12% SENIOR CONVERTIBLE NOTE

THE SECURITIES REPRESENTED HEREBY MAY NOT BE TRANSFERRED UNLESS (I) SUCH SECURITIES HAVE BEEN REGISTERED FOR SALE PURSUANT TO THE SECURITIES ACT OF 1933, AS AMENDED, (II) SUCH SECURITIES MAY BE SOLD PURSUANT TO RULE 144, OR (III) THE COMPANY HAS RECEIVED AN OPINION OF COUNSEL REASONABLY SATISFACTORY TO IT THAT SUCH TRANSFER MAY LAWFULLY BE MADE WITHOUT REGISTRATION UNDER THE ACT OR QUALIFICATION UNDER APPLICABLE STATE SECURITIES LAWS.

12% SENIOR CONVERTIBLE NOTE

$      
      , 2009
No. R-       

FOR VALUE RECEIVED, Pet DRx Corporation, a Delaware corporation (the “ Company ”), hereby unconditionally promises to pay to the order of        (the “ Holder ”), having an address at        , or at such address or at such other place as may be designated in writing by the Holder, or its assigns, the aggregate principal sum of        United States Dollars ($       ) (the “ Original Note Amount ”), together with interest from the date set forth above on the unpaid principal balance of this Note outstanding at a rate equal to twelve percent (12.0%) (computed on the basis of the actual number of days elapsed in a 360-day year) per annum and continuing on the outstanding principal until this 12% Senior Convertible Note (the “ Note ”) is converted into Common Stock as provided herein or paid in full by the Company. Subject to the other provisions of this Note, the principal amount of this Note, including any increase in such principal amount as a result of a PIK Payment (as defined below), and all accrued and unpaid interest hereon shall mature and, together with the Original Note Amount (as reduced by the aggregate principal amount of this Note that has been prepaid or converted) plus the Premium (as defined in Section 3 below), become due and payable on January 21, 2013 (the “ Stated Maturity Date ”). Except as provided herein, all payments of principal and interest by the Company under this Note shall be made in United States dollars in immediately available funds to an account specified by the Holder.

The Company will pay interest on this Note entirely by increasing the principal amount of this Note (“ PIK Interest ”). Interest on this Note will be payable semiannually on June 30 and December 31 of each year, commencing June 30, 2009. PIK Interest on this Note will accrue at a rate per annum equal to twelve percent (12%) and will be payable by increasing the principal amount of this Note by an amount equal to the amount of PIK Interest for the applicable interest period (a “ PIK Payment ”). Following an increase in the principal amount of this Note as a result of a PIK Payment, this Note will accrue interest on such increased principal amount from and after the related interest payment date of such PIK Payment. References herein to the “principal amount” of the Note include any increase in the principal amount of the Note as a result of a PIK Payment.

In the event that any amount due hereunder is not paid when due, such overdue amount shall bear interest at an annual rate of fifteen percent (15%) until paid in full. In no event shall any interest charged, collected or reserved under this Note exceed the maximum rate then permitted by applicable law and if any such payment is paid by the Company, then such excess sum shall be credited by the Holder as a payment of principal.

This Note is one of a series of Notes (the “ Company Notes ”) of like tenor in an aggregate principal amount of Five Million United States Dollars ($5,000,000) (subject to increase to an amount not exceeding Six Million Five Hundred Thousand Dollars ($6,500,000) in the event additional Company Notes are issued as provided in Section 7.8 of the Purchase Agreement hereinafter defined) issued by the Company pursuant to the terms of the Purchase Agreement, and subject further to increases resulting from PIK Payments, as hereinafter defined.

1.  Definitions. Capitalized terms used herein shall have the respective meanings ascribed thereto in the Purchase Agreement unless otherwise defined herein. Unless the context otherwise requires, when used herein the following terms shall have the meaning indicated:

“ Affiliate ” shall mean, with respect to any Person, any other Person which directly or indirectly through one or more intermediaries Controls, is controlled by, or is under common control with, such Person.

“ Board ” shall mean the Board of Directors of Company.

“ Board Calls ” has the meaning set forth in Section 5(b)(x) hereof.

“ Board Voting Agreement ” means that certain Board Voting Agreement dated as of January 4, 2008, by and among the Company (f/k/a Echo Healthcare Acquisition Corp.), certain stockholders of the Company and holders of options and/or warrants to aquire shares of capital stock of the Company identified therein, certain former stockholders of XLNT Veterinary Care, Inc. (“ XLNT ”) and holders of options and warrants to acquire shares of the capital stock of XLNT identified therein, and Galen, as the same may be amended from time to time in accordance with its terms.

