English Cocker Spaniel Dogs Research Articles

Effect of dogs characteristics on aggressive behaviour towards humans and other animals in English Cocker Spaniels

Aggression is a rising issue in many dog breeds and is an obstacle in proper dog-human interactions. However, the aggressive behaviour can also disturb the welfare of the dog. Aggression is particularly common in English Cocker Spaniels. Thus, the aim of this study was to examine factor associated with aggression of English Cocker Spaniels using an owner-completed survey. Information on aggressive behaviour was collected from 503 dogs by electronic surveys distributed and collected in November 2022 in Poland. We investigated whether the occurrence of aggression towards people and animals was affected by age, sex, adoption from a shelter, contact with children and other animals, whether the dog has a pedigree or by other behavioural disorders (jumping on people, pulling on leash, digging holes, destroying objects, disobedience, vagrancy, inappropriate urination and defecation, begging for food). We have showed that the dogs aggressive towards other animals are significantly more likely to be aggressive towards humans. Also the age of a dog, a pedigree and inappropriate urination and defecation, significantly affect which type of the animals the dog will be aggressive towards. The logistic regression was used to test the effect of different factors on aggression towards human and animals. Our results showed that aggressive behaviour toward humans is particularly exhibited by males and it increased with age. Also, dogs that do not have an official pedigree showed aggression much more frequently toward people and other animals. In addition, dogs adopted from a shelter were often more aggressive towards people. It was also found that dogs that jump on people are significantly more likely to be aggressive toward a human. Other behavioural disorders had no effect on the occurrence of aggression. Analysis of collected data provides knowledge on the factors that affect the occurrence of undesirable behaviour in English Cocker Spaniel dogs. Understanding the causes of aggression can significantly improve the relationship between owner and dog. Our findings should not necessarily preclude people from wanting to own an English Cocker Spaniels breed, rather to be prepared for a need of a proper training.

Canine coat color E locus updates: Identification of a new MC1R variant causing 'sable' coat color in English Cocker Spaniels and a proposed update to the E locus dominance hierarchy.

The coat color phenotype 'sable' occurs in the English Cocker Spaniel dog breed. It closely resembles other canine color patterns known as domino/grizzle/pied (eA allele) and grizzle/domino (eG allele) determined by variants in the melanocortin 1 receptor gene (MC1R; 'extension' or E locus), a key multi-allele regulator of coat color. We examined genetic variation in MC1R, and found one new non-synonymous variant, c.250G>A (p.(Asp84Asn)), consistently associated with the English Cocker Spaniel 'sable' phenotype. We propose calling this newly identified allele eH and further show that the eA , eH and eG (previously known as EG ) alleles associate with similar phenotypes in dogs impacting genotypes regulated by beta-defensin 103 gene (CBD103; K locus) and agouti signaling protein gene (ASIP; A locus) in the absence of the EM and E alleles. This suggests that all three alleles are putative reduced-function variants of the MC1R gene. We propose the revised and updated E locus dominance hierarchy to be EM > E > eA /eH /eG > e1-3 .

Лечение аутоиммунного панкреатита у английского кокер-спаниеля

Autoimmune pancreatitis (AIP) is a poorly studied pathology in veterinary medicine, which is due to the low prevalence of the English Cocker Spaniel breed in the Russian Federation, as well as the lack of specific diagnosis of the disease. In human medicine, the incidence of the disease is also low. The principal difference between the treatment of AIP and the treatment of pancreatitis of a non–immune nature is the use of immunosuppressive drugs. The main guideline in evaluating the effectiveness of the chosen therapy is a positive clinical response to the use of drugs of this group.

Application of Bifurcated Semitendinosus Muscle Transposition for Treatment of Fecal Incontinence in Two Dogs

A 4-year-old mixed breed dog and a 19-year-old English cocker spaniel dog were evaluated for fecal incontinence. The second dog's fecal incontinence was associated with the anal mass. In both dogs, reconstruction of the external anal sphincter was required to gain fecal continence. Especially in the dog with an anal mass, the whole musculature involved in fecal continence was removed with the affected anorectum. Conventional surgical treatments for fecal incontinence have limitations in terms of muscle flap length and complexity of the surgical procedure. A modified surgical technique using the semitendinosus muscle was devised in the present study to overcome these limitations. The distal part of the semitendinosus muscle was bifurcated to make two muscle bundles, used to completely encircle the anorectum. These muscle bundles were sutured to the surrounding rectal muscle and the pelvic diaphragm to simulate the function of the external anal sphincter. Three months after surgery, both dogs showed significantly improved fecal continence without severe complications, such as infection, dehiscence, or lameness of the limb where the semitendinosus muscle was harvested. The outcomes of the two dogs supported the acceptability of the bifurcated muscle flap for anal sphincter augmentation. In addition, this report showed the possibility of more diverse applications of semitendinosus muscle in dogs.

