CANINE THYMIC STROMAL LYMPHOPOIETIN PROTEIN AND USES THEREOF CROSS-REFERENCE TO RELATED APPLICATIONS This application is a non-provisional application that claims priority under 35 U.S.C. § 119(e) of provisional application U.S. Serial No. 60/875,135 filed December 14, 2006, the contents of which are hereby incorporated by reference in its entirety. FIELD OF THE INVENTION The present invention relates to canine thymic stromal lymphopoietin protein (canine "TSLP"), nucleic acid molecules, vectors and host cells encoding canine TSLP. and methods of making and using canine TSLP. BACKGROUND OF THE INVENTION Animals, including humans, that suffer from reagin-mediated disorders, such as atopic diseases, have a hereditary tendency to develop immediate allergic reactions involving IgE antibodies. Multiple genetic factors contribute to the expression of the resulting phenotype seen in such animals. The immediate hypersensitivity observed in atopic diseases results from exposure to specific allergens, such as the house dust mite {Dermatophagoides pteronyssinus), pollens, molds, and danders. Not surprisingly, individuals having an atopic disease are more likely to suffer from asthma, atopic dermatitis, as well as other disorders related to endogenous IgE release. Atopic diseases such as allergic dermatitis, asthma, and the like, also occur in the canine species, including in domestic dogs. Such dogs generally begin to show signs of atopy between one and three years of age. Due to the hereditary nature of the disease, several breeds, including golden retrievers, most terriers, Irish setters, Lhasa apsos, Dalmatians, bulldogs and Old English sheep dogs have a greater tendency to be atopic, though other types of dogs, including mixed breeds, also are known to suffer from this condition. The incidence of at least one particular type of atopy, atopic dermatitis, is increasing significantly in both humans and canines alike. Atopic canines will usually rub, lick, chew, bite or scratch at their feet, muzzle, ears, amipits or groin area, resulting in hair loss, reddening, and thickening of the skin. In some cases several skin conditions combine to cause an animal to itch when a single allergy alone would not have resulted in such itching. These aggravating problems can be due to air borne-allergens {pollens, etc.), allergens in food, and allergens from parasites (fleas, etc.). Bacterial and/or yeast infections of the skin also can augment the itching sensation. One simple means of alleviating the annoying symptoms of atopy is to avoid the inciting aliergen(s). Unfortunately, such avoidance is generally impractical. Heretofore, veterinary practitioners have treated canine atopic dermatitis by administering oral antihistamines, oral or topical corticosteroid anti-inflammatory agents, other immune system suppressants, such as cyclosporine or tacrolimus, fatty acid supplements, and allergen specific immunotherapy (which requires injection of the identified antigen). However, none of these treatments work in all cases. Moreover, such treatments are costly and/or give rise to significant side effects. Thus, there is a longstanding need for safer, more effective and more economical approaches to treating or suppressing the symptoms of canine atopic dermatitis. The mammalian immune response is based on a series of complex cellular interactions, called the "immune network". Much of the immune response revolves around the network-like interactions of lymphocytes, macrophages, granulocytes, and other cells, with soluble proteins called cytokines playing a critical role in mediating/controlling/regulating these cellular interactions. Thus, cytokines and immune cells serve to mediate specific physiological mechanisms or pathways leading to the various inflammatory disorders. Allergic inflammation is the result of a complex immunological cascade which leads T cells to produce dysregulated TH2-derived cytokines such as IL-4, IL-5, and IL-13. These cytokines, in turn, trigger bronchial hyperreactvity, IgE production, eosinophilia, and mucus production (see, e.g., Busse and Lemanske. Jr. (2001) N. Engl. J. Med. 344^350-62; Holgate (2000) Br. Med. J. 320:231-234); and Renauld (2001) J. Clin. Pathol. 54-577-589). Thymic Stromal Lymphopoietin protein (TSLP) is an IL-7-like cytokine that was initially identified in mice as a factor that supported: (i) the in vitro development of surface IgM* B cells, and (ii) B and T cell proliferation (Friend etai, 1994 Exp Hematology 22:321-328. see also. Levin et al., 1999, J. Immunol 162: 677 - 683). TSLP is now known to bind a cellular receptor comprising IL-7R-alpha subunit and a unique receptor subunit called TSLP-R. This interaction triggers signal transduction via STAT activation or Thymus and Activation-Regulated Chemokine (TARC) expression in a hematopoietic cell, such as a myeloid lineage cell such as a monocyte, or a dendritic cell, (see, e.g., co-owned U.S. Patent No. 6,890,734, incorporated herein by reference). TSLP also may play a significant role in mice in the pathogenesis of allergic diseases such as atopic dermatitis and asthma. For example, transgenic mice in which the expression of TSLP gene was specifically induced in the skin show immunological and clinical features of atopic dermatitis such as eczematous lesions containing inflammatory dermal cellular infiltrates, a dramatic increase in Th2 CD4*T cells expressing skin homing receptors, and elevated serum levels of IgE. Moreover, lungs of mice expressing a lung-speclfic TSLP transgene show immunological and clinical features of asthma including massive infiltration of leuckocytes, goblet cell hyperplasia, sub-epithelial fibrosis, an increase in T helper type 2 cytokines, and increased levels of IgE. Sims et al. obtained the cDNA sequence of murine TSLP employing expression cloning, but were unable to clone the human homologue with hybridization probes based on the murine TSLP (Sims et al. 2000, J exp Med, 192: 671 - 680). Subsequently, the human homologue was identified through detailed EST analysis. The human TSLP nucleotide sequence was found to have only 43% homology with the corresponding mouse sequence. Therefore, there remains a need to provide new and more practical treatments for atopic disorders in canines, including atopic dermatitis and its associated clinical manifestations. Moreover, there is a need to isolate factors that are involved in the immunological cascade that leads to atopic disorders in canines that could lead to the development of such treatments. The citation of any reference herein should not be construed as an admission that such reference is available as "prior art" to the instant application. SUMMARY OF THE