“ Business Day ” other than a Saturday or Sunday, on which banks in New York City are open for the general transaction of business.

“ Camden ” has the meaning set forth in the Purchase Agreement.

“ Change of Control ” shall be deemed to have occurred if, at any time (i) any Person or any Persons acting together that would constitute a “group” for purposes of Section 13(d) under the 1934 Act, or any successor provision thereto (other than one or more of the Investors and their Affiliates), shall acquire beneficial ownership (within the meaning of Rule 13d-3 under the 1934 Act, or any successor provision thereto) in a single transaction or a series of related transactions, of more than 50% of the aggregate voting power of the Company, other than one or more Investors ; (ii) the Company merges into or consolidates with any other Person, or any Person merges into or consolidates with the Company and, after giving effect to such transaction, the stockholders of the Company immediately prior to such transaction own less than 50% of the aggregate voting power of the Company or the successor entity of such transaction; or (iii) the Company sells or transfers its assets, as an entirety or substantially as an entirety, to another Person.

“ Common Stock ” shall mean the Common Stock, par value $0.0001 per share, of the Company or any securities into which shares of Common Stock may be reclassified after the date hereof.

“ Common Stock Equivalent Price ” means the amount equal to the quotient obtained by dividing (i) with respect to a single transaction or a series of transactions, the total aggregate consideration received by the Company upon the issuance of shares of Common Stock and/or Common Stock Equivalents and (ii) the number of shares of Common Stock issued or issuable upon the conversion, exchange or exercise of any Common Stock Equivalent in connection with such transaction or series of transactions.

“ Common Stock Equivalents ” means any securities of the Company or the Subsidiaries which would entitle the holder thereof to acquire at any time Common Stock, including without limitation, any debt, preferred stock, rights, options, warrants or other instrument that is at any time convertible into or exchangeable for, or otherwise entitles the holder thereof to receive, Common Stock.

“ Company ” has the meaning set forth in the first paragraph hereof.

“ Company Notes ” has the meaning set forth in the fourth paragraph hereof.

“ Control ” (including the terms “controlling”, “controlled by” or “under common control with”) means the possession, direct or indirect, of the power to direct or cause the direction of the management and policies of a Person, whether through the ownership of voting securities, by contract or otherwise.

“ Conversion Price ” shall mean initially $10.00 per share, subject to adjustment as provided in Section 4.

“ Conversion Shares ” has the meaning set forth in the Purchase Agreement.

“ DVM Acquisition Notes ” means certain promissory notes issued to doctors of veterinary medicine by the Company and/or any of its Affiliates in connection with the acquisition by the Company of such doctors’ respective veterinary practice.

“ DVM Participation Percentage ” means a fraction (expressed as a percentage), the numerator of which is the aggregate principal amount of the DVM Acquisition Notes that have been modified to include a Standstill Provision as of February 17, 2009, and the denominator of which is $8,922,647.

“ Event of Default ” has the meaning set forth in Section 6 hereof.

“ Fair Market Value ” shall mean (i) with respect to any publicly traded securities, the Market Price of such securities and (ii) with respect to any other securities or other assets, the fair market value of such other securities or other assets as determined by the Board in the good faith exercise of its reasonable business judgment.

“ Final Redemption Premium ” has the meaning set forth in Section 3(a) hereof.

“ Galen ” has the meaning set forth in the Purchase Agreement.

“ Holder ” has the meaning set forth in the first paragraph hereof.

“ Indebtedness ” means any liability or obligation (i) for borrowed money, other than trade payables incurred in the ordinary course of business, (ii) evidenced by bonds, debentures, notes, or other similar instruments, (iii) in respect of letters of credit or other similar instruments (or reimbursement obligations with respect thereto), except letters of credit or other similar instruments issued to secure payment of trade payables or obligations in respect of workers’ compensation, unemployment insurance and other social security laws or regulations, all arising in the ordinary course of business, (iv) to pay the deferred purchase price of property or services, except trade payables arising in the ordinary course of business, (v) as lessee under capitalized leases, or (vi) secured by a Lien on any asset of the Company or a Subsidiary, whether or not such obligation is assumed by the Company or such Subsidiary.

“ Investors ” has the meaning set forth in the Purchase Agreement.

“ Lien ” means any lien, mortgage, deed of trust, pledge, security interest, charge or encumbrance of any kind (including any conditional sale or other title retention agreement, any lease in the nature thereof and any agreement to give any of the foregoing).

“ Majority Holder Representative ” has the meaning set forth in the Purchase Agreement.

