Mandamus to compel the board of county commissioners of Lincoln county to levy a tax to carry out a contract for the testing *146 of cattle for tuberculosis under L. 1923, p. 350, c. 269. Findings were in favor of respondents. Eelators moved for amended findings or a new trial. Eespondents moved for an amended finding of fact, but not for a new trial. From an order denying each motion, the parties appeal.

The order denying respondents’ motion is not appealable, and their appeal must be and is dismissed. Desaman v. Butler Brothers, 118 Minn. 198, 136 N. W. 747, Ann. Cas. 1913E, 642; State v. Brobst, 165 Minn. 361, 206 N. W. 642.

The relators pleaded and the court found that proceedings had been properly taken under chapter 369, p. 350, Laws of 1923, to authorize the county board of Lincoln county to enter a contract with the State Sanitary Board and the Federal Bureau of Animal Industry to test all cattle in the county for tuberculosis with the object of making the county “a modified accredited tuberculosis-free area” as defined by the Federal Bureau .and the Sanitary Board. The contract was accordingly entered January 8, 1924. Pursuant to the contract the county board appropriated a sum equal to 25 , cents per head of the cattle in the county to assist in the expense of conducting the first test. This test was made and’ paid for out of the money appropriated and levied. By the terms of the contract the board agreed to appropriate like amounts to assist in paying for each additional test necessary to accomplish the object intended. The court found that it was necessary to make further tests, and that the cost of the same will be approximately $13,000. This money the county board refused to raise, and this proceeding is to compel the board to levy a tax for that purpose.

All the facts were found in relators’ favor except the following: “Chapter 230, Laws of 1925, changes the indemnity paid for cattle in these cases, so that, among other things, no indemnity is now paid for steers condemned. The changes made are material changes in the amount of indemnity paid to cattle owners.” From the memorandum appended to the decision it is clear that the learned trial court concluded that by the enactment of chapter 230 such a change was made in the indemnity to be paid for condemned animals that the county was released from the contracts.

*147 It must be admitted that tbe act of 1925 made material changes in tbe law as it stood at tbe time tbe contract was entered. Tbe findings point to a significant change and there are others. It must also be conceded that tbe purpose of tbe contract was at least twofold, viz., to protect health and to obtain compensation to tbe owners for animals condemned. Tbe primary object of tbe legislation is public health and welfare. Tbe county has no direct proprietary interests at stake. It is a mere arm of tbe government in tbe administration of tbe law. There is no substantial difference between tbe position which tbe county occupies in a drainage proceeding and in a case of this kind, after tbe contract is made. It is true that a judicial ditch may be established without tbe county’s consent, whilst in a proceeding of tbe sort here involved it is optional with the county to enter or refuse to enter a contract. Likewise it may be said that for tbe construction of a drainage system tbe county reimburses itself entirely from, assessments against benefited property, but for tbe money needed under this contract tbe county must look to tbe levy of a general tax. Notwithstanding these differences, we think tbe county as to tbe procedure under tbe statutes here applicable is a mere governmental agency to carry out a scheme designed to protect health and life of people as well as of domestic animals and thus promote public welfare. With that view of tbe law and tbe county’s part in carrying it out, we think tbe legislature may amend tbe statutes relating to testing animals and tbe payment for condemned animals without thereby releasing the parties from tbe contract. Tbe owners of tbe animals condemned are not parties to tbe contract; neither did tbe county act as their agent in entering tbe same. Tbe enactment of tbe statutes involved is an exercise of tbe police powers of tbe state. Schulte v. Fitch, 162 Minn. 18á, 202 N. W. 719. Contracts under such statutes must be entered into with tbe understanding that tbe legislature may amend-or alter tbe law pertaining to them without being charged with wrongful interference with vested rights. State v. Holm, 138 Minn. 281, 164 N. W. 989. Tbe act of 1925 did not lay any additional burden upon the county, and even if it bad we are not prepared to say it would have released *148 the county from the contract. - State v. Smith, 58 Minn. 35, 59 N. W. 545, 25 L. R. A. 759. The act impairs no right or obligation of the county under this contract. We think the principle in the above cited cases and in State v. George, 123 Minn. 59, 142 N. W. 945, and the decisions therein referred to, entitled the relators to the writ.

There is no occasion to consider the questions of estoppel and waiver, urged by the relator, for in our opinion the findings of fact as they were made require merely a modification of the conclusions of law awarding the writ.

The order is reversed.