INVENTION The present invention provides new and more practical treatments for atopic disorders in canines, including atopic dermatitis and its associated clinical manifestations. Accordingly, the present invention provides novel isolated and/or recombinant thymic stromal lymphopoietin protein (TSLP) proteins that are involved in the immunological cascade that leads to atopic disorders. The present invention further provides antigenic fragments of such TSLP proteins. In a particular aspect of the present invention, the TSLP protein is a canine TSLP protein. Therefore the present Invention provides a TSLP protein comprising an amino acid sequence that has 80% or greater identity to the amino acid sequence of SEQ ID NO: 2, excluding the 28 amino acid residue signal sequence, which when the protein is administered to a canine subject as a vaccine, antibodies that bind the canine TSLP protein comprising the amino acid sequence of SEQ ID NO: 2 are detectable in the resulting canine sera obtained from the vaccinated canine subject. In a related embodiment, the TSLP protein comprises an amino acid sequence that has 80% or greater identity to the amino acid sequence of SEQ ID NO: 2, excluding the 28 amino acid residue signal sequence; and is cross reactive with an antibody raised against the canine TSLP comprising the amino add of SEQ ID NO: 2. The present invention further provides a TSLP protein comprising an amino acid sequence that has 80% or greater identity to the amino acid sequence of SEQ ID NO: 2 (excluding the 28 amino acid residue signal sequence) which binds to an epitope-specific canine TSLP monoclonal antibody. in a more particular embodiment, that TSLP protein comprises an amino acid sequence that has 90% or greater identity to the amino acid sequence of SEQ ID NO: 2, excluding the 28 amino acid residue signal sequence. In still another embodiment, that TSLP protein comprises an amino acid sequence that has 95% or greater identity to the amino acid sequence of SEQ ID NO: 2. excluding the 28 amino acid residue signal sequence. In a specific embodiment of the present invention, the TSLP protein is the canine TSLP protein that comprises the amino acid sequence of SEQ ID NO: 2. In another embodiment, the TSLP protein Is the mature canine TSLP protein that comprises amino add residues 29-155 of SEQ ID NO: 2. Antigenic fragments of the TSLP proteins of the present invention are also provided. Such antigenic fragments include those that comprise one or more epitopes individually defined by the amino acid sequences of SEQ ID NOs: 8-101. In a particular embodiment, an antigenic fragment of the present invention comprises one or more epitopes that comprise an amino acid sequence of SEQ ID NOs: 30, 31, 32, and/or 34. In another embodiment, the antigenic fragments can have an amino acid sequence contained within the overlap of the amino acid sequences of SEQ ID NOs: 30, 31. 32, and/or 34. i.e., NPPDCLARIERLTLHRIRGCAS (SEQ ID NO: 118). In a particular embodiment, an antigenic fragment of the canine TSLP protein is capable of binding an anti-human TSLP monoclonal antibody. Antigenic fragments of the amino acid sequence of NPPDCLARIERLTLHRIRGCAS (SEQ ID NO: 118) can range in size from about 5 to about 21 amino acid residues. Vaccines are also provided that can include an effective amount of any TSLP protein of the present invention, one or more antigenic fragments thereof, or combinations of such full-length protein(s) and one or more of such fragments. In one embodiment the TSLP protein is a canine TSLP protein that comprises the amino acid sequence of SEQ ID NO; 2. In a particular embodiment, a vaccine contains one or more antigenic fragments of the canine TSLP protein that comprises 5 to 22 contiguous amino acids of amino acid residues 71-92 of SEQ ID NO: 2 (identified herein as SEQ ID NO: 118). Examples of such antigenic fragments include the epitopes disclosed herein that comprise amino acid sequences of SEQ ID NO: 30, SEQ ID NO: 31. SEQ ID NO: 32. SEQ ID NO: 33. or SEQ (D NO: 34. All of the vaccines of the present invention can further comprise a phamnaceutically acceptable adjuvant. A vaccine of the present invention may be employed in a method of inducing anti-canine TSLP antibodies. One such method comprises immunizing a mammal with an effective amount of the vaccine. This method optionally includes a method of downregulating TSLP activity in a canine and/or a method of treating or preventing allergic symptoms in an atopic canine that comprises immunizing the canine with an effective amount of the vaccine. The allergic symptoms ameliorated can include allergic dermatitis, asthma, and the like. A vaccine of the present invention may be administered by a route such as: intramuscular injection, subcutaneous injection, intravenous injection, intradermal injection, oral administration, intranasal administration, scarification, and combinations thereof. The present invention further provides a nucleic acid molecule encoding a TSLP protein of the present invention or an antigenic fragment thereof. In one such embodiment, the nucleic acid molecule encodes the amino acid sequence of SEQ ID NO: 2. In a particular embodiment of this type, the nucleic acid molecule comprises the nucleotide sequence of SEQ ID NO: 1. Fragments of the nucleotide sequence of SEQ ID N0;1 of about 18 contiguous nucleotides, about 24 contiguous nucleotides, about 36 contiguous nucleotides, about 45 contiguous nucleotides, about 66 contiguous nucleotides, or greater are also part of the present invention. Nucleic acids of about 18 nucleotides, about 24 nucleotides, about 36 nucleotides, about 45 nucleotides, about 66 nucleotides, or greater, including nucleic acids encoding full-length TSLP proteins, that hybridize to SEQ ID NO:1 under stringent hybridization conditions are also provided by the present invention. All of the nucleic acid molecules and fragments thereof of the present invention may further comprise a heterologous nucleotide sequence. The present invention also provides an expression vector that includes the previously noted nucleic acid molecules and/or fragments thereof. In addition, the present invention provides host cells that comprise such expression vectors. The host cell is optionally a prokaryote or a eukaryote host cell. In one embodiment, the prokaryote host cell is an Escherichia coli. In a particular embodiment of this type, the host cell is E. co//BL21(DE3)/pLysS that contains the T7 RNA polymerase gene under the control of the isopropyl-fi-D-thiogalactopyranoside (IPTG)-inducible lacUVS promoter. The present invention further provides recombinant viral vectors and/or naked DNA vectors comprising one of the above-noted