“ Majority Holders ” means the Required Investors; provided, however, that if none of the Required Investors holds the applicable Threshold Amount, then the term “Majority Holders” shall refer to the Holders of a majority of the principal amount of the Company Notes issued pursuant to the Purchase Agreement then outstanding; provided further, however, that upon the conversion of all Notes into Conversion Shares, the term “Majority Holders” shall refer to the original owners of a majority of the Warrants then outstanding. Any consent or approval of, or other notice or instruction from, the Majority Holders shall be evidenced by the signature of an authorized officer or representative of the Majority Holder Representative, which, as between the Investors and the Company, shall be binding and conclusive.

“ Market Price ”, as of a particular date (the “ Valuation Date ”), shall mean the following with respect to any class of securities: (A) if such security is then listed on a national stock exchange, the Market Price shall be the closing bid price of one share of such security on such exchange on the last Trading Day prior to the Valuation Date, provided that if such security has not traded in the prior ten (10) trading sessions, the Market Price shall be the average closing bid price of such security in the most recent ten (10) trading sessions during which such security has traded; (B) if such security is then included in the Over-the-Counter Bulletin Board, the Market Price shall be the closing sale price of one share of such security on the Over-the-Counter Bulletin Board on the last Trading Day prior to the Valuation Date or, if no such closing sale price is available, the average of the high bid and the low ask price quoted on the Over-the-Counter Bulletin Board as of the end of the last Trading Day prior to the Valuation Date, provided that if such security has not traded in the prior ten (10) trading sessions, the Market Price shall be the average closing price of one share of such security in the most recent ten (10) trading sessions during which such security has traded; or (C) if such security is then included in the “pink sheets,” the Market Price shall be the closing sale price of one share of such security on the “pink sheets” on the last Trading Day prior to the Valuation Date or, if no such closing sale price is available, the average of the high bid and the low ask price quoted on the “pink sheets” as of the end of the last Trading Day prior to the Valuation Date, provided that if such security has not traded in the prior ten (10) trading sessions, the Market Price shall be the average closing price of one share of such security in the most recent ten (10) trading sessions during which such security has traded.

“ Modified Operating Cash Flow ” means, with respect to the Company’s fiscal quarter ending March 31, 2009, the sum of (a) the cash flow from operations after required debt service of the Company, on a consolidated basis with its Subsidiaries, as calculated in the Company’s Statement of Cash Flows for such fiscal quarter and (b) the aggregate amount of outstanding accounts payable that (i) relate to invoices that are dated on or before December 6, 2008, and (ii) are actually paid by the Company during the fiscal quarter ending March 31, 2009; provided, however, that the amount described in clause (b) above shall not exceed $2,000,000.

“ Note ” has the meaning set forth in the first paragraph hereof.

“ Permitted Indebtedness ” means:

(a) Unsecured Indebtedness that is subordinate in right of payment to the Company Notes existing on January 21, 2009 and refinancings, renewals and extensions of any such Indebtedness if (i) the average life to maturity thereof is greater than or equal to that of the Indebtedness being refinanced or extended, (ii) if the principal amount thereof or interest payable thereon is not increased, (iii) the ranking thereof is subordinate in right of payment to the Company Notes at least to the same extent as the Indebtedness being refinanced, renewed or extended, and (iv) the terms thereof are not less favorable to the Company or the Subsidiary incurring such Indebtedness than the Indebtedness being refinanced, renewed or extended;

(b) Guaranties by any Subsidiary of any “Permitted Indebtedness” of the Company or another Subsidiary;

(c) Indebtedness representing the deferred purchase price of property and capital lease obligations which does not exceed (i) $100,000 individually and (ii) $500,000 in the aggregate;

(d) Indebtedness of the Company to any wholly owned Subsidiary and Indebtedness of any wholly owned Subsidiary to the Company or another wholly owned Subsidiary which constitutes “Permitted Indebtedness” or which is otherwise subordinate in right of payment to the Company Notes;

(e) Indebtedness outstanding on the date of the Purchase Agreement, and any modifications of the Indebtedness evidenced by the DVM Acquisition Notes in connection with implementing (i) subordination agreements approved by the Majority Holders or (ii) Standstill Provisions;

(f) Indebtedness incurred in connection with financing insurance premiums payable by the Company and its Subsidiaries in the ordinary course of business;

(g) Other Indebtedness consented to in writing by the Majority Holders; and

(h) Unsecured Indebtedness not otherwise permitted hereunder, not exceeding $100,000.