Thymol and eugenol microemulsion for Rhiphicephalus sanguineus sensu lato control: Formulation development, field efficacy, and safety on dogs

The present study aimed to develop a microemulsion formulation containing thymol and eugenol for field control of Rhipicephalus sanguineus sensu lato on dogs, as well to evaluate its safety and the physical characteristics of the formulation. The microemulsion using thymol and eugenol (5.0 + 5.0 mg/mL) had as vehicles water, propylene glycol, polysorbate 80 and canola oil. On the next day the preparation (formulation freshly prepared) and after 24 months, the size of the microemulsion droplets, polydispersion index (PdI), organoleptic properties (color, viscosity), and presence of precipitate in the microemulsion were evaluated. For the field assay, on day -1, 10 English Cocker Spaniel dogs were experimentally infested with 200 larvae, 100 nymphs and 30 adults of R. sanguineus s.l. On day 0, after tick counts, the animals were divided into two groups: treated with the freshly prepared microemulsion (10 mL/kg), and control, which received the vehicle (10 mL/kg). Tick counts on dogs were performed daily for three more days. Engorged females were recovered from the dogs and their biological and reproductive parameters were monitored. The dogs’ clinical parameters (temperature, mucosa color, and general physical condition) were evaluated daily. In addition, blood samples were collected before infestation to verify hematological (packed cell volume) and biochemical parameters (total serum protein, albumin, globulins, creatinine, urea, alanine transaminase, aspartate aminotransferase, and alkaline phosphatase). Freshly prepared and 24-month aged microemulsions had droplets with mean sizes of 30.94 nm and 27.93 nm, and PdI values of 0.214 and 0.161, respectively. In addition, no difference in the organoleptic properties and no precipitation formation were observed, indicating physical stability. Treatment with the microemulsion resulted in reduction of larvae (p < 0.05) parasitizing the dogs on day 1 while the number of nymphs and adults was not reduced (P> 0.05). In the evaluation of the reproductive biology of engorged females, the larval hatchability (%) was compromised (p < 0.05), and the microemulsion had control rate of 85.5 %. The microemulsion and its vehicles did not change the clinical, hematological and biochemical parameters of the dogs. We concluded that the microemulsion was efficient against R. sanguineus s.l. by reducing the number of larvae and affecting the reproductive parameters of engorged females, safe for dogs, and stable (physical stability) during a two-year interval.

Identification of a variant in NDP associated with X-linked retinal dysplasia in the English cocker spaniel dog.

PurposeThree related male English Cocker Spaniels (ECS) were reported to be congenitally blind. Examination of one of these revealed complete retinal detachment. A presumptive diagnosis of retinal dysplasia (RD) was provided and pedigree analysis was suggestive of an X-linked mode of inheritance. We sought to investigate the genetic basis of RD in this family of ECS.MethodsFollowing whole genome sequencing (WGS) of the one remaining male RD-affected ECS, two distinct investigative approaches were employed: a candidate gene approach and a whole genome approach. In the candidate gene approach, COL9A2, COL9A3, NHEJ1, RS1 and NDP genes were investigated based on their known associations with RD and retinal detachment in dogs and humans. In the whole genome approach, affected WGS was compared with 814 unaffected canids to identify candidate variants, which were filtered based on appropriate segregation and predicted pathogenic effects followed by subsequent investigation of gene function. Candidate variants were tested for appropriate segregation in the ECS family and association with disease was assessed using samples from a total of 180 ECS.ResultsThe same variant in NDP (c.653_654insC, p.Met114Hisfs*16) that was predicted to result in 15 aberrant amino acids before a premature stop in norrin protein, was identified independently by both approaches and was shown to segregate appropriately within the ECS family. Association of this variant with X-linked RD was significant (P = 0.0056).ConclusionsFor the first time, we report a variant associated with canine X-linked RD. NDP variants are already known to cause X-linked RD, along with other abnormalities, in human Norrie disease. Thus, the dog may serve as a useful large animal model for research.

