. Diagnosis of FeLV infection can be achieved by several methods, including virus isolation; IFA assay of a peripheral blood smear; and detection of a viral protein (called p27) by ELISA testing of whole blood, plasma, serum, saliva, or tears. Commercially available ELISA kits have revolutionized FeLV testing and have become very popular as "in-house" procedures. This article discusses the interpretation of ELISA results and compares them with IFA assay findings. Feline immunodeficiency virus is a lentivirus that causes immunosuppression, but not neoplasia, in cats. It originally was called feline T-lymphotropic lentivirus. Differentiating FIV infection from the immunosuppressive type of FeLV infection requires virus isolation or serology. The most rapid method for diagnosis of FIV infection is ELISA testing for antiviral antibody.

Stability of canine factor VIII: coagulant activity in vitro

A pilot study was undertaken to assess the stability of canine factor VIII:coagulant (FVIII:C) activity over three days, under various storage conditions (plasma at 4, 20 and 37 degrees C, whole blood at 4 and 20 degrees C). Blood collected from normal and hemophiliac dogs was used. Both plasma and whole blood samples appeared to be stable for up to 48 h at 4 and 20 degrees C. A subsequent study evaluated FVIII:C stability at 4 and 20 degrees C when stored as whole blood only. Samples were tested at 0, 24 and 48 h after collection. At 4 degree C there was a significant decline at 24 h (p less than 0.05), from 110% to 97% (mean values). Although the mean value was further decreased at 48 h (89%) this was not significant (p greater than 0.05). No significant change in FVIII:C activity was observed in whole blood stored at 20 degrees C for 24 or 48 h (110% and 107% respectively). These results suggest that canine whole blood samples collected into sodium citrate stored at 20 degrees C are adequate for routine FVIII:C assay for up to 48 h after collection.

Changes in equine carpal joint synovial fluid in response to the injection of two local anesthetic agents

The effects of repeated arthrocentesis and injection of local anesthetic agents, lidocaine HCl or mepivacaine HCl on the equine middle carpal joint were investigated. Synovial fluid samples were evaluated before, and 12, 24 and 48 hours following, treatment. The greatest changes from pretreatment values occurred in synovial fluid cellularity. Repeated arthrocentesis caused a moderate increase in cell counts, while injection of local anesthetics caused a greater increase. Alterations in mucin clot quality, hyaluronic acid content, fluid viscosity, total protein and immunoglobulin G were generally of no significance. The most sensitive sampling time to detect changes caused by a given treatment was 24 hours following treatment while the 12 hour sampling period appeared to be the best at detecting differences between treatments. Repeated arthrocentesis has a definite effect on synovial fluid composition but the effects appear to decrease with repeated centesis. Lidocaine HCl and mepivacaine HCl are irritating to the synovial environment. Clear differences between responses to the drugs could not be identified.

Haemophilia A in German shepherd dogs

Haemophilia A was diagnosed in 14 male German shepherd dogs. Factor VIII: coagulant (FVIII:C) activities ranged from 1.13% of a normal canine plasma pool. von Willebrand's factor antigen values were normal or increased in all 9 of these dogs which were tested. Twelve of these dogs had a common maternal grandsire. Five dogs had exhibited no tendency to bleed (when tested between 2 to 23 months of age). They were tested because of pedigree links with clinically affected animals. Common clinical signs in the latter dogs included: bleeding from the mouth, subcutaneous and intramuscular haematomas and lameness. Since these dogs usually had a mild to moderate deficiency of FVIII:C, they may survive to adulthood without exhibiting clinical signs severe enough to necessitate veterinary attention.

Use of clinical pathology in evaluation of horses with colic

Clinical pathology is a valuable adjunct to physical examination of cases of colic. The present review considers evaluation of cases of colic for three main purposes: (1) making a prognosis, (2) deciding whether to operate, and (3) making a diagnosis. Blood tests noted to be useful for prognostication were hematocrit, lactate and urea nitrogen concentrations, pH, anion gap, fibrin/fibrinogen degradation products, antithrombin III activity, prothrombin time, and thrombin time. Horses with a poor prognosis often have relative polycythemia, marked lactic acidosis, high anion gap, azotemia, and coagulation abnormalities evidenced by increased fibrin/fibrinogen degradation products, decreased antithrombin III activity, and prolonged prothrombin and thrombin times. The decision to operate is usually a clinical one, supported by relative polycythemia, hyperglycemia, and, possibly, abnormal peritoneal fluid analysis. Diagnosis of the primary problem (causing the colicky signs) is also often based largely on physical examination. However, peritoneal fluid analysis provides worthwhile data, especially in cases of peritonitis or intestinal ischemia and infarction.

Importance of uniform cuff application for equine blood pressure measurement

Seventeen horses were used to determine the variances associated with blood pressure cuff application (Sp2) and with other inherent errors (So2). Systolic pressure values had Sp2 = 3.9 mmHg and So2 = 5.6 mmHg, while diastolic pressure values had Sp2 = 1.1 mmHg and So2 = 4.4 mmHg. Thus, to be considered different, two blood pressure means (in mmHg), each derived from three readings, had to differ by at least 3.9 for systolic pressure and 3.4 for diastolic pressure when all readings were made without cuff displacement; 6.8 for systolic pressure and 4.6 for diastolic pressure when the cuff was reapplied between, but not during, measurement of each mean; and 5.0 for systolic pressure and 3.8 for diastolic pressure when the cuff was reapplied between all readings. It was concluded that uniform cuff application is readily achieved.