“ Permitted Liens ” means:

(a) Liens existing on the date of the Purchase Agreement;

(b) Liens imposed by law for taxes that are not yet due or are being contested in good faith and for which adequate reserves have been established on the Company’s books and records in accordance with U.S. generally accepted accounting principles, consistently applied;

(c) carriers’, warehousemen’s, mechanics’, materialmen’s, repairmen’s and other like Liens imposed by law, arising in the ordinary course of business and securing obligations that are not overdue by more than sixty (60) days or that are being contested in good faith and by appropriate proceedings;

(d) pledges and deposits made in the ordinary course of business in compliance with workers’ compensation, unemployment insurance and other social security laws or regulations;

(e) deposits to secure the performance of bids, trade contracts, leases, statutory obligations, surety and appeal bonds, performance bonds and other obligations of a like nature, in each case in the ordinary course of business;

(f) easements, zoning restrictions, rights-of-way and similar encumbrances on real property imposed by law or arising in the ordinary course of business that do not secure any monetary obligations and do not materially detract from the value of the affected property or materially interfere with the ordinary conduct of business of the Company or any of its Subsidiaries;

(g) Liens granted to secure the obligations of the Company or any Subsidiary under any Indebtedness permitted under clause (c) of the definition of “Permitted Indebtedness”, provided such Liens are limited to the property acquired or so financed, or to the assets of the Person so acquired, or both (and any accessions thereto and proceeds thereof);

(h) Judgment Liens that have not yet become an Event of Default;

(i) Other Liens consented to in writing by the Majority Holders; and

(j) Liens not otherwise permitted hereunder, securing obligations not exceeding $100,000 in the aggregate at any time outstanding.

“ Person ” means an individual, corporation, partnership, limited liability company, trust, business trust, association, joint stock company, joint venture, sole proprietorship, unincorporated organization, governmental authority or any other form of entity not specifically listed herein.

“ Preferred Stock ” shall mean the shares of preferred stock to be authorized and issued by the Company with such voting powers and such designations, preferences and other rights as stated and expressed in a resolution adopted by the Board of Directors providing for the issuance of such preferred stock and as permitted by the General Corporation Law of the State of Delaware. The Preferred Stock will have a liquidation preference over the Common Stock equal to the aggregate principal amount of the Company Notes (but excluding any Premium, as hereinafter defined), will be convertible into Common Stock on the terms specified in such Board resolution, will vote on an as-converted basis, and otherwise will have no special rights or preferences over the Common Stock.

“ Prepayment ” has the meaning set forth in Section 3(a) hereof.

“ Purchase Agreement ” shall mean the Purchase Agreement, dated as of January 21, 2009, and as that agreement may be amended from time to time, by and among the Company and the Investors.

“ Redemption Date ” means the earliest to occur of (i) the date this Note is prepaid and redeemed pursuant to Section 3(a) hereof, (ii) the effective time of a Change of Control or (iii) the date this Note is redeemed pursuant to Section 3(c) hereof.

“ Redemption Price ” has the meaning set forth in Section 3(b) hereof.

“ Required Investors ” means (i) Galen and Camden, if each of Galen and Camden holds the applicable Threshold Amount, (ii) Galen only, if Galen holds the Threshold Amount and Camden does not hold the Threshold Amount or (iii) Camden only, if Camden holds the Threshold Amount and Galen does not hold the Threshold Amount.

“ Standstill Provision ” has the meaning set forth in the Purchase Agreement.

“ Stated Maturity Date ” has the meaning set forth in the first paragraph hereof.

“ Stockholder Approval ” has the meaning set forth in the Purchase Agreement.

“ Subordinated Indebtedness ” shall mean Indebtedness of the Company or any Subsidiary that specifically provides that such Indebtedness is to rank junior to the Company Notes in right of payment and is subordinated by its terms in right of payment to the Company Notes.

“ Subsidiary ” of any Person means another Person, an amount of the voting securities, other voting ownership or voting partnership interests of which is sufficient to elect at least a majority of its Board of Directors or other governing body (or, if there are no such voting interests, 50% or more of the equity interests of which) is owned directly or indirectly by such first Person.

“ Threshold Amount ” means (i) with respect to Galen, an amount equal to at least $1,500,000 principal amount of the Company Notes issued to Galen pursuant to the Purchase Agreement and (ii) with respect to Camden, an amount equal to at least $750,000 principal amount of the Company Notes issued to Camden pursuant to the Purchase Agreement.

“ Warrants ” has the meaning set forth in the Purchase Agreement.

“ Warrant Shares ” has the meaning set forth in the Purchase Agreement.