Allele frequency of nonsense mutation responsible for hereditary nephropathy in English cocker spaniel dogs

Hereditary nephropathy is a primary progressive glomerular disease in dogs associated with the c.115A>T mutation in the COL4A4 gene in English cocker spaniel (ECS) dogs. The disease is inherited in an autosomal recessive manner. Hereditary nephropathy has been described in this breed since the late 1940s. To date, there are no data on the prevalence of this disease in Brazil, so the aim of this study was to evaluate the allelic frequency of this mutation in ECS dogs in this country. The DNA samples were purified from blood samples or buccal swabs from 221 ECS dogs. Fragments of the DNA containing the mutation were amplified by PCR and submitted to direct gene sequencing. The allele frequency of the mutation was 0.9%. The presence of the mutation in the ECS dog population in Brazil reveals the importance of performing the genotyping tests in these dogs as a method of diagnosing the disease and identifying heterozygous animals, aiming to reduce clinical cases of disease through mating.

Allele Frequency of the C.5G>A Mutation in the PRCD Gene Responsible for Progressive Retinal Atrophy in English Cocker Spaniel Dogs.

Simple SummaryProgressive retinal atrophy (PRA) in English cocker spaniels (ECSs) is associated with progressive rod–cone degeneration (prcd-PRA), an inherited autosomal recessive disease caused by the c.5G>A mutation in the progressive rod–cone degeneration (PRCD) gene. Data regarding the prevalence of the mutated allele are scarce in the global literature, and there is no study evaluating this frequency in Brazil. Therefore, the aim of this study was to evaluate the allele frequency of the c.5G>A mutation in the PRCD gene responsible for progressive retinal atrophy (prcd-PRA) in ECS dogs.Progressive retinal atrophy (PRA) due to the c.5G>A mutation in the progressive rod–cone degeneration (PRCD) gene is an important genetic disease in English cocker spaniel (ECS) dogs. Because the prevalence of this disease has not been verified in Brazil, this study aimed to evaluate the allele frequency of the c.5G>A mutation in the PRCD gene. Purified DNA from 220 ECS dogs was used for genotyping, of which 131 were registered from 18 different kennels and 89 were unregistered. A clinical eye examination was performed in 28 of the genotyped animals; 10 were homozygous mutants. DNA fragments containing the mutation region were amplified by PCR and subjected to direct genomic sequencing. The prcd-PRA allele frequency was 25.5%. Among the registered dogs, the allele frequency was 14.9%; among the dogs with no history of registration, the allele frequency was 41%. Visual impairment was observed in 80% (8/10) of the homozygous mutant animals that underwent clinical eye examination. The high mutation frequency found in this study emphasizes the importance of genotyping ECSs as an early diagnostic test, especially as part of an informed breeding program, to avoid clinical cases of PRA.

Brown dog tick, Rhipicephalus sanguineus sensu lato, infestation of susceptible dog hosts is reduced by slow release of semiochemicals from a less susceptible host

Domestic dog breeds are hosts for the brown dog tick, Rhipicephalus sanguineus sensu lato, but infestation levels vary among breeds. Beagles are less susceptible to tick infestations than English cocker spaniels due to enhanced production of 2-hexanone and benzaldehyde that act as volatile tick repellents. We report the use of prototype slow-release formulations of these compounds to reduce the burden of R. sanguineus s. l. on English cocker spaniel dogs. Twelve dogs were randomly assigned to two groups with six dogs each. The treated group received collars with slow-release formulations of the compounds attached, while the control group received collars with clean formulations attached. Five environmental infestations were performed, with the number of ticks (at all stages) on the dogs being counted twice a day for 45days. The counts on the number of tick stages found per dog were individually fitted to linear mixed effects models with repeated measures and normal distribution for errors. The mean tick infestation in the treated group was significantly lower than in the control group. For larvae and nymphs, a decrease in tick infestation was observed at the fifth count, and for adults, lower average counts were observed in all counts. The compounds did not interfere with the distribution of the ticks on the body of the dogs, as a similar percentage of ticks was found on the anterior half of the dogs (54.5% for the control group and 56.2% for the treated group). The biological and reproductive parameters of the ticks were not affected by the repellents. This study highlights for the first time the potential use of a novel allomone (repellent)-based formulation for reduction of tick infestation on susceptible dogs.