nucleic acid molecules encoding a canine TSLP. e.g.. SEQ ID NO: 1, and/or fragment thereof. Such vectors can be used, for example, e.g., in vaccines that are suitable for administration into a canine having atopic dermatitis. The present invention also provides methods of producing a TSLP protein of the present invention. One such method comprises culturing a host eel! of the present invention in a suitable culture medium. This method can further include the step of isolating and/or purifying the TSLP protein from the cultured host cell or the culture medium. The resulting Isolated and/or purified TSLP protein is also part of the present invention. Anti-TSLP antibodies elicited in a hybridoma system by a vaccine of the present invention, are also part of the present invention. In one embodiment of this type a mamma/ian hybridoma system is employed. In a particular embodiment, the antibodies are isolated and/or purified. The antibodies may be either polyclonol or monoclonal. According to the invention a monoclonal antibody elicited in a non-canine species can be optionally engineered to be caninized, so as to be minimally antigenic when injected into a canine subject. In certain preferred embodiments, the binding domains of any antibody according to the invention is optionally converted into binding fragments smaller than the original antibody, e.g., by cleavage and/or as a recombinant Fv, Fab, and F(ab')2 binding protein. Antibody-derived therapeutic proteins that contain the unique structural and functional properties of naturally-occurring heavy-chain antibodies (e.g., NANOBODIES®) are also included in the invention, In addition, antibody surrogates that have a high affinity for TSLP and \ow immunogenicity (e.g., avimers prepared from binding portions of the TSLP receptor) are also included in the present invention. The inventive anti-canine TSLP antibodies/avimers can be readily employed in a method of treating allergic symptoms in an atopic canine by administering an effective amount of that anti-canine TSLP antibody. The present invention also provides a vaccine comprising an effective amount of a non-TSLP immunogen in combination with an effective amount of TSLP protein of the present invention, one or more antigenic fragments thereof, or combinations of the full-length protein and one or more of such fragments. In a particular embodiment of this type, the TSLP protein is a canine TSLP protein. In a more particular embodiment, the canine TSLP protein comprises the amino acid sequence ofSEQIDNO:2. The present invention additionally provides diagnostic methods employing the inventive canine TSLP protein, fragments thereof and/or antibodies elicited by canine TSLP and fragments thereof. In one embodiment, the present invention provides a method of diagnosing atopic demiatitis in a canine comprising obtaining an epidennal sample from the canine and determining the presence of the canine TSLP protein in the epidermal sample. These and other aspects of the present Invention will be better appreciated by reference to the folfowing Figures and the Detailed Description. BRIEF DESCRIPTION OF THE DRAWINGS FIG. 1 illustrates SDS-PAGE analysis of protein from eukaryotic cell-free protein synthesis system expressing canine TSLP protein. Lane 1: Protein standard; Lane 2: Total protein; Lane 3: Soluble protein; Lane 4: Insoluble protein. TSLP protein bands are indicated by arrows. FIG. 2A illustrates Western blot analysis of protein from eulgi|36323560Igb|AACN010632090.11 Canis familraris ctg19866851299046. whole genome shotgun sequence Length = 1007 Hit 2: Score = 59.7 bits (143), Expect = 3e-08 Identities = 30/42 (71%). Positives = 33/42 (78%) Frame = -1 Query: 117 QINATQAMKKRRKRKVTTNKCLEQVSQLQGLWRRFNRPLLKQ 158 (SEQ ID NO: 104) QIN TQA KKR+KR VTTNKC EQV +L GLWRRF+R ?:Q Sbicc: 5S8 QINNTQAKKKRKKRGVTTMKCREQVAHLIGLWRRFSRIS'KQ 463 (SEQ ID NO: 105) SEQ ID NO: 104 human TSLP SEQ ID NO: 105 >gi | 36314527!gb!AACN010674832.1 Canis familiaris ctg19866851282529, whole genome shotgun sequence Length == 963 Hit 3 Score = 42.0 bits {97). Expect = 0.006 Identities = 21/44 (47%), Positives = 27/44 (61%) Frame = -2 Query: 76 LTEIQSLTFNPTAGCASLAKEMFAMKTKAALAIWCPGYSETQIN 119 (SEQ ID NO: 106) L 1+ LT + GCAS A+E FA T AALA CPGY+ ++ Sbjct: 359 LARIERLTLHRIRGCASGAREAFAEGTVAALAAECPGYAAAPVS 238 (SEQ ID NO: 107) SEQ ID NO: 106 : human TSLP SEQ ID NO: 107 >gi|36442813|gb|AACN011084208.1) CanJs familiaris ctg19866851499233, whole genome shotgun sequence Length = 370 Hit 4 Score = 38.9 bits (89), Expect = 0.047 Identities = 15/32 (46%). Positives = 22/32 (68%) Reading Frame = +1 Query: 87 TAGCASLAKEMFAMKTKAALAIWCPGYSETQI 118 (SEQ ID NO: 108) T GC AKE A-t- AL++WCPG4++TQ+ Sbjct: 178 TPGCGICAKEAAALGWFCRLSVWCPGWAQTQV 273 (SEQ ID NO: 109) SEQ ID NO: 108 : human TSLP SEQ ID NO: 109 >gi|36211043!gblAACN010354273.1l Canis familiaris ctg19866851087147, whole genome shotgun sequence Length = 1369 Hits Score = 42.0 bits (97). Expect = 0.006 Identities = 21/44 (47%). Positives = 27/44 (61%) Reading Frame = -2 Query: 76 LTEIQSLTFNPTAGCASLAKEMFAMKTKAALAIWCPGYSETQIN 119 (SEQ ID NO: 110) L 1+ LT + GCAS A-fE FA T AALA CPGY+ + + SbjCt:369 LARIERLTLHRIRGCASGAREAFAEGTVAALAAECPGYAAAPVS 238 (SEQ ID NO: 111) (SEQ ID NO; 110: human TSLP SEQ ID NO: x111 >gil36211043!gb|AACN010354273.1l Canis familiaris ctgl 9866851087147, whole genome shotgun sequence Length = 1369 Hit 6 Score = 38.9 bits (89). Expect = 0.047 Identities = 15/32 (46%). Positives = 22/32 (68%) Frame = +1 Query: 87 TAGCASLAKEMFAMKTKAALAIWCPGYSETQI 118 (SEQ ID NO" 112) T GC AKE A+ AL++WCPG+++TQ+ Sbjcc: 176 TPGCGICAKEAAALGWFCALSVWCPGWAQTQV 273 (SEQ ID NO: 1 13) SEQ ID NO: 112; human TSLP SEQ ID NO: 113: >gi[36211043[gb[AACN010354273.1l Canis famillaris ctg19866851087147, whole genome shotgun sequenc Length = 1369 A comparison of this electronically constructed sequence with human, monkey, rat, and mouse TSLP demonstrated the conserved intron/exon borders and substantial sequence identity, leading to the identification of this sequence as part of the canine ortholog of TSLP. PCR primers were subsequently designed based on this discovery and used to amplify the missing segments of the gene. Two partial overlapping clones were obtained by double nested PCR from a canine activated peripheral blood mononuclear cells (P8MC) cDNA library. Additional attempts to uncover the full canine TSLP cDNA by nested PCR or trying to extend sequences towards the 5' or 3' ends were not successful. However, iterative rounds of database searches using the extended sequence information from these clones on the canine whole genome shotgun sequence data (jdL University of California Santa Cruz) combined with manual assembly of the raw