Survey of resting blood pressure values in clinically normal horses

Resting coccygeal blood pressure values were measured, indirectly, on 296 horses (97 Thoroughbreds, 97 Standardbreds and 102 hacks). Blood pressure was found to vary with the class of horse examined; on average Thoroughbreds had significantly higher values than Standardbreds and hacks, whereas blood pressures of the last two groups were not significantly different. There was no demonstrable effect of sex, height or heart rate on blood pressure, but temperature and age did influence the value recorded. Mean (+/- sd) (n = 296) coccygeal uncorrected values (systolic pressure/diastolic pressure) were 112.1 +/- 16.5/77.3 +/- 14.3 mmHg. Allowing for bladder width to tail girth ratios used in each measurement, actual coccygeal pressures of 122.8 +/- 18.6/71.0 +/- 13.4 mmHg were determined. The latter corresponded to values of 149.4 +/- 19.0/97.6 +/- 14.0 mmHg, when corrected to heart (shoulder) level. Normal limits (defined as within 2.5th and 97.5th percentiles) for all horses, regardless of class, were 80 to 144 mmHg/49 to 105 mmHg for coccygeal uncorrected values and 86 to 159 mmHg/45 to 97 mmHg adjusted for bladder width to tail girth ratio.

Survey of 79 referral colic cases

The clinical, surgical and/or necropsy diagnosis of 79 horses admitted to a referral clinic for evaluation of colic are reported. Twenty-one horses were presented with conditions amenable to medical treatment and all were subsequently discharged. Exploratory laparotomies were performed on 44 horses during the present study, in some cases as a diagnostic procedure preceding euthanasia. In general, in surgical cases the mortality rate was highest for problems involving the small intestine, followed by those affecting the large colon and then the small colon. Postoperative sequelae included peritonitis, infarction, visceral rupture and acute circulatory failure. Colitis, visceral rupture and thromboembolic infarction generally had a fatal result. The overall recovery rate (for 79 horses) was about 50 per cent.

Prognosis in equine colic: a study of individual variables used in case assessment

The individual merit of the use of 43 variables to assess the prognosis of equine colic cases was examined. The following variables revealed highly significant (P less than 0.001) differences between cases which survived and those which died: blood pressure; heart rate; oral mucosal capillary refill time; degree of mental depression; venous haemoglobin concentration, haematocrit, erythrocyte count, urea concentration and lactate concentration; peritoneal fluid lactate concentration; and haematocrit/plasma protein and serum protein concentration ratios. Thus, in general, variables which assessed cardiovascular function were good prognostic guides.

Prognosis in equine colic: a comparative study of variables used to assess individual cases

The present retrospective study compared objectively the prognostic value of many variables routinely used in the assessment of equine colic cases. The best prognostic variables were those which assessed the integrity of cardiovascular function. Ranked in order of decreasing merit the following variables were able to discriminate between horses which lived and those which died: systolic pressure, blood lactate concentration, oral mucous membrane capillary refill time, diastolic pressure, arterial pulse amplitude, degree of mental depression, blood urea concentration, haematocrit, heart rate, haematocrit/plasma protein ratio, oral mucous membrane colour, jugular filling rate, frequency of gut sounds, differential blood leucocyte count, blood glucose concentration and respiratory rate. Assessment of systolic pressure alone appropriately classified the outcome (survival or death) of 86 per cent (64 out of 73) cases examined. Combined assessment of systolic pressure, blood lactate concentration, blood urea concentration and haematocrit permitted accurate classification of 93 per cent (68 of 73) of the cases examined. Outcome classification formulae for these four variables, alone and in all combinations, are presented.

Assessment of the necessity for surgical intervention in cases of equine colic: a retrospective study

The present study retrospectively examined clinical and clinicopathological findings in horses with colic to determine which variables distinguished between medically treatable cases and cases which required surgical intervention. Heart rate, haematocrit, haemoglobin concentration, blood erythrocyte count, frequency of borborygmi and degree of mental depression showed the greatest differences (P less than 0.001) between medical and surgical groups. However, some variables which primarily evaluated cardiovascular function, ie, blood pressure, oral mucosal capillary refill time and blood lactate concentration, were not significantly different between medical and surgical groups. When several of the following findings are observed together surgery is suggested: moderate to marked colic signs; tacky to dry oral mucosa which is discoloured (especially when brick-red or blue); decreased to absent borborygmi, probably associated with absence of rectal faeces; nasograstric intubation producing refluent fluid; leucocytosis with a left-shift; and tachypnoea, tachycardia, elevated haematocrit, hyperglycaemia and uraemia.

Influence of acepromazine maleate on the equine haematocrit

The effect of acepromazine maleate (ACP) on the equine venous haematocrit and total plasma protein concentration was studied in six clinically normal horses. Total plasma protein concentration was not appreciably influenced by ACP. However, the haematocrit decreased with the duration, but not the degree, of the decrease being dose-related. Mean haematocrit values returned to control levels by 12 h after 0.05 mg ACP/kg body weight and 21 h after 0.15 mg ACP/kg body weight.

Hypotension in the horse induced by acepromazine maleate

The hypotensive effect of acepromazine maleate was related to both the dose and route of administration. The degree and duration of hypotension varied between individual horses. In general, intravenous administration produced a more rapid maximum effect than intramuscular injection and the larger the dose the longer blood pressure remained at low levels. Average systolic pressure (of 6 horses) remained significantly below control values for more than 6 h after an intramuscular injection of 0.05 mg acepromazine maleate/kg body weight. Respiratory rate was markedly decreased, with the duration, but not the degree of bradypnoea related to the dose administered. A slight, transient decrease in body temperature was observed. Heart rate was not significantly influenced by administration of acepromazine maleate.