Myocardial velocities obtained by pulsed tissue Doppler in English Cocker Spaniels with dilated cardiomyopathy and congestive heart failure

Abstract: Dilated cardiomyopathy (DCM) is characterized by systolic myocardial dysfunction which is identified by low myocardial velocities obtained by pulsed tissue Doppler (PTD). However, increased preload is known to increase myocardial velocities which could overestimate myocardial function and turn dysfunction characterization into a challenge in dogs with DCM and congestive heart failure. To test the hypothesis that increased preload could hamper identification of low myocardial velocities in dogs with DCM and congestive heart failure the present study prospectively evaluated 32 English Cocker Spaniel dogs, being 16 with clinical DCM and 16 healthy for control purpose. The PTD analysis of regional velocities were performed in both longitudinal and radial myocardial displacements and systolic (Sm), early (Em) and late diastolic (Am) velocities were obtained in left ventricular free wall (LVFW) and interventricular septum (IVS). Peak radial subendocardial and subepicardial Sm velocities were lower in DCM group compared to control (0.065±0.018 vs. 0.102±0.020m/s and 0.059±0.014 vs. 0.094±0.025m/s respectively; p&lt;0.001). Peak longitudinal Sm velocities were lower in basal and medial portions of LVFW (0.093±0.034 vs. 0.155±0.034m/s and 0.091±0.033 vs. 0.134±0.037m/s respectively; p&lt;0.001) and IVS (0.063±0.021 vs. 0.136±0.039 and 0.066±0.026 vs. 0.104±0.032m/s respectively; p&lt;0.001). Most of diastolic velocities were not significantly different between groups, although advanced myocardial disease and dysfunction are expected in DCM group. Reduction in systolic basal and medial longitudinal myocardial velocities and in radial myocardial velocities was the most significant PTD findings. Increased preload did not represent a problem to evaluate systolic dysfunction by PTD in English Cocker Spaniels with DCM, but influence of preload on assessment of diastolic velocities should be better elucidated.

High-resolution fluorodeoxyglucose positron emission tomography and magnetic resonance imaging findings of a pituitary microtumor in a dog.

A 16-year-old, castrated, male English cocker spaniel dog was presented due to generalized alopecia. Routine clinical pathology, endocrine and abdominal ultrasonography results were consistent with a diagnosis of pituitary-dependent hyperadrenocorticism. The adenohypophyseal lesion was clearly visualized on both 3 T and 7 T magnetic resonance imaging (MRI) of the pituitary gland. Although biochemical and MRI findings were consistent with a functional pituitary microtumor, a pituitary lesion was not detected using 18F-fluorodeoxyglucose positron emission tomography (FDG-PET). This report firstly describes the application of high-resolution FDG-PET to a spontaneous pituitary microtumor in a dog.

Probiotic dietary supplementation in a dog with chronic kidney disease

A 7-year-old spayed female English Cocker Spaniel dog presented with polyuria (PU), polydipsia (PD), intermittent vomiting, and weight loss. Physical examination revealed pale, tacky mucous membranes and severe emaciation. Hematological and biochemical examinations revealed moderate normocytic normochromic non-regenerative anemia and moderate azotemia. Abdominal ultrasonography demonstrated bilaterally small lumpy-bumpy kidneys with hyperechoic parenchyma as well as loss of renal corticomedullary junction. Based on clinical history and examinations, the dog was diagnosed with chronic kidney disease (CKD). The dog was treated with supportive care including fluid therapy, phosphate-binding agent, and histamine H2-receptor antagonist. Darbepoetin Alfa was administered to control renal secondary non-regenerative anemia. Prescribed diet with low-protein and low-phosphorus was fed to alleviate CKD signs. Further, dietary probiotics were supplemented. This case demonstrates that oral probiotic supplementation helped reduce blood urea-nitrogen (BUN) levels. This case indicates that dietary probiotics can be a potential alternative therapeutic agent for management of renal failure.