DNA sequence from this library led to the electronic assembly of the full length canine TSLP cDNA. A physical clone of this cDNA sequence was then synthesized using a DNA synthesizer, in vitro. In conclusion, using current and state of the art molecular cloning techniques it was not possible to derive the canine TSLP sequence directly from the human. mouse, rat or monkey sequences. Only sophisticated iterative database searches using assembled hOman. mouse, rat and NHP TSLP genes, with use of intron/exon boundary assignments and sequence identity on genomic databases, combined with molecular PCR cloning techniques, led to identification of the gene encoding canine TSLP. Once obtained, the canine TSLP showed 58/132 changes compared to the amino acid sequence of the mature human TSLP protein (61% identity) and 83/129 changes compared to the amino acid sequence of the mature mouse TSLP protein (33% identity) (see below). Sequence Comparison Between Canis famifiaris and Human TSLP Mature Protein TSLP__CF (Canis familiaris) Length 141 (1 .. 141) TSLP_H (Human) Length 145 (1 .. 145) Score = 167 bits (423), Expect = 1e-40 Identities = 85/139 (61%), Positives = 101/139 (72%) Query: 1 RKIPVLQLVGLVLTYNFIDCDFEKIRWKYQEVIYQALEKYMDGTRSTEFSHPVYCANPPD 6 0 RKIP-tLQLVGLVLTY+F +CDFEKI+ Y I + L YM GT+STEF++ V C+N P Sbjct: 1 RKrPILQLVGLVLTYDFTNCDFEKIKAAYLSTISKDLITYMSGTKSTEFNNTVSCSNRPH 60 Query: 61 CLARIERLTLHRIRGCASGAREAFAEGTVAALAAECPGYAAAPINNTQAKKKRKKRGVTT 120 CL I-t- LT + GCAS A+E FA T AAiA CPGY+ IN TQA KKR+KR VTT Sbjct; 61 CLTEIQSLTFNPTAGCASLAKEMFAMKTKAALAIWCPGYSETQINATQAMKKRRKRKVTT 120 Query: 121 NKCREQVAHLIGLWRRFSR 139 (SEQ ID NO: 114) NKC EQV+ L GLWRRF+R Sbjct: 121 NKCLEQVSQLQGLWRRFNR 139 (SEQ ID NO: 115) SEQ ID NO: 114: Canine familiaris TSLP SEQ ID NO; 115: Human TSLP Sequence Comparison Between Canis familiaris and Murine TSLP Mature Protein TSLP„CF Length 141 (1 .. 141) TSLP_M Length 136 (1 .. 136) Score = 72.0 bits (175). Expect = 7e-12 ■ Identities = 46/138 (33%). Positives = 67/138 (48%), Gaps = 8/138 (5%) Query: 1 RKIFVLQ-LVGLVLTYNFIDCDFEKIRWKYQEVIYQALEKYMDGTRSTEFSHPVYCANPP 59 R tF + LQ LV + LTYNr ^C + F I Y +1* L + G ■*- + C * P SbjcC: 1 RSLFILQVLVRMGLTYNFSNCNFTSITKIYCNIIFHDLTGDLKGAKFEQIED--- CESKP 57 Query: SO DCLARIERLTLKRIRGCASGAREAFAEGTVAALAAECfGYAAAPINNTQAKKKRKKRGVT 119 Ch +IE TL^ I GC S + FA T AL CPGY N+ + ++ SbjCC: 58 ■ ACLLKIEYYTLNPIPGCPSLPDKTFARRTREIALNDHCPGYPETERNDGTQEMAQE V 113 Query: 120 TNKCREQVAHLIGLWRRF 137 (SEQ ID NO: 116) NC Q+++LW F Sbjct: 114 QNICLNQTSQILRLHYSF 131 (SEQIDNOMIT) SEQ ID NO: 116: Canine familiaris TSLP SEC ID NO: 117: Mouse TSLP Thus, by overcoming the previously noted difficulties, the present trrvention now provides DNA sequences encoding canine TSLP and the encoded canine TSLP protein. Canine TSLP protein and certain fragments thereof are useful antigens, e.g., immunogens, for raising antibodies to various epitopes on the pnDtein. both linear and conformational epitopes. The DNA encoding canine TSLP is also useful in providing vectors and host cells for pnsducing TSLP protein for Immunization and/or as a research reagent, as well as providing DNA-based vaccines for raising anti-TSLP antibodies, whether as "naked" DNA or in the form of a plasmid or animal virus vector suitable for expressing TSLP in the cells of a vaccinated animal. The thus obtained canine TSLP gene sequence is illustrated by FIG. 8A (SEQ ID NO: 1), and the predicted expressed TSLP protein is illustrated by FIG. 8B {SEQ ID NO: 2). Residues 1-28 represent the signal sequence, and residues 29 to 155 represent the mature protein. Assay for Identifying Homologous TSLP proteins The present invention also provides TSLP proteins that comprise an amino acid sequence that has 80% or greater identity to the amino acid sequence of SEQ ID NO: 2, excluding the 28 amino acid residue signal sequence, which when they are administered to a canine as a vaccine, raise antibodies that bind the canine TSLP protein comprising the amino acid sequence of SEQ ID NO: 2. Antigenic fragments of such TSLP proteins are also provided. Indeed, one way to demonstrate that a putativeTSLP protein is a TSLP of the present Invention is to test whether such a protein can generate antibodies that bind to canine TSLP comprising the amino acid sequence of SEQ ID NO; 2. One such method is to vaccinate {e.g., inject) dogs with various doses ranging from 5-500 fjQ of a putative TSLP-GST antigen. Such antigens can be formulated in an aluminum hydroxide-based adjuvant such as Rehydroget. The dogs are then injected intramuscularly three times: at day 0, day 21, and day 42. Serum samples are collected from vaccinated and control (non-immunized) dogs on days 0, 21, 42, and 63. The induction of antibodies in dogs vaccinated with the antigens can be evaluated with an ELISA assay as follows: canine TSLP protein comprising the amino acid sequence of SEQ ID NO: 2 is diluted to 5 pg/ml in coating buffer (Sodium Bicarbonate pH 9.0) and dispensed at 100 pl/well of 96 well plates (Pierce). The plates are incubated at 4°C overnight. Next the plates are washed three times with phosphate buffer saline containing 0.05% Tween-20 (PBST). Then, 200 ^JI of blocking buffer (2% skim milk in PBST) is added to each well and the plates are incubated at room temperature for 60 minutes. The plates are then washed three times with PBST. Next, 100 plAwell of 1:100 dilution of the test dog antisera is added to the top row of the appropriate wells. Serum samples are then diluted 10 fold to the appropriate plate position. Following the incubation of the plates at room temperature for 60 minutes, the plates are washed three times with PBST-Next, 100 pt/well of a 1:20,000 dilution of a horse-radish peroxidase conjugated goat anti-dog IgG (Bethyl Laboratories) is added to each well. Then the plates are incubated at room temperature for 60 minutes. Next the plates are washed three times with PBST. and 100 pl/well of TMB substrate (3,3', 5,5' tetramethyl benzidine, Sigma Chemical Co., St. Louis. MO) is then added to all wells. The color reaction is allowed to develop for 10-20 minutes at room temperature prior to being stopped by adding 50 pl/well of 0.18 M sulfuric acid. The optical density (O.D.) of all of the wells is determined at the wavelength of 450 nm using an ELISA plate reader (Thermo Max; Molecular Devices. Sunnyvale, CA). Serum samples obtained from canines injected with the putative TSLP antigens are considered detectable and thereby, the antigens are identified as TSLP proteins of the present invention when the assay produces an O.D. value equal to or more than three times the background produced by serum samples obtained from the dogs prior to immunization. Similarly, relative