The Field Spaniel has a history that closely resembles that of the English Cocker Spaniel. Its forefathers came to England from Spain, and English breeders developed it for hunting upland game birds. Today's Field Spaniel has gained respect of dog fanciers and is steadily gaining in popularity. However, at one time the breed suffered in popularity, and today remains one of the rarest of the sporting breeds. This loss of popularity started in England because of some breeders who were originally producing the Field Spaniel. In their effort to produce a sturdier dog than the English Cocker, they indiscriminately bred a dog with a number of negative traits. Concerned breeders removed these negative traits in later generations. Today's Field Spaniel is a well balanced and desirable hunting companion.
Field Spaniel Varieties
The varieties of the field spaniel breed have the coat colours black, black and tan, liver, liver and tan; with or without roan colouration. Retrospective analysis of litter data reveals that the colours are produced by the agouti mutant alleles solid black (As) and black and tan (at), black pigmentation B, and liver brown b. Roan colouration is engendered by the gene combination sps PTT. The breed is homozygous for long hair and the long coat enhances the effect of admixture of intermingled coloured and white hairs for the variety known as roan.
Although it is possible to form generalizations for the heredity of coat colour in the dog (Little, 1957; Robinson, 1990), it has become apparent as work in the field spaniel has progressed that certain breeds possess unique mutant alleles. It is important, therefore, to investigate the inheritance of colour varieties in individual breeds. Comparatively recently, it has been shown that two alleles at the same locus, one dominant and the other recessive to wild type, can produce a completely black coat (Willis, 1970; Carver, 1984). It follows that it is no longer safe to assume that all black dogs are due to the same allele (Little, 1957).
Even more recently, it has been discovered that the unique harlequin pattern of the Great Dane is genetically different from the merle pattern of other breeds which it resembles phenotypically (Sponenberg, 1985; O’Sullivan and Robinson, 1989). Tweed is another colour which resembles merle but which is genetically unique to the Australian Shepherd dog (Sponenberg and Lamoreux, 1985). In the past, each of these colours would have been ascribed to the merle gene.
The present report describes an analysis of colour variation in the field spaniel, one of several breeds of the spaniel group. The breed is long coated and is bred in a number of different color varieties. The most common variety is the self-coloured liver brown. Two less common varieties are the self-black and the black and tan. In the latter, the whole body is black with tan-coloured markings. These comprise two tan patches on the front of the chest, tan on the inside of the legs, and on the front of the legs from the carpal to the hock, together with two characteristic small tan spots above the eyes. The roan variety is a spotted animal, with variable areas of white in the coat which are liberally interspersed with coloured hairs. Each of the previous varieties may be combined with roan, with appropriate changes for the coloured hairs.
FIELD SPANIEL MATERIAL AND METHODS
The completely black colour behaved as a monogenic dominant to liver, as evidenced by the first three entries . The observed frequencies of segregation are in accord with expectation, as shown by the nonsignificant x2 values. In confirmation of the recessive nature of liver, mating of liver to liver gave 1452 liver pups. The black and tan colouration is relatively uncommon and this is reflected by the small amount of data on this variety. However, it is apparent that the colour segregated as recessive to both self-black and self-liver. The roan (spotted) varieties are relatively more common and the segregation of non-roan versus roan on the expectation of the latter being a recessive trait is. The precise genetics of roan are discussed later.
FIELD SPANIEL DISCUSSION
A general exposition of the nature and heredity of coat color in the field spaniel dog may be found in Little (1957) and Robinson (1990). To comprehend the basis of the color varieties for the field spaniel, it is necessary to briefly review the phenotypes of the relevant coat-colour mutants. The solid black colour may be produced by either of two alleles at the agouti locus A. These are (1) dominant black AS and (2) non-agouti or recessive black a. Black and tan at is also a member of the agouti series of alleles and is recessive to AS
but dominant to a. Black pigmentation is due to a gene B which is dominant to its liver-brown allele b. The colour known as roan is produced by a combination of two genes, piebald white spotting sP, which is a recessive mutant of S, and ticking T. The T gene induces variable number of coloured hairs in the white areas produced by the sP gene. Gene S is epistatic to T.
|Field Spaniel Puppy|
The predominant color of the field spaniel is liver, as documented by the large number of inter se liver matings which produced only liver progeny. Liver is inherited as recessive to black pigmentation and is due to the well-established b gene. The solid black variety could be due to either As or a. Of the two, the AS allele is indicated because if the colour is due to the a allele, matings between black parents could not produce black and tan offspring The genotype of roan (spotted) is sPsPTT and the segregation data relate to genes S and sP. Gene T is only manifested in the white areas of sP and the fully coloured S individuals are epistatic to it. The evidence is that T is widespread, if not homozygous, in the field spaniel population. The roan colouration is enhanced by the long coat which causes a greater visual random admixture of colours than if the coat is short.
The phenotype is termed roan by breeders and is not roan as strictly interpreted as a mixture of coloured or white hairs throughout the coat. Accordingly, the genotypes of the colour varieties of the field spaniel may be written as: black !-B-s-r-! liver AbbS-9T-, black and tan atatB-S-T- and liver and tan atatbbS-T-; where the dash sign indicates possible homozygosity or heterozygosity of the recessive allele. Each of the four varieties may be found combined with roan when tP he s replaces S. The investigation provided some information on the distribution of litter sizes for the breed. The range varied from one to nine pups per litter, with a mean of 4.46 ! 0.11 per litter. The frequency distribution was notably skewed towards the smaller litters but without statistical significance.
For the Field Spaniel I recommend foods that have a blend of wheat, oats, poultry, and lamb. However, I feel you should avoid feeding a Field Spaniel any soy, white rice, beet pulp, beef, and horse meats or their by products. Native food supplies for this breed would have been woodcock, chukker, quail, pheasant, and other upland game birds combined with the grain crops and vegetables found in middle latitude England.