Cutaneous hemangiopericytoma in a dog : Cytologic and Histopathologic findings

A 10-year-old, castrated male, English cocker spaniel dog was presented for evaluation of a mass in the left forelimb. Physical examination revealed a solitary subcutaneous mass measuring 2.7 × 2.1 × 1 ㎝ in size. Radiographs and ultrasonography showed a well-circumscribed, focally mineralized, non-invasive to muscle layer mass without signs of further bone invasion and periosteal reaction. Cytologic evaluation of the mass through fine needle aspiration revealed a mesenchymal cell type malignant tumor without distant metastasis. An excisional biopsy was performed for definitive diagnosis and the mass was diagnosed as cutaneous hemangiopericytoma. This case report presents disagreement between fine needle aspiration and histopathology during diagnostic procedures of cutaneous hemangiopericytoma in a dog.

A- and B-modes echobiometry in cataractous and noncataractous eyes of English Cocker Spaniel dogs

A- and B-modes ultrasonographic changes in the thickness of various structures of the eyeball in male and female English Cocker Spaniel dogs with and without nondiabetic cataracts were evaluated. Sixteen dogs with cataracts (32 eyes) and seven normal dogs (14 eyes) older than eight years were selected. A- and B-modes ultrasonography was performed with a 10MHz transducer. Data was statistically evaluated by one way ANOVA. Mean and standard deviations of various ocular structures for dogs with and without cataracts were, respectively, anterior chamber: 3.041±0.828mm, 3.373±1.040mm; lens: 6.817±1.117mm, 7.062±0.477mm; vitreous: 10.056±0.754mm, 9.523±0.705mm; and axial length: 19.909±1.103mm, 19.958±1.050mm. Ocular measurements between right and left eyes, males and females, as well as in eyes with and without cataract were not different (P&gt;0.05).

Acupuncture treatment for idiopathic Horner's syndrome in a dog

A one-year-old female English Cocker Spaniel dog with idiopathic Horner's Syndrome is described. The specific clinical signs in this specimen were miosis, ptosis, enophthalmos, and prolapsed nictitans for 2 days following sudden onset. According to history taking, ophthalmic, neurological, and radiological examination, the patient was diagnosed with idiopathic Horner's syndrome. Manual acupuncture treatment was applied to the dog on local points two times in 2 days. The local acupoints were ST-4 (Di Chang) and GB-1 (Tong Zi Liao). The day after the initial acupuncture treatment, clinical signs related to idiopathic Horner's syndrome had almost disappeared. The day after the second treatment, specific clinical signs were completely absent. During this period, the dog did not receive any orthodox treatment. Thus, it is suggested that manual acupuncture might be an effective therapy for idiopathic Horner's syndrome.

Seasonal dynamics of Rhipicephalus sanguineus (Acari: Ixodidae) in dogs from a police unit in Goiânia, Goiás, Brazil

The seasonal dynamics of Rhipicephalus sanguineus ticks was developed in dogs from a Police Unit in Goiânia, Goiás, Brazil, from July 2001 to July 2002. The study was carried out on seven naturally infested dogs (two English Cocker Spaniels and five mongrel dogs), with ages between six months and 10 years. Every two weeks, the numbers of feeding larvae, nymphs, and adults were determined. Dogs showing infestation levels above 500 adult ticks received three acaricide treatments. Considering that the treatments had affected the development of some peaking populations of ticks, it was inferred the occurrence of the following peaks: - larvae (four peaks): from August to November, from November to February, from March to May, and from May to July; - nymphs (five peaks): from July to September, from October to December, from December to February, from March to May, and from June to July; - adults (four peaks): from July to October, from October to January, from January to March, and from April to July. The occurrence of these consecutive peaks of activity of each stage of R. sanguineus may indicate that this tick can develop up to four generations per year in Goiânia. On the other hand, if the acaricide treatment did not interfere with the development of R. sanguineus peaks, more than four peaks of each stage have occurred on the dogs. In this case, it is acceptable to infer that more than one population of R. sanguineus was developing within the kennel concomitantly. The mean numbers of each tick stage was similar in the different seasons. The main attachment sites were located on the neck, chest, forelegs, armpits, ears, between toes and on the head. The number of adult ticks feeding on English Cocker Spaniel dogs was 1.4 to 11.5 times higher than that feeding on mongrel dogs.

Antioxidant profile of cataractous English Cocker Spaniels.