antibody titers for the TSLP antigens can be determined based on the highest senjm dilution producing an O.D. value equal to or more than three times the background produced by serum samples obtained from dogs prior to the immunization with the antigens. Antibodies to Specific Epitopes of Canine TSLP Protein Antibodies can be raised to various epitopes of the canine TSLP proteins, including species, polymorphic, or allelic variants, and fragments thereof, both in their naturally occurring forms and in their recombinant forms. Additionally, antibodies can be rajsed to canine TSLPs in either their active forms or in their inactive forms, including native or denatured versions. Anti-idiotypic antibodies are also contemplated. Antibodies, including binding fragments and single chain versions, against predetermined fragments of the antigens can be raised by immunization of animals with canine TSLP and/or fragments thereof, together with art-standard adjuvants and/or conjugated to immunogenic proteins. Animals so immunized can be canines that are immunized in order to downregulate canine TSLP activity An appropriate host, e.g., an inbred strain of mice such as Balb/c, is immunized with the selected protein, typically using a standard adjuvant, and a standard mouse immunization protocol (see Harlow and Lane, \± supra). An adjuvant may be administered to the target animal before, in combination with, or after the administration of the vaccine. Alternatively, a synthetic peptide derived from the sequences disclosed herein and conjugated to a carrier protein can be used an immunogen. Polyclonal sera are collected and titered against the immunogen protein in an immunoassay, e.g., a solid phase immunoassay with the immunogen immobilized on a solid support. Polyclonal antisera with a titer of 1 x 10^ or greater are selected and tested for their cross reactivity against other IL-7 family niembers, e.g., rodent IL-7, using a competitive binding immunoassay such as the one described in Harlow and Lane, Id. supra, at pages 570-573. Preferably at least one other IL-7 family member is used in this determination in conjunction with, e.g., the primate IL-7. The IL-7 family members can be produced as recombinant proteins and isolated using standard molecular biology and protein chemistry techniques as described herein. immunoassays in the competitive binding format can be used for the crossreactivity determinations. For example, the protein of SEQ ID NO: 2 can be immobilized to a solid support. Proteins added to the assay compete with the binding of the antisera to the immobilized antigen. The ability of the above proteins to compete with the binding of the antisera to the immobilized protein is compared to the protein comprising the amino acid sequence of SEQ ID NO: 2. The percent crossreactivity for the above proteins is calculated employing standard calculations. Those antisera with less than 10% crossreactivity with each of the proteins listed above are selected and pooled. The cross-reacting antibodies are then removed from the pooled antisera by immunoabsorption with the above-listed proteins. The Immunoabsorbed and pooled antisera are then used in a competitive binding immunoassay as described above to compare a second protein to the immunogen protein {e.g.. the IL-7 like protein of SEQ ID NO: 2). In order to make this comparison, the two proteins are each assayed at a wide range of concentrations and the amount of each protein required to inhibit 50% of the binding of the antisera to the immobilized protein is detennined. If the amount of the second protein required is less than twice the amount of the protein of the selected protein or proteins that is required, then the second protein is said to specifically bind to an antibody generated to the immunogen. The antibodies of this invention can also be useful in diagnostic applications. As capture or non-neutralizing antibodies, they can be screened for ability to bind to the antigens without inhibiting binding to a receptor. As neutralizing antibodies, they can be useful in competitive binding assays. They will also be useful in detecting or quantifying canine TSLP protein or its receptors. [See. e.g.. Chan (ed. 1987) JmmunoloQv: A Practical Guide. Academic Press, Orlando, Fla.; Price and Newman (eds. 1991) Princioles and Practice of Immunoassay. Stockton Press. N.Y.; and Ngo (ed. 1988) Nonisotopic Immunoassay. Plenum Press, N.Y.] Cross absorptions, depletions, or other means will provide preparations of defined selectivity, e.g., unique or shared species specificities. These may be the basis for tests which will identify various groups of antigens. Further, the antibodies, including antigen binding fragments, of this invention can be potent antagonists that bind to the antigen and inhibit functional binding, e.g.. to a receptor which may elicit a biological response. Further, these antibodies can be conjugated to drugs or other therapeutic agents, either directly or indirectly by means of a linker, and may effect dnjg targeting. A synthetic peptide derived from the sequences disclosed herein and conjugated to a carrier protein can be used an immunogen. In any case, antigen fragments may be joined to other materials, particulariy polypeptides, as fused or covalently joined polypeptides to be used as immunogens. An antigen and its fragments may be fused or covalently linked to a variety of immunogens, such as keyhole limpet hemocyanin, bovine serum albumin, tetanus toxoid, etc. See Microbiology. Hoeber Medical Division, Harper and Row, 1969; Landsteiner (1962) Specificity of Serological Reactions. Dover Publications, New York; Williams, et al. f1967) Methods in immunology and Immunochemistrv. vol. 1, Academic Press, New York; and Harlow and Lane (1988) Antibodies: A Laboratory Manual. CSH Press, NY, for descriptions of methods of preparing polyclonal antisera. In some instances, it is desirable to prepare monoclonal antibodies from various mammalian hosts, such as mice, rodents, primates, humans, etc. Description of techniques for preparing such monoclonal antibodies may be found in, e.g., Stites, etal. (eds.) Basic and Clinical Immunology (4th ed.), Lange Medical Publications. Los Altos, Calif, and references cited therein; Harlow and Lane (1988) Antibodies: A Laboratory Manual. CSH Press; Coding f1986^ Monoclonal Antibodies: Principles and Practice (2d ed.). Academic Press, New York; and particulariy in Kohler and Milstein (1975) in Nature 256:495-497, which discusses one method of generating monoclonal antibodies. Other suitable techniques involve in vitro exposure of lymphocytes to the antigenic polypeptides or alternatively to selection of libraries of antibodies in