2.  Purchase Agreement . This Note is one of the several 12% Senior Convertible Notes of the Company issued pursuant to the Purchase Agreement. This Note is subject to the terms and conditions of, and entitled to the benefit of, the provisions of the Purchase Agreement.

3.  Prepayment; Change of Control .

(a) The Company may, from time to time at its option, upon ten (10) days’ prior written notice to the Payee, prepay all or part of this Note (with all accrued and unpaid interest thereon) prior to the Stated Maturity Date (each, a “ Prepayment ”); provided that any such Prepayment shall be subject to a premium equal to 150% of the Original Note Amount being prepaid (the “ Premium ”) which shall be paid to Payee in immediately available funds simultaneously with such Prepayment; provided , however , that the Premium shall be adjusted on February 17, 2009 (as adjusted, the “ Final Redemption Premium ”) based on the aggregate principal amount of DVM Acquisition Notes that are modified to include a Standstill Provision such that (i) if the DVM Participation Percentage is less than 30%, the Premium will be equal to 400% of the Original Note Amount, (ii) if the DVM Participation Percentage is at least 30% but less than 45%, the Premium will be equal to 250% of the Original Note Amount, and (iii) if the DVM Participation Percentage is at least 60%, the Premium will remain at 150% of the Original Note Amount. The adjustment to the Premium will be interpolated between 400% and 250% and between 250% and 150% for DVM Participation Percentages between 30% and 45% and between 45% and 60%, respectively. For example, if a Holder originally invested $1,000 and the DVM Participation Percentage is less than 30% as of February 17, 2009, then upon prepayment of such Holder’s Note, such Holder would receive $5,000 (which represents the sum of (A) $1,000 of such Holder’s original principal investment and (B) a prepayment penalty equal to $4,000) plus all accrued and unpaid interest payable on the Note. If the DVM Participation Percentage is 35% as of February 17, 2009, then upon prepayment of such Holder’s Note, such Holder would receive $4,500 (which represents the sum of (A) $1,000 of such Holder’s original principal investment and (B) a prepayment penalty equal to $3,500) plus all accrued and unpaid interest payable on the Note. If, however, the DVM Participation Percentage is 55% as of February 17, 2009, then upon prepayment of such Holder’s Note, such Holder would receive $2,833.33 (which represents the sum of (A) $1,000 of such Holder’s original principal investment and (B) a prepayment penalty equal to $1,833.33) plus all accrued and unpaid interest payable on the Note. The Company shall deliver to Galen and Camden no later than February 17, 2009, the documentation evidencing that such DVM Acquisition Note has been modified to include a Standstill Provision, including executed copies of the agreements with any holder of such DVM Acquisition Notes. Upon a Change of Control, dissolution or winding up of the Company, the Investors will first receive the Final Redemption Premium on the outstanding principal amount of the Company Notes before any Subordinated Indebtedness is paid or distribution is made in respect of capital stock. For the avoidance of doubt, the term “ Premium ” as used herein shall be deemed to mean (i) prior to February 17, 2009, the Premium (i.e., equal to 150% of the Original Note Amount) and (ii) from and after February 17, 2009, the Final Redemption Premium.

(b) In the event that a Change of Control occurs prior to the Stated Maturity Date, the Company shall redeem as of the effective time of the Change of Control all, but not less than all, of the then-outstanding principal amount of this Note and all accrued interest thereon at a cash redemption price equal to the greater of (i) the then-outstanding principal amount of this Note and all accrued interest thereon plus the Premium and (ii) the product of (A) the number of shares of Common Stock into which such Note would have been converted if the Note were converted on the Redemption Date and (B) the Fair Market Value of the consideration per share to be received by holders of Common Stock in connection with a Change of Control as of the Redemption Date (the “ Redemption Price ”). The Company shall provide written notice to the Holder of this Note of any pending Change of Control not less than 15 days prior to the effective date of such Change of Control. On the Redemption Date, the Company shall pay the Redemption Price to the Holder in immediately available funds to an account previously specified in writing by the Holder. The Holder shall not be required to surrender this Note prior to payment of the Redemption Price, and the Note shall be deemed redeemed as of the tender of the Redemption Price. Upon payment in full of the Redemption Price to the Holder as provided in this Section 3, this Note shall be deemed to have been paid in full and shall no longer be outstanding for any purpose.

(c) In the event the Company fails to obtain the Stockholder Approval on or before October 31, 2009, then the Holder will be entitled to demand immediate repayment of the then-outstanding principal amount of this Note and all accrued interest thereon at a cas