Cataracts have been attributed to oxidative injury in proteins and lipids. Primary defenses that directly protect the lens against oxidative damage include small molecule antioxidants (vitamin C, vitamin E, glutathione and carotenoids) and antioxidant enzymes (superoxide dismutase, catalase, and the glutathione enzyme systems - glutathione peroxidase, glutathione reductase and glucose-6-phosphate dehydrogenase). In humans, low plasmatic levels of vitamin C, vitamin E and carotenoids have been associated with a high risk of senile cataracts. Dogs are more prone to develop cataracts. A decrease in antioxidant defenses could be responsible for increased lens oxidation and cataract development. In this study we report the levels of erythrocytic enzymatic antioxidants (superoxide dismutase, catalase, glutathione peroxidase and glucose-6-phosphate dehydrogenase) and plasma vitamin C as well as malondialdehyde, in normal and cataractous English Cocker Spaniel dogs. Plasma vitamin C levels were consistently lower in cataractous dogs (20.17 &mgr;M +/- 8.2 &mgr;M) when compared with normal dogs (24.1 &mgr;M +/- 9.4 &mgr;M). These results indicate a possibly decreased synthesis in vitamin C, leading to lower aqueous humor levels of this vitamin. Considering that vitamin C levels in the aqueous humor may be responsible for lens antioxidant maintenance, and that these levels are obtained from plasma secretion through the ciliary epithelium, decreased plasma levels may indicate a decrease in the antioxidant capacity of the aqueous humor.

A model of autosomal recessive Alport syndrome in English cocker spaniel dogs

Dogs with naturally occurring genetic disorders of basement membrane (type IV) collagen may serve as animal models of Alport syndrome. An autosomal recessive form of progressive hereditary nephritis (HN) was studied in 10 affected, 3 obligate carrier, and 4 unaffected English cocker spaniel (ECS) dogs. Clinical, pathological, and ultrastructural features of the disease were characterized. Expression of basement membrane (BM) proteins was examined with an immunohistochemical technique using monospecific antibodies. Affected dogs had proteinuria and juvenile-onset chronic renal failure. Glomerular basement membrane (GBM) thickening and multilamellation typical of HN were observed in all renal specimens obtained from proteinuric dogs, and severity of GBM ultrastructural abnormalities varied with the clinical stage of disease. Expression of alpha3(IV) and alpha4(IV) chains was totally absent in the kidney of affected dogs. Expression of alpha5(IV) and a6(IV) chains was normal in Bowman's capsule, collecting tubular BM and epidermal BM of affected dogs. The alpha5(IV) chain was not expressed in distal tubular BM of affected dogs. Expression of alpha5(IV) chains was markedly reduced but not absent, and expression of alpha6(IV) chains was present in GBM of affected dogs. Expression of alpha1-alpha2(IV) chains in GBM of affected dogs was increased. Features of obligate carriers were similar to those of unaffected dogs. We conclude that HN in ECS dogs is a naturally occurring animal model of autosomal recessive Alport syndrome. However, it differs from human disease in the persistence of alpha5(IV) chains in GBM and in the appearance of a6(IV) chains in GBM.

Inheritance of serum autoantibody, reduced serum IgA and autoimmune disease in a canine breeding colony

Immunological parameters were examined in 113 English cocker spaniel dogs from two breeding kennels. Dogs from kennel 1 (n = 86) were grouped as having idiopathic cardiomyopathy (n = 19), autoimmune or other disease (n = 7) or being clinically normal (n = 60). Dogs from kennel 2 (n = 27) were all clinically normal and used for comparative purposes. There was a high incidence of serum antinuclear antibody (ANA) amongst all groups from kennel 1 (39/82 dogs tested), with anti-thyroglobulin and anti-erythrocyte antibodies also recorded in a dog with systemic lupus erythematosus. Thirty percent of dogs with idiopathic cardiomyopathy had anti-mitochondrial antibody. Thirteen dogs from kennel 1 had reduced serum IgA (< or = 0.3 mg/ml), but there was no consistent abnormality in the concentration of serum IgG, IgM, complement C3 or C4 in these thirteen dogs, or other dogs from this kennel. No immunological abnormality was recorded in dogs from kennel 2. Pedigree analysis of dogs from kennel 1 revealed inheritance of autoimmune disease, serum ANA and low serum IgA within several breeding lines. Inheritance of idiopathic cardiomyopathy was recorded through three generations and a strong association demonstrated between the presence of this disorder and a particular complement C4 phenotype (C4: 4).