phage or similar vectors. [See, Huse. et ai (1989) "Generation of a Large Combinatorial Library of the Immunoglobulin Repertoire in Phage Lambda," Science 246:1275-1281; and Ward, etal. (1989) Nature 341:544-546.1 The polypeptides and antibodies of the present invention may be used with or without modification, including chimeric, caninized, and/or humanized antibodies. Frequently, the polypeptides and antibodies of the present invention will be labeled by joining a substance which provides for a detectable signal. Such joining can be accomplished either covalently or non-covalently. A wide variety of labels and conjugation techniques are known and are reported extensively in both the scientific and patent literature. Suitable labels include radionuclides, enzymes, substrates, cofactors, inhibitors, fluorescent moieties, chemiluminescent moieties, magnetic particles, and the like. Patents, teaching the use of such labels include U.S. Pat. Nos. 3,817.837; 3,850.752; 3,939,350; 3.996,345; 4,277,437; 4.275,149; and 4,366.241. Also, recombinant or chimeric immunoglobulins may be produced, see Cabilly, U.S. Pat. No. 4,816,567; Moore, etal., U.S. Pat. No. 4.642.334; and Queen, etal. (1989) Proc. Nat'l Acad. Sci. US/^ 86^10029-10033; or made in transgenic mice, see Mendez, etal. (1997) Nature GeA?e//cs 1^:146-156. These references are incorporated herein by reference. The antibodies of this invention can also be used for affinity chromatography in isolating the protein. Columns can be prepared where the antibodies are linked to a solid support, (see, e.g., Wllchek etal. (1984) Meth. Enzymol. 104:3-55). Alternatively, antigens bound to a solid support may be used to purify the corresponding antibodies. Antibodies raised against each canine TSLP will also be useful to raise anti-idiotypic antibodies. These will be useful in detecting or diagnosing various immunological conditions related to expression of the respective antigens. RNA Inhibition Interference with RNA encoding canine TSLP in cells producing canine TSLP is an additional means of inhibiting the biological activity of TSLP and consequently, treating a number of TSLP-associated disorders such as atopic dermatitis. For this purpose, double stranded RNA molecules either synthesized chemically or cloned within appropriate delivery vectors such as plasmids or viral vectors may be introduced into cells actively producing TSLP mRNA with the aim of reducing endogenous mRNA levels encoding TSLP. Following entry of these RNA molecules (in the case of exogenously delivered molecules or transcription of RNA following entry of plasmids or viral vectors into desired cells), they are processed through the cleavage activity of a hbonuclease Ill-type protein into short nucleotide fragments which are termed siRNA. These siRNA fragments are then incorporated into a nuclease-containing multi-protein complex called RISC (RNA-lnduced Silencing Complex), which becomes activated as a result of the unwinding of the siRNA duplex through the activity of an RNA helicase. The now single stranded siRNA strand guides the RISC complex to its target mRNA, which is then cleaved and subsequently degraded by the endonucleolytic activity of RISC. More particularly, plasmids containing the TSLP gene or fragment thereof are cloned in any one of a number of commercially available eucaryotic plasmids wherein the transcription of the TSLP gene or its fragments is driven by an appropriate promoter, e.g., the CMV or SV40 promoter. Purified plasmid DNA (1-100 ug) is then injected into skin lesions or into areas surrounding the skin lesions characteristic of atopic dermatitis. The injection of plasmid DNA may then be repeated on a frequency necessary to cause a significant reduction in TSLP mRNA. This reduction may be evaluated by obtaining skin biopsies from affected areas and determining the level of TSLP mRNA by methods such as quantitative PCR. The following preparative examples of the present invention serves to provide further appreciation of the invention, but are not meant in any way to restrict the effective scope of the invention. EXAMPLES EXAMPLE 1 THE CANINE TSLP DNA AND PROTEIN SEQUENCES A canine gene expressing canine TSLP was identified by an iterative process employing data mining in electronic data bases and molecular biology methods, as described in detail supra. Results The canine TSLP gene sequence is illustrated by FIG. 8A (SEQ ID NO: 1), and the predicted protein expressed TSLP protein is illustrated by FIG. 8B (SEQ ID NO: 2). Residues 1-28 of FIG. 8B (SEQ ID NO: 2) marked by ttie asterisk, represent the signal sequence, and residues 29 to 155 represent the mature protein. EXAMPLE 2 CLONING AND EXPRESSION OF CANINE TSLP The DNA encoding canine TSLP was identified as described herein and cloned into a donor vector art standard methods pDONR221 {Invitrogen Gateway System). Gene assembly and cloning into the donor vector was performed at a contract research organization called DNA 2.0., and resulted in the construction of a plasmid called pDONR221.G03276 which contains the identified genomic canine TSLP gene. DNA encoding mature (i.e. without signal sequence) canine TSLP protein was PCR-amplified from pDONR221.G03276 using two primers which contain Nco t and EcoR V sites, respectively: Primers #1: 5' AATAATCCATGGCATACAATTTCATTGACTGTGAC-3' (SEQ ID NO: 4); and #2: 5'-AAAATAGAIAICTGAAATGCGACTGAAACGACG-3' (SEQ ID NO: 5). After Nco I and EcoR V digestion, the PCR products were inserted into Nco I and Sma I sites of vector pIVEX 1.3 WG (Roche Applied Sciences, Cat# 3728803). This resulted in a plasmid containing the gene which encodes the mature canine TSLP fused with six His residues at the C-tenminal end ("His6 tag"). The plasmid containing correct sequences of the inserts was named plasmid1265-93.D. Plasmid 1265-93.D was used to express TSLP in the RTS Proteomaster Instrument according to manufacturer's recommendations (Roche Applied Sciences, Cat# 3064859 ). As shown in FIG. 1, a band of @16 kDa was evident in lanes 2 and 4 (arrows). Western blot experiments (FIG. 2A & 2B) show that this band reacted specifically with anti-His tag antibody (FIG. 2A) and a rat monoclonal antibody specific for human TSLP (FIG. 2B). EXAMPLE 3 PRODUCTION OF CANINE TSLP FROM HOST CELLS To express recombinant TSLP protein in £. coli, the nucleotide sequence encoding cTSLP {i.e.. TSLP lacking nucleotides encoding the signal sequence) was amplified by PCR using plasmid 1265-66C as a template together with a forwar(i primer and reverse primers that contain Ncol and Hind III site, respectively: FopA/ard Primer 5'.AATAATCCATGGCATACAATTTCATTGACTGTGAC-3' (SEQ ID NO: 6) Reverse Primer 5'-ACATAAAAGCTTTGAAATGCGACTGAAACGACG-3' (SEQ ID NO: 7) After Nco I and Hind HI digestion, the PCR products were inserted into Ncoi/Hindlll sites of pET42b(+) expression vector (Novagen). This process produced a plasmid which encodes the mature cTSLP fused with GST tag at the N terminus and a 6xHis tag at the C terminus. The plasmid containing correct sequences of the insert was named as 1265-93B. Expression of the GST-TSLP-Hls fusion protein was carried out in E. coll BL21 (DE3)/pLysS which contains the T7 RNA polymerase gene under the control of the isopropyl-fi-D-thiogalactopyranoside(IPTG)-inducible lacUVS promoter. E. coH cells carrying plasmid 1265-93B were grown at 30° C to an O.D. 600 of 0.6 and then protein expression was induced by the addition of 0.5 mM IPTG and further incubation at 30°C for 2 hours. SDS-PAGE displays a protein band (arrow) with the correct size (~ 61 kDa) present in the soluble E. coli fraction (FIG. 3A). Western biot shows that the expressed protein reacts with anti-GST antibody (Fig. 3D). The GST-TSLP-His protein can be purified by Glutathione Sepharose 48 resin (FIG. 3B). After additional purification by Ni-NTA resin, the majority of the GST-TSLP protein was contained in the column flow through (FIG. 3C). EXAMPLE 4 IMMUNOFLUORESCENT DETECTION OF CANINE TSLP The expression of canine TSLP protein in canine skin and tonsil tissues was determined by immunohistochemistry ("IHC") using rabbit polyclonal antibodies raised against human TSLP protein. Immunohistochemistry was carried out on paraffin-embedded tissue blocks obtained from normal dog skin injected with saline as well as skin of dogs diagnosed with various skin diseases including atopic dermatitis, cutaneous lupus erythematosus, erythema multiforme, and junctional epidermolysis bullosa. Additionally, TSLP protein expression was determined in frozen tonsil tissues from two dogs. The procedure for determining TSLP expression by IHC is as follows: I. Preparation of Sections: 1. Paraffin blocks with embedded skin samples were sectioned at a thickness of 5-7microns and mounted on slides treated with po!y-L-Lysine to promote adhesion. 2. Sections were de-paraffinized with xylene and rehydrated with serial ethanol solutions. 3. Antigen retrieval was carried out in citrate buffer [10mM sodium citrate containing Tween-20 at a concentration of O.Sml/Iiter for 25 min using laboratory microwave to reach about 99-100 °C]. This is a process that recovers the antigenicity of tissue sections that are masked during the paraffin-embedding process. II. Immunostaining: 1. Sections were incubated in 10% nomial donkey serum diluted in phosphate buffer solution (PBS) for 1 hr at room temperature to reduce non-specific binding of the antibody. , 2. Excess serum was gently removed, and the sections covered with rabbit antibody (1:100) diluted in PBS and incubated either at room temperature for 1 hour or overnight at 4*'C in a humidity chamber. 3. Sections were then rinsed twice for 5 minutes in PBS, with gentle shaking. 4. Excess PBS was gently removed and sections covered with biotinylated donkey anti-rabbit IgG antibody diluted 1:5000 in PBS for 30 minutes at room temperature in the humidity chamber. 5. Sections were then rinsed twice for 5 minutes in PBS, with gentle shaking. 6. Excess PBS was removed and the sections incubated for 30 min at room temperature in Streptavidin-fluorescein Isothiocyanate (StreptavJdin-F(TC) conjugate in PBS at a concentration of 5 microgram/ml. 7. Sections were then rinsed twice for 5 minutes in PBS, shaking gently. 8. The sections were then counterstalned with hemotoxylm for 2-3 min. 9. The sections were then examined under fluorescent microscope. 10. Pertinent images were photographed. 11. Experimental controls included omission of the primary anti-TSLP antibodies, or replacing the primary anti-TSLP antibody with normal rabbit antibodies. Table 1. below, summarizes the results of the IHC experiments. TABLE 1 Immunohistochemistry with rabbit anti-human TSLP Conducted on paraffin-embedded blocks of skin tissue from dogs with various skin diseases. Disease condition (Total number of blocks) Positive blocks Negative blocks AD lesional skin (* n=10) 8 2 Normal skin injected with PBS (n=5) 1 4 Junctional epidermolysis bullosa {n=2) 2 0 Canine cutaneous lupus erythematsus (n=3) 0 3 Erythema multiforme (n=3) 2 1 * n= the number of animals. TSLP expression was detected in 80% of skin tissues from dogs diagnosed with AD, but only in 20% of normal skin tissues injected with saline. TSLP was also detected in 66% and 100% of tissues from dogs with Erythema multifomre and dogs with the genetic skin disease, junctional epidermolysis bullosa; respectively. There was no expression of TSLP protein in skin tissues from dogs with cutaneous lupus erythematusus. In paraffin-embedded skin tissues, the expression of TSLP was detected in sweat glands. Expression of TSLP in frozen canine tonsil tissue was detected in the stratified squamous epithelium and associated salivary glands. An example of positive IHC staining in dog skin samples is shown in FIG. 4 which represents paraffin-embedded skin tissue samples from a dog diagnosed with atopic dermatitis. EXAMPLE 6 IMMUNOPEROXIDASE DETECTION OF CANINE TSLP The expression of canine TSLP protein in paraffin-embedded tissue blocks prepared from skin of dogs diagnosed with atopic dermatitis was also determined by immunohistochemistry using immunoperoxidase staining as the detection method. In this method, an epitope-specific rat monoclonal antibody which was raised against human TSLP protein was used as the primary antibody. The procedure for determining TSLP expression by immunoperoxidase staining was as follows: Special Reagents Normal newborn calf serum: #N-4762 Sigma Paraffin-embedded skin tissue Primary antibody: Rat anti-human TSLP mAb rat lgG2a Secondary antibody; Rabbit anti-rat IgG (biotinylated): BA-4000 Vector Lab. Burlingame, CA. Detection reagent: Streptavidin-HRP: #43-8323 Zymed Labs. San Francisco, CA AEG substrate Kit: Biogenex #HK129-5K San Ramon. CA 1. Section specimen 4-6 um. 2. Air dry 10 min. room temp. 3. Fix 10 min. In acetone. 4. Rinse in PBS (0.01 Phosphate Buffered Saline) 3 min. 5. Quench by incubation in 0.3 % hydrogen peroxide with 0.1 % sodium azide for 7-10 min. 6. Rinse 5 min. PBS. 7. Block sections with 1% Normal newborn calve serum 20 minutes in moist chamber. 8. Drain slides and apply primary antibody at 1:100 dllrution for 2 hrs. at room temperature. 9. Rinses min. 10. Apply secondary antibody (Rabbit anti-rat IgG @1:400) 30 minutes in moist chambers at room temperature. 11. Rinse 5 min. 12. Drain and apply detection reagent (Streptavidin-HRP @1:400) for 30 min at room temperature 13. Rinse 2X5 minutes. 14. Apply AEC 2.5 min. Adjust according to desired staining intensity and background. 15. Counterstain with Hematoxylin and mount. A set of canine skin tissues from dogs with AD was tested by IHC using an epitope specific canine TSLP antibody. The results shown in FIG. 5 indicate that this antibody reacts with a molecule that shares antigenic epitopes with human TSLP. The staining of canine AD skin specimens was strong in areas of chronic inflammation where the epidermis is thickened. This pattern is consistent with what is known about the location of TSLP expression in human AD skin lesions and further suggests the recognized molecule in canine skin AD lesions is canine TSLP. There was no staining obsen/ed with either PBS or a different rat monoclonal specific for a different protein (a lymphocyte protein). EXAMPLE 7 EPITOPE MAPPING OF CANINE TSLP In order to Identify epitopes on canine TSLP that are useful for inclusion in a vaccine capable of neutralizing TSLP activity, a set of overlapping peptides based on the canine TSLP protein sequence were synthesized and tested for their ability to react with a neutralizing anti-human TSLP monoclonal antibody. For this purpose a set of overlapping peptides each 15 amino acid long and off set by two amino acids were synthesized on pins at MIMOTOPES (Minneapolis, MN). The sequences of these peptides are listed in Table 2. Peptides 1-57 were synthesized with an amidated terminus In the configuration NH2-PEPTIDE-PIN. Peptides 58-94 (duplicates of parent peptides 1-37) were made with an acytelated terminus in the configuration ACETYL-PEPTIDE-PIN. The pins carrying the peptide listed in Table 2 were tested in an ELISA assay format according to manufacturer's recommended procedures (Mimotopes, Minneapolis, MN). As shown in FIG. 6. peptide # 25 (epitope 25) with the amino add sequence NH2-ARIERLTLHRIRGCA(SEQ ID NO: 32) had the highest reactivity against the PAB100 monoclonal antibody. A comparison of this peptide sequence with a con-esponding putative human TSLP peptide sequence is shown in FIG. 7. 4 5 PINNTQAKKKRKKRG 52 92 AFAEGTVAALAAECP 99 4 6 NNTQAKKKRKKRGVT 53 9 3 AEGTVAALAAECPGY 100 4 7 TQAKKKRKKRGVTTN 54 94 GTVAALAAECPGYAA 101 The present invention is not to be limited in scope by the specific embodiments described herein. Indeed, various modifications of the invention in addition to those described herein will become apparent to those sl^iiled in the art from the foregoing description. Such modifications are intended to fall within the scope of the appended claims. It is further to be understood that all base sizes or amino acid sizes, and all molecular weight or molecular mass values, given for nucleic acids or polypeptides are approximate, and are provided for description. Various publications are cited herein, the disclosures of which are hereby incorporated by reference in their entireties. WE CLAIM: 1. A thymic stromal lymphopoietin protein (TSLP) or an antigenic fragment thereof, wherein said TSLP protein comprises an amino acid sequence that has 80% or greater identity to the amino acid sequence of SEQ ID NO: 2. excluding the 28. amino acid residue signal sequence; and wherein said TSLP protein is cross reactive with an antibody raised against the canine TSLP comprising the amino acid of SEQ ID NO: 2. 2. The TSLP of Claim 1 wherein the TSLP binds to an epitope-specific canine TSLP antibody. 3. The TSLP of Claim 1 that is a canine TLSP. 4. The canine TSLP protein of Claim 3 that comprises amino acid residues 29-155 of SEQ ID NO: 2. 5. An antigenic fragment of the canine TSLP protein of Claim 4, wherein said fragment comprises an amino acid sequence selected from the group consisting of SEQ ID NOs: 8-101 or a combination of two or more thereof. 6. The antigenic fragment of Claim 5 comprising an amino acid sequence selected from the group consisting of SEQ ID NO: 30. SEQ ID NO: 31, SEQ ID NO: 32, SEQ ID NO: 33. SEQ ID NO: 34. or a combination of two or more thereof. 7. An antigenic fragment of the TSLP protein of Claim 4, wherein said antigenic fragment comprises an amino acid sequence of 5 to 22 contiguous amino acids of NPPDCLARIERLTLHRIRGCAS (SEQ ID NO: 118); and wherein said antigenic fragment binds to an epitope-specific canine TSLP antibody. 8. A vaccine comprising a pharmaceutically acceptable adjuvant and an effective amount of an immunogen selected from the group consisting of the TSLP protein of Claim 1, an antigenic fragment of the TSLP protein, and combinations thereof. 9. The vaccine of Claim 8, wherein the antigenic fragment of the TSLP protein comprises an amino acid sequence selected from the group consisting of SEQ ID NO: 30, SEQ ID NO: 31. SEQ ID NO: 32, SEQ ID NO: 33. SEQ ID NO: 34, or combinations thereof. 10. A nucleic acid molecule encoding the TSLP protein of Claim 1. 11. A nucleic acid molecule encoding the TSLP protein of Claim 4 or encoding an antigenic fragment thereof. 12. The nucleic acid molecule of Claim 11 that comprises the nucleotide sequence of SEQ ID NO: 1. 13. An expression vector that comprises the nucleic acid molecule of Claim 11. 14. A vaccine comprising the expression vector of Claim 13. 15. A method of producing a TSLP protein comprising culturing a host ceil in a suitable culture medium, wherein said host cell comprises the expression vector of Claim 13, and wherein the TSLP protein is expressed. 16. The method of Claim 15 further comprising isolating the TSLP protein from the cultured host cell or the culture medium. 17. A method of inducing anti-TSLP antibodies in a mammal comprising immunizing the mammal with an effective amount of the vaccine of Claim 8. 18. A method of downregulating TSLP activity in a canine comprising immunizing the canine with an effective amount of the vaccine of Claim 8. 19. A method of treating or preventing allergic synnptoms in an atopic canine comprising immunizing a canine with an effective amount of the vaccine of Claim 8. 20. The method of Claim 19 wherein the allergic symptoms comprise allergic dermatitis or asthma. 21. An anti-canine TSLP antibody elicited in a mammal or in a mammalian hybridoma system, by the vaccine of Claim 8. 22. A method of treating allergic symptoms in an atopic canine comprising administering an effective amount of the anti-canine TSLP antibody of Claim 21. 23. The vaccine of Claim 8 that further comprises an effective amount of a non- TSLP immunogen. 24. The vaccine of Claim 9 that further comprises an effective amount of a non- TSLP immunogen. 25. A method of diagnosing atopic dermatitis in £> canine comprising obtaining an epidermal sample from the canine and determining the presence of the canine TSLP protein of Claim 4 in the epidermal sample.